From 533511dfd1622eb33b06ea526115c405cfda4f38 Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Mon, 16 Sep 2024 17:16:15 +0200
Subject: [PATCH 01/11] Migrate last Nunit tests to Xunit

---
 TESTGUIDE.md                                  |    8 -
 .../UnitTests/DocCommentIdParserTests.fs      |    4 +-
 .../Tests.LanguageService.Completion.fs       | 1262 ++++++++---------
 .../Tests.LanguageService.ErrorList.fs        |  196 +--
 .../Tests.LanguageService.ErrorRecovery.fs    |   48 +-
 .../Tests.LanguageService.General.fs          |   57 +-
 .../Tests.LanguageService.GotoDefinition.fs   |  285 ++--
 .../Tests.LanguageService.NavigationBar.fs    |    6 +-
 .../Tests.LanguageService.ParameterInfo.fs    |  556 +++-----
 .../Tests.LanguageService.QuickInfo.fs        |  489 +++----
 .../Tests.LanguageService.QuickParse.fs       |  112 +-
 .../Tests.LanguageService.Script.fs           |  289 ++--
 .../Tests.LanguageService.TimeStamp.fs        |   39 +-
 .../Tests.ProjectSystem.Configs.fs            |   33 +-
 .../Tests.ProjectSystem.Miscellaneous.fs      |  174 ++-
 .../Tests.ProjectSystem.MultiTargeting.fs     |   85 +-
 .../Tests.ProjectSystem.Project.fs            |   85 +-
 .../Tests.ProjectSystem.ProjectItems.fs       |   21 +-
 .../Tests.ProjectSystem.References.fs         |  135 +-
 .../Tests.ProjectSystem.RoundTrip.fs          |   23 +-
 .../Tests.ProjectSystem.UpToDate.fs           |  155 +-
 .../tests/UnitTests/TestLib.Utils.fs          |    2 +-
 vsintegration/tests/UnitTests/Tests.Build.fs  |   83 +-
 .../UnitTests/Tests.InternalCollections.fs    |   70 +-
 .../tests/UnitTests/Tests.TaskReporter.fs     |   23 +-
 vsintegration/tests/UnitTests/Tests.Watson.fs |   79 +-
 .../tests/UnitTests/Tests.XmlDocComments.fs   |   17 +-
 .../tests/UnitTests/UnusedOpensTests.fs       |  149 +-
 .../UnitTests/VisualFSharp.UnitTests.fsproj   |    9 +-
 .../UnitTests/Workspace/WorkspaceTests.fs     |   33 +-
 vsintegration/tests/UnitTests/app.runsettings |    8 -
 .../tests/UnitTests/xunit.runner.json         |    4 +
 32 files changed, 1983 insertions(+), 2556 deletions(-)
 delete mode 100644 vsintegration/tests/UnitTests/app.runsettings
 create mode 100644 vsintegration/tests/UnitTests/xunit.runner.json

diff --git a/TESTGUIDE.md b/TESTGUIDE.md
index d9faeafde73..265241917a4 100644
--- a/TESTGUIDE.md
+++ b/TESTGUIDE.md
@@ -151,14 +151,6 @@ Tags are in the left column, paths to to corresponding test folders are in the r
 
 If you want to re-run a particular test area, the easiest way to do so is to set a temporary tag for that area in test.lst (e.g. "RERUN") and adjust `ttags` [run.fsharpqa.test.fsx script](tests/fsharpqa/run.fsharpqa.test.fsx) and run it.
 
-### VisualFSharp.UnitTests
-
-These are currently NUnit tests (we hope to migrate them to xUnit). You can execute these tests individually via the Visual Studio NUnit3 runner
-extension or the command line via `nunit3-console.exe`.
-
-Note that for compatibility reasons, the IDE unit tests should be run in a 32-bit process,
-using the `--x86` flag to `nunit3-console.exe`
-
 ### Logs and output
 
 All test execution logs and result files will be dropped into the `tests\TestResults` folder, and have file names matching
diff --git a/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs b/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs
index b9cc39f66dc..3541c14043e 100644
--- a/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs
+++ b/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs
@@ -2,13 +2,13 @@
 [<NUnit.Framework.TestFixture>]
 module Tests.ServiceAnalysis.DocCommentIdParser
 
-open NUnit.Framework
+open Xunit
 open Microsoft.VisualStudio.FSharp.Editor
 
 
 
 
-[<Test>]
+[<Fact>]
 let ``Test DocCommentId parser``() =
     let testData = dict [
         "T:N.X.Nested", DocCommentId.Type ["N"; "X"; "Nested"];
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Completion.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Completion.fs
index be79eb48a9f..cb08d34ae88 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Completion.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Completion.fs
@@ -7,7 +7,7 @@ open Microsoft.VisualStudio.FSharp.LanguageService
 open Salsa.Salsa
 open Salsa.VsMocks
 open Salsa.VsOpsUtils
-open NUnit.Framework
+open Xunit
 open UnitTests.TestLib.Salsa
 open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
@@ -25,7 +25,6 @@ module StandardSettings =
     let AC x y = AutoCompleteExpected(x,y)
     let DC x y = DotCompleteExpected(x,y)
 
-[<TestFixture>][<Category "LanguageService">]  
 type UsingMSBuild() as this  = 
     inherit LanguageServiceBaseTests()
 
@@ -212,11 +211,10 @@ type UsingMSBuild() as this  =
             fileContents,
             marker,
             (fun completions -> 
-                Assert.AreNotEqual(0,completions.Length)
+                Assert.NotEqual(0,completions.Length)
                 let found = completions |> Array.exists(fun (CompletionItem(s,_,_,_,_)) -> s = expected)
                 if not(found) then 
-                    printfn "Expected: %A to contain %s" completions expected  
-                    Assert.Fail()                
+                    failwithf "Expected: %A to contain %s" completions expected  
             ),
             ?addtlRefAssy = addtlRefAssy
         )
@@ -232,7 +230,7 @@ type UsingMSBuild() as this  =
         let (_, _, file) = this.CreateSingleFileProject(fileContents)
         MoveCursorToEndOfMarker(file,marker)
         let completions = AutoCompleteAtCursor file
-        Assert.AreNotEqual(0,completions.Length)
+        Assert.NotEqual(0,completions.Length)
 
     member public this.TestCompletionNotShowingWhenFastUpdate (firstSrc : string list) secondSrc marker =     
         let (_, _, file) = this.CreateSingleFileProject(firstSrc)
@@ -270,7 +268,7 @@ type UsingMSBuild() as this  =
         let completions = DotCompletionAtStartOfMarker file marker
         AssertCompListIsEmpty(completions)
 
-    [<Test>]
+    [<Fact>]
     member this.``AutoCompletion.ObjectMethods``() = 
         let code =
             [
@@ -315,7 +313,7 @@ type UsingMSBuild() as this  =
         test "DU_3." "DU_3." ["ExtensionPropObj"; "ExtensionMethodObj"; "Equals"] ["GetHashCode"] // no gethashcode, has equals defined in DU3 type
         test "DU_4." "DU_4." ["ExtensionPropObj"; "ExtensionMethodObj"; "GetHashCode"] ["Equals"] // no equals, has gethashcode defined in DU4 type
 
-    [<Test>]
+    [<Fact>]
     member this.``AutoCompletion.BeforeThis``() = 
         let code = 
             [
@@ -348,9 +346,7 @@ type UsingMSBuild() as this  =
             AssertCtrlSpaceCompletionListIsEmptyNoCoffeeBreak c "this."
             AssertAutoCompleteCompletionListIsEmptyNoCoffeeBreak c "this."
                     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``TypeProvider.VisibilityChecksForGeneratedTypes``() = 
         let extraRefs = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")]
         let check = DoWithAutoCompleteUsingExtraRefs extraRefs None true SourceFileKind.FS BackgroundRequestReason.MemberSelect
@@ -385,49 +381,48 @@ type UsingMSBuild() as this  =
                 AssertCompListDoesNotContainAny(ci, ["f"; "ProtectedProp"; "ProtectedM"; "PrivateProp"; "PrivateM"])
                 
                
-    [<Test>] member public this.``AdjacentToDot_01``() = testAutoCompleteAdjacentToDot ".."
-    [<Test>] member public this.``AdjacentToDot_02``() = testAutoCompleteAdjacentToDot ".<"
-    [<Test>] member public this.``AdjacentToDot_03``() = testAutoCompleteAdjacentToDot ".>"
-    [<Test>] member public this.``AdjacentToDot_04``() = testAutoCompleteAdjacentToDot ".="
-    [<Test>] member public this.``AdjacentToDot_05``() = testAutoCompleteAdjacentToDot ".!="
-    [<Test>] member public this.``AdjacentToDot_06``() = testAutoCompleteAdjacentToDot ".$"
-    [<Test>] member public this.``AdjacentToDot_07``() = testAutoCompleteAdjacentToDot ".[]"
-    [<Test>] member public this.``AdjacentToDot_08``() = testAutoCompleteAdjacentToDot ".[]<-"
-    [<Test>] member public this.``AdjacentToDot_09``() = testAutoCompleteAdjacentToDot ".[,]<-"
-    [<Test>] member public this.``AdjacentToDot_10``() = testAutoCompleteAdjacentToDot ".[,,]<-"
-    [<Test>] member public this.``AdjacentToDot_11``() = testAutoCompleteAdjacentToDot ".[,,,]<-"
-    [<Test>] member public this.``AdjacentToDot_12``() = testAutoCompleteAdjacentToDot ".[,,,]"
-    [<Test>] member public this.``AdjacentToDot_13``() = testAutoCompleteAdjacentToDot ".[,,]"
-    [<Test>] member public this.``AdjacentToDot_14``() = testAutoCompleteAdjacentToDot ".[,]"
-    [<Test>] member public this.``AdjacentToDot_15``() = testAutoCompleteAdjacentToDot ".[..]"
-    [<Test>] member public this.``AdjacentToDot_16``() = testAutoCompleteAdjacentToDot ".[..,..]"
-    [<Test>] member public this.``AdjacentToDot_17``() = testAutoCompleteAdjacentToDot ".[..,..,..]"
-    [<Test>] member public this.``AdjacentToDot_18``() = testAutoCompleteAdjacentToDot ".[..,..,..,..]"
-    [<Test>] member public this.``AdjacentToDot_19``() = testAutoCompleteAdjacentToDot ".()"
-    [<Test>] member public this.``AdjacentToDot_20``() = testAutoCompleteAdjacentToDot ".()<-"
-    [<Test>] member public this.``AdjacentToDot_02_Negative``() = testAutoCompleteAdjacentToDotNegative ".<"
-    [<Test>] member public this.``AdjacentToDot_03_Negative``() = testAutoCompleteAdjacentToDotNegative ".>"
-    [<Test>] member public this.``AdjacentToDot_04_Negative``() = testAutoCompleteAdjacentToDotNegative ".="
-    [<Test>] member public this.``AdjacentToDot_05_Negative``() = testAutoCompleteAdjacentToDotNegative ".!="
-    [<Test>] member public this.``AdjacentToDot_06_Negative``() = testAutoCompleteAdjacentToDotNegative ".$"
-    [<Test>] member public this.``AdjacentToDot_07_Negative``() = testAutoCompleteAdjacentToDotNegative ".[]"
-    [<Test>] member public this.``AdjacentToDot_08_Negative``() = testAutoCompleteAdjacentToDotNegative ".[]<-"
-    [<Test>] member public this.``AdjacentToDot_09_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,]<-"
-    [<Test>] member public this.``AdjacentToDot_10_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,]<-"
-    [<Test>] member public this.``AdjacentToDot_11_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,,]<-"
-    [<Test>] member public this.``AdjacentToDot_12_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,,]"
-    [<Test>] member public this.``AdjacentToDot_13_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,]"
-    [<Test>] member public this.``AdjacentToDot_14_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,]"
-    [<Test>] member public this.``AdjacentToDot_15_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..]"
-    [<Test>] member public this.``AdjacentToDot_16_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..,..]"
-    [<Test>] member public this.``AdjacentToDot_17_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..,..,..]"
-    [<Test>] member public this.``AdjacentToDot_18_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..,..,..,..]"
-    [<Test>] member public this.``AdjacentToDot_19_Negative``() = testAutoCompleteAdjacentToDotNegative ".()"
-    [<Test>] member public this.``AdjacentToDot_20_Negative``() = testAutoCompleteAdjacentToDotNegative ".()<-"
-    [<Test>] member public this.``AdjacentToDot_21_Negative``() = testAutoCompleteAdjacentToDotNegative ".+."
-
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact>] member public this.``AdjacentToDot_01``() = testAutoCompleteAdjacentToDot ".."
+    [<Fact>] member public this.``AdjacentToDot_02``() = testAutoCompleteAdjacentToDot ".<"
+    [<Fact>] member public this.``AdjacentToDot_03``() = testAutoCompleteAdjacentToDot ".>"
+    [<Fact>] member public this.``AdjacentToDot_04``() = testAutoCompleteAdjacentToDot ".="
+    [<Fact>] member public this.``AdjacentToDot_05``() = testAutoCompleteAdjacentToDot ".!="
+    [<Fact>] member public this.``AdjacentToDot_06``() = testAutoCompleteAdjacentToDot ".$"
+    [<Fact>] member public this.``AdjacentToDot_07``() = testAutoCompleteAdjacentToDot ".[]"
+    [<Fact>] member public this.``AdjacentToDot_08``() = testAutoCompleteAdjacentToDot ".[]<-"
+    [<Fact>] member public this.``AdjacentToDot_09``() = testAutoCompleteAdjacentToDot ".[,]<-"
+    [<Fact>] member public this.``AdjacentToDot_10``() = testAutoCompleteAdjacentToDot ".[,,]<-"
+    [<Fact>] member public this.``AdjacentToDot_11``() = testAutoCompleteAdjacentToDot ".[,,,]<-"
+    [<Fact>] member public this.``AdjacentToDot_12``() = testAutoCompleteAdjacentToDot ".[,,,]"
+    [<Fact>] member public this.``AdjacentToDot_13``() = testAutoCompleteAdjacentToDot ".[,,]"
+    [<Fact>] member public this.``AdjacentToDot_14``() = testAutoCompleteAdjacentToDot ".[,]"
+    [<Fact>] member public this.``AdjacentToDot_15``() = testAutoCompleteAdjacentToDot ".[..]"
+    [<Fact>] member public this.``AdjacentToDot_16``() = testAutoCompleteAdjacentToDot ".[..,..]"
+    [<Fact>] member public this.``AdjacentToDot_17``() = testAutoCompleteAdjacentToDot ".[..,..,..]"
+    [<Fact>] member public this.``AdjacentToDot_18``() = testAutoCompleteAdjacentToDot ".[..,..,..,..]"
+    [<Fact>] member public this.``AdjacentToDot_19``() = testAutoCompleteAdjacentToDot ".()"
+    [<Fact>] member public this.``AdjacentToDot_20``() = testAutoCompleteAdjacentToDot ".()<-"
+    [<Fact>] member public this.``AdjacentToDot_02_Negative``() = testAutoCompleteAdjacentToDotNegative ".<"
+    [<Fact>] member public this.``AdjacentToDot_03_Negative``() = testAutoCompleteAdjacentToDotNegative ".>"
+    [<Fact>] member public this.``AdjacentToDot_04_Negative``() = testAutoCompleteAdjacentToDotNegative ".="
+    [<Fact>] member public this.``AdjacentToDot_05_Negative``() = testAutoCompleteAdjacentToDotNegative ".!="
+    [<Fact>] member public this.``AdjacentToDot_06_Negative``() = testAutoCompleteAdjacentToDotNegative ".$"
+    [<Fact>] member public this.``AdjacentToDot_07_Negative``() = testAutoCompleteAdjacentToDotNegative ".[]"
+    [<Fact>] member public this.``AdjacentToDot_08_Negative``() = testAutoCompleteAdjacentToDotNegative ".[]<-"
+    [<Fact>] member public this.``AdjacentToDot_09_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,]<-"
+    [<Fact>] member public this.``AdjacentToDot_10_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,]<-"
+    [<Fact>] member public this.``AdjacentToDot_11_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,,]<-"
+    [<Fact>] member public this.``AdjacentToDot_12_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,,]"
+    [<Fact>] member public this.``AdjacentToDot_13_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,,]"
+    [<Fact>] member public this.``AdjacentToDot_14_Negative``() = testAutoCompleteAdjacentToDotNegative ".[,]"
+    [<Fact>] member public this.``AdjacentToDot_15_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..]"
+    [<Fact>] member public this.``AdjacentToDot_16_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..,..]"
+    [<Fact>] member public this.``AdjacentToDot_17_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..,..,..]"
+    [<Fact>] member public this.``AdjacentToDot_18_Negative``() = testAutoCompleteAdjacentToDotNegative ".[..,..,..,..]"
+    [<Fact>] member public this.``AdjacentToDot_19_Negative``() = testAutoCompleteAdjacentToDotNegative ".()"
+    [<Fact>] member public this.``AdjacentToDot_20_Negative``() = testAutoCompleteAdjacentToDotNegative ".()<-"
+    [<Fact>] member public this.``AdjacentToDot_21_Negative``() = testAutoCompleteAdjacentToDotNegative ".+."
+
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LambdaOverloads.Completion``() = 
         let prologue = "open System.Linq"
         let cases = 
@@ -452,8 +447,7 @@ type UsingMSBuild() as this  =
             let code = [prologue; case]
             AssertCtrlSpaceCompleteContains code "(*$*)x.Len" ["Length"] []
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.CompletionInJoinOn``() = 
         let code = 
             [
@@ -467,7 +461,7 @@ type UsingMSBuild() as this  =
 
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``TupledArgsInLambda.Completion.Bug312557_1``() = 
         let code = 
             [
@@ -477,7 +471,7 @@ type UsingMSBuild() as this  =
             ]
         AssertCtrlSpaceCompleteContains code "(*MARKER*)" ["xxx"; "yyy"] []
 
-    [<Test>]
+    [<Fact>]
     member public this.``TupledArgsInLambda.Completion.Bug312557_2``() = 
         let code = 
             [
@@ -491,7 +485,7 @@ type UsingMSBuild() as this  =
         AssertCtrlSpaceCompleteContains code "b a" ["aaa"; "bbb"] []
         AssertCtrlSpaceCompleteContains code "a b" ["aaa"; "bbb"] []
 
-    [<Test>]
+    [<Fact>]
     member this.``AutoCompletion.OnTypeConstraintError``() =
         let code =
             [
@@ -508,14 +502,12 @@ type UsingMSBuild() as this  =
             ]
         AssertCtrlSpaceCompleteContains code "abcd." ["Bar"; "Equals"; "GetHashCode"; "GetType"; "InternalMethod"; "PublicMethodForIntellisense"; "ToString"] []
 
-    [<Test>]
-    [<Category("RangeOperator")>]
+    [<Fact>]
     member public this.``RangeOperator.IncorrectUsage``() = 
         AssertCtrlSpaceCompletionListIsEmpty [".."] ".."
         AssertCtrlSpaceCompletionListIsEmpty ["..."] "..."
     
-    [<Test>]
-    [<Category("Completion in Inherit")>]
+    [<Fact>]
     member public this.``Inherit.CompletionInConstructorArguments1``() = 
         let code = 
             [
@@ -524,8 +516,7 @@ type UsingMSBuild() as this  =
             ]
         AssertCtrlSpaceCompleteContains code "inherit A(a" ["abs"] []
 
-    [<Test>]
-    [<Category("Completion in Inherit")>]
+    [<Fact>]
     member public this.``Inherit.CompletionInConstructorArguments2``() = 
         let code = 
             [
@@ -534,8 +525,7 @@ type UsingMSBuild() as this  =
             ]
         AssertCtrlSpaceCompleteContains code "System.String." ["Empty"] ["Array"; "Collections"]
     
-    [<Test>]
-    [<Category("Completion in object initializer")>]
+    [<Fact>]
     member public this.``ObjectInitializer.CompletionForProperties``() =
         let typeDef1 = 
             [
@@ -602,8 +592,7 @@ type UsingMSBuild() as this  =
         AssertCtrlSpaceCompleteContains (typeDef4 @ ["new M.A<_, _>(S = 1)"]) "A<_, _>(S = 1" [] ["NonSettableProperty"; "SettableProperty"] 
         AssertCtrlSpaceCompleteContains (typeDef4 @ ["new M.A<_, _>(S = 1,)"]) "A<_, _>(S = 1," ["AnotherSettableProperty"] ["NonSettableProperty"] 
 
-    [<Test>]
-    [<Category("Completion in object initializer")>]
+    [<Fact>]
     member public this.``ObjectInitializer.CompletionForSettableExtensionProperties``() =
         let typeDef = 
             [
@@ -615,8 +604,7 @@ type UsingMSBuild() as this  =
         AssertCtrlSpaceCompleteContains (typeDef @ ["open Ext"; "A((**))"]) "A((**)" ["XYZ"] [] // positive
         AssertCtrlSpaceCompleteContains (typeDef @ ["A((**))"]) "A((**)" [] ["XYZ"] // negative
 
-    [<Test>]
-    [<Category("Completion in object initializer")>]
+    [<Fact>]
     member public this.``ObjectInitializer.CompletionForNamedParameters``() =
         let typeDef1 = 
             [
@@ -639,8 +627,7 @@ type UsingMSBuild() as this  =
         AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(x = 1)"]) ".Run<_>(x" ["xyz"] [] 
         AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(x = 1,)"]) ".Run<_>(x = 1," ["xyz"; "zyx"] [] 
     
-    [<Test>]
-    [<Category("Completion in object initializer")>]
+    [<Fact>]
     member public this.``ObjectInitializer.CompletionForSettablePropertiesInReturnValue``() =
         let typeDef1 = 
             [
@@ -675,8 +662,7 @@ type UsingMSBuild() as this  =
         AssertCtrlSpaceCompleteContains (typeDef2 @ ["A.Run<_>(Settable = 1,)"]) ".Run<_>(Settable = 1," ["Settable0"] ["NonSettable"] 
 
 
-    [<Test>]
-    [<Category("RangeOperator")>]
+    [<Fact>]
     member public this.``RangeOperator.CorrectUsage``() = 
         let useCases = 
             [
@@ -697,7 +683,7 @@ type UsingMSBuild() as this  =
         
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.Length.InForRange``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "let a = [|1;2;3|]
@@ -706,7 +692,7 @@ for i in 0..a."]
           [ "Length" ] // should contain
           [ ] // should not contain   
     
-    [<Test>]
+    [<Fact>]
     member public this.``ProtectedMembers.BaseClass`` () = 
         let sourceCode = 
             [
@@ -716,7 +702,7 @@ for i in 0..a."]
             ]
         AssertCtrlSpaceCompleteContains sourceCode "x." ["Message"; "HResult"] []
 
-    [<Test>]
+    [<Fact>]
     member public this.``ProtectedMembers.SelfOrDerivedClass`` () = 
         let sources = 
             [
@@ -737,9 +723,7 @@ for i in 0..a."]
             AssertCtrlSpaceCompleteContains src "x." ["Message"; "HResult"] []
 
     
-    [<Test>]
-    [<Ignore("Should be enabled after fixing 279738")>]
-    [<Category("Records")>]
+    [<Fact(Skip = "Should be enabled after fixing 279738")>]
     member public this.``Records.DotCompletion.ConstructingRecords1``() = 
         let prologue = "type OuterRec = {XX : int; YY : string}"
         
@@ -754,8 +738,7 @@ for i in 0..a."]
             let code = [prologue; code]
             AssertCtrlSpaceCompleteContains code marker should ["abs"]
     
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.DotCompletion.ConstructingRecords2``() = 
         let prologue = 
             [
@@ -774,8 +757,7 @@ for i in 0..a."]
             let code = prologue @ [code]
             AssertCtrlSpaceCompleteContains code marker should shouldnot
     
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.CopyOnUpdate``() =
         let prologue = 
             [
@@ -793,8 +775,7 @@ for i in 0..a."]
             let code = prologue @ [code]
             AssertCtrlSpaceCompleteContains code marker ["a"; "b"] ["abs"]
     
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.CopyOnUpdate.NoFieldsCompletionBeforeWith``() =
         let code = 
             [
@@ -804,8 +785,7 @@ for i in 0..a."]
             ]
         AssertCtrlSpaceCompleteContains code "{r " [] ["AAA"]
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.Constructors1``() =
         let prologue = 
             [
@@ -825,8 +805,7 @@ for i in 0..a."]
             let code = prologue @ [code]
             AssertCtrlSpaceCompleteContains code marker ["field1"; "field2"] ["abs"]
     
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.Constructors2.UnderscoresInNames``() =
         let prologue = 
             [
@@ -845,14 +824,12 @@ for i in 0..a."]
             AssertCtrlSpaceCompleteContains code marker ["_field1"; "_field2"] ["abs"]  
 
     
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.NestedRecordPatterns``() =
         let code = ["[1..({contents = 5}).]"]
         AssertCtrlSpaceCompleteContains code "5})." ["Value"; "contents"] ["CompareTo"]  
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.Separators1``() =
         let useCases = 
             [
@@ -872,8 +849,7 @@ for i in 0..a."]
             printfn "%A" code
             AssertCtrlSpaceCompleteContains code marker ["abs"] ["AAA"; "BBB"]
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.Separators2``() =
         let useCases = 
             [
@@ -909,8 +885,7 @@ for i in 0..a."]
             printfn "%A" code
             AssertCtrlSpaceCompleteContains code marker should ["abs"]
     
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.Inherits``() = 
         let prologue = 
             [
@@ -935,8 +910,7 @@ for i in 0..a."]
             printfn "%s" (String.concat "\r\n" code)
             AssertCtrlSpaceCompleteContains code marker should ["abs"]
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.MissingBindings``() = 
         let prologue = 
             [
@@ -956,8 +930,7 @@ for i in 0..a."]
             printfn "%s" (String.concat "\r\n" code)
             AssertCtrlSpaceCompleteContains code marker should ["abs"]
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.WRONG.ErrorsInFirstBinding``() =
         // errors in the first binding are critical now
         let prologue = 
@@ -976,8 +949,7 @@ for i in 0..a."]
             let code = prologue @ [code]
             AssertCtrlSpaceCompleteContains code marker [] ["field1"; "field2"]
             
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.InferByFieldsInPriorMethodArguments``() =
         
         let prologue = 
@@ -1005,7 +977,7 @@ for i in 0..a."]
             let code = prologue @ [code]
             AssertCtrlSpaceCompleteContains code marker should []
 
-    [<Test>]
+    [<Fact>]
     member this.``Completion.DetectInterfaces``() = 
         let shouldBeInterface =
             [
@@ -1028,7 +1000,7 @@ for i in 0..a."]
             AssertCtrlSpaceCompleteContains ifs "(*M*)" ["seq"] ["obj"]
 
 
-    [<Test>]
+    [<Fact>]
     member this.``Completion.DetectClasses``() = 
     
         let shouldBeClass = 
@@ -1056,7 +1028,7 @@ for i in 0..a."]
         for cls in shouldBeClass do
             AssertCtrlSpaceCompleteContains cls "(*M*)" ["obj"] ["seq"]
 
-    [<Test>]
+    [<Fact>]
     member this.``Completion.DetectUnknownCompletionContext``() = 
         let content = 
             [
@@ -1066,7 +1038,7 @@ for i in 0..a."]
 
         AssertCtrlSpaceCompleteContains content "(*M*)" ["obj"; "seq"] ["abs"]
 
-    [<Test>]
+    [<Fact>]
     member this.``Completion.DetectInvalidCompletionContext``() = 
         let shouldBeInvalid = 
             [
@@ -1105,7 +1077,7 @@ for i in 0..a."]
             AssertCtrlSpaceCompletionListIsEmpty invalid "(*M*)"
 
     
-    [<Test>]
+    [<Fact>]
     member this.``Completion.LongIdentifiers``() = 
         // System.Diagnostics.Debugger.Launch() |> ignore
         AssertCtrlSpaceCompleteContains
@@ -1188,8 +1160,7 @@ for i in 0..a."]
             ["Collections"; "IDisposable"]
             []
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.GroupJoin.CompletionInIncorrectJoinRelations``() = 
         let code = 
             [
@@ -1202,8 +1173,7 @@ for i in 0..a."]
         AssertCtrlSpaceCompleteContains code "(x." ["CompareTo"] ["abs"]
         AssertCtrlSpaceCompleteContains code "? y." ["Chars"; "Length"] ["abs"]
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.Join.CompletionInIncorrectJoinRelations``() = 
         let code = 
             [
@@ -1216,8 +1186,7 @@ for i in 0..a."]
         AssertCtrlSpaceCompleteContains code "(x." ["CompareTo"] ["abs"]
         AssertCtrlSpaceCompleteContains code "? y." ["Chars"; "Length"] ["abs"]
 
-    [<Test>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Query.ForKeywordCanCompleteIntoIdentifier``() = 
         let code = 
             [
@@ -1229,7 +1198,7 @@ for i in 0..a."]
             ]
         AssertCtrlSpaceCompleteContains code "for" ["form"] []  // 'for' is a keyword, but should not prevent completion
     
-    [<Test>]
+    [<Fact>]
     member public this.``ObjInstance.InheritedClass.MethodsWithDiffAccessibility``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "type Base =
@@ -1249,7 +1218,7 @@ derived.derivedField"]
           [ "baseField"; "derivedField" ] // should contain
           [ "baseFieldPrivate"; "derivedFieldPrivate" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``ObjInstance.InheritedClass.MethodsWithDiffAccessibilityWithSameNameMethod``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "type Base =
@@ -1270,7 +1239,7 @@ derived.derivedField"]
           [ "baseField"; "derivedField" ] // should contain
           [ "baseFieldPrivate"; "derivedFieldPrivate" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Visibility.InheritedClass.MethodsWithDiffAccessibility``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "type Base =
@@ -1289,7 +1258,7 @@ type Derived =
           [ "baseField"; "derivedField"; "derivedFieldPrivate" ] // should contain
           [ "baseFieldPrivate" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Visibility.InheritedClass.MethodsWithDiffAccessibilityWithSameNameMethod``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "type Base =
@@ -1309,7 +1278,7 @@ type Derived =
           [ "baseField"; "derivedField"; "derivedFieldPrivate" ] // should contain
           [ "baseFieldPrivate" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Visibility.InheritedClass.MethodsWithSameNameMethod``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "type MyClass =
@@ -1330,7 +1299,7 @@ let x = new MyClass2(0)
           [ "foo" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.Array.AfterassertKeyword``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "let x = [1;2;3] "
@@ -1339,7 +1308,7 @@ let x = new MyClass2(0)
           [ "Head" ] // should contain (from List<int>)
           [ "Listeners" ] // should not contain (from System.Diagnostics.Debug)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CtrlSpaceCompletion.Bug130670.Case1``() =
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak 
           [ "let i = async.Return(4)" ]
@@ -1347,7 +1316,7 @@ let x = new MyClass2(0)
           [ "AbstractClassAttribute" ] // should contain (top-level)
           [ "GetType" ] // should not contain (object instance method)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CtrlSpaceCompletion.Bug130670.Case2``() =
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak 
           [ """
@@ -1357,7 +1326,7 @@ let x = new MyClass2(0)
           [ "AbstractClassAttribute" ] // should contain (top-level)
           [ "CompareTo" ] // should not contain (instance method on int)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CtrlSpaceCompletion.Bug294974.Case1``() =
         
         AssertCtrlSpaceCompleteContains
@@ -1368,7 +1337,7 @@ let x = new MyClass2(0)
           [ "xxx" ] // should contain (completions before dot)
           [ "IsEmpty" ] // should not contain (completions after dot)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CtrlSpaceCompletion.Bug294974.Case2``() =
         AssertCtrlSpaceCompleteContains
           [ """
@@ -1378,7 +1347,7 @@ let x = new MyClass2(0)
           [ "AbstractClassAttribute" ] // should contain (top-level)
           [ "IsEmpty" ] // should not contain (completions after dot)
 
-    [<Test>]
+    [<Fact>]
     member public this.``ObsoleteProperties.6377_1``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "System.Security.SecurityManager." ]
@@ -1386,7 +1355,7 @@ let x = new MyClass2(0)
           [ "GetStandardSandbox" ] // should contain
           [ "get_SecurityEnabled"; "set_SecurityEnabled" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``ObsoleteProperties.6377_2``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "System.Threading.Thread.CurrentThread." ]
@@ -1394,7 +1363,7 @@ let x = new MyClass2(0)
           [ "CurrentCulture" ] // should contain: just make sure something shows
           [ "get_ApartmentState"; "set_ApartmentState" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``PopupsVersusCtrlSpaceOnDotDot.FirstDot.Popup``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "System.Console..BackgroundColor" ]
@@ -1402,7 +1371,7 @@ let x = new MyClass2(0)
           [ "BackgroundColor" ] // should contain (from prior System.Console)
           [ "abs" ] // should not contain (top-level autocomplete on empty identifier)
 
-    [<Test>]
+    [<Fact>]
     member public this.``PopupsVersusCtrlSpaceOnDotDot.FirstDot.CtrlSpace``() =
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak 
           [ "System.Console..BackgroundColor" ]
@@ -1410,17 +1379,17 @@ let x = new MyClass2(0)
           [ "BackgroundColor" ] // should contain (from prior System.Console)
           [ "abs" ] // should not contain (top-level autocomplete on empty identifier)
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotCompletionInPatternsPartOfLambda``() = 
         let content = ["let _ = fun x . -> x + 1"]
         AssertCtrlSpaceCompletionListIsEmpty content "x ."
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotCompletionInBrokenLambda``() = 
         let content = ["1 |> id (fun x .> x)"]
         AssertCtrlSpaceCompletionListIsEmpty content "x ."
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotCompletionInPatterns``() = 
         let useCases = 
             [
@@ -1433,7 +1402,7 @@ let x = new MyClass2(0)
             AssertCtrlSpaceCompletionListIsEmpty source marker
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotCompletionWithBrokenLambda``() = 
         let errors = 
             [
@@ -1458,8 +1427,7 @@ let x = new MyClass2(0)
             AssertCtrlSpaceCompleteContains source marker should shouldnot
 
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``AfterConstructor.5039_1``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "let someCall(x) = null"
@@ -1468,8 +1436,7 @@ let x = new MyClass2(0)
           [ "ReadBlock" ] // should contain (StringReader)
           [ "LastIndexOfAny" ] // should not contain (String)
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``AfterConstructor.5039_1.CoffeeBreak``() =
         AssertAutoCompleteContains
           [ "let someCall(x) = null"
@@ -1478,7 +1445,7 @@ let x = new MyClass2(0)
           [ "ReadBlock" ] // should contain (StringReader)
           [ "LastIndexOfAny" ] // should not contain (String)
 
-    [<Test>]
+    [<Fact>]
     member public this.``AfterConstructor.5039_2``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "System.Random()." ]
@@ -1486,7 +1453,7 @@ let x = new MyClass2(0)
           [ "NextDouble" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``AfterConstructor.5039_3``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "System.Collections.Generic.List<int>()." ]
@@ -1494,7 +1461,7 @@ let x = new MyClass2(0)
           [ "BinarySearch" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``AfterConstructor.5039_4``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "System.Collections.Generic.List()." ]
@@ -1502,7 +1469,7 @@ let x = new MyClass2(0)
           [ "BinarySearch" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Literal.809979``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "let value=uint64." ]
@@ -1510,7 +1477,7 @@ let x = new MyClass2(0)
           [ ] // should contain
           [ "Parse" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``NameSpace.AsConstructor``() =        
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak 
           [ "new System.DateTime()" ]
@@ -1518,7 +1485,7 @@ let x = new MyClass2(0)
           ["System";"Array2D"]
           ["DaysInMonth"; "AddDays" ] // should contain top level info, no static or instance DateTime members!
          
-    [<Test>]
+    [<Fact>]
     member public this.``DotAfterApplication1``() = 
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let g a = new System.Random()"
@@ -1527,7 +1494,7 @@ let x = new MyClass2(0)
           ["Next"]
           [ ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotAfterApplication2``() = 
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let g a = new System.Random()"
@@ -1536,7 +1503,7 @@ let x = new MyClass2(0)
           ["Head"]
           [ ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``Quickinfo.809979``() =
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "let value=uint64." ]
@@ -1545,19 +1512,19 @@ let x = new MyClass2(0)
           [ "Parse" ] // should not contain
 
     /// No intellisense in comments/strings!
-    [<Test>]
+    [<Fact>]
     member public this.``InString``() = 
         this.VerifyCtrlSpaceCompListIsEmptyAtEndOfMarker(
             fileContents = """ // System.C """ ,  
             marker = "// System.C" )
-    [<Test>]
+    [<Fact>]
     member public this.``InComment``() = 
         this.VerifyCtrlSpaceCompListIsEmptyAtEndOfMarker(
             fileContents = """ let s = "System.C" """,
             marker = "\"System.C")
                  
     /// Intellisense at the top level (on white space)
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``Identifier.OnWhiteSpace.AtTopLevel``() =  
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak
           ["(*marker*)  "] 
@@ -1566,7 +1533,7 @@ let x = new MyClass2(0)
           ["Int32"]
      
     /// Intellisense at the top level (after a partial token). All matches should be shown even if there is a unique match
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``TopLevelIdentifier.AfterPartialToken1``() =  
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak
           ["let foobaz = 1"
@@ -1575,7 +1542,7 @@ let x = new MyClass2(0)
           ["System";"Array2D";"foobaz"]
           ["Int32"]
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``TopLevelIdentifier.AfterPartialToken2``() =  
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak
           ["let foobaz = 1"
@@ -1585,7 +1552,7 @@ let x = new MyClass2(0)
           []
 
 (* these issues have not been fixed yet, but when they are, here are some tests
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug65730``() =        
         AssertAutoCompleteContains 
           [ "let f x y = x.Equals(y)" ]
@@ -1593,7 +1560,7 @@ let x = new MyClass2(0)
           [ "Equals" ] // should contain
           [  ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug65731_A``() =        
         AssertAutoCompleteContains 
           [ 
@@ -1605,7 +1572,7 @@ let x = new MyClass2(0)
           [ "a" ] // should contain
           [  ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug65731_B``() =        
         AssertAutoCompleteContains 
           [ 
@@ -1617,7 +1584,7 @@ let x = new MyClass2(0)
           [ "a" ] // should contain
           [  ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug69654_0``() =        
         let code = [ @"
                         let q =
@@ -1646,7 +1613,7 @@ let x = new MyClass2(0)
 
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug69654_1``() =        
         let code = [ 
                     "let s = async {"
@@ -1685,7 +1652,7 @@ let x = new MyClass2(0)
 
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug69654_2``() =        
         let code = [ 
                     "let s = async {"
@@ -1725,7 +1692,7 @@ let x = new MyClass2(0)
         gpatcc.AssertExactly(0,0)
 *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``List.AfterAddLinqNamespace.Bug3754``() =        
         let code = 
                 ["open System.Xml.Linq"
@@ -1735,7 +1702,7 @@ let x = new MyClass2(0)
         let completions = AutoCompleteAtCursor file
         AssertCompListContainsAll(completions, [ "map"; "filter" ] )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Global``() =    
         AssertAutoCompleteContainsNoCoffeeBreak
           ["global."]
@@ -1743,7 +1710,7 @@ let x = new MyClass2(0)
           ["System"; "Microsoft" ]
           []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Duplicates.Bug4103a``() =        
         let code = 
             [ 
@@ -1762,7 +1729,7 @@ let x = new MyClass2(0)
         AssertEqualWithMessage(2, occurrences, "The entry for 'Expr.Var' is duplicated.")
       
     /// Testing autocomplete after a dot directly following method call
-    [<Test>]
+    [<Fact>]
     member public this.``AfterMethod.Bug2296``() =        
         AssertAutoCompleteContainsNoCoffeeBreak
           [ "type System.Int32 with"
@@ -1773,7 +1740,7 @@ let x = new MyClass2(0)
           []
 
     /// Testing autocomplete after a dot directly following overloaded method call
-    [<Test>]
+    [<Fact>]
     member public this.``AfterMethod.Overloaded.Bug2296``() =      
         AssertAutoCompleteContainsNoCoffeeBreak
           ["type System.Boolean with"
@@ -1783,7 +1750,7 @@ let x = new MyClass2(0)
           ["BooleanMember"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``BasicGlobalMemberList``() =  
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let x = 1"
@@ -1792,7 +1759,7 @@ let x = new MyClass2(0)
           ["CompareTo"; "GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``CharLiteral``() =  
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let x = \"foo\""
@@ -1802,7 +1769,7 @@ let x = new MyClass2(0)
           ["CompareTo";"GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``GlobalMember.ListOnIdentifierEndingWithTick``() =      
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let x' = 1"
@@ -1811,7 +1778,7 @@ let x = new MyClass2(0)
           ["CompareTo";"GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``GlobalMember.ListOnIdentifierContainingTick``() =   
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let x'y = 1"
@@ -1820,7 +1787,7 @@ let x = new MyClass2(0)
           ["CompareTo";"GetHashCode"]
           []
         
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``GlobalMember.ListWithPartialMember1``() =    
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak
           ["let x = 1"
@@ -1829,7 +1796,7 @@ let x = new MyClass2(0)
           ["CompareTo";"GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``GlobalMember.ListWithPartialMember2``() =    
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let x = 1"
@@ -1839,7 +1806,7 @@ let x = new MyClass2(0)
           []
 
     /// Wrong intellisense for array              
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.Parenthesized.Expr``() =       
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let string_of_int (x:int) = x.ToString()"
@@ -1850,7 +1817,7 @@ let x = new MyClass2(0)
           []
 
     /// Wrong intellisense for array
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.ArrayIndexerNotation``() =  
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let string_of_int (x:int) = x.ToString()"
@@ -1861,7 +1828,7 @@ let x = new MyClass2(0)
           []
 
     /// Wrong intellisense for array
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.ArraySliceNotation1``() =    
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let string_of_int (x:int) = x.ToString()"
@@ -1873,7 +1840,7 @@ let x = new MyClass2(0)
           ["Length"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.ArraySliceNotation2``() =    
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let string_of_int (x:int) = x.ToString()"
@@ -1885,7 +1852,7 @@ let x = new MyClass2(0)
           ["Length"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.ArraySliceNotation3``() =    
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let string_of_int (x:int) = x.ToString()"
@@ -1897,7 +1864,7 @@ let x = new MyClass2(0)
           ["Length"]
           []
            
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.DictionaryIndexer``() =        
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let dict = new System.Collections.Generic.Dictionary<int,string>()"
@@ -1907,13 +1874,13 @@ let x = new MyClass2(0)
           []
 
     /// intellisense on DOT
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``EmptyFile.Dot.Bug1115``() =   
         this.VerifyAutoCompListIsEmptyAtEndOfMarker(
             fileContents = "." ,
             marker = ".")    
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``Identifier.NonDottedNamespace.Bug1347``() =     
         this.AssertCtrlSpaceCompletionContains(
             ["open System"
@@ -1926,7 +1893,7 @@ let x = new MyClass2(0)
             "let x = Mic",
             "Microsoft")
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``MatchStatement.WhenClause.Bug2519``() =   
         AssertAutoCompleteContainsNoCoffeeBreak
           ["type DU = X of int"
@@ -1938,7 +1905,7 @@ let x = new MyClass2(0)
           ["CompareTo";"GetHashCode"]
           []
         
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``String.BeforeIncompleteModuleDefinition.Bug2385``() =     
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let s = \"hello\"."
@@ -1947,7 +1914,7 @@ let x = new MyClass2(0)
           ["Substring";"GetHashCode"]
           []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Project.FsFileWithBuildAction``() =
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let i = 4"
@@ -1958,7 +1925,7 @@ let x = new MyClass2(0)
           []
 
      /// Dotting off a string literal should work.
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``DotOff.String``() =
         AssertAutoCompleteContainsNoCoffeeBreak
           ["\"x\". (*marker*)"
@@ -1968,7 +1935,7 @@ let x = new MyClass2(0)
           []
                    
     /// FEATURE: Pressing dot (.) after an local variable will produce an Intellisense list of members the user may select.
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``BasicLocalMemberList``() = 
         AssertAutoCompleteContainsNoCoffeeBreak 
           ["let MyFunction (s:string) = "
@@ -1979,7 +1946,7 @@ let x = new MyClass2(0)
           ["Substring";"GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``LocalMemberList.WithPartialMemberEntry1``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak
           ["let MyFunction (s:string) = "
@@ -1990,7 +1957,7 @@ let x = new MyClass2(0)
           ["Substring";"GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``LocalMemberList.WithPartialMemberEntry2``() = 
         AssertAutoCompleteContainsNoCoffeeBreak
           ["let MyFunction (s:string) = "
@@ -2001,8 +1968,7 @@ let x = new MyClass2(0)
           ["Substring";"GetHashCode"]
           []
 
-    [<Test;Category("Repro")>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``CurriedArguments.Regression1``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak  
            ["let fffff x y = 1"
@@ -2014,7 +1980,7 @@ let x = new MyClass2(0)
            ["fffff"]
            []   
            
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``CurriedArguments.Regression2``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak  
            ["let fffff x y = 1"
@@ -2026,7 +1992,7 @@ let x = new MyClass2(0)
            ["fffff"]
            []       
            
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``CurriedArguments.Regression3``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak  
            ["let fffff x y = 1"
@@ -2038,7 +2004,7 @@ let x = new MyClass2(0)
            ["ggggg"]
            []                                 
       
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``CurriedArguments.Regression4``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak  
            ["let fffff x y = 1"
@@ -2050,7 +2016,7 @@ let x = new MyClass2(0)
            ["ggggg"]
            []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``CurriedArguments.Regression5``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak  
            ["let fffff x y = 1"
@@ -2062,7 +2028,7 @@ let x = new MyClass2(0)
            ["ggggg"]
            []
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``CurriedArguments.Regression6``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak  
            ["let fffff x y = 1"
@@ -2075,7 +2041,7 @@ let x = new MyClass2(0)
            []
 
     // Test whether standard types appear in the completion list under both F# and .NET name
-    [<Test>]
+    [<Fact>]
     member public this.``StandardTypes.Bug4403``() = 
         AssertCtrlSpaceCompleteContainsNoCoffeeBreak
           ["open System"; "let x=" ]
@@ -2084,7 +2050,7 @@ let x = new MyClass2(0)
           [ ]
 
     // Test whether standard types appear in the completion list under both F# and .NET name            
-    [<Test>]
+    [<Fact>]
     member public this.``ValueDeclarationHidden.Bug4405``() = 
         AssertAutoCompleteContainsNoCoffeeBreak
           [ "do  "
@@ -2094,7 +2060,7 @@ let x = new MyClass2(0)
           ["IndexOf"; "Substring"]
           [ ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``StringFunctions``() = 
         let code = 
             [
@@ -2105,7 +2071,7 @@ let x = new MyClass2(0)
         MoveCursorToEndOfMarker(file,"String.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length > 0)
+        Assert.True(completions.Length > 0)
         for completion in completions do
             match completion with 
               | CompletionItem(_,_,_,_,DeclarationType.Method) -> ()
@@ -2113,7 +2079,7 @@ let x = new MyClass2(0)
                          
     // FEATURE: Pressing ctrl+space or ctrl+j will give a list of valid completions.
     
-    [<Test>]
+    [<Fact>]
     //Verified at least "Some" is contained in the Ctrl-Space Completion list
     member public this.``NonDotCompletion``() =  
         this.AssertCtrlSpaceCompletionContains(
@@ -2121,10 +2087,7 @@ let x = new MyClass2(0)
             "x = S",
             "Some")
      
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks Pressing ctrl+space on the provided Type instance method shows list of valid completions
     member this.``TypeProvider.EditorHideMethodsAttribute.InstanceMethod.CtrlSpaceCompletionContains``() =
         this.AssertCtrlSpaceCompletionContains(
@@ -2135,10 +2098,7 @@ let x = new MyClass2(0)
             expected = "IM1",    
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks Pressing ctrl+space on the provided Type Event shows list of valid completions
     member this.``TypeProvider.EditorHideMethodsAttribute.Event.CtrlSpaceCompletionContains``() =
         this.AssertCtrlSpaceCompletionContains(
@@ -2149,9 +2109,7 @@ let x = new MyClass2(0)
             expected = "Event1",          
             addtlRefAssy = [PathRelativeToTestAssembly(@"EditorHideMethodsAttribute.dll")])
      
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
+    [<Fact>]
     // This test case checks Pressing ctrl+space on the provided Type static parameter and verify "int" is in the list just to make sure bad things don't happen and autocomplete window pops up
     member this.``TypeProvider.EditorHideMethodsAttribute.Type.CtrlSpaceCompletionContains``() =
         this.AssertCtrlSpaceCompletionContains(
@@ -2163,7 +2121,7 @@ let x = new MyClass2(0)
     
         
     // In this bug, pressing dot after this was producing an invalid member list.       
-    [<Test>]
+    [<Fact>]
     member public this.``Class.Self.Bug1544``() =     
         this.VerifyAutoCompListIsEmptyAtEndOfMarker(
             fileContents = "
@@ -2172,14 +2130,14 @@ let x = new MyClass2(0)
             marker = "this.")
 
     // No completion list at the end of file. 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.AfterDefined.Bug1545``() = 
         this.AutoCompletionListNotEmpty
             ["let x = [|\"hello\"|]"
              "x."]
             "x."                              
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug243082.DotAfterNewBreaksCompletion`` () = 
         this.AutoCompletionListNotEmpty
             [
@@ -2190,7 +2148,7 @@ let x = new MyClass2(0)
             "let z = new A."]
             "s."        
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug243082.DotAfterNewBreaksCompletion2`` () = 
         this.AutoCompletionListNotEmpty
             [
@@ -2199,9 +2157,7 @@ let x = new MyClass2(0)
             "new System."]
             "s."        
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("QueryExpressions")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSmokeTest0``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2211,9 +2167,7 @@ let x = new MyClass2(0)
               list = ["sin"],
               addtlRefAssy=standard40AssemblyRefs )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("QueryExpressions")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSmokeTest0b``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2223,9 +2177,7 @@ let x = new MyClass2(0)
               list = ["query"],
               addtlRefAssy=standard40AssemblyRefs   )
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
-    [<Category("QueryExpressions")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSmokeTest1``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2235,9 +2187,7 @@ let x = new MyClass2(0)
               list = ["select"],
               addtlRefAssy=standard40AssemblyRefs  )
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
-    [<Category("QueryExpressions")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSmokeTest1b``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2249,9 +2199,7 @@ let x = new MyClass2(0)
 
 
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSmokeTest2``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2262,9 +2210,7 @@ let x = new MyClass2(0)
               addtlRefAssy=standard40AssemblyRefs  )
 
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("QueryExpressions")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSmokeTest3``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2275,8 +2221,7 @@ let x = new MyClass2(0)
               addtlRefAssy=standard40AssemblyRefs  )
 
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
+    [<Fact>]
     member this.``QueryExpression.CtrlSpaceSmokeTest3b``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2288,8 +2233,7 @@ let x = new MyClass2(0)
 
 
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
+    [<Fact>]
     member this.``QueryExpression.CtrlSpaceSmokeTest3c``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2300,8 +2244,7 @@ let x = new MyClass2(0)
               addtlRefAssy=standard40AssemblyRefs  )
 
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
+    [<Fact>]
     member this.``AsyncExpression.CtrlSpaceSmokeTest3d``() = 
            this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
               fileContents = """
@@ -2349,11 +2292,8 @@ let x = new MyClass2(0)
                                 let y = x + 1
                                 (*TYPING*)""" ]
 
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     /// This is the case where at (*TYPING*) we first type 1...N-1 characters of the target custom operation and then invoke the completion list, and we check that the completion list contains the custom operation
-    [<Category("QueryExpressions")>]
-    [<Category("Expensive")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.CtrlSpaceSystematic1``() = 
        let rec strictPrefixes (s:string) = seq { if s.Length > 1 then let s = s.[0..s.Length-2] in yield s; yield! strictPrefixes s}
        for customOperation in ["select";"skip";"contains";"groupJoin"] do
@@ -2433,10 +2373,7 @@ let x = new MyClass2(0)
         if failures.Count <> 0 || unexpectedSuccesses.Count <> 0 then 
             raise <| new Exception("there were unexpected results, see console output for details")
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
-    [<Category("Expensive")>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``QueryExpressions.QueryAndSequenceExpressionWithForYieldLoopSystematic``() = 
 
         let prefix =  """
@@ -2494,9 +2431,7 @@ let aaaaaa = [| "1" |]
 
         this.WordByWordSystematicTestWithSpecificExpectations(prefix, suffixes, lines, ["seq";"query"], knownFailures) 
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
-    [<Category("Expensive")>]
+    [<Fact>]
     /// Incrementally enter a seq{ .. while ...} loop and check for availability of intellisense etc.
     member this.``SequenceExpressions.SequenceExprWithWhileLoopSystematic``() = 
 
@@ -2535,10 +2470,7 @@ let aaaaaa = 0
         this.WordByWordSystematicTestWithSpecificExpectations(prefix, suffixes, lines, [""], knownFailures) 
              
 
-    [<Test>]
-    [<Category("QueryExpressions")>]
-    [<Category("Expensive")>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     /// Incrementally enter query with a 'join' and check for availability of quick info, auto completion and dot completion 
     member this.``QueryAndOtherExpressions.WordByWordSystematicJoinQueryOnSingleLine``() = 
 
@@ -2589,11 +2521,8 @@ let aaaaaa = 0
 
         this.WordByWordSystematicTestWithSpecificExpectations(prefix, suffixes, lines, [""], knownFailures) 
 
-    [<Test>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     /// This is a sanity check that the multiple-line case is much the same as the single-line case
-    [<Category("QueryExpressions")>]
-    [<Category("Expensive")>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``QueryAndOtherExpressions.WordByWordSystematicJoinQueryOnMultipleLine``() = 
 
         let prefix =  """
@@ -2739,8 +2668,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
 
         this.WordByWordSystematicTestWithSpecificExpectations(prefix, suffixes, lines, [""], knownFailures) 
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     /// This is the case where (*TYPING*) nothing has been typed yet and we invoke the completion list
     /// This is a known failure right now for some of the example files above.
     member this.``QueryExpression.CtrlSpaceSystematic2``() = 
@@ -2767,14 +2695,14 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completions = time1 CtrlSpaceCompleteAtCursor file "Time of first autocomplete."
         AssertCompListContainsAll(completions, expected)
             
-    [<Test>]
+    [<Fact>]
     member public this.``Parameter.CommonCase.Bug2884``() =     
         this.AutoCompleteRecoveryTest
             ([ 
                "type T1(aaa1) ="
                "  do (" ], "do (", [ "aaa1" ])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Parameter.SubsequentLet.Bug2884``() =     
         this.AutoCompleteRecoveryTest
             ([ 
@@ -2782,7 +2710,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                "  do ("
                "let a = 0" ], "do (", [ "aaa1" ]) 
                       
-    [<Test>]
+    [<Fact>]
     member public this.``Parameter.SubsequentMember.Bug2884``() =     
         this.AutoCompleteRecoveryTest
             ([ 
@@ -2791,7 +2719,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                "    do ("
                "  member x.Bar = 0" ], "do (", [ "aaa1"; "aaa2" ])        
 
-    [<Test>]
+    [<Fact>]
     member public this.``Parameter.System.DateTime.Bug2884``() =     
         this.AutoCompleteRecoveryTest
             ([ 
@@ -2799,7 +2727,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                "  member x.Foo(aaa2) = "
                "    let dt = new System.DateTime(" ], "Time(", [ "aaa1"; "aaa2" ])        
 
-    [<Test>]
+    [<Fact>]
     member public this.``Parameter.DirectAfterDefined.Bug2884``() =     
         this.AutoCompleteRecoveryTest
             ([  
@@ -2807,21 +2735,21 @@ let x = query { for bbbb in abbbbc(*D0*) do
                "  let aaa1 = 0"
                "  (" ], "(", [ "aaa1" ])
 
-    [<Test>]
+    [<Fact>]
     member public this.``NotShowInfo.LetBinding.Bug3602``() =  
         this.VerifyAutoCompListIsEmptyAtEndOfMarker(
             fileContents = "let s. = \"Hello world\"
                             ()",
             marker = "let s.")   
     
-    [<Test>]
+    [<Fact>]
     member public this.``NotShowInfo.FunctionParameter.Bug3602``() = 
         this.VerifyAutoCompListIsEmptyAtEndOfMarker(
             fileContents = "let foo s. = s + \"Hello world\"
                             ()",
             marker = "let foo s.") 
                                                
-    [<Test>]
+    [<Fact>]
     member public this.``NotShowInfo.ClassMemberDeclA.Bug3602``() =     
         this.TestCompletionNotShowingWhenFastUpdate
             [ 
@@ -2837,7 +2765,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             "(*marker*) this."
                                             
     // Another test case for the same thing - this goes through a different code path
-    [<Test>]
+    [<Fact>]
     member public this.``NotShowInfo.ClassMemberDeclB.Bug3602``() =     
         this.TestCompletionNotShowingWhenFastUpdate
             [  
@@ -2852,7 +2780,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
               "()" ]        
             "marker$"
 
-    [<Test>]
+    [<Fact>]
     member public this.``ComputationExpression.LetBang``() =     
         AssertAutoCompleteContainsNoCoffeeBreak
             ["let http(url:string) = "
@@ -2884,19 +2812,19 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertCompListContainsAll(completions, expected)
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Generics.Typeof``() =        
         this.TestGenericAutoComplete ("let _ = typeof<int>.", [ "Assembly"; "AssemblyQualifiedName"; (* ... *) ])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Generics.NonGenericTypeMembers``() =        
         this.TestGenericAutoComplete ("let _ = GT2.", [ "R"; "S" ])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Generics.GenericTypeMembers``() =        
         this.TestGenericAutoComplete ("let _ = GT<int>.", [ "P"; "Q" ])
 
-   //[<Test>]    // keep disabled unless trying to prove that UnhandledExceptionHandler is working
+   //[<Fact>]    // keep disabled unless trying to prove that UnhandledExceptionHandler is working
     member public this.EnsureThatUnhandledExceptionsCauseAnAssert() =
         // Do something that causes LanguageService to load
         AssertAutoCompleteContains 
@@ -2913,7 +2841,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         t.Start()
         System.Threading.Thread.Sleep(1000)
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotBetweenParens.Bug175360.Case1``() =
         AssertAutoCompleteContains 
             [
@@ -2923,7 +2851,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "ToDecimal" ] // should contain
             [] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``DotBetweenParens.Bug175360.Case2``() =
         AssertAutoCompleteContains 
             [ "[| 1 |].(0)" ]
@@ -2931,8 +2859,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Clone" ] // should contain
             [] // should not contain
 
-    [<Test>]
-    [<Ignore("Not worth fixing right now")>]
+    [<Fact(Skip = "Not worth fixing right now")>]
     member public this.``GenericType.Self.Bug69673_1.01``() =    
         AssertCtrlSpaceCompleteContains
             ["type Base(o:obj) = class end"
@@ -2945,7 +2872,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["this"]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``GenericType.Self.Bug69673_1.02``() =    
         AssertCtrlSpaceCompleteContains
             ["type Base(o:obj) = class end"
@@ -2958,7 +2885,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["this"]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``GenericType.Self.Bug69673_1.03``() =    
         AssertCtrlSpaceCompleteContains
             ["type Base(o:obj) = class end"
@@ -2971,7 +2898,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["this"]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``GenericType.Self.Bug69673_1.04``() =    
         AssertAutoCompleteContains
             ["type Base(o:obj) = class end"
@@ -2984,8 +2911,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["Bar"]
             []
 
-    [<Test>]
-    [<Ignore("this is not worth fixing")>]
+    [<Fact(Skip = "this is not worth fixing")>]
     member public this.``GenericType.Self.Bug69673_2.1``() =  
         AssertAutoCompleteContains
             ["type Base(o:obj) = class end"
@@ -2999,8 +2925,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["this"] 
             []       
             
-    [<Test>]
-    [<Ignore("this is not worth fixing")>]
+    [<Fact(Skip = "this is not worth fixing")>]
     member public this.``GenericType.Self.Bug69673_2.2``() =  
         AssertAutoCompleteContains
             ["type Base(o:obj) = class end"
@@ -3014,7 +2939,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["this"] 
             []                       
 
-    [<Test>]
+    [<Fact>]
     member public this.``UnitMeasure.Bug78932_1``() =        
         AssertAutoCompleteContains 
           [ @"
@@ -3027,7 +2952,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Kg" ] // should contain
           [  ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``UnitMeasure.Bug78932_2``() =        
         // Note: in this case, pressing '.' does not automatically pop up a completion list in VS, but ctrl-space does get the right list
         // This is just like how
@@ -3044,7 +2969,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Kg" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterOperator...Bug65732_A``() =        
         AssertAutoCompleteContains 
           [ "let r = [1 .. System.Int32.MaxValue]" ]
@@ -3052,7 +2977,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Int32" ] // should contain
           [ "abs" ] // should not contain (from top level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterOperator...Bug65732_B``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let r = [System.Int32.MaxValue..42]" ]
@@ -3060,7 +2985,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "abs" ] // should contain (top level)
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterOperator...Bug65732_B2``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let r = [System.Int32.MaxValue.. 42]" ]
@@ -3068,7 +2993,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "abs" ] // should contain (top level)
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterOperator...Bug65732_B3``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let r = [System.Int32.MaxValue .. 42]" ]
@@ -3076,7 +3001,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "abs" ] // should contain (top level)
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterOperator...Bug65732_C``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let r = [System.Int32.MaxValue..]" ]
@@ -3084,7 +3009,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "abs" ] // should contain (top level)
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterOperator...Bug65732_D``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let r = [System.Int32.MaxValue .. ]" ]
@@ -3094,7 +3019,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
 
     // Verify the auto completion after the close-parentheses,
     // there should be auto completion
-    [<Test>]
+    [<Fact>]
     member public this.``Array.AfterParentheses.Bug175360``() =        
         AssertAutoCompleteContainsNoCoffeeBreak 
           [ "let a = 10."
@@ -3103,7 +3028,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "ToDecimal" ] // should contain (top level)
           [ ] // should not contain 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.FuzzyDefined.Bug67133``() =  
         AssertAutoCompleteContainsNoCoffeeBreak
           [ "let gDateTime (arr: System.DateTime[]) ="
@@ -3112,7 +3037,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           ["AddDays"]
           []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.FuzzyDefined.Bug67133.Negative``() =        
         let code = [ "let gDateTime (arr: DateTime[]) ="  // Note: no 'open System', so DateTime is unknown
                      "    arr.[0]." ]
@@ -3124,7 +3049,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertCompListContainsExactly(completions, []) // we don't want any completions on <expr>. when <expr> has unknown type due to errors
         // (In particular, we don't want the "didn't find any completions, so just show top-level entities like 'abs' here" logic to kick in.)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Class.Property.Bug69150_A``() =        
         AssertCtrlSpaceCompleteContains 
           [ "type ClassType(x : int) ="
@@ -3134,7 +3059,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Value" ] // should contain
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Class.Property.Bug69150_B``() =        
         AssertCtrlSpaceCompleteContains 
           [ "type ClassType(x : int) ="
@@ -3144,7 +3069,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Value" ] // should contain
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Class.Property.Bug69150_C``() =        
         AssertCtrlSpaceCompleteContains 
           [ "type ClassType(x : int) ="
@@ -3155,7 +3080,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Value" ] // should contain
           [ "CompareTo" ] // should not contain (from Int32)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Class.Property.Bug69150_D``() =        
         AssertCtrlSpaceCompleteContains 
           [ "type ClassType(x : int) ="
@@ -3165,7 +3090,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Value" ] // should contain
           [ "VolatileFieldAttribute" ] // should not contain (from top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Class.Property.Bug69150_E``() =        
         AssertCtrlSpaceCompleteContains 
           [ "type ClassType(x : int) ="
@@ -3175,7 +3100,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Value" ] // should contain
           [ "VolatileFieldAttribute" ] // should not contain (from top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``AssignmentToProperty.Bug231283``() =        
         AssertCtrlSpaceCompleteContains 
             ["""
@@ -3190,7 +3115,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "AbstractClassAttribute" ] // top-level completions
             [ "Bar" ] // not stuff from the lhs of assignment
 
-    [<Test>]
+    [<Fact>]
     member public this.``Dot.AfterOperator.Bug69159``() =        
         AssertAutoCompleteContains 
           [ "let x1 = [|0..1..10|]." ]
@@ -3198,7 +3123,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Length" ] // should contain (array)
           [ "abs" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Residues1``() =        
         AssertCtrlSpaceCompleteContains 
           [ "System   .   Int32   .   M" ]
@@ -3206,7 +3131,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "MaxValue"; "MinValue" ] // should contain
           [ "MailboxProcessor"; "Map" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Residues2``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let x = 42"
@@ -3215,7 +3140,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "CompareTo" ] // should contain (Int32)
           [ "CLIEventAttribute"; "Checked"; "Choice" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Residues3``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let x = 42"
@@ -3224,7 +3149,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "CompareTo" ] // should contain (Int32)
           [ "CLIEventAttribute"; "Checked"; "Choice" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Residues4``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let x = 42"
@@ -3233,7 +3158,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "CompareTo" ] // should contain (Int32)
           [ "CLIEventAttribute"; "Checked"; "Choice" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CtrlSpaceInWhiteSpace.Bug133112``() =        
         AssertCtrlSpaceCompleteContains 
           [ """
@@ -3246,7 +3171,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "AbstractClassAttribute" ] // should contain (top-level)
           [ "A"; "B" ] // should not contain (Foo)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Residues5``() =        
         AssertCtrlSpaceCompleteContains 
           [ "let x = 42"
@@ -3254,7 +3179,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           ".  "       // marker
           [ "CompareTo" ] // should contain (Int32)
           [ "CLIEventAttribute"; "Checked"; "Choice" ] // should not contain (top-level)
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionInDifferentEnvs1``() = 
         AssertCtrlSpaceCompleteContains
             ["let f1 num ="
@@ -3265,7 +3190,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["completeword"] // should contain
             [""]
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionInDifferentEnvs2``() = 
         AssertCtrlSpaceCompleteContains
             ["let aaa = 1"
@@ -3276,7 +3201,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["aaa"; "aab"]
             ["aac"] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionInDifferentEnvs3``() = 
         AssertCtrlSpaceCompleteContains
             ["let mb1 = new MailboxProcessor<AsyncReplyChannel<int>>(fun inbox -> async { let! msg = inbox.Receive()"
@@ -3285,7 +3210,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["msg"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionInDifferentEnvs4``() = 
         AssertCtrlSpaceCompleteContains
             ["async {"
@@ -3305,7 +3230,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["b"]
             ["i"]
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_BaseLine0``() = 
         AssertCtrlSpaceCompleteContains
             ["type Builder() ="
@@ -3320,7 +3245,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["xxx3"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_BaseLine1``() = 
         AssertCtrlSpaceCompleteContains
             ["type Builder() ="
@@ -3337,7 +3262,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["xxx1"; "xxx2"; "xxx3"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_BaseLine2``() = 
         /// Without closing '}'
         AssertCtrlSpaceCompleteContains
@@ -3354,7 +3279,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["yyy1"; "yyy2"; "yyy3"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_BaseLine3``() = 
         /// Without closing ')'
         AssertCtrlSpaceCompleteContains
@@ -3371,7 +3296,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["zzz1"; "zzz2"; "zzz3"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_BaseLine4``() = 
         AssertCtrlSpaceCompleteContains
             ["type Builder() ="
@@ -3386,7 +3311,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["zzz1"; "zzz3"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_MergeSources_Bind_Return0``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3404,7 +3329,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["xxx3"; "xxx4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_MergeSources_Bind_Return1``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3424,7 +3349,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["xxx1"; "xxx2"; "xxx3"; "xxx4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_MergeSources_Bind_Return2``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3443,7 +3368,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["yyy1"; "yyy2"; "yyy3"; "yyy4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_MergeSources_Bind_Return3``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3462,7 +3387,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["zzz1"; "zzz2"; "zzz3"; "zzz4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_MergeSources_Bind_Return4``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3480,7 +3405,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["zzz1"; "zzz3"; "zzz4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_Bind2Return0``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3496,7 +3421,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["xxx3"; "xxx4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_Bind2Return1``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3514,7 +3439,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["xxx1"; "xxx2"; "xxx3"; "xxx4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_Bind2Return2``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3531,7 +3456,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["yyy1"; "yyy2"; "yyy3"; "yyy4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_Bind2Return3``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3548,7 +3473,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["zzz1"; "zzz2"; "zzz3"; "zzz4"]
             [] 
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompletionForAndBang_Test_Bind2Return4``() = 
         AssertCtrlSpaceCompleteContainsWithOtherFlags
             "/langversion:preview"
@@ -3565,7 +3490,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [] 
 
             (**)
-    [<Test>]
+    [<Fact>]
     member public this.``Bug229433.AfterMismatchedParensCauseWeirdParseTreeAndExceptionDuringTypecheck``() =        
         AssertAutoCompleteContains [ """
             type T() =
@@ -3588,7 +3513,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Bar"; "X" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.LongIdSet.CtrlSpace``() =        
         AssertCtrlSpaceCompleteContains [ """
             type C() =
@@ -3600,7 +3525,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.LongIdSet.Dot``() =        
         AssertAutoCompleteContains [ """
             type C() =
@@ -3612,7 +3537,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.ExprDotSet.CtrlSpace``() =        
         AssertCtrlSpaceCompleteContains [ """
             type C() =
@@ -3624,7 +3549,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.ExprDotSet.Dot``() =        
         AssertAutoCompleteContains [ """
             type C() =
@@ -3637,7 +3562,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             []
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.Nested.LongIdSet.CtrlSpace``() =        
         AssertCtrlSpaceCompleteContains [ """
             type C() =
@@ -3650,7 +3575,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.Nested.LongIdSet.Dot``() =        
         AssertAutoCompleteContains [ """
             type C() =
@@ -3663,7 +3588,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.Nested.ExprDotSet.CtrlSpace``() =        
         AssertCtrlSpaceCompleteContains [ """
             type C() =
@@ -3676,7 +3601,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.Nested.ExprDotSet.Dot``() =        
         AssertAutoCompleteContains [ """
             type C() =
@@ -3689,7 +3614,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.NamedIndexedPropertyGet.Dot``() =        
         AssertAutoCompleteContains [ """
             let str = "foo"
@@ -3698,7 +3623,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "CompareTo" ] // char
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug130733.NamedIndexedPropertyGet.CtrlSpace``() =        
         AssertCtrlSpaceCompleteContains [ """
             let str = "foo"
@@ -3707,7 +3632,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "CompareTo" ] // char
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug230533.NamedIndexedPropertySet.CtrlSpace.Case1``() =        
         AssertCtrlSpaceCompleteContains [ """
             type Foo() =
@@ -3721,7 +3646,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "MutableInstanceIndexer" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug230533.NamedIndexedPropertySet.CtrlSpace.Case2``() =        
         AssertCtrlSpaceCompleteContains [ """
             type Foo() =
@@ -3737,7 +3662,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "MutableInstanceIndexer" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug230533.ExprDotSet.CtrlSpace.Case1``() =        
         AssertCtrlSpaceCompleteContains [ """
             type C() =
@@ -3750,7 +3675,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Bug230533.ExprDotSet.CtrlSpace.Case2``() =        
         AssertCtrlSpaceCompleteContains [ """
             type C() =
@@ -3763,21 +3688,21 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "XX" ]
             []
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToLet.Bug70080``() =        
         this.AutoCompleteBug70080Helper @"
                     open System
                     [<Attr     // expect AttributeUsage from System namespace
                     let f() = 4"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToType.Bug70080``() =        
         this.AutoCompleteBug70080Helper(@"
                     open System
                     [<Attr     // expect AttributeUsage from System namespace
                     type MyAttr() = inherit Attribute()")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToLetInNamespace.Bug70080``() =        
         this.AutoCompleteBug70080Helper @"
                     namespace Foo
@@ -3785,7 +3710,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                     [<Attr     // expect AttributeUsage from System namespace
                     let f() = 4"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToTypeInNamespace.Bug70080``() =        
         this.AutoCompleteBug70080Helper(@"
                     namespace Foo
@@ -3793,7 +3718,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                     [<Attr     // expect AttributeUsage from System namespace
                     type MyAttr() = inherit Attribute()")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToNothingInNamespace.Bug70080``() =        
         this.AutoCompleteBug70080Helper(@"
                     namespace Foo
@@ -3801,7 +3726,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                     [<Attr     // expect AttributeUsage from System namespace
                     // nothing here")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToModuleInNamespace.Bug70080``() =        
         this.AutoCompleteBug70080Helper(@"
                     namespace Foo
@@ -3810,7 +3735,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                     module Foo = 
                         let x = 42")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Attribute.WhenAttachedToModule.Bug70080``() =        
         this.AutoCompleteBug70080Helper(@"
                     open System
@@ -3818,7 +3743,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                     module Foo = 
                         let x = 42")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifer.InMatchStatement.Bug72595``() =        
         // in this bug, "match blah with let" caused the lexfilter to go awry, which made things hopeless for the parser, yielding no parse tree and thus no intellisense
         AssertAutoCompleteContains 
@@ -3842,7 +3767,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Chars" ] // should contain
             [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``HandleInlineComments1``() =        
         AssertAutoCompleteContains 
           [ "let rrr = System  (* boo! *)  .  Int32  .  MaxValue" ]
@@ -3850,7 +3775,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Int32"]
           [ "abs" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``HandleInlineComments2``() =    
         AssertAutoCompleteContains 
           [ "let rrr = System  (* boo! *)  .  Int32  .  MaxValue" ]
@@ -3858,7 +3783,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "MaxValue" ] // should contain 
           [ "abs" ] // should not contain (top-level)
 
-    [<Test>]
+    [<Fact>]
     member public this.``OpenNamespaceOrModule.CompletionOnlyContainsNamespaceOrModule.Case1``() =        
         AssertAutoCompleteContains 
             [ "open System." ]
@@ -3866,7 +3791,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Collections" ] // should contain (namespace)
             [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``OpenNamespaceOrModule.CompletionOnlyContainsNamespaceOrModule.Case2``() =        
         AssertAutoCompleteContains 
             [ "open Microsoft.FSharp.Collections.Array." ]
@@ -3874,7 +3799,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Parallel" ] // should contain (module)
             [ "map" ] // should not contain (let-bound value)
 
-    [<Test>]
+    [<Fact>]
     member public this.``BY_DESIGN.CommonScenarioThatBegsTheQuestion.Bug73940``() =        
         AssertAutoCompleteContains 
             [ @"
@@ -3887,7 +3812,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ ] // should contain (ideally would be string)
             [ "Chars" ] // should not contain (documenting the undesirable behavior, that this does not show up)
 
-    [<Test>]
+    [<Fact>]
     member public this.``BY_DESIGN.ExplicitlyCloseTheParens.Bug73940``() =        
         AssertAutoCompleteContains 
             [ @"
@@ -3903,7 +3828,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Chars" ] // should contain (string)
             [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``BY_DESIGN.MismatchedParenthesesAreHardToRecoverFromAndHereIsWhy.Bug73940``() =        
         AssertAutoCompleteContains 
             [ @"
@@ -3920,7 +3845,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [ "Chars" ] // should not contain (string)
 
 (*
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug72596_A``() =        
         AssertAutoCompleteContains 
           [ "type ClassType() ="
@@ -3930,7 +3855,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "foo" ] // should not contain
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``AutoComplete.Bug72596_B``() =        
         AssertAutoCompleteContains 
           [ "let f() ="
@@ -3940,7 +3865,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "foo" ] // should not contain
 *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Expression.MultiLine.Bug66705``() =        
         AssertAutoCompleteContains 
           [ "let x = 4"
@@ -3950,7 +3875,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "ToString" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Expressions.Computation``() =        
         AssertAutoCompleteContains 
           [
@@ -3962,7 +3887,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Next" ] // should contain
           [ "GetEnumerator" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.DefineByVal.InFsiFile.Bug882304_1``() =        
         AutoCompleteInInterfaceFileContains
           [
@@ -3974,7 +3899,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ ] // should contain
           [ "Equals" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``NameSpace.InFsiFile.Bug882304_2``() =        
         AutoCompleteInInterfaceFileContains
           [
@@ -3989,7 +3914,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ] // should contain
           [  ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``CLIEvents.DefinedInAssemblies.Bug787438``() =        
         AssertAutoCompleteContains 
           [ "let mb = new MailboxProcessor<int>(fun _ -> ())"
@@ -3998,7 +3923,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Error" ] // should contain
           [ "add_Error"; "remove_Error" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.CLIEventsWithByRefArgs() =
         AssertAutoCompleteContains 
           [ "type MyDelegate = delegate of obj * string byref  -> unit"
@@ -4009,7 +3934,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "add_myEvent"; "remove_myEvent" ] // should contain
           [ "myEvent" ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.AfterParenthesis.Bug835276``() =        
         AssertAutoCompleteContains 
             [ "let f ( s : string ) ="
@@ -4021,7 +3946,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Length" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.AfterParenthesis.Bug6484_1``() =        
         AssertAutoCompleteContains 
             [ "for x in 1..10 do"
@@ -4030,7 +3955,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "CompareTo" ] // should contain (a method on the 'int' type)
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.AfterParenthesis.Bug6484_2``() =        
         AssertAutoCompleteContains 
             [ "for x = 1 to 10 do"
@@ -4039,7 +3964,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "CompareTo" ] // should contain (a method on the 'int' type)
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``Type.Indexers.Bug4898_1``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4052,7 +3977,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "ToString" ] // should contain
           [ "Value" ] // should not contain      
           
-    [<Test>]
+    [<Fact>]
     member public this.``Type.Indexers.Bug4898_2``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4070,7 +3995,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "ToString" ] // should contain
           [ "Chars" ] // should not contain    
                                              
-    [<Test>]
+    [<Fact>]
     member public this.``Expressions.Sequence``() =        
         AssertAutoCompleteContains 
           [  
@@ -4079,7 +4004,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "GetEnumerator" ] // should contain
           [ ] // should not contain
                       
-    [<Test>]
+    [<Fact>]
     member public this.``LambdaExpression.WithoutClosing.Bug1346``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4093,7 +4018,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Length" ] // should contain
           [ ] // should not contain
                       
-    [<Test>]
+    [<Fact>]
     member public this.``LambdaExpression.WithoutClosing.Bug1346c``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4107,7 +4032,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Length" ] // should contain
           [ ] // should not contain
                   
-    [<Test>]
+    [<Fact>]
     member public this.``LambdaExpression.WithoutClosing.Bug1346b``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4122,7 +4047,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Length" ] // should contain
           [ ] // should not contain
                                            
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.If_A``() =        
         AssertAutoCompleteContains 
           [
@@ -4132,7 +4057,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
                                           
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.If_C``() =        
         AssertAutoCompleteContains 
           [  
@@ -4143,7 +4068,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
                                          
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.Try_A``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4153,7 +4078,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
                       
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.Try_B``() =        
         AssertAutoCompleteContains 
           [
@@ -4163,7 +4088,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
                       
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.Try_C``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4173,7 +4098,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.Try_D``() =        
         AssertAutoCompleteContains 
           [
@@ -4184,7 +4109,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
                                         
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.Match_A``() =        
         AssertAutoCompleteContains 
           [  
@@ -4194,7 +4119,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteStatement.Match_C``() =        
         AssertAutoCompleteContains 
           [ 
@@ -4205,7 +4130,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           [ "Contains" ] // should contain
           [ ] // should not contain
 
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteIfClause.Bug4594``() = 
         AssertCtrlSpaceCompleteContains 
           [ "let Bar(xyz) =";
@@ -4219,7 +4144,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
     (* dot completions on them                                                               *)
  
     // Obsolete and CompilerMessage(IsError=true) should not appear.
-    [<Test>]
+    [<Fact>]
     member public this.``ObsoleteAndOCamlCompatDontAppear``() = 
         let code=
             [    
@@ -4287,28 +4212,28 @@ let x = query { for bbbb in abbbbc(*D0*) do
     // When the module isn't empty, we should show completion for the module
     // (and not type-inference based completion on strings - therefore test for 'Chars')
     
-    [<Test>]
+    [<Fact>]
     member public this.``Obsolete.TopLevelModule``() =
       this.AutoCompleteObsoleteTest "level <- O" false [ "None" ] [ "ObsoleteTop"; "Chars" ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``Obsolete.NestedTypeOrModule``() =
       this.AutoCompleteObsoleteTest "level <- Module" true [ "Other" ] [ "ObsoleteM"; "ObsoleteT"; "Chars" ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``Obsolete.CompletionOnObsoleteModule.Bug3992``() =
       this.AutoCompleteObsoleteTest "level <- Module.ObsoleteM" true [ "A" ] [ "ObsoleteNested"; "Chars" ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``Obsolete.DoubleNested``() =
       this.AutoCompleteObsoleteTest "level <- Module.ObsoleteM.ObsoleteNested" true [ "C" ] [ "Chars" ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``Obsolete.CompletionOnObsoleteType``() =
       this.AutoCompleteObsoleteTest "level <- Module.ObsoleteT" true [ "B" ] [ "Chars" ]
 
     /// BUG: Referencing a nonexistent DLL caused an assert.
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``WithNonExistentDll``() = 
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -4365,7 +4290,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         // This is some tag in the tooltip that also contains the overload name text
         if descr.Contains("[Signature:") then occurrences - 1 else occurrences
                                       
-    [<Test>]
+    [<Fact>]
     member public this.``Duplicates.Bug4103b``() = 
         for args in 
               [ "Test.", "foo", "foo"; 
@@ -4378,7 +4303,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
                 "TestType.", "Event", "TestType.Event" ] do   
             this.AutoCompleteDuplicatesTest args      
 
-    [<Test>]
+    [<Fact>]
     member public this.``Duplicates.Bug4103c``() =       
         let code =
             [  
@@ -4394,7 +4319,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let occurrences = this.CountMethodOccurrences(descrFunc(), "File.Open")
         AssertEqualWithMessage(3, occurrences, "Found wrong number of overloads for 'File.Open'.")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Duplicates.Bug2094``() =
         let code = 
             [  
@@ -4409,7 +4334,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let occurrences = this.CountMethodOccurrences(descrFunc(), "Start")
         AssertEqualWithMessage(2, occurrences, sprintf "Found wrong number of overloads for 'MailboxProcessor.Start'.  Found %A." completions)
        
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``WithinMatchClause.Bug1603``() =        
         let code = 
                                     [  
@@ -4424,11 +4349,11 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"let y = xx.")
         let completions = AutoCompleteAtCursor file
         // Should contain something
-        Assert.AreNotEqual(0,completions.Length)      
-        Assert.IsTrue(completions |> Array.exists (fun (CompletionItem(name,_,_,_,_)) -> name.Contains("AddMilliseconds")))  
+        Assert.NotEqual(0,completions.Length)      
+        Assert.True(completions |> Array.exists (fun (CompletionItem(name,_,_,_,_)) -> name.Contains("AddMilliseconds")))  
         
     // FEATURE: Saving file N does not cause files 1 to N-1 to re-typecheck (but does cause files N to <end> to 
-    [<Test>]
+    [<Fact>]
     member public this.``Performance.Bug5774``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -4462,8 +4387,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         gpatcc.AssertExactly(notAA[file2], notAA[file2;file3])
 
     /// FEATURE: References added to the project bring corresponding new .NET and F# items into scope.
-    [<Test;Category("ReproX")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``AfterAssemblyReferenceAdded``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -4476,18 +4400,17 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"System.Deployment.Application.")
         let completions = AutoCompleteAtCursor(file)
         // printf "Completions=%A\n" completions
-        Assert.AreEqual(0, completions.Length) // Expect none here because reference hasn't been added.
+        Assert.Equal(0, completions.Length) // Expect none here because reference hasn't been added.
         
         // Now, add a reference to the given assembly.
         this.AddAssemblyReference(project,"System.Deployment")
 
         TakeCoffeeBreak(this.VS)
         let completions = AutoCompleteAtCursor(file)
-        Assert.AreNotEqual(0, completions.Length, "Expected some items in the list after adding a reference.") 
+        Assert.NotEqual(0, completions.Length) 
 
     /// FEATURE: Updating the active project configuration influences the language service
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``AfterUpdateProjectConfiguration``() = 
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -4505,17 +4428,16 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"System.Deployment.Application.")
         let completions = AutoCompleteAtCursor(file)
         // printf "Completions=%A\n" completions
-        Assert.AreEqual(0, completions.Length) // Expect none here because reference hasn't been added.
+        Assert.Equal(0, completions.Length) // Expect none here because reference hasn't been added.
         
         // Now, update active configuration
         SetConfigurationAndPlatform(project, "Foo|x86")
         TakeCoffeeBreak(this.VS)
         let completions = AutoCompleteAtCursor(file)
-        Assert.AreNotEqual(0, completions.Length, "Expected some items in the list after updating configuration.") 
+        Assert.NotEqual(0, completions.Length) 
 
     /// FEATURE: Updating the active project platform influences the language service
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``AfterUpdateProjectPlatform``() = 
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -4534,16 +4456,16 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"System.Deployment.Application.")
         let completions = AutoCompleteAtCursor(file)
         // printf "Completions=%A\n" completions
-        Assert.AreEqual(0, completions.Length) // Expect none here because reference hasn't been added.
+        Assert.Equal(0, completions.Length) // Expect none here because reference hasn't been added.
         
         // Now, update active platform
         SetConfigurationAndPlatform(project, "Debug|x86")
         let completions = AutoCompleteAtCursor(file)
-        Assert.AreNotEqual(0, completions.Length, "Expected some items in the list after updating platform.") 
+        Assert.NotEqual(0, completions.Length) 
 
 (*
 /// FEATURE: The fileName on disk and the fileName in the project can differ in case.
-    [<Test>]
+    [<Fact>]
     member this.``Filenames.MayBeDifferentlyCased``() =
         use _guard = this.UsingNewVS() 
         let solution = this.CreateSolution()
@@ -4556,16 +4478,16 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"System.Deployment.Application.")
         let completions = AutoCompleteAtCursor(file)
         // printf "Completions=%A\n" completions
-        Assert.AreEqual(0, completions.Length) // Expect none here because reference hasn't been added.
+        Assert.Equal(0, completions.Length) // Expect none here because reference hasn't been added.
         
         // Now, add a reference to the given assembly.
         this.AddAssemblyReference(project,"System.Deployment")
         let completions = AutoCompleteAtCursor(file)
-        Assert.AreNotEqual(0, completions.Length, "Expected some items in the list after adding a reference.") 
+        Assert.NotEqual(0, completions.Length, "Expected some items in the list after adding a reference.") 
 *)
 
     /// In this bug, a bogus flag caused the rest of flag parsing to be ignored.
-    [<Test>]
+    [<Fact>]
     member public this.``FlagsAndSettings.Bug1969``() = 
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -4580,30 +4502,29 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"System.Deployment.Application.")
         let completions = AutoCompleteAtCursor(file)
         // printf "Completions=%A\n" completions
-        Assert.AreEqual(0, completions.Length) // Expect none here because reference hasn't been added.
+        Assert.Equal(0, completions.Length) // Expect none here because reference hasn't been added.
         
         // Add an unknown flag followed by the reference to our assembly.
         let deploymentAssembly = sprintf @"%s\Microsoft.NET\Framework\v4.0.30319\System.Deployment.dll" (System.Environment.GetEnvironmentVariable("windir"))
         SetOtherFlags(project,"--doo-da -r:" + deploymentAssembly) 
         let completions = AutoCompleteAtCursor(file)
         // Now, make sure the reference added after the erroneous reference is still honored.       
-        Assert.AreNotEqual(0, completions.Length, "Expected some items in the list after adding a reference.")         
+        Assert.NotEqual(0, completions.Length)         
         ShowErrors(project)      
         
     /// In this bug there was an exception if the user pressed dot after a long identifier
     /// that was unknown.
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``OfSystemWindows``() = 
         let code = ["let y=new System.Windows."]
         let (_, _, file) = this.CreateSingleFileProject(code, references = ["System.Windows.Forms"])
         MoveCursorToEndOfMarker(file,"System.Windows.")
         let completions = AutoCompleteAtCursor(file)
         printfn "Completions=%A" completions
-        Assert.AreEqual(3, completions.Length)
+        Assert.Equal(3, completions.Length)
         
     /// Tests whether we're correctly showing both type and module when they have the same name
-    [<Test>]
+    [<Fact>]
     member public this.``ShowSetAsModuleAndType``() = 
         let code = ["let s = Set"]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -4619,16 +4540,16 @@ let x = query { for bbbb in abbbbc(*D0*) do
             Assert.Fail("'Set' not found in the completion list")           
         
     /// FEATURE: The user may type namespace followed by dot and see a completion list containing members of that namespace.
-    [<Test>]
+    [<Fact>]
     member public this.``AtNamespaceDot``() = 
         let code = ["let y=new System.String()"]
         let (_, _, file) = this.CreateSingleFileProject(code)
         MoveCursorToEndOfMarker(file,"System.")
         let completions = AutoCompleteAtCursor(file)
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         
     /// FEATURE: The user will see appropriate glyphs in the autocompletion list.
-    [<Test>]
+    [<Fact>]
     member public this.``OfSeveralModuleMembers``() = 
         let code = 
                                     [ 
@@ -4670,7 +4591,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file," Module.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
 
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         for completion in completions do
             match completion with 
               | CompletionItem("A",_,_,_,DeclarationType.EnumMember)                          -> ()
@@ -4700,7 +4621,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"AbbreviationModule.")
         let completions = time1 AutoCompleteAtCursor file "Time of second autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         for completion in completions do
             match completion with 
               | CompletionItem("Int32",_,_,_,_) 
@@ -4722,7 +4643,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
               | CompletionItem("TupleTypeAbbreviation",_,_,_,_) -> ()
               | CompletionItem(name,_,_,_,x) -> failwith (sprintf "Unexpected union member %s seen with declaration type %A" name x)
         
-    [<Test>]
+    [<Fact>]
     member public this.ListFunctions() = 
         let code = 
                                     [ 
@@ -4733,7 +4654,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"List.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         for completion in completions do
             match completion with 
               | CompletionItem("Cons",_,_,_,DeclarationType.Method) -> ()
@@ -4743,7 +4664,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
               | CompletionItem(_,_,_,_,DeclarationType.Method) -> ()
               | CompletionItem(name,_,_,_,x) -> failwith (sprintf "Unexpected item %s seen with declaration type %A" name x)
 
-    [<Test>]
+    [<Fact>]
     member public this.``SystemNamespace``() =
         let code =
                                     [ 
@@ -4753,7 +4674,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"System.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         
         let AssertIsDecl(name,decl,expected) =
             if decl<>expected then failwith (sprintf "Expected %A for %s but was %A" expected name decl)
@@ -4765,7 +4686,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
               | _ -> ()
       
     // If there is a compile error that prevents a data tip from resolving then show that data tip.
-    [<Test>]
+    [<Fact>]
     member public this.``MemberInfoCompileErrorsShowInDataTip``() =     
         let code = 
                                     [ 
@@ -4779,7 +4700,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
     
         use scope = AutoCompleteMemberDataTipsThrowsScope(this.VS, "Simulated compiler error")
         let completions = time1 CtrlSpaceCompleteAtCursor file "Time of first autocomplete."
-        Assert.IsTrue(completions.Length>0)      
+        Assert.True(completions.Length>0)      
         for completion in completions do 
             let (CompletionItem(_,_,_,descfunc,_)) = completion
             let desc = descfunc()
@@ -4787,7 +4708,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             AssertContains(desc,"Simulated compiler error")
 
     // Bunch of crud in empty list. This test asserts that unwanted things don't exist at the top level.
-    [<Test>]
+    [<Fact>]
     member public this.``Editor.WithoutContext.Bug986``() =     
         let code = ["(*mark*)"]
         let (_,_, file) = this.CreateSingleFileProject(code)
@@ -4800,17 +4721,17 @@ let x = query { for bbbb in abbbbc(*D0*) do
               | CompletionItem("ICorRuntimeHost" as s,_,_,_,_) -> failwith (sprintf "Unexpected item %s at top level."  s)
               | _ -> ()
               
-    [<Test>]
+    [<Fact>]
     member public this.``LetBind.TopLevel.Bug1650``() =   
         let code =["let x = "]          
         let (_,_, file) = this.CreateSingleFileProject(code)
         let gpatcc = GlobalParseAndTypeCheckCounter.StartNew(this.VS)
         MoveCursorToEndOfMarker(file,"let x = ")
         let completions = time1 CtrlSpaceCompleteAtCursor file "Time of first autocomplete."
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         gpatcc.AssertExactly(0,0)
               
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.Invalid.Bug876b``() =  
         let code =
                                     [ 
@@ -4822,9 +4743,9 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"x.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         ShowErrors(project)
-        Assert.IsTrue(completions.Length>0)      
+        Assert.True(completions.Length>0)      
         
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.Invalid.Bug876c``() =     
         let code =
                                     [ 
@@ -4834,9 +4755,9 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let (_,_, file) = this.CreateSingleFileProject(code, references = ["System"; "System.Drawing"; "System.Windows.Forms"])
         MoveCursorToEndOfMarker(file,"x.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
-        Assert.IsTrue(completions.Length>0)     
+        Assert.True(completions.Length>0)     
         
-    [<Test>]
+    [<Fact>]
     member public this.``EnumValue.Bug2449``() =     
         let code =
                                     [ 
@@ -4849,7 +4770,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         AssertCompListDoesNotContain(completions, "value__")
                
-    [<Test>]
+    [<Fact>]
     member public this.``EnumValue.Bug4044``() =   
         let code =
                                     [ 
@@ -4866,7 +4787,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
     /// There was a bug (2584) that IntelliSense should treat 'int' as a type instead of treating it as a function
     /// However, this is now deprecated behavior. We want the user to use 'System.Int32' and 
     /// we generally prefer information from name resolution (also see 4405)
-    [<Test>]
+    [<Fact>]
     member public this.``PrimTypeAndFunc``() =     
         let code =
                                     [ 
@@ -4883,7 +4804,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertCompListDoesNotContain(completions,"MinValue")
            
  /// This is related to Bug1605--since the file couldn't parse there was no information to provide the autocompletion list.    
-    [<Test>]
+    [<Fact>]
     member public this.``MatchStatement.Clause.AfterLetBinds.Bug1603``() = 
         let code =
                                     [ 
@@ -4898,7 +4819,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"xs -> f xs.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         
         let mutable count = 0
         
@@ -4915,10 +4836,10 @@ let x = query { for bbbb in abbbbc(*D0*) do
                 AssertIsDecl(name,decl,DeclarationType.Property) 
               | CompletionItem(name,_,_,_,x) -> ()        
         
-        Assert.AreEqual(2,count)
+        Assert.Equal(2,count)
         
     // This was a bug in which the third level of dotting was ignored.
-    [<Test>]
+    [<Fact>]
     member public this.``ThirdLevelOfDotting``() =     
         let code =
                                     [ 
@@ -4928,7 +4849,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"Console.Wr")
         let completions = time1 CtrlSpaceCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         
         let AssertIsDecl(name,decl,expected) =
             if decl<>expected then failwith (sprintf "Expected %A for %s but was %A" expected name decl)
@@ -4940,7 +4861,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
               | CompletionItem(name,_,_,_,x) -> ()
 
     // Test completions in an incomplete computation expression (case 1: for "let")
-    [<Test>]
+    [<Fact>]
     member public this.``ComputationExpressionLet``() =     
         let code =
                     [  
@@ -4953,7 +4874,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         AssertCompListContainsAll(completions, ["Next"])
  
-    [<Test>]
+    [<Fact>]
     member public this.``BestMatch.Bug4320a``() = 
         let code = [ " let x = System." ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -4975,7 +4896,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertEqual(Some ("GCCollectionMode", true, true),   Match "GCC" (Some "GC"))
         AssertEqual(Some ("GCCollectionMode", false, false), Match "GCCZ" (Some "GC"))
     
-    [<Test>]
+    [<Fact>]
     member public this.``BestMatch.Bug4320b``() = 
         let code = [ " let x = List." ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -4987,7 +4908,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertEqual(Some ("empty", false, true),  Match "e")
         AssertEqual(Some ("empty", true, true), Match "em")
       
-    [<Test>]
+    [<Fact>]
     member public this.``BestMatch.Bug5131``() = 
         let code = [ "System.Environment." ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -4998,7 +4919,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         // isPrefix=true means it will be selected, instead of just outlined
         AssertEqual(Some ("OSVersion", true, true),  Match "o")
     
-    [<Test>]
+    [<Fact>]
     member public this.``COMPILED.DefineNotPropagatedToIncrementalBuilder``() =
         use _guard = this.UsingNewVS()
  
@@ -5026,10 +4947,10 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completionItems = 
             AutoCompleteAtCursor(file)
             |> Array.map (fun (CompletionItem(name, _, _, _, _)) -> name)
-        Assert.AreEqual(1, completionItems.Length, "Expected 1 item in the list")
-        Assert.AreEqual("x", completionItems.[0], "Expected 'x' in the list")
+        Assert.Equal(1, completionItems.Length)
+        Assert.Equal("x", completionItems.[0])
  
-    [<Test>]
+    [<Fact>]
     member public this.``VisualStudio.CloseAndReopenSolution``() = 
         use _guard = this.UsingNewVS()
         // This test exposes what was once a bug, where closing a solution and then re-opening
@@ -5048,17 +4969,16 @@ let x = query { for bbbb in abbbbc(*D0*) do
         MoveCursorToEndOfMarker(file,"x.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
         this.CloseSolution(solution)
         let project,solution = OpenExistingProject(this.VS, dir, projName)
         let file = List.item 0 (GetOpenFiles(project))
         MoveCursorToEndOfMarker(file,"x.")
         let completions = time1 AutoCompleteAtCursor file "Time of first autocomplete."
         // printf "Completions=%A\n" completions
-        Assert.IsTrue(completions.Length>0)
+        Assert.True(completions.Length>0)
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``BadCompletionAfterQuicklyTyping.Bug72561``() =        
         let code = [ "        " ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -5079,8 +4999,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertCompListDoesNotContainAny(completions, ["AbstractClassAttribute"]) 
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``BadCompletionAfterQuicklyTyping.Bug72561.Noteworthy.NowWorks``() =        
         let code = [ "123      " ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -5102,8 +5021,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertCompListDoesNotContainAny(completions, ["AbstractClassAttribute"]) 
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``BadCompletionAfterQuicklyTyping.Bug130733.NowWorks``() =        
         let code = [ "let someCall(x) = null"
                      "let xe = someCall(System.IO.StringReader()  "]
@@ -5167,7 +5085,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completions = CtrlSpaceCompleteAtCursor(file)   
         AssertEqual(0,completions.Length)              
                 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.WithoutPreDefinedMethods``() = 
         this.VerifyCtrlSpaceListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -5175,7 +5093,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*HERE*)",
             list = ["FSharpDelegateEvent"; "PrivateMethod"; "PrivateType"])
                     
-    [<Test>]
+    [<Fact>]
     member this.``Expression.WithPreDefinedMethods``() = 
         this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
             fileContents = """
@@ -5193,7 +5111,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["PrivateField"; "PrivateMethod"; "PrivateType"])                 
          
     // Regression for bug 2116 -- Consider making selected item in completion list case-insensitive       
-    [<Test>]
+    [<Fact>]
     member this.``CaseInsensitive``() =
         this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
             fileContents = """
@@ -5210,7 +5128,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*Marker1*)",
             list = ["Xyzzy"; "xYzzy"; "xyZzy"; "xyzZy"; "xyzzY"])  
       
-    [<Test>]
+    [<Fact>]
     member this.``Attributes.CanSeeOpenNamespaces.Bug268290.Case1``() =
         AssertCtrlSpaceCompleteContains 
             ["""
@@ -5222,7 +5140,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["AttributeUsage"]
             []
 
-    [<Test>]
+    [<Fact>]
     member this.``Selection``() =
         AssertCtrlSpaceCompleteContains 
             ["""
@@ -5234,7 +5152,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             []
             
     // Regression test for 1653 -- Both the F# exception and the .NET exception representing it are shown in completion lists
-    [<Test>]
+    [<Fact>]
     member this.``NoDupException.Postive``() = 
         this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
             fileContents = """
@@ -5242,7 +5160,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*MarkerException*)",
             list = ["MatchFailureException"])
 
-    [<Test>]
+    [<Fact>]
     member this.``DotNetException.Negative``() =
         this.VerifyCtrlSpaceListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -5251,7 +5169,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["MatchFailure"])        
 
     // Regression for bug 921 -- intellisense case-insensitive? 
-    [<Test>]
+    [<Fact>]
     member this.``CaseInsensitive.MapMethod``() =
         this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
             fileContents = """
@@ -5261,8 +5179,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["map"])
                         
     //Regression for bug   69644    69654  Fsharp: no completion for an identifier when 'use'd inside an 'async' block
-    [<Test>]
-    [<Ignore("69644 - no completion for an identifier when 'use'd inside an 'async' block")>]
+    [<Fact(Skip = "69644 - no completion for an identifier when 'use'd inside an 'async' block")>]
     member this.``InAsyncAndUseBlock``() =
         this.VerifyCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5281,7 +5198,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*Marker1*)",
             list = ["reader"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``WithoutOpenNamespace``() =
         AssertCtrlSpaceCompleteContains 
             ["""
@@ -5293,7 +5210,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             [] // should
             ["Single"] // should not
 
-    [<Test>]
+    [<Fact>]
     member this.``PrivateVisible``() =
         AssertCtrlSpaceCompleteContains 
             ["""
@@ -5315,7 +5232,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["fieldPrivate";"MethodPrivate";"TypePrivate"]
             []
 
-    [<Test>]
+    [<Fact>]
     member this.``InternalVisible``() =
         AssertCtrlSpaceCompleteContains 
             ["""
@@ -5336,8 +5253,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             ["fieldInternal";"MethodInternal";"TypeInternal"]  // should
             [] // should not
 
-    [<Test>]
-    [<Category("Unit of Measure")>]
+    [<Fact>]
     // Verify that we display the correct list of Unit of Measure (Names) in the autocomplete window. 
     // This also ensures that no UoM are accidentally added or removed.
     member public this.``UnitMeasure.UnitNames``() =
@@ -5349,8 +5265,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             "ohm"; "pascal"; "second"; "siemens"; "sievert"; "tesla"; "volt"; "watt"; "weber";] // should contain; exact match
           [ ] // should not contain 
 
-    [<Test>]
-    [<Category("Unit of Measure")>]
+    [<Fact>]
     // Verify that we display the correct list of Unit of Measure (Symbols) in the autocomplete window. 
     // This also ensures that no UoM are accidentally added or removed.
     member public this.``UnitMeasure.UnitSymbols``() =
@@ -5371,9 +5286,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         AssertCompListContainsAll(completions, contained)
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Custom operators appear in Intellisense list after entering a valid query operator
     // on the previous line and invoking Intellisense manually
     // Including in a nested query
@@ -5391,9 +5304,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           marker = "do ma",
           contained = [ "maxBy"; "maxByNullable"; ])
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Custom operators appear in Intellisense list after entering a valid query operator
     // on the previous line and invoking Intellisense manually
     // Including in a nested query
@@ -5409,7 +5320,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
           marker = "gro",
           contained = [ "groupBy"; "groupJoin"; "groupValBy";])
 
-    [<Test>]
+    [<Fact>]
     member this.``Namespace.System``() =
         this.VerifyDotCompListContainAllAtEndOfMarker(
             fileContents = """
@@ -5422,7 +5333,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "open System",
             list = [ "IO"; "Collections" ]) 
                     
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.String.Positive``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5434,7 +5345,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*usage*)",
             list = ["Chars"; "ToString"; "Length"; "GetHashCode"])   
             
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.String.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -5448,7 +5359,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
 
     // Verify add_* methods show up for non-standard events. These are events
     // where the associated delegate type does not return "void" 
-    [<Test>]
+    [<Fact>]
     member this.``Event.NonStandard.PrefixMethods``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """System.AppDomain.CurrentDomain(*usage*)""",
@@ -5457,28 +5368,28 @@ let x = query { for bbbb in abbbbc(*D0*) do
         
     // Verify the events do show up. An error is generated when they are used asking the user to use add_* and remove_* instead.
     // That is, they are legitimate name resolutions but do not pass type checking.
-    [<Test>]
+    [<Fact>]
     member this.``Event.NonStandard.VerifyLegitimateNameShowUp``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "System.AppDomain.CurrentDomain(*usage*)",
             marker = "(*usage*)",
             list = ["AssemblyResolve"; "ReflectionOnlyAssemblyResolve"; "ResourceResolve"; "TypeResolve" ])
 
-    [<Test>]
+    [<Fact>]
     member this.``Array``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "let arr = [| for i in 1..10 -> i |](*Mexparray*)",
             marker = "(*Mexparray*)",
             list = ["Clone"; "IsFixedSize"]) 
         
-    [<Test>]
+    [<Fact>]
     member this.``List``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "let lst = [ for i in 1..10 -> i](*Mexplist*)",
             marker = "(*Mexplist*)",
             list = ["Head"; "Tail"]) 
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5490,7 +5401,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["Clone"])  // should contain method on array (result of M call)
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test2``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5505,7 +5416,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["Clone"])  // should contain method on array (result of M call)
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test3``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5520,7 +5431,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
 
 
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test4``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5533,7 +5444,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["InterfaceMethods"])  
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test5``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5545,7 +5456,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["GetEnumerator"])  
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test6``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5557,7 +5468,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["AddHandler"])  
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test7``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5569,7 +5480,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["Assembly"])  
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test8``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5582,7 +5493,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["CompareTo"])  
 
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug187799.Test9``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5594,11 +5505,8 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*marker*)",
             list = ["CompareTo"])  
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
     // This test case checks that autocomplete on the provided Type DOES NOT show System.Object members
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``TypeProvider.EditorHideMethodsAttribute.Type.DoesnotContain``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """ 
@@ -5608,10 +5516,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["Equals";"GetHashCode"],            
             addtlRefAssy = [PathRelativeToTestAssembly(@"EditorHideMethodsAttribute.dll")])
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks if autocomplete on the provided Type shows only the Event1 elements
     member this.``TypeProvider.EditorHideMethodsAttribute.Type.Contains``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
@@ -5622,10 +5527,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["Event1"],            
             addtlRefAssy = [PathRelativeToTestAssembly(@"EditorHideMethodsAttribute.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks if autocomplete on the provided Type shows the instance method IM1
     member this.``TypeProvider.EditorHideMethodsAttribute.InstanceMethod.Contains``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
@@ -5636,9 +5538,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["IM1"],            
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
-    [<Category("TypeProvider")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks that nested types show up only statically and not on instances
     member this.``TypeProvider.TypeContainsNestedType``() =
         // should have it here
@@ -5657,10 +5557,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["SomeNestedType"],            
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks if autocomplete on the provided Event shows only the AddHandler/RemoveHandler elements
     member this.``TypeProvider.EditorHideMethodsAttribute.Event.Contain``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
@@ -5671,9 +5568,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["AddHandler";"RemoveHandler"],            
             addtlRefAssy = [PathRelativeToTestAssembly(@"EditorHideMethodsAttribute.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
+    [<Fact>]
     // This test case checks if autocomplete on the provided Method shows no elements 
     // You can see this as a "negative case" (to check that the usage of the attribute on a method is harmless)
     member this.``TypeProvider.EditorHideMethodsAttribute.Method.Contain``() =
@@ -5683,10 +5578,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*Marker*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"EditorHideMethodsAttribute.dll")])
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.EditorHideMethodsAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // This test case checks if autocomplete on the provided Property (the type of which is not synthetic) shows the usual elements... like GetType()
     // 1. I think it does not make sense to use this attribute on a synthetic property unless it's type is also synthetic (already covered)
     // 2. You can see this as a "negative case" (to check that the usage of the attribute is harmless)
@@ -5698,7 +5590,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             list = ["GetType"; "Equals"],   // just a couple of System.Object methods: we expect them to be there!
             addtlRefAssy = [PathRelativeToTestAssembly(@"EditorHideMethodsAttribute.dll")])
                                           
-    [<Test>]
+    [<Fact>]
     member this.CompListInDiffFileTypes() =
         let fileContents = """
             val x:int = 1
@@ -5718,7 +5610,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completions = DotCompletionAtStartOfMarker file "(*MarkerInsideSourceFile*)"
         AssertCompListContainsAll(completions, ["CompareTo"; "Equals"])
   
-    [<Test>]
+    [<Fact>]
     member this.ConstrainedTypes() =
         let fileContents = """
             type Pet() = 
@@ -5748,35 +5640,35 @@ let x = query { for bbbb in abbbbc(*D0*) do
         let completions = DotCompletionAtStartOfMarker file "(*Mconstrainedtoint*)"
         AssertCompListContainsAll(completions, ["ToString"])    
 
-    [<Test>]
+    [<Fact>]
     member this.``Literal.Float``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "let myfloat = (42.0)(*Mconstantfloat*)",
             marker = "(*Mconstantfloat*)",
             list = ["GetType"; "ToString"])
             
-    [<Test>] 
+    [<Fact>] 
     member this.``Literal.String``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """let name = "foo"(*Mconstantstring*)""",
             marker = "(*Mconstantstring*)",
             list = ["Chars"; "Clone"]) 
             
-    [<Test>]
+    [<Fact>]
     member this.``Literal.Int``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "let typeint = (10)(*Mint*)",
             marker = "(*Mint*)",
             list = ["GetType";"ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InLambdaExpression``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "let funcLambdaExp = fun (x:int)-> x(*MarkerinLambdaExp*)",
             marker = "(*MarkerinLambdaExp*)",
             list = ["ToString"; "Equals"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InClass``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5785,7 +5677,7 @@ let x = query { for bbbb in abbbbc(*D0*) do
             marker = "(*MarkerLetBindinClass*)",
             list = ["ToString"; "Equals"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InNestedLetBind``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "
@@ -5796,7 +5688,7 @@ let funcNestedLetBinding (x:int) =
             marker = "(*MarkerNestedLetBind*)",
             list = ["ToString"; "Equals"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InModule``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "
@@ -5806,7 +5698,7 @@ module ModuleLetBindIn =
             marker = "(*MarkerLetBindinModule*)",
             list = ["ToString"; "Equals"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InMatchStatement``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "
@@ -5819,7 +5711,7 @@ match x(*MarkerMatchStatement*) with
             marker = "(*MarkerMatchStatement*)",
             list = ["ToString"; "Equals"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InMatchClause``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "
@@ -5834,7 +5726,7 @@ let rec f l =
             marker = "(*MarkerMatchClause*)",
             list = ["Add";"Date"]) 
                            
-    [<Test>]
+    [<Fact>]
     member this.``Expression.ListItem``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5844,7 +5736,7 @@ let rec f l =
             marker = "(*MarkerListItem*)",
             list = ["CompareTo"; "ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.FunctionParameter``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5854,7 +5746,7 @@ let rec f l =
             marker = "(*MarkerParameter*)",
             list = ["CompareTo"; "ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.Function``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5864,7 +5756,7 @@ let rec f l =
             marker = "(*MarkerFunction*)",
             list = ["CompareTo"; "ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.RecordPattern``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5876,7 +5768,7 @@ let rec f l =
             marker = "(*MarkerRecordPattern*)",
             list = ["Value"; "ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.2DArray``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5886,7 +5778,7 @@ let rec f l =
             marker = "(*Marker2DArray*)",
             list = ["ToString"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.LetBind``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5897,7 +5789,7 @@ let rec f l =
             marker = "(*MarkerContext1*)",
             list = ["CompareTo";"ToString"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.WhileLoop``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5908,14 +5800,14 @@ let rec f l =
             marker = "(*MarkerContext3*)",
             list = ["CompareTo";"ToString"])  
 
-    [<Test>] 
+    [<Fact>] 
     member this.``Expression.List``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """[1;2](*MarkerList*)   """,
             marker = "(*MarkerList*)",
             list = ["Head"; "Item"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.Nested.InLetBind``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5926,7 +5818,7 @@ let rec f l =
             marker = "(*MarkerNested1*)",
             list = ["Chars";"Length"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.Nested.InWhileLoop``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5937,7 +5829,7 @@ let rec f l =
             marker = "(*MarkerNested2*)",
             list = ["Chars";"Length"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.ArrayItem.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5947,7 +5839,7 @@ let rec f l =
             marker = "(*MarkerArrayIndexer*)",
             list = ["Chars";"Split"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.ArrayItem.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -5957,7 +5849,7 @@ let rec f l =
             marker = "(*MarkerArrayIndexer*)",
             list = ["IsReadOnly";"Rank"])
                                                                                                                                                                 
-    [<Test>]
+    [<Fact>]
     member this.``ObjInstance.InheritedClass.MethodsDefInBase``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5972,7 +5864,7 @@ let rec f l =
             marker = "(*Mderived*)",
             list = ["Name"; "dog"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ObjInstance.AnonymousClass.MethodsDefInInterface``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -5993,7 +5885,7 @@ let rec f l =
             marker = "(*Mexpnewtype*)",
             list = ["DoStuff"; "DoStuff2"])
              
-    [<Test>]
+    [<Fact>]
     member this.``SimpleTypes.SystemTime``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6002,7 +5894,7 @@ let rec f l =
             marker = "(*Mstruct*)",
             list = ["AddDays"; "Date"])
 
-    [<Test>]
+    [<Fact>]
     member this.``SimpleTypes.Record``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6012,7 +5904,7 @@ let rec f l =
             marker = "(*Mrecord*)",
             list = ["DateOfBirth"; "Name"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``SimpleTypes.Enum``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6027,7 +5919,7 @@ let rec f l =
             marker = "(*Menum*)",
             list = ["GetType"; "ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``SimpleTypes.DisUnion``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6043,7 +5935,7 @@ let rec f l =
             marker = "(*Mdiscriminatedunion*)",
             list = ["GetType"; "ToString"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``InheritedClass.BaseClassPrivateMethod.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -6069,7 +5961,7 @@ let rec f l =
             marker = "(*MUnShowPrivate*)",
             list = ["MethodPrivate";"fieldPrivate"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``InheritedClass.BaseClassPublicMethodAndProperty``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6095,14 +5987,14 @@ let rec f l =
             marker = "(*MShowPublic*)",
             list = ["MethodPublic";"fieldPublic"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Visibility.InternalNestedClass.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """System.Console(*Marker1*)""",
             marker = "(*Marker1*)",
             list = ["ControlCDelegateData"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Visibility.PrivateIdentifierInDiffModule.Negative``() = 
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6116,7 +6008,7 @@ let rec f l =
                     Module1(*Marker1*)  """,
             marker = "(*Marker1*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Visibility.PrivateIdentifierInDiffClass.Negative``() = 
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -6133,7 +6025,7 @@ let rec f l =
             marker = "(*MarkerOutType*)",
             list = ["fieldPrivate";"MethodPrivate"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Visibility.PrivateFieldInSameClass``() =  
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6150,7 +6042,7 @@ let rec f l =
             marker = "(*MarkerFieldInType*)",
             list = ["PrivateField"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Visibility.PrivateMethodInSameClass``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6167,7 +6059,7 @@ let rec f l =
             marker = "(*MarkerMethodInType*)",
             list = ["PrivateMethod"])       
 
-//    [<Test>]
+//    [<Fact>]
     member this.``VariableIdentifier.AsParameter``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6178,7 +6070,7 @@ let rec f l =
             marker = "(*Maftervariable1*)",
             list = ["Tag"])
 
-    [<Test>]
+    [<Fact>]
     member this.``VariableIdentifier.InMeasure.DefineInDiffNamespace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6202,7 +6094,7 @@ let rec f l =
             marker = "(*Maftervariable2*)",
             list = [])
 
-    [<Test>]
+    [<Fact>]
     member this.``VariableIdentifier.MethodsInheritFromBase``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6221,7 +6113,7 @@ let rec f l =
             marker = "(*Maftervariable3*)",
             list = ["Name";"Speak"])
 
-    [<Test>]
+    [<Fact>]
     member this.``VariableIdentifier.AsParameter.DefineInDiffNamespace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6245,7 +6137,7 @@ let rec f l =
             marker = "(*Maftervariable4*)",
             list = ["DuType"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``VariableIdentifier.SystemNamespace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6269,7 +6161,7 @@ let rec f l =
             marker = "(*Maftervariable5*)",
             list = ["BinaryReader";"Stream";"Directory"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.AsAttribute``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6279,7 +6171,7 @@ let rec f l =
             marker = "(*Mattribute*)",
             list = ["Obsolete"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ImportStatement.System.ImportDirectly``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6288,7 +6180,7 @@ let rec f l =
             marker = "(*Mimportstatement1*)",
             list = ["Collections"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ImportStatement.System.ImportAsIdentifier``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6297,7 +6189,7 @@ let rec f l =
             marker = "(*Mimportstatement2*)",
             list = ["IO"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.PatternMatch.AsVariable.DefFromDiffNamespace``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6317,7 +6209,7 @@ let rec f l =
             marker = "(*Mpatternmatch1*)",
             list = ["Direction";"ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.PatternMatch.AsConstantValue.DefFromDiffNamespace``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6337,7 +6229,7 @@ let rec f l =
             marker = "(*Mpatternmatch2*)",
             list = ["longident"])
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.PInvoke.AsReturnType``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6358,7 +6250,7 @@ let rec f l =
             marker = "(*Mpinvokereturntype*)",
             list = ["Boolean";"Int32"])
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.PInvoke.AsAttribute``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6379,7 +6271,7 @@ let rec f l =
             marker = "(*Mpinvokeattribute*)",
             list = ["SomeAttrib"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.PInvoke.AsParameterType``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6392,7 +6284,7 @@ let rec f l =
             marker = "(*Mpinvokeparametertype*)",
             list = ["Boolean";"Int32"])
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.Record.AsField``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6405,7 +6297,7 @@ let rec f l =
             marker = "(*Mrecord*)",
             list = ["person"])   
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.DiscUnion.AsTypeParameter.DefInDiffNamespace``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6426,7 +6318,7 @@ let rec f l =
             marker = "(*Mtypeparameter1*)",
             list = ["Dog";"DuType"])
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.AnonymousFunction.AsTypeParameter.DefFromDiffNamespace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6447,7 +6339,7 @@ let rec f l =
             marker = "(*Mtypeparameter2*)",
             list = ["Tag"])
 
-    [<Test>]
+    [<Fact>]
     member this.``LongIdent.UnitMeasure.AsTypeParameter.DefFromDiffNamespace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6468,7 +6360,7 @@ let rec f l =
             marker = "(*Mtypeparameter3*)",
             list = [])
 
-    [<Test>]
+    [<Fact>]
     member this.``RedefinedIdentifier.DiffScope.InScope.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6480,7 +6372,7 @@ let rec f l =
             marker = "(*MarkerShowLastOneWhenInScope*)",
             list = ["DayOfWeek"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``RedefinedIdentifier.DiffScope.InScope.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -6492,7 +6384,7 @@ let rec f l =
             marker = "(*MarkerShowLastOneWhenInScope*)",
             list = ["Chars"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``RedefinedIdentifier.DiffScope.OutScope.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6504,7 +6396,7 @@ let rec f l =
             marker = "(*MarkerShowLastOneWhenOutscoped*)",
             list = ["Chars"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ObjInstance.ExtensionMethods.WithoutDef.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -6514,7 +6406,7 @@ let rec f l =
             marker = "(*MWithoutReference*)",
             list = ["NextDice";"DiceValue"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Class.DefInDiffNameSpace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6546,7 +6438,7 @@ let rec f l =
             marker = "(*MarkerType*)" ,
             list = ["TestType"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Class.DefInDiffNameSpace.WithAttributes.Negative``() = 
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -6578,7 +6470,7 @@ let rec f l =
             marker = "(*MarkerType*)",
             list = ["ObsoleteType";"CompilerMessageType"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Method.DefInDiffNameSpace``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6611,7 +6503,7 @@ let rec f l =
             marker = "(*MarkerMethod*)",
             list = ["TestMethod"; "VisibleMethod";"VisibleMethod2"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Method.DefInDiffNameSpace.WithAttributes.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -6642,7 +6534,7 @@ let rec f l =
             marker = "(*MarkerMethod*)",
             list = ["ObsoleteMethod";"CompilerMessageMethod";"HiddenMethod"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ObjInstance.ExtensionMethods.WithDef.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6657,7 +6549,7 @@ let rec f l =
             marker = "(*MWithReference*)",
             list = ["NextDice";"DiceValue"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Keywords.If``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6665,13 +6557,13 @@ let rec f l =
                     () """,
             marker ="(*MarkerKeywordIf*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Keywords.Let``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """let(*MarkerKeywordLet*) a = 1""",
             marker = "(*MarkerKeywordLet*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Keywords.Match``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6679,31 +6571,31 @@ let rec f l =
                     | pattern -> exp""",
             marker = "(*MarkerKeywordMatch*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``MacroDirectives.nowarn``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """#nowarn(*MarkerPreProcessNowarn*)""",
             marker = "(*MarkerPreProcessNowarn*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``MacroDirectives.light``() = 
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """#light(*MarkerPreProcessLight*)""",
             marker = "(*MarkerPreProcessLight*)") 
 
-    [<Test>]
+    [<Fact>]
     member this.``MacroDirectives.define``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """#define(*MarkerPreProcessDefine*)""",
             marker = "(*MarkerPreProcessDefine*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``MacroDirectives.PreProcessDefine``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """#define Foo(*MarkerPreProcessDefineConst*)""",
             marker = "(*MarkerPreProcessDefineConst*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InClass.WithoutDef``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6711,7 +6603,7 @@ let rec f l =
                     val mutable x(*MarkerValue*) : string""",
             marker = "(*MarkerValue*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InDiscUnion.WithoutDef``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6719,31 +6611,31 @@ let rec f l =
                     |Tag(*MarkerDU*) of int""",
             marker = "(*MarkerDU*)") 
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InRecord.WithoutDef``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """type Rec =  { X(*MarkerRec*) : int }""",
             marker = "(*MarkerRec*)")
             
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsNamespace``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """namespace Namespace1(*MarkerNamespace*)""",
             marker = "(*MarkerNamespace*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsModule``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """module Module1(*MarkerModule*)""",
             marker = "(*MarkerModule*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.WithoutDef``() = 
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """ abcd(*MarkerUndefinedIdentifier*)  """,
             marker = "(*MarkerUndefinedIdentifier*)") 
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InMatch.UnderScore``() = 
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6754,7 +6646,7 @@ let rec f l =
                     |_(*MarkerIdentifierIsUnderScore*) -> 0 """,
             marker = "(*MarkerIdentifierIsUnderScore*)") 
 
-    [<Test>]
+    [<Fact>]
     member this.MemberSelf() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6762,7 +6654,7 @@ let rec f l =
                     member this(*Mmemberself*)""",
             marker = "(*Mmemberself*)")   
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.InComment``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6770,14 +6662,14 @@ let rec f l =
                 //open IO = System(*Mcomment*)""",
             marker = "(*Mcomment*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.InString``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """let x = "System.Console(*Minstring*)" """,
             marker = "(*Minstring*)")
 
     // Regression test for 1067 -- Completion lists don't work after generic arguments  - for generic functions and for static members of generic types
-    [<Test>]
+    [<Fact>]
     member this.``Regression1067.InstanceOfGenericType``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6800,7 +6692,7 @@ let rec f l =
             marker = "(*Marker2*)",
             list = ["P"; "Q"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression1067.ClassUsingGenericTypeAsAttribute``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6823,7 +6715,7 @@ let rec f l =
             marker = "(*Marker4*)",
             list = ["Assembly"; "FullName"; "GUID"])
 
-    [<Test>] 
+    [<Fact>] 
     member this.NoInfiniteLoopInProperties() =
         let fileContents = """
                 open System.Windows.Forms
@@ -6837,7 +6729,7 @@ let rec f l =
         AssertCompListDoesNotContainAny(completions, ["Nodes"])
     
     // Regression for bug 3225 -- Invalid intellisense when inside of a quotation
-    [<Test>]
+    [<Fact>]
     member this.``Regression3225.Identifier.InQuotation``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6847,7 +6739,7 @@ let rec f l =
            list = ["Chars"; "Length"])
 
     // Regression for bug 1911 -- No completion list of expr in match statement
-    [<Test>]
+    [<Fact>]
     member this.``Regression1911.Expression.InMatchStatement``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6860,8 +6752,7 @@ let rec f l =
           
     // Bug 3627 - Completion lists should be filtered in many contexts
     // This blocks six testcases and is slated for Dev11, so these will be disabled for some time.
-    [<Test>]
-    [<Ignore("Bug 3627 - Completion lists should be filtered in many contexts")>] 
+    [<Fact(Skip = "Bug 3627 - Completion lists should be filtered in many contexts")>] 
     member this.AfterTypeParameter() =
         let fileContents = """
             type Type1 = Tag of string(*MarkerDUTypeParam*)
@@ -6890,7 +6781,7 @@ let rec f l =
         let completions = DotCompletionAtStartOfMarker file "(*MarkerParamTypeof*)"
         AssertCompListIsEmpty(completions)
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsClassName.InInitial``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6898,33 +6789,32 @@ let rec f l =
                     val field: int""",
             marker = "(*MarkerType*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsFunctionName.InInitial``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """let f2(*MarkerFunctionIdentifier*) x = x+1 """,
             marker = "(*MarkerFunctionIdentifier*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsParameter.InInitial``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """ let f3 x(*MarkerParam*) = x+1""",
             marker = "(*MarkerParam*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsFunctionName.UsingFunKeyword``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """fun f4(*MarkerFunctionDeclaration*)  x -> x+1""",
             marker = "(*MarkerFunctionDeclaration*)")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.EqualityConstraint.Bug65730``() =  
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """let g3<'a when 'a : equality> (x:'a) = x(*Marker*)""",
             marker = "(*Marker*)",
             list = ["Equals"; "GetHashCode"]) // equality constraint should make these show up
  
-    [<Test>]
-    [<Ignore("this no longer works, but I'm unclear why - now you get all the top-level completions")>]
+    [<Fact(Skip = "this no longer works, but I'm unclear why - now you get all the top-level completions")>]
     member this.``Identifier.InFunctionMatch``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6933,7 +6823,7 @@ let rec f l =
                     | 2 -> printfn "2" """,
             marker = "(*MarkerFunctionMatch*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.This``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6941,7 +6831,7 @@ let rec f l =
                     member this(*MarkerMemberThis*).Foo () = 3""",
             marker = "(*MarkerMemberThis*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.AsProperty``() =
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -6949,7 +6839,7 @@ let rec f l =
                     member this.Foo(*MarkerMemberThisProperty*) = 1""",
             marker = "(*MarkerMemberThisProperty*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``ExpressionPropertyAssignment.Bug217051``() =  
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6960,7 +6850,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["Prop"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ExpressionProperty.Bug234687``() =  
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -6971,8 +6861,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["CodeBase"]) // expect instance properties of Assembly, not static Assembly methods
 
-    [<Test>]
-    [<Ignore("Bug 3627 - Completion lists should be filtered in many contexts")>] 
+    [<Fact(Skip = "Bug 3627 - Completion lists should be filtered in many contexts")>] 
     member this.NotShowAttribute() =
         let fileContents = """
                 open System
@@ -6995,8 +6884,7 @@ let rec f l =
         let completions = DotCompletionAtStartOfMarker file "(*Mattribute2*)"
         AssertCompListIsEmpty(completions)
         
-    [<Test>]
-    [<Ignore("Bug 3627 - Completion lists should be filtered in many contexts")>] 
+    [<Fact(Skip = "Bug 3627 - Completion lists should be filtered in many contexts")>] 
     member this.NotShowPInvokeSignature() =
         let fileContents = """
                 //open System
@@ -7035,7 +6923,7 @@ let rec f l =
         let completions = DotCompletionAtStartOfMarker file "(*Mparameterlist*)"
         AssertCompListIsEmpty(completions)
 
-    [<Test>]
+    [<Fact>]
     member this.``Basic.Completion.UnfinishedLet``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7046,8 +6934,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["CompareTo"])
 
-    [<Test>]
-    [<Ignore("I don't understand why this test doesn't work, but the product works")>]
+    [<Fact(Skip = "I don't understand why this test doesn't work, but the product works")>]
     member this.``ShortFormSeqExpr.Bug229610``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7061,7 +6948,7 @@ let rec f l =
             list = ["Value"])
 
     //Regression test for bug 69159 Fsharp: dot completion is mission for an array
-    [<Test>]
+    [<Fact>]
     member this.``Array.InitialUsing..``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """let x1 = [| 0.0 .. 0.1 .. 10.0 |](*Marker*)""",
@@ -7069,8 +6956,7 @@ let rec f l =
             list = ["Length";"Clone";"ToString"])
 
     //Regression test for bug 65740 Fsharp: dot completion is mission after a '#' statement
-    [<Test>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member this.``Identifier.In#Statement``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7086,7 +6972,7 @@ let rec f l =
 
     //This test is about CompletionList which should be moved to completionList, it's too special to refactor.
     //Regression test for bug 72595 typing quickly yields wrong intellisense
-    [<Test>]
+    [<Fact>]
     member this.``BadCompletionAfterQuicklyTyping``() =        
         let code = [ "        " ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -7105,7 +6991,7 @@ let rec f l =
         AssertCompListContainsAll(completions, ["Length"])
         AssertCompListDoesNotContainAny(completions, ["AbstractClassAttribute"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``SelfParameter.InDoKeywordScope``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7115,7 +7001,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``SelfParameter.InDoKeywordScope.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7125,7 +7011,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["Value";"Contents"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ReOpenNameSpace.StaticProperties``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7141,7 +7027,7 @@ let rec f l =
             marker = "(*Marker1*)",
             list = ["Prop";"Event"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ReOpenNameSpace.EnumTypes``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7158,7 +7044,7 @@ let rec f l =
             marker = "(*Marker2*)",
             list = ["Foo"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ReOpenNameSpace.SystemLibrary``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7171,7 +7057,7 @@ let rec f l =
             marker = "(*Marker3*)",
             list = ["Open"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ReOpenNameSpace.FsharpQuotation``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7183,7 +7069,7 @@ let rec f l =
             marker = "(*Marker4*)",
             list = ["Value"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ReOpenNameSpace.MailboxProcessor``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7195,7 +7081,7 @@ let rec f l =
             marker = "(*Marker6*)",
             list = ["Start"])
 
-    [<Test>]
+    [<Fact>]
     member this.``ReopenNamespace.Module``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7209,7 +7095,7 @@ let rec f l =
             marker = "(*Marker7*)",
             list = ["foo"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.InLetScope``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7224,7 +7110,7 @@ let rec f l =
             marker = "(*Marker1*)",
             list = ["IsFixedSize";"Initialize"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.InFunScope.FirstParameter``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7238,7 +7124,7 @@ let rec f l =
             marker = "(*Marker2*)",
             list = ["CompareTo"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.InFunScope.SecParameter``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7253,7 +7139,7 @@ let rec f l =
             marker = "(*Marker3*)",
             list = ["GetType";"ToString"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Expression.InMatchWhenClause``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7269,7 +7155,7 @@ let rec f l =
             list = ["CompareTo";"ToString"])
 
     //Regression test for bug 3223 in PS: No intellisense at point
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InActivePattern.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7288,7 +7174,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["Attributes";"CallingConvention";"ContainsGenericParameters"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Identifier.InActivePattern.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7308,7 +7194,7 @@ let rec f l =
             list = ["Head";"ToInt"])
 
    //Regression test of bug 2296:No completion lists on the direct results of a method call
-    [<Test>] 
+    [<Fact>] 
     member this.``Regression2296.DirectResultsOfMethodCall``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7327,7 +7213,7 @@ let rec f l =
             marker = "(*Marker1*)",
             list = ["Attributes";"CallingConvention";"IsFamily"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.DirectResultsOfMethodCall.Negative``() = 
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7346,7 +7232,7 @@ let rec f l =
             marker = "(*Marker1*)",
             list = ["value__"])                     
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.Identifier.String.Reflection01``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7369,7 +7255,7 @@ let rec f l =
             marker = "(*Marker2*)",
             list = ["CompareTo";"GetType";"ToString"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.Identifier.String.Reflection01.Negative``() = 
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7392,7 +7278,7 @@ let rec f l =
             marker = "(*Marker2*)",
             list = ["value__"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.Identifier.String.Reflection02``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7416,7 +7302,7 @@ let rec f l =
             marker = "(*Marker3*)",
             list = ["CompareTo";"GetType";"ToString"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.Identifier.String.Reflection02.Negative``() = 
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7437,7 +7323,7 @@ let rec f l =
             marker = "(*Marker3*)",
             list = ["value__"])  
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.System.StaticMethod.Reflection``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7462,7 +7348,7 @@ let rec f l =
             marker = "(*Marker4*)",
             list = ["CompareTo";"GetType";"ToString"]) 
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression2296.System.StaticMethod.Reflection.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7487,7 +7373,7 @@ let rec f l =
             marker = "(*Marker4*)",
             list = ["value__"])    
 
-    [<Test>]
+    [<Fact>]
     member this.``Seq.NearTheEndOfFile``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7501,8 +7387,7 @@ let rec f l =
             list = ["cache";"find"])
 
     //Regression test of bug 3879: intellisense glitch for computation expression
-    [<Test>]
-    [<Ignore("This is still fail")>]
+    [<Fact(Skip = "This is still fail")>]
     member this.``ComputationExpression.WithClosingBrace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7520,8 +7405,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["AsyncGetResponse";"GetResponseAsync";"ToString"])
 
-    [<Test>]
-    [<Ignore("This is still fail")>]
+    [<Fact(Skip = "This is still fail")>]
     member this.``ComputationExpression.WithoutClosingBrace``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7540,7 +7424,7 @@ let rec f l =
             list = ["AsyncGetResponse";"GetResponseAsync";"ToString"])  
 
     //Regression Test of 4405:intellisense has wrong type for identifier, using most recently bound of same name rather than the one in scope?
-    [<Test>]
+    [<Fact>]
     member this.``Regression4405.Identifier.ReBound``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7552,14 +7436,14 @@ let rec f l =
             list = ["Chars";"StartsWith"])
 
     //Regression test for FSharp1.0:4702
-    [<Test>]
+    [<Fact>]
     member this.``Regression4702.SystemWord``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = "System(*Marker*)",
             marker = "(*Marker*)",
             list = ["Console";"Byte";"ArgumentException"])
 
-    [<Test>]
+    [<Fact>]
     member this.``TypeAbbreviation.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7569,7 +7453,7 @@ let rec f l =
             marker = "(*Marker1*)",
             list = ["int16";"int32";"int64"])
 
-    [<Test>]
+    [<Fact>]
     member this.``TypeAbbreviation.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7580,7 +7464,7 @@ let rec f l =
             list = ["Int16";"Int32";"Int64"])    
 
     //Regression test of bug 3754:tupe forwarder bug? intellisense bug?
-    [<Test>]
+    [<Fact>]
     member this.``Regression3754.TypeOfListForward.Positive``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7604,7 +7488,7 @@ let rec f l =
             marker = "(*Marker*)",
             list = ["append";"choose";"isEmpty"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Regression3754.TypeOfListForward.Negative``() =
         this.VerifyDotCompListDoesNotContainAnyAtStartOfMarker(
             fileContents = """
@@ -7628,8 +7512,7 @@ let rec f l =
             marker = "Marker",
             list = ["<Note>"])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``NonApplicableExtensionMembersDoNotAppear.Bug40379``() =
         let code =
                                     [ "open System.Xml.Linq"
@@ -7657,7 +7540,7 @@ let rec f l =
         let completions = AutoCompleteAtCursor file
         AssertCompListContainsAll(completions, ["Ancestors"; "AncestorsAndSelf"])
 
-    [<Test>]
+    [<Fact>]
     member this.``Visibility.InternalMethods.DefInSameAssembly``() =
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7677,8 +7560,7 @@ let rec f l =
             marker = "(*MarkerSameAssemb*)",
             list = ["fieldInternal";"MethodInternal"])
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.DotCompletionSmokeTest1``() = 
         this.VerifyDotCompListContainAllAtStartOfMarker(
             fileContents = """
@@ -7689,8 +7571,7 @@ let rec f l =
             list = ["Chars";"Length"],
             addtlRefAssy=standard40AssemblyRefs)
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.DotCompletionSmokeTest2``() = 
            this.VerifyDotCompListContainAllAtStartOfMarker(
               fileContents = """
@@ -7700,8 +7581,7 @@ let rec f l =
               list = ["Chars"; "Length"],
               addtlRefAssy=standard40AssemblyRefs )
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.DotCompletionSmokeTest0``() = 
            this.VerifyDotCompListContainAllAtStartOfMarker(
               fileContents = """
@@ -7712,8 +7592,7 @@ let rec f l =
               addtlRefAssy=standard40AssemblyRefs )
 
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.DotCompletionSmokeTest3``() = 
            this.VerifyDotCompListContainAllAtStartOfMarker(
               fileContents = """
@@ -7724,8 +7603,7 @@ let rec f l =
               addtlRefAssy=standard40AssemblyRefs )
 
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``QueryExpression.DotCompletionSystematic1``() = 
       for customOperation in ["select";"sortBy";"where"] do
         let fileContentsList = 
@@ -7783,8 +7661,7 @@ let rec f l =
                 list = ["Chars";"Length"],
                 addtlRefAssy=standard40AssemblyRefs)
 
-    [<Test>] 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``QueryExpression.InsideJoin.Bug204147``() =        
            this.VerifyDotCompListContainAllAtStartOfMarker(
               fileContents = """
@@ -7842,9 +7719,7 @@ let rec f l =
         let completions = DotCompletionAtStartOfMarker file2 marker
         AssertCompListContainsAll(completions, list) 
 
-    [<Test>]
-    [<Category("Query")>]
-    [<Ignore("196230")>]
+    [<Fact(Skip = "196230")>]
     // Intellisense still appears on arguments when the operator is used in error 
     member public this.``Query.HasErrors.Bug196230``() =
         this.AssertDotCompletionListInQuery(
@@ -7862,10 +7737,8 @@ let rec f l =
               marker = "(*Marker*)",
               list = ["ProductID";"ProductName"] )
 
-    [<Test>]
-    [<Category("Query")>]
     // Intellisense still appears on arguments when the operator is used in error 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.HasErrors2``() =
         this.AssertDotCompletionListInQuery(
               fileContents = """
@@ -7879,9 +7752,7 @@ let rec f l =
               marker = "(*Marker*)",
               list = ["ProductID";"ProductName"] )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Shadowed variables have correct Intellisense
     member public this.``Query.ShadowedVariables``() =
         this.AssertDotCompletionListInQuery(
@@ -7897,9 +7768,7 @@ let rec f l =
               marker = "(*Marker*)",
               list = ["Category";"ProductName"] )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Intellisense works correctly in a nested query
     member public this.``Query.InNestedQuery``() =
         let fileContents = """
@@ -7917,9 +7786,7 @@ let rec f l =
         this.VerifyDotCompListContainAllAtStartOfMarker(fileContents, "(*Marker2*)", 
             ["Equals";"CompareTo"], queryAssemblyRefs )
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Intellisense works correctly in a nested expression within a lamda
     member public this.``Query.NestedExpressionWithinLamda``() =
         let fileContents = """
@@ -7935,7 +7802,7 @@ let rec f l =
         this.VerifyDotCompListContainAllAtStartOfMarker(fileContents, "(*Marker*)", 
             ["Chars";"Length"], queryAssemblyRefs )
 
-    [<Test>]
+    [<Fact>]
     member this.``Verify no completion on dot after module definition``() = 
         this.VerifyDotCompListIsEmptyAtStartOfMarker(
             fileContents = """
@@ -7945,7 +7812,7 @@ let rec f l =
                 let bar = 1""",
             marker = "(*Marker*)")
 
-    [<Test>]
+    [<Fact>]
     member this.``Verify no completion after module definition``() = 
         this.VerifyCtrlSpaceCompListIsEmptyAtEndOfMarker(
             fileContents = """
@@ -7955,7 +7822,7 @@ let rec f l =
                 let bar = 1""",
             marker = "module BasicTest ")
 
-    [<Test>]
+    [<Fact>]
     member this.``Verify no completion in hash directives``() =
         this.VerifyCtrlSpaceCompListIsEmptyAtEndOfMarker(
             fileContents = """
@@ -7965,7 +7832,7 @@ let rec f l =
                 let bar = 1""",
             marker = "(*Marker*)")
 
-    [<Test;Category("Repro")>]
+    [<Fact>]
     member public this.``ExpressionDotting.Regression.Bug3709``() = 
         this.VerifyCtrlSpaceListContainAllAtStartOfMarker(
             fileContents = """
@@ -7975,7 +7842,6 @@ let rec f l =
             list = ["EndsWith"])  
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
 
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
index 51a8e3f0856..758d9344c91 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
@@ -4,7 +4,7 @@ namespace Tests.LanguageService.ErrorList
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open Microsoft.VisualStudio.FSharp
 open Salsa.Salsa
 open Salsa.VsOpsUtils
@@ -13,14 +13,10 @@ open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 
-[<SetUpFixture>]
 type public AssemblyResolverTestFixture () =
 
-    [<OneTimeSetUp>]
     member public _.Init () = AssemblyResolver.addResolver ()
 
-[<TestFixture>]
-[<Category "LanguageService">] 
 type UsingMSBuild() as this = 
     inherit LanguageServiceBaseTests()
 
@@ -55,7 +51,7 @@ type UsingMSBuild() as this =
 
     let assertContains (errors : list<Error>) text = 
         let ok = errors |> List.exists (fun err -> err.Message = text)
-        Assert.IsTrue(ok, sprintf "Error list should contain '%s' message" text)
+        Assert.True(ok, sprintf "Error list should contain '%s' message" text)
 
     let assertExpectedErrorMessages expected (actual: list<Error>) =
         let normalizeCR input = System.Text.RegularExpressions.Regex.Replace(input, @"\r\n|\n\r|\n|\r", "\r\n")
@@ -66,14 +62,7 @@ type UsingMSBuild() as this =
             |> normalizeCR
         let expected = expected |> String.concat Environment.NewLine |> normalizeCR
         
-        let message = 
-            sprintf """
-=[ expected ]============
-%s
-=[ actual ]==============
-%s
-=========================""" expected actual
-        Assert.AreEqual(expected, actual, message)
+        Assert.Equal(expected, actual)
 
     //verify the error list Count
     member private this.VerifyErrorListCountAtOpenProject(fileContents : string, num : int) =
@@ -99,7 +88,7 @@ type UsingMSBuild() as this =
         
         TakeCoffeeBreak(this.VS) // Wait for the background compiler to catch up.
         let warnList = GetWarnings(project)
-        Assert.AreEqual(expectedNum,warnList.Length)
+        Assert.Equal(expectedNum,warnList.Length)
 
     //verify no the error list 
     member private this.VerifyNoErrorListAtOpenProject(fileContents : string, ?addtlRefAssy : string list) = 
@@ -110,7 +99,7 @@ type UsingMSBuild() as this =
         for error in errorList do
             printfn "%A" error.Severity
             printf "%s\n" (error.ToString()) 
-        Assert.IsTrue(errorList.IsEmpty)
+        Assert.True(errorList.IsEmpty)
     
     //Verify the error list contained the expected string
     member private this.VerifyErrorListContainedExpectedString(fileContents : string, expectedStr : string, ?addtlRefAssy : string list) =
@@ -132,8 +121,7 @@ type UsingMSBuild() as this =
             else
                 failwithf "The error list number is not the expected %d" num
     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``OverloadsAndExtensionMethodsForGenericTypes``() = 
         let fileContent = 
             """
@@ -153,13 +141,13 @@ let g (t : T) = t.Count()
         this.VerifyNoErrorListAtOpenProject(fileContent)
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorsInScriptFile``() = 
         let (solution, project, file) = this.CreateSingleFileProject("", fileKind = SourceFileKind.FSX)
         
         let checkErrors expected = 
             let l = List.length (GetErrors project)
-            Assert.AreEqual(expected, l, "Unexpected number of errors in error list")
+            Assert.Equal(expected, l)
         
         TakeCoffeeBreak(this.VS)
         checkErrors 0
@@ -179,8 +167,7 @@ let g (t : T) = t.Count()
         TakeCoffeeBreak(this.VS)
         checkErrors 0
 
-    [<Test>]
-    [<Ignore("GetErrors function does not work for this case")>]
+    [<Fact(Skip = "GetErrors function does not work for this case")>]
     member public this.``LineDirective``() = 
         use _guard = this.UsingNewVS()
         let fileContents = """
@@ -193,12 +180,12 @@ let g (t : T) = t.Count()
 
         let file = OpenFile(project, "File1.fs")
         let _ = OpenFile(project,"File2.fs")
-        Assert.IsFalse(Build(project).BuildSucceeded)
+        Assert.False(Build(project).BuildSucceeded)
 
         this.VerifyCountAtSpecifiedFile(project,1)
         VerifyErrorListContainedExpectedStr("The value or constructor 'y' is not defined",project)
 
-    [<Test>]
+    [<Fact>]
     member public this.``InvalidConstructorOverload``() = 
         let content = """
         type X private() = 
@@ -213,8 +200,7 @@ let g (t : T) = t.Count()
         CheckErrorList content (assertExpectedErrorMessages expectedMessages)
             
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact>]
     member public this.``Query.InvalidJoinRelation.GroupJoin``() = 
         let content = """
 let x = query { 
@@ -226,12 +212,11 @@ let x = query {
             fun errors ->
                 match errors with
                 | [err] ->
-                    Assert.AreEqual("Invalid join relation in 'groupJoin'. Expected 'expr <op> expr', where <op> is =, =?, ?= or ?=?.", err.Message)
+                    Assert.Equal("Invalid join relation in 'groupJoin'. Expected 'expr <op> expr', where <op> is =, =?, ?= or ?=?.", err.Message)
                 | errs -> 
                     Assert.Fail("Unexpected content of error list")
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact>]
     member public this.``Query.NonOpenedNullableModule.Join``() = 
         let content = """
 let t = 
@@ -244,12 +229,11 @@ let t =
             fun errors ->
                 match errors with
                 | [err] ->
-                    Assert.AreEqual("The operator '?=?' cannot be resolved. Consider opening the module 'Microsoft.FSharp.Linq.NullableOperators'.", err.Message)
+                    Assert.Equal("The operator '?=?' cannot be resolved. Consider opening the module 'Microsoft.FSharp.Linq.NullableOperators'.", err.Message)
                 | errs -> 
                     Assert.Fail("Unexpected content of error list")
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact>]
     member public this.``Query.NonOpenedNullableModule.GroupJoin``() = 
         let content = """
 let t = 
@@ -262,13 +246,12 @@ let t =
             fun errors ->
                 match errors with
                 | [err] ->
-                    Assert.AreEqual("The operator '?=?' cannot be resolved. Consider opening the module 'Microsoft.FSharp.Linq.NullableOperators'.", err.Message)
+                    Assert.Equal("The operator '?=?' cannot be resolved. Consider opening the module 'Microsoft.FSharp.Linq.NullableOperators'.", err.Message)
                 | errs -> 
                     Assert.Fail("Unexpected content of error list")
 
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact>]
     member public this.``Query.InvalidJoinRelation.Join``() = 
         let content = """
 let x = 
@@ -282,11 +265,11 @@ let x =
             fun errors ->
                 match errors with
                 | [err] ->
-                    Assert.AreEqual("Invalid join relation in 'join'. Expected 'expr <op> expr', where <op> is =, =?, ?= or ?=?.", err.Message)
+                    Assert.Equal("Invalid join relation in 'join'. Expected 'expr <op> expr', where <op> is =, =?, ?= or ?=?.", err.Message)
                 | errs -> 
                     Assert.Fail("Unexpected content of error list")
 
-    [<Test>]
+    [<Fact>]
     member public this.``InvalidMethodOverload``() = 
         let content = """
         System.Console.WriteLine(null)
@@ -294,7 +277,7 @@ let x =
         let expectedMessages = [ "A unique overload for method 'WriteLine' could not be determined based on type information prior to this program point. A type annotation may be needed.\u001d\u001dKnown type of argument: 'a0 when 'a0: null\u001d\u001dCandidates:\u001d - System.Console.WriteLine(buffer: char array) : unit\u001d - System.Console.WriteLine(format: string, [<System.ParamArray>] arg: obj array) : unit\u001d - System.Console.WriteLine(value: obj) : unit\u001d - System.Console.WriteLine(value: string) : unit" ]
         CheckErrorList content (assertExpectedErrorMessages expectedMessages)
 
-    [<Test>]
+    [<Fact>]
     member public this.``InvalidMethodOverload2``() = 
         let content = """
 type A<'T>() = 
@@ -309,7 +292,7 @@ b.Do(1, 1)
         let expectedMessages = [ "A unique overload for method 'Do' could not be determined based on type information prior to this program point. A type annotation may be needed.\u001d\u001dKnown types of arguments: int * int\u001d\u001dCandidates:\u001d - member A.Do: a: int * b: 'T -> unit\u001d - member A.Do: a: int * b: int -> unit" ]
         CheckErrorList content (assertExpectedErrorMessages expectedMessages)
 
-    [<Test; Category("Expensive")>]
+    [<Fact>]
     member public this.``NoErrorInErrList``() = 
         use _guard = this.UsingNewVS()
         let fileContents1 = """
@@ -343,7 +326,7 @@ b.Do(1, 1)
         TakeCoffeeBreak(this.VS)
         this.VerifyCountAtSpecifiedFile(project,0)
 
-    [<Test; Category("Expensive")>]
+    [<Fact>]
     member public this.``NoLevel4Warning``() = 
         use _guard = this.UsingNewVS()
         let fileContents = """
@@ -361,14 +344,14 @@ b.Do(1, 1)
 
         this.VerifyCountAtSpecifiedFile(project,0)
         
-    [<Test>]
+    [<Fact>]
     //This is an verify action test & example
     member public this.``TestErrorMessage``() =
         let fileContent = """Console.WriteLine("test")"""
         let expectedStr = "The value, namespace, type or module 'Console' is not defined"
         this.VerifyErrorListContainedExpectedString(fileContent,expectedStr)
     
-    [<Test>]
+    [<Fact>]
     member public this.``TestWrongKeywordInInterfaceImplementation``() = 
         let fileContent = 
             """
@@ -382,14 +365,11 @@ type staticInInterface =
             
         CheckErrorList fileContent (function
             | err1 :: _ ->
-                Assert.IsTrue(err1.Message.Contains("No static abstract member was found that corresponds to this override"))
+                Assert.True(err1.Message.Contains("No static abstract member was found that corresponds to this override"))
             | x ->
                 Assert.Fail(sprintf "Unexpected errors: %A" x))
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.MultipleErrors")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.MultipleErrors`` () =
         let tpRef = PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")
         let checkList n = 
@@ -402,57 +382,51 @@ type staticInInterface =
             for err in errorList do
                 printfn "Severity: %A, Message: %s" err.Severity err.Message
 
-            Assert.IsTrue(List.length errorList = n, "Unexpected size of error list")
+            Assert.True(List.length errorList = n, "Unexpected size of error list")
             let uniqueErrors = 
                 errorList 
                 |> Seq.map (fun m -> m.Message, m.Severity) 
                 |> set
-            Assert.IsTrue(uniqueErrors.Count = n, "List should not contain duplicate errors")
+            Assert.True(uniqueErrors.Count = n, "List should not contain duplicate errors")
             for x = 0 to (n - 1) do
                 let expectedName = sprintf "The type provider 'DummyProviderForLanguageServiceTesting.TypeProviderThatThrowsErrors' reported an error: Error %d" x
-                Assert.IsTrue(Set.contains (expectedName, Microsoft.VisualStudio.FSharp.LanguageService.Severity.Error) uniqueErrors)
+                Assert.True(Set.contains (expectedName, Microsoft.VisualStudio.FSharp.LanguageService.Severity.Error) uniqueErrors)
 
         for i = 1 to 10 do
             checkList i
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.ErrorList.IncorrectBindings1``() = 
         for code in [ "{_}"; "{_ = }"] do
             printfn "checking %s" code
             CheckErrorList code <|
                 fun errs ->
                     printfn "%A" errs
-                    Assert.IsTrue((List.length errs) = 2)
+                    Assert.True((List.length errs) = 2)
                     assertContains errs "Field bindings must have the form 'id = expr;'"
                     assertContains errs "'_' cannot be used as field name"
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.ErrorList.IncorrectBindings2``() =
         CheckErrorList "{_ = 1}" <|
             function
-            | [err] -> Assert.AreEqual("'_' cannot be used as field name", err.Message)
+            | [err] -> Assert.Equal("'_' cannot be used as field name", err.Message)
             | x -> printfn "%A" x; Assert.Fail("unexpected content of error list")
 
-    [<Test>]
-    [<Category("Records")>]
+    [<Fact>]
     member public this.``Records.ErrorList.IncorrectBindings3``() =
         CheckErrorList "{a = 1; _; _ = 1}" <|
             fun errs -> 
-                Assert.IsTrue((List.length errs) = 3)
+                Assert.True((List.length errs) = 3)
                 let groupedErrs = errs |> Seq.groupBy (fun e -> e.Message) |> Seq.toList
-                Assert.IsTrue((List.length groupedErrs) = 2)
+                Assert.True((List.length groupedErrs) = 2)
                 for (msg, e) in groupedErrs do
-                    if msg = "'_' cannot be used as field name" then Assert.AreEqual(2, Seq.length e)
-                    elif msg = "Field bindings must have the form 'id = expr;'" then Assert.AreEqual(1, Seq.length e)
+                    if msg = "'_' cannot be used as field name" then Assert.Equal(2, Seq.length e)
+                    elif msg = "Field bindings must have the form 'id = expr;'" then Assert.Equal(1, Seq.length e)
                     else Assert.Fail (sprintf "Unexpected message %s" msg)
 
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test case Verify the Error List shows the correct error message when the static parameter type is invalid
     //Intent: We want to make sure that both errors coming from the TP and the compilation of things specific to type provider are properly flagged in the error list.
     member public this.``TypeProvider.StaticParameters.IncorrectType `` () =
@@ -463,10 +437,7 @@ type staticInInterface =
         this.VerifyErrorListContainedExpectedString(fileContent,expectedStr,
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("This is ignored because currently the Mock Type Provider is not evaluating the static parameter.")>]
+    [<Fact(Skip = "This is ignored because currently the Mock Type Provider is not evaluating the static parameter.")>]
     //This test case Verify the Error List shows the correct error message when applying invalid static parameter to the provided type
     member public this.``TypeProvider.StaticParameters.Incorrect `` () =
         
@@ -477,10 +448,7 @@ type staticInInterface =
         this.VerifyErrorListContainedExpectedString(fileContent,expectedStr,
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
    
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test case Verify that Error List shows the correct error message when Type Provider that takes two static parameter is given only one static parameter.
     member public this.``TypeProvider.StaticParameters.IncorrectNumberOfParameter  `` () =
         
@@ -491,9 +459,7 @@ type staticInInterface =
        
         this.VerifyErrorListContainedExpectedString(fileContent,expectedStr,
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.ProhibitedMethods`` () =
         let cases = 
             [
@@ -509,9 +475,7 @@ type staticInInterface =
                     addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")]
                 )    
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact>]
     //This test case verify that the Error list count is one in the Error list item when given invalid static parameter that raises an error.
     member public this.``TypeProvider.StaticParameters.ErrorListItem `` () =
         
@@ -520,10 +484,7 @@ type staticInInterface =
                             type foo = N1.T< const "Hello World",2>""",
             num = 1) 
     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test case Verify that there is No Error list count in the Error list item when the file content is correct.
     member public this.``TypeProvider.StaticParameters.NoErrorListCount `` () =
                  
@@ -533,7 +494,7 @@ type staticInInterface =
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")]) 
     
 
-    [<Test>]
+    [<Fact>]
     member public this.``NoError.FlagsAndSettings.TargetOptionsRespected``() =
         let fileContent = """
             [<System.Obsolete("x")>]
@@ -544,10 +505,9 @@ type staticInInterface =
 
         TakeCoffeeBreak(this.VS) // Wait for the background compiler to catch up.
         let errorList = GetErrors(project)
-        Assert.IsTrue(errorList.IsEmpty)
+        Assert.True(errorList.IsEmpty)
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``UnicodeCharacters``() = 
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -558,12 +518,12 @@ type staticInInterface =
         let file = OpenFile(project,"新規baProgram.fsi")  
         let file = OpenFile(project,"新規bcrogram.fs") 
 
-        Assert.IsFalse(Build(project).BuildSucceeded)
-        Assert.IsTrue(GetErrors(project) 
+        Assert.False(Build(project).BuildSucceeded)
+        Assert.True(GetErrors(project) 
                         |> List.exists(fun error -> (error.ToString().Contains("新規baProgram")))) 
 
     // In this bug, particular warns were still present after nowarn        
-    [<Test>]
+    [<Fact>]
     member public this.``NoWarn.Bug5424``() =  
         let fileContent = """
             #nowarn "67" // this type test or downcast will always hold
@@ -576,7 +536,7 @@ type staticInInterface =
         this.VerifyNoErrorListAtOpenProject(fileContent)
 
     /// FEATURE: Errors in flags are sent in Error list.
-    [<Test>]
+    [<Fact>]
     member public this.``FlagsAndSettings.ErrorsInFlagsDisplayed``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -587,7 +547,7 @@ type staticInInterface =
         TakeCoffeeBreak(this.VS) // Wait for the background compiler to catch up.
         VerifyErrorListContainedExpectedStr("nonexistent",project)
 
-    [<Test>]
+    [<Fact>]
     member public this.``BackgroundComplier``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
@@ -614,7 +574,7 @@ type staticInInterface =
                     """,
             num = 2)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList1``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
@@ -624,7 +584,7 @@ type staticInInterface =
                     let a = NoVal""",
             num = 1 )
 
-    // [<Test>] disabled for F#8, legacy service, covered in FCS tests instead
+    // [<Fact>] disabled for F#8, legacy service, covered in FCS tests instead
     member public this.``CompilerErrorsInErrList4``() = 
         this.VerifyNoErrorListAtOpenProject(
             fileContents = """
@@ -644,7 +604,7 @@ type staticInInterface =
   
                 let _fsyacc_gotos = [| 0us; 1us; 2us|] """ )
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList5``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """                
@@ -653,7 +613,7 @@ type staticInInterface =
                 let x = 0 """,
             num = 1)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList6``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """               
@@ -666,7 +626,7 @@ type staticInInterface =
                     | B = 0N """,
             num = 2)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList7``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """               
@@ -697,14 +657,14 @@ type staticInInterface =
                 let foo = 1 """,
             num = 5)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList8``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """              
                 type EnumInt8s      = | A1 = - 10y """ ,
             num = 1 )
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList9``() = 
         use _guard = this.UsingNewVS()
         let fileContents1 = """
@@ -732,7 +692,7 @@ type staticInInterface =
         Build(project) |> ignore
         this.VerifyCountAtSpecifiedFile(project,1)
 
-    [<Test>]
+    [<Fact>]
     member public this.``CompilerErrorsInErrList10``() = 
         let fileContents = """
             namespace Errorlist
@@ -744,26 +704,26 @@ type staticInInterface =
 
         this.VerifyCountAtSpecifiedFile(project,1)
 
-    [<Test>]
+    [<Fact>]
     member public this.``DoubleClickErrorListItem``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
                 let x = x """,
             num = 1)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FixingCodeAfterBuildRemovesErrors01``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
                 let x = 4 + "x" """,
             num = 2)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FixingCodeAfterBuildRemovesErrors02``() = 
         this.VerifyNoErrorListAtOpenProject(
             fileContents = "let x = 4" )   
                                  
-    [<Test>]
+    [<Fact>]
     member public this.``IncompleteExpression``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
@@ -775,7 +735,7 @@ type staticInInterface =
                 List.map (fun x -> x + 1) """ ,
             num = 2)
 
-    [<Test>]
+    [<Fact>]
     member public this.``IntellisenseRequest``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
@@ -783,7 +743,7 @@ type staticInInterface =
                     member a.B(*Marker*) : int = "1" """,
             num = 1)
 
-    [<Test>]
+    [<Fact>]
     member public this.``TypeChecking1``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
@@ -800,7 +760,7 @@ type staticInInterface =
                     x.Next <- Some x  """,
             num = 1)
             
-    [<Test>]
+    [<Fact>]
     member public this.``TypeChecking2``() = 
         this.VerifyErrorListContainedExpectedString(
             fileContents = """
@@ -817,7 +777,7 @@ type staticInInterface =
                     x.Next <- Some x  """,
             expectedStr = "Foo.Thread option")
             
-    [<Test>]
+    [<Fact>]
     member public this.``TypeChecking3``() = 
         this.VerifyErrorListCountAtOpenProject(
             fileContents = """
@@ -833,7 +793,7 @@ type staticInInterface =
                     x.Next <- Some 1 """,
             num = 1)
             
-    [<Test>]
+    [<Fact>]
     member public this.``TypeChecking4``() = 
         this.VerifyErrorListContainedExpectedString(
             fileContents = """
@@ -883,7 +843,7 @@ type staticInInterface =
         AssertContains(tooltip,"string")
 *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Warning.ConsistentWithLanguageService``() =  
         let fileContent = """
             open System
@@ -892,9 +852,9 @@ type staticInInterface =
         let (_, project, file) = this.CreateSingleFileProject(fileContent, fileKind = SourceFileKind.FSX)
         TakeCoffeeBreak(this.VS) // Wait for the background compiler to catch up.
         let warnList = GetWarnings(project)
-        Assert.AreEqual(20,warnList.Length)
+        Assert.Equal(20,warnList.Length)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Warning.ConsistentWithLanguageService.Comment``() =  
         let fileContent = """
             open System
@@ -903,10 +863,9 @@ type staticInInterface =
         let (_, project, file) = this.CreateSingleFileProject(fileContent, fileKind = SourceFileKind.FSX)
         TakeCoffeeBreak(this.VS) // Wait for the background compiler to catch up.
         let warnList = GetWarnings(project)
-        Assert.AreEqual(0,warnList.Length)
+        Assert.Equal(0,warnList.Length)
 
-    [<Test>]
-    [<Ignore("GetErrors function does not work for this case")>]
+    [<Fact(Skip = "GetErrors function does not work for this case")>]
     member public this.``Errorlist.WorkwithoutNowarning``() =  
         let fileContent = """
             type Fruit (shelfLife : int) as x =
@@ -915,12 +874,11 @@ type staticInInterface =
             """
         let (_, project, file) = this.CreateSingleFileProject(fileContent)
 
-        Assert.IsTrue(Build(project).BuildSucceeded)
+        Assert.True(Build(project).BuildSucceeded)
         TakeCoffeeBreak(this.VS)
         let warnList = GetErrors(project)
-        Assert.AreEqual(1,warnList.Length) 
+        Assert.Equal(1,warnList.Length) 
         
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorRecovery.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorRecovery.fs
index 9b3b00bfa3c..e38c503c17d 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorRecovery.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorRecovery.fs
@@ -4,7 +4,7 @@ namespace Tests.LanguageService.ErrorRecovery
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
@@ -12,8 +12,6 @@ open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 
-[<TestFixture>]
-[<Category "LanguageService">] 
 type UsingMSBuild()  = 
     inherit LanguageServiceBaseTests()
 
@@ -25,14 +23,13 @@ type UsingMSBuild()  =
             [ for i = 0 to errorList.Length - 1 do
                 yield errorList.[i].Message]
             
-        Assert.IsTrue(errorList
+        Assert.True(errorList
                           |> GetErrorMessages
                           |> Seq.exists (fun errorMessage ->
                                 errorMessage.Contains(expectedStr)))
 
    // Not a recovery case, but make sure we get a squiggle at the unfinished Main()
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4538_3``() = 
         let fileContent = """
             type MyType() = 
@@ -43,8 +40,7 @@ type UsingMSBuild()  =
         this.VerifyErrorListContainedExpectedString(fileContent,expectedStr)
 
     // Not a recovery case, but make sure we get a squiggle at the unfinished Main()
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4538_4``() =  
         let fileContent = """
             type MyType() = 
@@ -54,8 +50,7 @@ type UsingMSBuild()  =
         let expectedStr = "The block following this 'use' is unfinished. Every code block is an expression and must have a result. 'use' cannot be the final code element in a block. Consider giving this block an explicit result."
         this.VerifyErrorListContainedExpectedString(fileContent,expectedStr)
 
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4881_1``() =  
         let code = 
                                     ["let s = \"\""
@@ -70,8 +65,7 @@ type UsingMSBuild()  =
         let completions = AutoCompleteAtCursor file
         AssertCompListContains(completions,"Split")       
         
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4881_2``() =  
         let code =
                                     ["let s = \"\""
@@ -87,8 +81,7 @@ type UsingMSBuild()  =
         let completions = AutoCompleteAtCursor file
         AssertCompListContains(completions,"Split")      
 
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4881_3``() =  
         let code = 
                                     ["let s = \"\""
@@ -105,8 +98,7 @@ type UsingMSBuild()  =
         AssertCompListContains(completions,"Split")  
         
 
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4881_4``() =  
         let code = 
                                     ["let s = \"\""
@@ -122,8 +114,7 @@ type UsingMSBuild()  =
         
         
     // This case was fixed while investigating 4538.            
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.NotFixing4538_1``() =  
         let code = 
                                     ["type MyType() = "
@@ -139,8 +130,7 @@ type UsingMSBuild()  =
         AssertCompListContains(completions,"MyType")
         
     // This case was fixed while investigating 4538.            
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.NotFixing4538_2``() =  
         let code =
                                     ["type MyType() = "
@@ -156,8 +146,7 @@ type UsingMSBuild()  =
         AssertCompListContains(completions,"MyType")
         
     // This case was fixed while investigating 4538.            
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.NotFixing4538_3``() =  
         let code = 
                                     ["type MyType() = "
@@ -171,8 +160,7 @@ type UsingMSBuild()  =
         let completions = CtrlSpaceCompleteAtCursor file
         AssertCompListContains(completions,"MyType")
         
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4538_1``() =  
         let code = 
                                     ["type MyType() = "
@@ -187,8 +175,7 @@ type UsingMSBuild()  =
         let completions = CtrlSpaceCompleteAtCursor file
         AssertCompListContains(completions,"MyType")    
         
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4538_2``() =  
         let code = 
                                     ["type MyType() = "
@@ -207,8 +194,7 @@ type UsingMSBuild()  =
         
       
         
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4538_5``() =  
         let code = 
                                     ["type MyType() = "
@@ -224,8 +210,7 @@ type UsingMSBuild()  =
         AssertCompListContains(completions,"MyType")          
         
         
-    [<Test>]
-    [<Category("error_recovery")>]
+    [<Fact>]
     member public this.``ErrorRecovery.Bug4594_1``() =  
         let code = 
                                     ["let Bar(xyz) ="
@@ -241,7 +226,7 @@ type UsingMSBuild()  =
     /// In this bug, the Module. at the very end of the file was treated as if it were in the scope
     /// of Module rather than right after it. This check just makes sure we can see a data tip because
     /// Module is available.
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorRecovery.5878_1``() =
         Helper.AssertMemberDataTipContainsInOrder
             (
@@ -268,6 +253,5 @@ type UsingMSBuild()  =
 
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
\ No newline at end of file
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.General.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.General.fs
index 96911faaa3b..a86a6ad5126 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.General.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.General.fs
@@ -2,7 +2,7 @@
 
 namespace Tests.LanguageService.General
 
-open NUnit.Framework
+open Xunit
 open System
 open System.IO
 open System.Reflection
@@ -21,10 +21,9 @@ open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 
-[<TestFixture>][<Category "LanguageService">] 
 module IFSharpSource_DEPRECATED = 
 
-    [<Test>]
+    [<Fact>]
     let MultipleSourceIsDirtyCallsChangeTimestamps() = 
         let recolorizeWholeFile() = ()
         let recolorizeLine (_line:int) = ()
@@ -42,8 +41,8 @@ module IFSharpSource_DEPRECATED =
         let secondDirtyTime = source.DirtyTime
         let lastTickCount =  System.Environment.TickCount
             
-        Assert.AreEqual(originalChangeCount + 1, secondChangeCount)
-        Assert.AreNotEqual(secondDirtyTime, originalDirtyTime)
+        Assert.Equal(originalChangeCount + 1, secondChangeCount)
+        Assert.NotEqual(secondDirtyTime, originalDirtyTime)
             
         // Here's the test. NeedsVisualRefresh is true now, we call RecordChangeToView() and it should cause a new changeCount and dirty time.
         while System.Environment.TickCount = lastTickCount do 
@@ -52,13 +51,12 @@ module IFSharpSource_DEPRECATED =
         let thirdChangeCount = source.ChangeCount
         let thirdDirtyTime = source.DirtyTime
             
-        Assert.AreEqual(secondChangeCount + 1, thirdChangeCount)
-        Assert.AreNotEqual(thirdDirtyTime, secondDirtyTime)            
+        Assert.Equal(secondChangeCount + 1, thirdChangeCount)
+        Assert.NotEqual(thirdDirtyTime, secondDirtyTime)            
 
 
 
 
-[<TestFixture>][<Category "LanguageService">]  
 type UsingMSBuild() =
     inherit LanguageServiceBaseTests()
 
@@ -104,7 +102,7 @@ type UsingMSBuild() =
                             n
                    ) 0
 
-    [<Test>]
+    [<Fact>]
     member public this.``ReconcileErrors.Test1``() = 
         let (_solution, project, file) = this.CreateSingleFileProject(["erroneous"])
         Build project |> ignore
@@ -112,7 +110,7 @@ type UsingMSBuild() =
         ()
  
     /// FEATURE: (Project System only) Adding a file outside the project directory creates a link
-    [<Test>]
+    [<Fact>]
     member public this.``ProjectSystem.FilesOutsideProjectDirectoryBecomeLinkedFiles``() =
         use _guard = this.UsingNewVS()
         if OutOfConeFilesAreAddedAsLinks(this.VS) then
@@ -127,7 +125,7 @@ type UsingMSBuild() =
             let projFileText = System.IO.File.ReadAllText(ProjectFile(project))
             AssertMatchesRegex '<' @"<ItemGroup>\s*<Compile Include=""..\\link.fs"">\s*<Link>link.fs</Link>" projFileText
                                   
-    [<Test>]
+    [<Fact>]
     member public this.``Lexer.CommentsLexing.Bug1548``() =
         let scan = new FSharpScanner_DEPRECATED(fun source -> 
                         let fileName = "test.fs"
@@ -195,7 +193,7 @@ type UsingMSBuild() =
            
         
     // This was a bug in ReplaceAllText (subsequent calls to SetMarker would fail)
-    [<Test>]
+    [<Fact>]
     member public this.``Salsa.ReplaceAllText``() =
         let code = 
                 ["#light"; 
@@ -225,7 +223,7 @@ type UsingMSBuild() =
     
 
     // Make sure that possible overloads (and other related errors) are shown in the error list
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorLogging.Bug5144``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -242,13 +240,13 @@ type UsingMSBuild() =
                                        "p.Plot(sin, 0., 0.)"])
         let build = time1 Build project "Time to build project"
         
-        Assert.IsTrue(not build.BuildSucceeded, "Expected build to fail")              
+        Assert.True(not build.BuildSucceeded, "Expected build to fail")              
         
         if SupportsOutputWindowPane(this.VS) then 
             Helper.AssertListContainsInOrder(GetOutputWindowPaneLines(this.VS), 
                                       ["error FS0041: A unique overload for method 'Plot' could not be determined based on type information prior to this program point. A type annotation may be needed. Candidates: member N.M.LineChart.Plot : f:(float -> float) * xmin:float * xmax:float -> unit, member N.M.LineChart.Plot : f:System.Func<double,double> * xmin:float * xmax:float -> unit"])
 
-    [<Test; Category("Expensive")>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.ThisOnceAsserted``() =     
         Helper.ExhaustivelyScrutinize(
           this.TestRunner,
@@ -258,7 +256,7 @@ type UsingMSBuild() =
             """    else [],""            """ ]
             )
 
-    [<Test; Category("Expensive")>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.ThisOnceAssertedToo``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -268,7 +266,7 @@ type UsingMSBuild() =
               "        member _.CompareTo(v:obj) = 1" ]
             )
 
-    [<Test; Category("Expensive")>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.ThisOnceAssertedThree``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -278,7 +276,7 @@ type UsingMSBuild() =
               "        with get() = x.Data"
               "        and set(v) = x.Data <- v" ]
               )
-    [<Test>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.ThisOnceAssertedFour``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -286,12 +284,11 @@ type UsingMSBuild() =
               "let z=4" ]
               )
 
-    [<Test>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.ThisOnceAssertedFive``() =     
         Helper.ExhaustivelyScrutinize(this.TestRunner, [ """CSV.File<@"File1.txt">.[0].""" ])  // <@ is one token, wanted < @"...
 
-    [<Category("Expensive")>]
-    [<Test>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.Bug2277``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -305,8 +302,7 @@ type UsingMSBuild() =
                "let pp= plot(Area(xs,ys))" ]
                 )
                                      
-    [<Category("Expensive")>]
-    [<Test>]
+    [<Fact>]
     member public this.``ExhaustivelyScrutinize.Bug2283``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -322,7 +318,7 @@ type UsingMSBuild() =
 
    /// Verifies that token info returns correct trigger classes 
     /// - this is used in MPF for triggering various intellisense features
-    [<Test>]
+    [<Fact>]
     member public this.``TokenInfo.TriggerClasses``() =      
       let important = 
         [ // Member select for dot completions
@@ -340,7 +336,7 @@ type UsingMSBuild() =
         let info = TestExpose.TokenInfo tok
         AssertEqual(expected, info)
 
-    [<Test>]
+    [<Fact>]
     member public this.``MatchingBraces.VerifyMatches``() = 
         let content = 
             [|
@@ -383,15 +379,15 @@ type UsingMSBuild() =
             let (endRow, endCol) = getPos endMarker
 
             let checkTextSpan (actual : TextSpan) expectedRow expectedCol = 
-                Assert.IsTrue(actual.iStartLine = actual.iEndLine, "Start and end of the span should be on the same line")
-                Assert.AreEqual(expectedRow, actual.iStartLine, "Unexpected row")
-                Assert.AreEqual(expectedCol, actual.iStartIndex, "Unexpected column")
-                Assert.IsTrue(actual.iEndIndex = (actual.iStartIndex + expectedSpanLen), sprintf "Span should have length == %d" expectedSpanLen)
+                Assert.True(actual.iStartLine = actual.iEndLine, "Start and end of the span should be on the same line")
+                Assert.Equal(expectedRow, actual.iStartLine)
+                Assert.Equal(expectedCol, actual.iStartIndex)
+                Assert.True(actual.iEndIndex = (actual.iStartIndex + expectedSpanLen), sprintf "Span should have length == %d" expectedSpanLen)
 
             let checkBracesForPosition row col = 
                 setPos row col
                 let braces = GetMatchingBracesForPositionAtCursor(file)
-                Assert.AreEqual(1, braces.Length, "One result expected")
+                Assert.Equal(1, braces.Length)
 
                 let (lbrace, rbrace) = braces.[0]
                 checkTextSpan lbrace startRow startCol
@@ -412,7 +408,6 @@ type UsingMSBuild() =
 
 
 // Context project system
-[<TestFixture>]
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
 
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs
index 5b3a685b1ea..4c43e7f92c1 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs
@@ -4,7 +4,7 @@ namespace Tests.LanguageService.GotoDefinition
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
@@ -15,9 +15,8 @@ open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 open FSharp.Compiler.CodeAnalysis
 open FSharp.Compiler.EditorServices
+open Xunit
 
-[<TestFixture>]
-[<Category "LanguageService">] 
 type UsingMSBuild()  = 
     inherit LanguageServiceBaseTests()
 
@@ -37,11 +36,11 @@ type UsingMSBuild()  =
         let (_, _, file) = this.CreateSingleFileProject(fileContents, ?references = extraRefs)
         MoveCursorToStartOfMarker (file, marker)
         let result = GotoDefinitionAtCursor file
-        Assert.IsTrue(result.Success, "result.Success")
+        Assert.True(result.Success, "result.Success")
         let actualPos = (result.Span.iStartLine, result.Span.iStartIndex)
         let line = GetLineNumber file (result.Span.iStartLine + 1)
         printfn "Actual line:%s, actual pos:%A" line actualPos
-        Assert.AreEqual(pos, actualPos, "pos")
+        Assert.Equal(pos, actualPos)
                     
     //GoToDefinitionFail Helper Function
     member private this.VerifyGoToDefnFailAtStartOfMarker(fileContents : string,  marker :string,?addtlRefAssy : string list) =
@@ -84,7 +83,7 @@ type UsingMSBuild()  =
                 file 
                 result 
     
-    [<Test>]                                  
+    [<Fact>]                                  
     member this.``Operators.TopLevel``() = 
         this.VerifyGotoDefnSuccessForNonIdentifierAtStartOfMarker(
             fileContents = """
@@ -95,7 +94,7 @@ type UsingMSBuild()  =
             pos=(1,21)
             )
 
-    [<Test>]                                  
+    [<Fact>]                                  
     member this.``Operators.Member``() = 
         this.VerifyGotoDefnSuccessForNonIdentifierAtStartOfMarker(
             fileContents = """
@@ -108,7 +107,7 @@ type UsingMSBuild()  =
             pos=(3,35)
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Value``() = 
         this.VerifyGoToDefnSuccessAtStartOfMarker(
             fileContents = """
@@ -123,7 +122,7 @@ type UsingMSBuild()  =
             marker = "valueX (*GotoValDef*)",
             definitionCode = "let valueX = Beta(1.0M, ())(*GotoTypeDef*)")
     
-    [<Test>]
+    [<Fact>]
     member public this.``DisUnionMember``() =
         this.VerifyGoToDefnSuccessAtStartOfMarker(
                             fileContents = """
@@ -138,7 +137,7 @@ type UsingMSBuild()  =
             marker = "Beta(1.0M, ())(*GotoTypeDef*)",
             definitionCode = "| Beta of decimal * unit")        
 
-    [<Test>]
+    [<Fact>]
     member public this.``PrimitiveType``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
             fileContents = """
@@ -146,7 +145,7 @@ type UsingMSBuild()  =
                 let bi = 123456I""",
             marker = "123456I")
            
-    [<Test>]
+    [<Fact>]
     member public this.``OnTypeDefinition``() =
         this.VerifyGoToDefnSuccessAtStartOfMarker(
             fileContents = """
@@ -157,7 +156,7 @@ type UsingMSBuild()  =
             marker = "One (*Marker1*)",
             definitionCode = "type One (*Marker1*) = One")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Parameter``() = 
         this.VerifyGoToDefnSuccessAtStartOfMarker(
             fileContents = """
@@ -168,13 +167,10 @@ type UsingMSBuild()  =
             marker = "One (*Marker2*)",
             definitionCode = "type One (*Marker1*) = One")    
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute")>]
     // This test case check the GotoDefinition (i.e. the TypeProviderDefinitionLocation Attribute)
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // We expect the correct FilePath, Line and Column on provided: Type, Event, Method, and Property
     // TODO: add a case for a provided Field
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute``() =
         use _guard = this.UsingNewVS()
         // Note that the verification helped method is custom because we *do* care about the column as well, 
@@ -207,7 +203,7 @@ type UsingMSBuild()  =
             let column' = column - 2
 
             match result.ToOption() with 
-            | Some(span,_) -> Assert.AreEqual(column',span.iStartIndex, "The cursor landed on the incorrect column!") 
+            | Some(span,_) -> Assert.Equal(column',span.iStartIndex) 
             | None ->  Assert.Fail <| sprintf "Expected to find the definition at column '%d' but GotoDefn failed." column'
 
         // Basic scenario on a provided Type
@@ -293,19 +289,19 @@ type UsingMSBuild()  =
         ``Event.BasicScenario``()
 
     
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.NoSourceCodeAvailable``() = 
         this.VerifyGoToDefnFailAtStartOfMarker
             (
                 fileContents = "System.String.Format(\"\")",
                 marker = "ormat",
                 f = (fun (_, result) ->
-                    Assert.IsFalse(result.Success)
-                    Assert.IsTrue(result.ErrorDescription.Contains("Source code is not available"))
+                    Assert.False(result.Success)
+                    Assert.True(result.ErrorDescription.Contains("Source code is not available"))
                     )
             )
     
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.NoIdentifierAtLocation``() = 
         let useCases = 
             [
@@ -319,12 +315,12 @@ type UsingMSBuild()  =
                     fileContents = source,
                     marker = marker,
                     f = (fun (_, result) ->
-                        Assert.IsFalse(result.Success)
-                        Assert.IsTrue(result.ErrorDescription.Contains("Cursor is not on identifier"))
+                        Assert.False(result.Success)
+                        Assert.True(result.ErrorDescription.Contains("Cursor is not on identifier"))
                         )
                 )
 
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ProvidedTypeNoDefinitionLocationAttribute``() =  
 
         this.VerifyGoToDefnFailAtStartOfMarker
@@ -333,12 +329,11 @@ type UsingMSBuild()  =
                 type T = N1.T<"", 1>
                 """,
                 marker = "T<",
-                f = (fun (_, result) -> Assert.IsFalse(result.Success) ),
+                f = (fun (_, result) -> Assert.False(result.Success) ),
                 addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")]
             )
         
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``GotoDefinition.ProvidedMemberNoDefinitionLocationAttribute``() = 
         let useCases = 
             [
@@ -359,15 +354,13 @@ type UsingMSBuild()  =
                     fileContents = source,
                     marker = marker,
                     f = (fun (_, result) ->
-                        Assert.IsFalse(result.Success)
+                        Assert.False(result.Success)
                         let expectedText = sprintf "provided member '%s'" name
-                        Assert.IsTrue(result.ErrorDescription.Contains(expectedText))
+                        Assert.True(result.ErrorDescription.Contains(expectedText))
                         ),
                     addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")]
                 )
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute.Negative")>]
+    [<Fact>]
     // This test case is when the TypeProviderDefinitionLocationAttribute filepath doesn't exist  for TypeProvider Type
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute.Type.FileDoesnotExist``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
@@ -379,10 +372,7 @@ type UsingMSBuild()  =
             marker = "T(*GotoValDef*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DefinitionLocationAttributeFileDoesnotExist.dll")])
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute.Negative")>]
-    [<Ignore("Need some work to detect the line does not exist.")>]
+    [<Fact(Skip = "Need some work to detect the line does not exist.")>]
     //This test case is when the TypeProviderDefinitionLocationAttribute Line doesn't exist  for TypeProvider Type
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute.Type.LineDoesnotExist``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
@@ -394,9 +384,7 @@ type UsingMSBuild()  =
             marker = "T(*GotoValDef*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DefinitionLocationAttributeLineDoesnotExist.dll")])
      
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute.Negative")>]
+    [<Fact>]
     // This test case is when the TypeProviderDefinitionLocationAttribute filepath doesn't exist  for TypeProvider Constructor
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute.Constructor.FileDoesnotExist``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
@@ -410,9 +398,7 @@ type UsingMSBuild()  =
 
 
          
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute.Negative")>]
+    [<Fact>]
     //This test case is when the TypeProviderDefinitionLocationAttribute filepath doesn't exist  for TypeProvider Method
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute.Method.FileDoesnotExist``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
@@ -424,9 +410,7 @@ type UsingMSBuild()  =
             marker = "M(*GotoValDef*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DefinitionLocationAttributeFileDoesnotExist.dll")])
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute.Negative")>]
+    [<Fact>]
     // This test case is when the TypeProviderDefinitionLocationAttribute filepath doesn't exist  for TypeProvider Property
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute.Property.FileDoesnotExist``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
@@ -438,9 +422,7 @@ type UsingMSBuild()  =
             marker = "StaticProp(*GotoValDef*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DefinitionLocationAttributeFileDoesnotExist.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.DefinitionLocationAttribute.Negative")>]
+    [<Fact>]
     //This test case is when the TypeProviderDefinitionLocationAttribute filepath doesn't exist  for TypeProvider Event
     member public this.``GotoDefinition.TypeProvider.DefinitionLocationAttribute.Event.FileDoesnotExist``() =
         this.VerifyGoToDefnFailAtStartOfMarker(
@@ -453,7 +435,7 @@ type UsingMSBuild()  =
             marker = "Event1(*GotoValDef*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DefinitionLocationAttributeFileDoesnotExist.dll")])
 
-    [<Test>]
+    [<Fact>]
     member public this.``ModuleDefinition``() =
         this.VerifyGoToDefnSuccessAtStartOfMarker(
             fileContents = """
@@ -464,7 +446,7 @@ type UsingMSBuild()  =
             marker = "Foo (*MarkerModuleDefinition*)",
             definitionCode = "module Foo (*MarkerModuleDefinition*) =")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Record.Field.Definition``() = 
         this.VerifyGoToDefnSuccessAtStartOfMarker(
             fileContents = """
@@ -481,7 +463,7 @@ type UsingMSBuild()  =
             marker = "myX (*MarkerXFieldDefinition*)",   
             definitionCode = "{ myX (*MarkerXFieldDefinition*) : int")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Record.Field.Usage``() = 
         this.VerifyGoToDefnSuccessAtStartOfMarker(
             fileContents = """
@@ -508,14 +490,14 @@ type UsingMSBuild()  =
     member internal this.GotoDefinitionCheckResultAgainst (exp : (string * string * string) option)(file : OpenFile)(act : GotoDefnResult) : unit =
       match (exp, act.ToOption()) with
       | (Some (toFind, expLine, expFile), Some (span, actFile)) -> printfn "%s" "Result received, as expected; checking."
-                                                                   Assert.AreEqual (expFile, actFile)
+                                                                   Assert.Equal (expFile, actFile)
                                                                    printfn "%s" "Filename matches expected."
                                                                    MoveCursorTo(file, span.iStartLine + 1, span.iStartIndex + 1) // adjust & move to the identifier
                                                                    match GetIdentifierAtCursor file with // REVIEW: actually check that we're on the leftmost character of the identifier
                                                                    | None         -> Assert.Fail("No identifier at cursor!")
-                                                                   | Some (id, _) -> Assert.AreEqual (toFind, id) // are we on the identifier we expect?
+                                                                   | Some (id, _) -> Assert.Equal (toFind, id) // are we on the identifier we expect?
                                                                                      printfn "%s" "Identifier at cursor matches expected."
-                                                                                     Assert.AreEqual (expLine.Trim (), (span.iStartLine |> (+) 1 |> GetLineNumber file).Trim ()) // ignore initial- / final-whitespace-introduced noise; adjust for difference in index numbers
+                                                                                     Assert.Equal (expLine.Trim (), (span.iStartLine |> (+) 1 |> GetLineNumber file).Trim ()) // ignore initial- / final-whitespace-introduced noise; adjust for difference in index numbers
                                                                                      printfn "%s" "Line at cursor matches expected."
       | (None,                            None)                 -> printfn "%s" "No result received, as expected." // sometimes we may expect GotoDefinition to fail, e.g., when the cursor isn't placed on a valid position (i.e., over an identifier, and, maybe, a constant if we decide to support that)
       | (Some _,                          None)                 -> Assert.Fail("No result received, but one was expected!") // distinguish this and the following case to give insight in case of failure
@@ -528,11 +510,11 @@ type UsingMSBuild()  =
     member internal this.GotoDefinitionCheckResultAgainstAnotherFile (proj : OpenProject)(exp : (string * string) option)(act : GotoDefnResult) : unit =
       match (exp, act.ToOption()) with
       | (Some (toFind, expFile), Some (span, actFile)) -> printfn "%s" "Result received, as expected; checking."
-                                                          Assert.AreEqual (expFile, Path.GetFileName actFile)
+                                                          Assert.Equal (expFile, Path.GetFileName actFile)
                                                           printfn "%s" "Filename matches expected."
                                                           let file = OpenFile (proj, actFile)
                                                           let line = span.iStartLine |> ((+) 1) |> GetLineNumber file // need to adjust line number here
-                                                          Assert.AreEqual (toFind, line.Substring (span.iStartIndex, toFind.Length))
+                                                          Assert.Equal (toFind, line.Substring (span.iStartIndex, toFind.Length))
                                                           printfn "%s" "Identifier at cursor matches expected."
       | (None,                   None)                 -> printfn "%s" "No result received, as expected." // sometimes we may expect GotoDefinition to fail, e.g., when the cursor isn't placed on a valid position (i.e., over an identifier, and, maybe, a constant if we decide to support that)
       | (Some _,                 None)                 -> Assert.Fail("No result received, but one was expected!") // distinguish this and the following case to give insight in case of failure
@@ -542,7 +524,7 @@ type UsingMSBuild()  =
     member this.GotoDefinitionTestWithSimpleFile (startLoc : string)(exp : (string * string) option) : unit =
         this.SolutionGotoDefinitionTestWithSimpleFile startLoc exp 
 
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.OverloadResolution``() =
         let lines =
           [ "type D() ="
@@ -559,7 +541,7 @@ type UsingMSBuild()  =
             "d.ToString$4$(\"aaa\") "
           ]
         this.GotoDefinitionTestWithMarkup lines
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.OverloadResolutionForProperties``() =
         let lines = [ "type D() ="
                       "  member this.#1##2#Foo"
@@ -577,7 +559,7 @@ type UsingMSBuild()  =
             ]
         this.GotoDefinitionTestWithMarkup lines
 
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.OverloadResolutionWithOverrides``() =
         let lines =
           [ "[<AbstractClass>]"
@@ -596,7 +578,7 @@ type UsingMSBuild()  =
           ]
         this.GotoDefinitionTestWithMarkup lines
 
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.OverloadResolutionStatics``() =
         let lines =
           [   "type T ="
@@ -608,7 +590,7 @@ type UsingMSBuild()  =
           ]
         this.GotoDefinitionTestWithMarkup lines
 
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.Constructors``() =
         let lines =
           [   "type #1a##1b##1c##1d#B() ="
@@ -677,12 +659,12 @@ type UsingMSBuild()  =
           MoveCursorTo(file, line, col)
           let res = GotoDefinitionAtCursor file
           match res.ToOption() with
-          |   None -> Assert.IsFalse(targets.ContainsKey(marker), sprintf "%s: definition not found " marker)
+          |   None -> Assert.False(targets.ContainsKey(marker), sprintf "%s: definition not found " marker)
           |   Some (span,text) ->
                   match targets.TryGetValue(marker) with
                   |   false, _ ->  Assert.Fail(sprintf "%s: unexpected definition found" marker)
                   |   true, (line1, col1) -> 
-                          Assert.IsTrue(span.iStartIndex = col1 && span.iStartLine = line1, 
+                          Assert.True(span.iStartIndex = col1 && span.iStartLine = line1, 
                                 sprintf "%s: wrong definition found expected %d %d but found %d %d %s" marker line1 col1 span.iStartLine span.iStartIndex text )
 
     
@@ -890,7 +872,7 @@ type UsingMSBuild()  =
     // ensure that we've found the correct position (i.e., these must be unique
     // in any given test source file)
 
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.InheritedMembers``() =
         let lines =
             [ "[<AbstractClass>]"
@@ -910,299 +892,298 @@ type UsingMSBuild()  =
 
 
     /// let #x = () in $x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.InsideClass.Bug3176`` () =
       this.GotoDefinitionTestWithSimpleFile "id77 (*loc-77*)" (Some("val id77 (*loc-77*) : int", "id77"))
 
     /// let #x = () in $x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.TrivialLetRHS`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-1*)" (Some("let x = () (*loc-2*)", "x"))
 
     /// let #x = () in x$
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.TrivialLetRHSToRight`` () =
       this.GotoDefinitionTestWithSimpleFile " (*loc-1*)" (Some("let x = () (*loc-2*)", "x"))
 
     /// let $x = () in x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.TrivialLetLHS`` () =
       this.GotoDefinitionTestWithSimpleFile "x = () (*loc-2*)" (Some("let x = () (*loc-2*)", "x"))
 
     /// let x = () in let #x = () in $x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.NestedLetWithSameNameRHS`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-4*)" (Some("let x = () (*loc-3*)", "x"))
 
     /// let x = () in let $x = () in x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.NestedLetWithSameNameLHSInner`` () =
       this.GotoDefinitionTestWithSimpleFile "x = () (*loc-3*)" (Some("let x = () (*loc-3*)", "x"))
 
     /// let $x = () in let x = () in x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.NestedLetWithSameNameLHSOuter`` () =
       this.GotoDefinitionTestWithSimpleFile "x = () (*loc-5*)" (Some("let x = () (*loc-5*)", "x"))
 
     /// let #x = () in let x = $x in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.NestedLetWithXIsX`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-6*)" (Some("let x = () (*loc-7*)", "x"))
 
     /// let x = () in let rec #x = fun y -> $x y in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.NestedLetWithXRec`` () =
       this.GotoDefinitionTestWithSimpleFile "x y (*loc-8*)" (Some("let rec x = (*loc-9*)", "x"))
 
     /// let x = () in let rec x = fun #y -> x $y in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Binding.NestedLetWithXRecParam`` () =
       this.GotoDefinitionTestWithSimpleFile "y (*loc-8*)" (Some("fun y -> (*loc-10*)", "y"))
 
     /// let #(+) x _ = x in 2 $+ 3
-    [<Test>]
-    [<Ignore "Bug 2514 filed.">]
+    [<Fact(Skip = "Bug 2514 filed.")>]
     member public this.``GotoDefinition.Simple.Binding.Operator`` () =
       this.GotoDefinitionTestWithSimpleFile "+ 3 (*loc-11*)" (Some("let (+) x _ = x (*loc-2*)", "+"))
 
     /// type #Zero =
     /// let f (_ : $Zero) = 0
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NullType`` () =
       this.GotoDefinitionTestWithSimpleFile "Zero) : 'a = failwith \"hi\" (*loc-14*)" (Some("type Zero = (*loc-13*)", "Zero"))
 
     /// type One = $One
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.UnitTypeConsDef`` () =
       this.GotoDefinitionTestWithSimpleFile "One (*loc-15*)" (Some("One (*loc-15*)", "One"))
 
     /// type $One = One
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.UnitTypeTypenameDef`` () =
       this.GotoDefinitionTestWithSimpleFile "One = (*loc-16*)" (Some("type One = (*loc-16*)", "One"))
 
     /// type One = #One
     /// let f (_ : One) = $One
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.UnitTypeCons`` () =
       this.GotoDefinitionTestWithSimpleFile "One (*loc-18*)" (Some("One (*loc-15*)", "One"))
 
     /// type #One = One
     /// let f (_ : $One) = One
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.UnitTypeTypename`` () =
       this.GotoDefinitionTestWithSimpleFile "One) = (*loc-17*)" (Some("type One = (*loc-16*)", "One"))
 
     /// type $Nat = Suc of Nat | Zro
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NatTypeTypenameDef`` () =
       this.GotoDefinitionTestWithSimpleFile "Nat = (*loc-19*)" (Some("type Nat = (*loc-19*)", "Nat"))
 
     /// type #Nat = Suc of $Nat | Zro
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NatTypeConsArg`` () =
       this.GotoDefinitionTestWithSimpleFile "Nat (*loc-20*)" (Some("type Nat = (*loc-19*)", "Nat"))
 
     /// type Nat = Suc of Nat | #Zro
     /// fun m -> match m with | $Zro -> () | _ -> ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NatPatZro`` () =
       this.GotoDefinitionTestWithSimpleFile "Zro   -> (*loc-24*)" (Some("| Zro (*loc-21*)", "Zro"))
 
     /// type Nat = $Suc of Nat | Zro
     /// fun m -> match m with | Zro -> () | $Suc _ -> ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NatPatSuc`` () =
       this.GotoDefinitionTestWithSimpleFile "Suc m -> (*loc-25*)" (Some("| Suc of Nat (*loc-20*)", "Suc"))
 
     /// let rec plus m n = match m with | Zro -> n | Suc #m -> Suc (plus $m n)
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NatPatSucVarUse`` () =
       this.GotoDefinitionTestWithSimpleFile "m n) (*loc-26*)" (Some("| Suc m -> (*loc-25*)", "m"))
 
     /// let rec plus m n = match m with | Zro -> n | Suc #m -> Suc (plus $m n)
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.NatPatSucOuterVarUse`` () =
       this.GotoDefinitionTestWithSimpleFile "n) (*loc-26*)" (Some("let rec plus m n = (*loc-23*)", "n"))
 
     /// type $MyRec = { myX : int ; myY : int }
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.RecordTypenameDef`` () =
       this.GotoDefinitionTestWithSimpleFile "MyRec = (*loc-27*)" (Some("type MyRec = (*loc-27*)", "MyRec"))
 
     /// type MyRec = { $myX : int ; myY : int }
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.RecordField1Def`` () =
       this.GotoDefinitionTestWithSimpleFile "myX : int (*loc-28*)" (Some("{ myX : int (*loc-28*)", "myX"))
 
     /// type MyRec = { myX : int ; $myY : int }
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.RecordField2Def`` () =
       this.GotoDefinitionTestWithSimpleFile "myY : int (*loc-29*)" (Some("myY : int (*loc-29*)", "myY"))
 
     /// type MyRec = { #myX : int ; myY : int }
     /// let rDefault = { $myX = 2 ; myY = 3 }
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.RecordField1Use`` () =
       this.GotoDefinitionTestWithSimpleFile "myX = 2 (*loc-30*)" (Some("{ myX : int (*loc-28*)", "myX"))
 
     /// type MyRec = { myX : int ; #myY : int }
     /// let rDefault = { myX = 2 ; $myY = 3 }
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.RecordField2Use`` () =
       this.GotoDefinitionTestWithSimpleFile "myY = 3 (*loc-31*)" (Some("myY : int (*loc-29*)", "myY"))
 
     /// type MyRec = { #myX : int ; myY : int }
     /// let rDefault = { myX = 2 ; myY = 3 }
     /// let _ = { rDefault with $myX = 7 }
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Datatype.RecordField1UseInWith`` () =
       this.GotoDefinitionTestWithSimpleFile "myX = 7 } (*loc-32*)" (Some("{ myX : int (*loc-28*)", "myX"))
 
 
     /// let a = () in let id (x : '$a) : 'a = x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Polymorph.Leftmost`` () =
       this.GotoDefinitionTestWithSimpleFile "a) (*loc-33*)" (Some("let id (x : 'a) (*loc-33*)", "'a"))
 
     /// let a = () in let id (x : 'a) : '$a = x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Polymorph.NotLeftmost`` () =
       this.GotoDefinitionTestWithSimpleFile "a = x (*loc-34*)" (Some("let id (x : 'a) (*loc-33*)", "'a"))
 
     /// let foo = () in let f (_ as $foo) = foo in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.AsPatLHS`` () =
       this.GotoDefinitionTestWithSimpleFile "foo) = (*loc-35*)" (Some("let f (_ as foo) = (*loc-35*)", "foo"))
 
     /// let foo = () in let f (_ as #foo) = $foo in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.AsPatRHS`` () =
       this.GotoDefinitionTestWithSimpleFile "foo (*loc-36*)" (Some("let f (_ as foo) = (*loc-35*)", "foo"))
 
     /// fun $x x -> x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.LambdaMultBind1`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-37*)" (Some("fun x (*loc-37*)", "x"))
 
     /// fun x $x -> x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.LambdaMultBind2`` () =
       this.GotoDefinitionTestWithSimpleFile "x -> (*loc-38*)" (Some("x -> (*loc-38*)", "x"))
 
     /// fun x $x -> x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.LambdaMultBindBody`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-39*)" (Some("x -> (*loc-38*)", "x"))
 
     /// let f = () in let $f = function f -> f in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.LotsOfFsFunc`` () =
       this.GotoDefinitionTestWithSimpleFile "f = (*loc-41*)" (Some("let f = (*loc-41*)", "f"))
 
     /// let f = () in let f = function $f -> f in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.LotsOfFsPat`` () =
       this.GotoDefinitionTestWithSimpleFile "f -> (*loc-42*)" (Some("function f -> (*loc-42*)", "f"))
 
     /// let f = () in let f = function #f -> $f in ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.LotsOfFsUse`` () =
       this.GotoDefinitionTestWithSimpleFile "f (*loc-43*)" (Some("function f -> (*loc-42*)", "f"))
 
     /// let f x = match x with | Suc $x | x -> x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.OrPatLeft`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-44*)" (Some("| Suc x (*loc-44*)", "x"))
 
     /// let f x = match x with | Suc x | $x -> x
-    [<Test >]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.OrPatRight`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-45*)" (Some("| Suc x (*loc-44*)", "x"))  // NOTE: or-patterns bind at first occurrence of the variable
 
     /// let f x = match x with | Suc #y & z -> $y
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.AndPat`` () =
       this.GotoDefinitionTestWithSimpleFile "y (*loc-46*)" (Some("| Suc y & z -> (*loc-47*)", "y"))
 
     /// let f xs = match xs with | #x :: xs -> $x
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.ConsPat`` () =
       this.GotoDefinitionTestWithSimpleFile "x (*loc-48*)" (Some("| x :: xs -> (*loc-49*)", "x"))
 
     /// let f p = match p with (#y, z) -> $y
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.PairPat`` () =
       this.GotoDefinitionTestWithSimpleFile "y (*loc-50*)" (Some("| (y : int, z) -> (*loc-51*)", "y"))
 
     /// fun xs -> match xs with x :: #xs when $xs <> [] -> x :: xs
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.ConsPatWhenClauseInWhen`` () =
       this.GotoDefinitionTestWithSimpleFile "xs <> [] -> (*loc-52*)" (Some("| x :: xs (*loc-54*)", "xs"))
 
     /// fun xs -> match xs with #x :: xs when xs <> [] -> $x :: xs
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.ConsPatWhenClauseInWhenRhsX`` () =
       this.GotoDefinitionTestWithSimpleFile "x :: xs (*loc-53*)" (Some("| x :: xs (*loc-54*)", "x"))
 
     /// fun xs -> match xs with x :: #xs when xs <> [] -> x :: $xs
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.ConsPatWhenClauseInWhenRhsXs`` () =
       this.GotoDefinitionTestWithSimpleFile "xs (*loc-53*)" (Some("| x :: xs (*loc-54*)", "xs"))
 
     /// let x = "$x"
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.InStringFails`` () =
       this.GotoDefinitionTestWithSimpleFile "x(*loc-72*)" None
 
     /// let x = "hello
     ///          $x
     ///         "
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.InMultiLineStringFails`` () =
       this.GotoDefinitionTestWithSimpleFile "x(*loc-73*)" None
 
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Tricky.QuotedKeyword`` () =
       this.GotoDefinitionTestWithSimpleFile "let`` = (*loc-74*)" (Some("let rec ``let`` = (*loc-74*)", "``let``"))
 
     /// module $Too = let foo = ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Module.DefModname`` () =
       this.GotoDefinitionTestWithSimpleFile "Too = (*loc-55*)" (Some("module Too = (*loc-55*)", "Too"))
 
     /// module Too = $foo = ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Module.DefMember`` () =
       this.GotoDefinitionTestWithSimpleFile "foo = 0 (*loc-56*)" (Some("let foo = 0 (*loc-56*)", "foo"))
 
     /// module #Too = foo = ()
     /// module Bar = open $Too
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Module.Open`` () =
       this.GotoDefinitionTestWithSimpleFile "Too (*loc-57*)" (Some("module Too = (*loc-55*)", "Too"))
 
     /// module #Too = foo = ()
     /// $Too.foo
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Module.QualifiedModule`` () =
       this.GotoDefinitionTestWithSimpleFile "Too.foo (*loc-58*)" (Some("module Too = (*loc-55*)", "Too"))
 
     /// module Too = #foo = ()
     /// Too.$foo
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.Module.QualifiedMember`` () =
       this.GotoDefinitionTestWithSimpleFile "foo (*loc-58*)" (Some("let foo = 0 (*loc-56*)", "foo"))
 
     /// type Parity = Even | Odd
     /// let (|$Even|Odd|) x = if x % 0 = 0 then Even else Odd
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.ActivePat.ConsDefLHS`` () =
       this.GotoDefinitionTestWithSimpleFile "Even|Odd|) x = (*loc-59*)" (Some("let (|Even|Odd|) x = (*loc-59*)", "|Even|Odd|"))
 
     /// type Parity = Even | Odd
     /// let (|#Even|Odd|) x = if x % 0 = 0 then $Even else Odd
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.ActivePat.ConsDefRhs`` () =
       this.GotoDefinitionTestWithSimpleFile "Even (*loc-60*)" (Some("let (|Even|Odd|) x = (*loc-59*)", "|Even|Odd|"))
 
@@ -1212,17 +1193,16 @@ type UsingMSBuild()  =
     ///   match x with
     ///   | $Even -> 1
     ///   | Odd  -> 0
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.ActivePat.PatUse`` () =
       this.GotoDefinitionTestWithSimpleFile "Even -> 1 (*loc-61*)" (Some("let (|Even|Odd|) x = (*loc-59*)", "|Even|Odd|"))
 
     /// let patval = (|Even|Odd|) (*loc-61b*)
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Simple.ActivePat.PatUseValue`` () =
       this.GotoDefinitionTestWithSimpleFile "en|Odd|) (*loc-61b*)" (Some("let (|Even|Odd|) x = (*loc-59*)", "|Even|Odd|"))
 
-    [<Test>]
-    [<Ignore("This is currently broken for dev enlistments.")>]
+    [<Fact(Skip = "This is currently broken for dev enlistments.")>]
     member public this.``GotoDefinition.Library.InitialTest`` () =
       this.GotoDefinitionTestWithLib "map (*loc-1*)" (Some("map", "lis.fs"))
 
@@ -1230,32 +1210,32 @@ type UsingMSBuild()  =
 
     /// type #Class$ () =
     ///   member c.Method () = ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.ClassNameDef`` () =
       this.GotoDefinitionTestWithSimpleFile " () = (*loc-62*)" (Some("type Class () = (*loc-62*)", "Class"))
 
     /// type Class () =
     ///   member c.#Method$ () = ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.ILMethodDef`` () =
       this.GotoDefinitionTestWithSimpleFile " () = () (*loc-63*)" (Some("member c.Method () = () (*loc-63*)", "c.Method"))
 
     /// type Class () =
     ///   member #c$.Method () = ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.ThisDef`` () =
       this.GotoDefinitionTestWithSimpleFile ".Method () = () (*loc-63*)" (Some("member c.Method () = () (*loc-63*)", "c"))
 
     /// type Class () =
     ///   static member #Foo$ () = ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.StaticMethodDef`` () =
       this.GotoDefinitionTestWithSimpleFile " () = () (*loc-64*)" (Some("static member Foo () = () (*loc-64*)", "Foo"))
 
     /// type #Class () =
     ///   member Method () = ()
     /// let c = Class$ ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.ConstructorUse`` () =
       this.GotoDefinitionTestWithSimpleFile " () (*loc-65*)" (Some("type Class () = (*loc-62*)", "Class"))
 
@@ -1263,27 +1243,27 @@ type UsingMSBuild()  =
     ///   member #Method () = ()
     /// let c = Class ()
     /// c.Method$ ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.MethodInvocation`` () =
       this.GotoDefinitionTestWithSimpleFile " () (*loc-66*)" (Some("member c.Method () = () (*loc-63*)", "c.Method"))
 
     /// type Class () =
     ///   static member #Foo () = ()
     /// Class.Foo$ ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.StaticMethodInvocation`` () =
       this.GotoDefinitionTestWithSimpleFile " () (*loc-67*)" (Some("static member Foo () = () (*loc-64*)", "Foo"))
 
     /// type Class () =
     ///   member c.Method# () = c.Method$ ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.MethodSelfInvocation`` () =
       this.GotoDefinitionTestWithSimpleFile " () (*loc-68*)" (Some("member c.Method  () = c.Method () (*loc-68*)", "c.Method"))
 
     /// type Class () =
     ///   member c.Method1 ()  = c.Method2$ ()
     ///   member #c.Method2 () = c.Method1 ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.MethodToMethodForward`` () =
       this.GotoDefinitionTestWithSimpleFile " () (*loc-69*)" (Some("member c.Method2 () = c.Method1 () (*loc-70*)", "c.Method2"))
 
@@ -1293,7 +1273,7 @@ type UsingMSBuild()  =
     ///   member c.Method () =
     ///     let #c = Class ()
     ///     c$.Method ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.ShadowThis`` () =
       this.GotoDefinitionTestWithSimpleFile ".Method () (*loc-71*)" (Some("let c = Class ()", "c"))
 
@@ -1303,11 +1283,11 @@ type UsingMSBuild()  =
     ///   member c.Method () =
     ///     let c = Class ()
     ///     c.Method$ ()
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.ObjectOriented.ShadowThisMethodInvocation`` () =
       this.GotoDefinitionTestWithSimpleFile " () (*loc-71*)" (Some("member c.Method () = () (*loc-63*)", "c.Method"))
 
-    [<Test>]
+    [<Fact>]
     member this.``GotoDefinition.ObjectOriented.StructConstructor`` () =
       let lines = 
         [ "#light"
@@ -1350,7 +1330,7 @@ type UsingMSBuild()  =
       match (QuickParse.GetCompleteIdentifierIsland tolerate s n, exp) with
       | (Some (s1, _, _), Some s2) -> 
         printfn "%s" "Received result, as expected."
-        Assert.AreEqual (s1, s2)
+        Assert.Equal (s1, s2)
       | (None,         None)    -> 
         printfn "%s" "Received no result, as expected."
       | (Some _,       None)    -> 
@@ -1358,53 +1338,53 @@ type UsingMSBuild()  =
       | (None,         Some _)  -> 
         Assert.Fail("Expected result, but didn't receive one!")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.TrivialBefore`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let $ThisIsAnIdentifier = ()" (Some "ThisIsAnIdentifier")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.TrivialMiddle`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let This$IsAnIdentifier = ()" (Some "ThisIsAnIdentifier")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.TrivialEnd`` () =
       this.GetCompleteIdTest true "let ThisIsAnIdentifier$ = ()" (Some "ThisIsAnIdentifier")
       this.GetCompleteIdTest false "let ThisIsAnIdentifier$ = ()" None
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.GetsUpToDot1`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let ThisIsAnIdentifier = Te$st.Moo.Foo.bar" (Some "Test")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.GetsUpToDot2`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let ThisIsAnIdentifier = Test.Mo$o.Foo.bar" (Some "Test.Moo")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.GetsUpToDot3`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let ThisIsAnIdentifier = Test.Moo.Fo$o.bar" (Some "Test.Moo.Foo")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.GetsUpToDot4`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let ThisIsAnIdentifier = Test.Moo.Foo.ba$r" (Some "Test.Moo.Foo.bar")
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.GetsUpToDot5`` () =
       this.GetCompleteIdTest true "let ThisIsAnIdentifier = Test.Moo.Foo.bar$" (Some "Test.Moo.Foo.bar")
       this.GetCompleteIdTest false "let ThisIsAnIdentifier = Test.Moo.Foo.bar$" None
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetCompleteIdTest.GetOperator`` () =
       for tolerate in [true;false] do
           this.GetCompleteIdTest tolerate "let ThisIsAnIdentifier = 3 +$ 4" None
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.IsConstructor.Bug2516``() =
         let fileContents = """
             module GotoDefinition
@@ -1413,7 +1393,7 @@ type UsingMSBuild()  =
         let definitionCode = "type One(*Mark1*) = One"
         this.VerifyGoToDefnSuccessAtStartOfMarker(fileContents,"(*Mark1*)",definitionCode) 
         
-    [<Test>]
+    [<Fact>]
     member public this.``Identifier.IsTypeName.Bug2516``() =
         let fileContents = """
             module GotoDefinition
@@ -1422,7 +1402,7 @@ type UsingMSBuild()  =
         let definitionCode = "type One(*Mark1*) = One"
         this.VerifyGoToDefnSuccessAtStartOfMarker(fileContents,"(*Mark2*)",definitionCode)       
        
-    [<Test>]
+    [<Fact>]
     member public this.``ModuleName.OnDefinitionSite.Bug2517``() =
         let fileContents = """
             namespace GotoDefinition
@@ -1432,7 +1412,7 @@ type UsingMSBuild()  =
         this.VerifyGoToDefnSuccessAtStartOfMarker(fileContents,"(*Mark*)",definitionCode) 
 
     /// GotoDef on abbreviation
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.Abbreviation.Bug193064``() =
         let fileContents = """
             type X = int
@@ -1442,7 +1422,7 @@ type UsingMSBuild()  =
 
     /// Verify the GotoDefinition on UoM yield does NOT jump out error dialog, 
     /// will do nothing in automation lab machine or GTD SI.fs on dev machine with enlistment.
-    [<Test>]
+    [<Fact>]
     member public this.``GotoDefinition.UnitOfMeasure.Bug193064``() =
         let fileContents = """
             open Microsoft.FSharp.Data.UnitSystems.SI
@@ -1451,6 +1431,5 @@ type UsingMSBuild()  =
 
 
 // Context project system
-[<TestFixture>]
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.NavigationBar.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.NavigationBar.fs
index 06c9bc76a62..99422f89e91 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.NavigationBar.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.NavigationBar.fs
@@ -3,7 +3,7 @@
 namespace Tests.LanguageService.NavigationBar
 
 open System
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
@@ -11,9 +11,6 @@ open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 
-[<Ignore("FSROSLYNTODO: Refactor/enable once navigation bars are fully tested")>]
-[<TestFixture>]
-[<Category "LanguageService">]
 type UsingMSBuild() =
     inherit LanguageServiceBaseTests()
 
@@ -100,6 +97,5 @@ type UsingMSBuild() =
     
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
\ No newline at end of file
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ParameterInfo.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ParameterInfo.fs
index 4ccfee95276..de36960f819 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ParameterInfo.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ParameterInfo.fs
@@ -3,7 +3,7 @@
 namespace Tests.LanguageService.ParameterInfo
 
 open System
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
@@ -16,8 +16,6 @@ module ParamInfoStandardSettings =
     let standard40AssemblyRefs  = [| "System"; "System.Core"; "System.Numerics" |]
     let queryAssemblyRefs = [ "System.Xml.Linq"; "System.Core" ]
 
-[<TestFixture>]
-[<Category "LanguageService">] 
 type UsingMSBuild()  = 
     inherit LanguageServiceBaseTests()
 
@@ -28,7 +26,7 @@ type UsingMSBuild()  =
                             yield display ] ]
       
     let AssertEmptyMethodGroup(resultMethodGroup:Microsoft.VisualStudio.FSharp.LanguageService.MethodListForAMethodTip_DEPRECATED option) =
-        Assert.IsTrue(resultMethodGroup.IsNone, "Expected an empty method group")              
+        Assert.True(resultMethodGroup.IsNone, "Expected an empty method group")              
         
     let AssertMethodGroupDescriptionsDoNotContain(methods:Microsoft.VisualStudio.FSharp.LanguageService.MethodListForAMethodTip_DEPRECATED, expectNotToBeThere) = 
         for i = 0 to methods.GetCount() - 1 do
@@ -38,10 +36,10 @@ type UsingMSBuild()  =
                 AssertNotContains(description,expectNotToBeThere)
  
     let AssertMethodGroup(resultMethodGroup:Microsoft.VisualStudio.FSharp.LanguageService.MethodListForAMethodTip_DEPRECATED option, expectedParamNamesSet:string list list) =
-        Assert.IsTrue(resultMethodGroup.IsSome, "Expected a method group")
+        Assert.True(resultMethodGroup.IsSome, "Expected a method group")
         let resultMethodGroup = resultMethodGroup.Value
-        Assert.AreEqual(expectedParamNamesSet.Length, resultMethodGroup.GetCount())           
-        Assert.IsTrue(resultMethodGroup 
+        Assert.Equal(expectedParamNamesSet.Length, resultMethodGroup.GetCount())           
+        Assert.True(resultMethodGroup 
                          |> GetParamDisplays
                          |> Seq.forall (fun paramDisplays -> 
                                 expectedParamNamesSet |> List.exists (fun expectedParamNames -> 
@@ -50,9 +48,9 @@ type UsingMSBuild()  =
                                            paramDisplay.Contains(expectedParamName)))))
     
     let AssertMethodGroupContain(resultMethodGroup:Microsoft.VisualStudio.FSharp.LanguageService.MethodListForAMethodTip_DEPRECATED option, expectedParamNames:string list) = 
-        Assert.IsTrue(resultMethodGroup.IsSome, "Expected a method group")
+        Assert.True(resultMethodGroup.IsSome, "Expected a method group")
         let resultMethodGroup = resultMethodGroup.Value
-        Assert.IsTrue(resultMethodGroup
+        Assert.True(resultMethodGroup
                           |> GetParamDisplays
                           |> Seq.exists (fun paramDisplays ->
                                 expectedParamNames.Length = paramDisplays.Length &&
@@ -84,48 +82,48 @@ type UsingMSBuild()  =
     //Verify the parameterInfo of one of the list order
     member private this.VerifyParameterInfoOverloadMethodIndex(fileContents : string, marker : string, index : int, expectedParams:string list, ?addtlRefAssy : string list) = 
         let methodstr = this.GetMethodListForAMethodTip(fileContents,marker,?addtlRefAssy=addtlRefAssy)
-        Assert.IsTrue(methodstr.IsSome, "Expected a method group")
+        Assert.True(methodstr.IsSome, "Expected a method group")
         let methodstr = methodstr.Value
 
         let paramDisplays = 
             [ for i = 0 to methodstr.GetParameterCount(index) - 1 do
                 let (name,display,description) = methodstr.GetParameterInfo(index,i)
                 yield display]
-        Assert.IsTrue((expectedParams, paramDisplays) ||> List.forall2 (fun expectedParam paramDisplay -> paramDisplay.Contains(expectedParam)))
+        Assert.True((expectedParams, paramDisplays) ||> List.forall2 (fun expectedParam paramDisplay -> paramDisplay.Contains(expectedParam)))
 
     //Verify there is at least one parameterInfo
     member private this.VerifyHasParameterInfo(fileContents : string, marker : string) =
         let methodstr = this.GetMethodListForAMethodTip(fileContents,marker)
-        Assert.IsTrue(methodstr.IsSome, "Expected a method group")
+        Assert.True(methodstr.IsSome, "Expected a method group")
         let methodstr = methodstr.Value
 
-        Assert.IsTrue (methodstr.GetCount() > 0)
+        Assert.True (methodstr.GetCount() > 0)
 
     //Verify return content after the colon
     member private this.VerifyFirstParameterInfoColonContent(fileContents : string, marker : string, expectedStr : string, ?addtlRefAssy : string list) =
         let methodstr = this.GetMethodListForAMethodTip(fileContents,marker,?addtlRefAssy=addtlRefAssy)
-        Assert.IsTrue(methodstr.IsSome, "Expected a method group")
+        Assert.True(methodstr.IsSome, "Expected a method group")
         let methodstr = methodstr.Value
 
-        Assert.AreEqual(expectedStr, methodstr.GetReturnTypeText(0)) // Expecting a method info like X(a:int,b:int) : int [used to be  X(a:int,b:int) -> int]
+        Assert.Equal(expectedStr, methodstr.GetReturnTypeText(0)) // Expecting a method info like X(a:int,b:int) : int [used to be  X(a:int,b:int) -> int]
 
     member private this.VerifyParameterCount(fileContents : string, marker : string, expectedCount: int) =
         let methodstr = this.GetMethodListForAMethodTip(fileContents,marker)
-        Assert.IsTrue(methodstr.IsSome, "Expected a method group")
+        Assert.True(methodstr.IsSome, "Expected a method group")
         let methodstr = methodstr.Value
-        Assert.AreEqual(0, methodstr.GetParameterCount(expectedCount))
+        Assert.Equal(0, methodstr.GetParameterCount(expectedCount))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.OnConstructor.881644``() =
         let fileContent = """new System.IO.StreamReader((*Mark*)"""
         let methodstr = this.GetMethodListForAMethodTip(fileContent,"(*Mark*)")
-        Assert.IsTrue(methodstr.IsSome, "Expected a method group")
+        Assert.True(methodstr.IsSome, "Expected a method group")
         let methodstr = methodstr.Value
 
         if not (methodstr.GetDescription(0).Contains("#ctor")) then
             failwith "Expected parameter info to contain #ctor"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.InsideWorkflow.6437``() =
         let fileContent = """
             open System.IO 
@@ -134,13 +132,13 @@ type UsingMSBuild()  =
                         let! buffer = file.AsyncRead((*Mark*)0)
                         return 0 }"""
         let methodstr = this.GetMethodListForAMethodTip(fileContent,"(*Mark*)")
-        Assert.IsTrue(methodstr.IsSome, "Expected a method group")
+        Assert.True(methodstr.IsSome, "Expected a method group")
         let methodstr = methodstr.Value
 
         if not (methodstr.GetDescription(0).Contains("AsyncRead")) then
             failwith "Expected parameter info to contain AsyncRead"
     
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MethodInfo.WithColon.Bug4518_1``() =
         let fileContent = """
             type T() =
@@ -149,7 +147,7 @@ type UsingMSBuild()  =
             ((new T()).X((*Mark*)"""
         this.VerifyFirstParameterInfoColonContent(fileContent,"(*Mark*)",": int")
     
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MethodInfo.WithColon.Bug4518_2``() =
         let fileContent = """
            type IFoo = interface
@@ -159,7 +157,7 @@ type UsingMSBuild()  =
            i.f((*Mark*)"""
         this.VerifyFirstParameterInfoColonContent(fileContent,"(*Mark*)",": int")
         
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MethodInfo.WithColon.Bug4518_3``() =
         let fileContent = """
            type M() = 
@@ -168,7 +166,7 @@ type UsingMSBuild()  =
            m.f((*Mark*)"""
         this.VerifyFirstParameterInfoColonContent(fileContent,"(*Mark*)",": unit")
         
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MethodInfo.WithColon.Bug4518_4``() =
         let fileContent = """
            type T() =
@@ -177,14 +175,14 @@ type UsingMSBuild()  =
            t.Foo((*Mark*)"""
         this.VerifyFirstParameterInfoColonContent(fileContent,"(*Mark*)",": string")    
         
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MethodInfo.WithColon.Bug4518_5``() =
         let fileContent = """
            let f x y = x + y
            f((*Mark*)"""
         this.VerifyFirstParameterInfoColonContent(fileContent,"(*Mark*)",": (int -> int) ")  
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.StaticVsInstance.Bug3626.Case1``() =
         let fileContent = """
             type Foo() = 
@@ -193,7 +191,7 @@ type UsingMSBuild()  =
             let z = Foo.Bar((*Mark*))"""
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark*)",[["staticReturnsInt"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.StaticVsInstance.Bug3626.Case2``() =
         let fileContent = """
             type Foo() = 
@@ -203,21 +201,21 @@ type UsingMSBuild()  =
             let y = Hoo.Bar((*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark*)",[["instanceReturnsString"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MethodInfo.Bug808310``() =
         let fileContent = """System.Console.WriteLine((*Mark*)"""
         let methodGroup = this.GetMethodListForAMethodTip(fileContent,"(*Mark*)")   
-        Assert.IsTrue(methodGroup.IsSome, "Expected a method group")
+        Assert.True(methodGroup.IsSome, "Expected a method group")
         let methodGroup = methodGroup.Value
 
         let description = methodGroup.GetDescription(0)
         // Make sure that System.Console.WriteLine is not mentioned anywhere exception in the XML comment signature
         let xmlCommentIndex = description.IndexOf("System.Console.WriteLine]")
         let noBracket =       description.IndexOf("System.Console.WriteLine")
-        Assert.IsTrue(noBracket>=0)
-        Assert.AreEqual(noBracket, xmlCommentIndex)
+        Assert.True(noBracket>=0)
+        Assert.Equal(noBracket, xmlCommentIndex)
 
-    [<Test>]
+    [<Fact>]
     member public this.``NoArguments``() =
         // we want to see e.g. 
         //     g() : int
@@ -240,20 +238,19 @@ type UsingMSBuild()  =
         this.VerifyParameterCount(fileContents,"(*3*)", 0)
         this.VerifyParameterCount(fileContents,"(*4*)", 0)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Constructor1``() =
         let fileContent = """new System.DateTime((*Mark*)"""
         this.VerifyHasParameterInfo(fileContent, "(*Mark*)")
     
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Constructor2``() =
         let fileContent = """
             open System
             new DateTime((*Mark*)"""
         this.VerifyHasParameterInfo(fileContent, "(*Mark*)")
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.DotNet.StaticMethod``() =
         let code = 
                                     ["#light"
@@ -266,26 +263,26 @@ type UsingMSBuild()  =
         AssertMethodGroup(methodGroup, [["objA"; "objB"]])
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.NoParameterInfo.100I.Bug5038``() =
         let fileContent = """100I((*Mark*)"""
         this.VerifyNoParameterInfoAtStartOfMarker(fileContent,"(*Mark*)")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.DotNet.InstanceMethod``() =
         let fileContent = """
             let s = "Hello"
             s.Substring((*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark*)",[["startIndex"]; ["startIndex"; "length"]])
     
-    [<Test>]
+    [<Fact>]
     member public this.``Single.BasicFSharpFunction``() =
         let fileContent = """
             let foo(x) = 1
             foo((*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark*)",[["'a"]])
         
-    // [<Test>] disabled for F#8, legacy service, covered in FCS tests instead
+    // [<Fact>] disabled for F#8, legacy service, covered in FCS tests instead
     member public this.``Single.DiscriminatedUnion.Construction``() =
         let fileContent = """
             type MyDU = 
@@ -305,7 +302,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark3*)",[["``Long Name`` : int"; "string"]])
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark4*)",[["int"]])
         
-    // [<Test>] disabled for F#8, legacy service, covered in FCS tests instead
+    // [<Fact>] disabled for F#8, legacy service, covered in FCS tests instead
     member public this.``Single.Exception.Construction``() =
         let fileContent = """
             exception E1 of int * string
@@ -321,10 +318,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark2*)",[["V1: int"; "string"; "V3: bool" ]])
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Mark3*)",[["``Long Name`` : int"; "string" ]])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo on a provided type that exposes one (static) method that takes one argument works normally.
     member public this.``TypeProvider.StaticMethodWithOneParam`` () =
         let fileContent = """
@@ -333,10 +327,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Marker*)",[["arg1"]],
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
                   
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo on a provided type that exposes a (static) method that takes >1 arguments works normally.
     member public this.``TypeProvider.StaticMethodWithMoreParam`` () =
         let fileContent = """
@@ -345,12 +336,9 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Marker*)",[["arg1";"arg2"]],
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test case verify the TypeProvider static method return type or colon content of the method
     //This test verifies that ParamInfo on a provided type that exposes one (static) method that takes one argument
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //and returns something works correctly (more precisely, it checks that the return type is 'int')
     member public this.``TypeProvider.StaticMethodColonContent`` () =
         let fileContent = """
@@ -360,10 +348,7 @@ type UsingMSBuild()  =
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo on a provided type that exposes a Constructor that takes no argument works normally.
     member public this.``TypeProvider.ConstructorWithNoParam`` () =
         let fileContent = """
@@ -372,10 +357,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoOverloadMethodIndex(fileContent,"(*Marker*)",0,[],
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
               
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo on a provided type that exposes a Constructor that takes one argument works normally.
     member public this.``TypeProvider.ConstructorWithOneParam`` () =
         let fileContent = """
@@ -384,10 +366,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoOverloadMethodIndex(fileContent,"(*Marker*)",1,["arg1"],
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
          
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo on a provided type that exposes a Constructor that takes >1 argument works normally.
     member public this.``TypeProvider.ConstructorWithMoreParam`` () =
         let fileContent = """
@@ -396,10 +375,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoOverloadMethodIndex(fileContent,"(*Marker*)",2,["arg1";"arg2"],
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
          
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo on a provided type that exposes a static parameter that takes >1 argument works normally.
     member public this.``TypeProvider.Type.WhenOpeningBracket`` () =
         let fileContent = """
@@ -408,10 +384,7 @@ type UsingMSBuild()  =
         this.VerifyParameterInfoAtStartOfMarker(fileContent,"(*Marker*)",[["Param1";"ParamIgnored"]],
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
         
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that after closing bracket ">" the ParamInfo isn't showing on a provided type that exposes a static parameter that takes >1 argument works normally.
     //This is a regression test for Bug DevDiv:181000
     member public this.``TypeProvider.Type.AfterCloseBracket`` () =
@@ -421,10 +394,7 @@ type UsingMSBuild()  =
         this.VerifyNoParameterInfoAtStartOfMarker(fileContent,"(*Marker*)",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test verifies that ParamInfo is showing after delimiter "," on a provided type that exposes a static parameter that takes >1 argument works normally.
     member public this.``TypeProvider.Type.AfterDelimiter`` () =
         let fileContent = """
@@ -434,8 +404,7 @@ type UsingMSBuild()  =
              [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
         
               
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.InMatchClause``() =
         let v461 = Version(4,6,1)
         let fileContent = """
@@ -534,23 +503,22 @@ type UsingMSBuild()  =
         
         let methodGroup = GetParameterInfoAtCursor file
         if (methReq = []) then
-            Assert.IsTrue(methodGroup.IsNone, "Expected no method group")
+            Assert.True(methodGroup.IsNone, "Expected no method group")
         else
             AssertMethodGroup(methodGroup, methReq)
             
     // Test on .NET functions with no parameter
-    [<Test>]
+    [<Fact>]
     member public this.``Single.DotNet.NoParameters`` () = 
         this.TestSystematicParameterInfo("x.ToUpperInvariant(", [ [] ])
 
     // Test on .NET function with one parameter
-    [<Test>]
+    [<Fact>]
     member public this.``Single.DotNet.OneParameter`` () = 
         this.TestSystematicParameterInfo("System.DateTime.Today.AddYears(", [ ["value: int"] ] )
 
     // Test appearance of PI on second parameter of .NET function
-    [<Test>]
-    [<Ignore("FSharp1.0:2394")>]
+    [<Fact(Skip = "FSharp1.0:2394")>]
     member public this.``Single.DotNet.OnSecondParameter`` () = 
         this.TestSystematicParameterInfo("loc-1*),", [ ["format"; "args"];
                                                        ["format"; "arg0"];
@@ -558,8 +526,7 @@ type UsingMSBuild()  =
                                                        ["format"; "arg0"; "arg1"];
                                                        ["format"; "arg0"; "arg1"; "arg2"] ] )
     // Test on .NET functions with parameter array
-    [<Test>]
-    [<Ignore("FSharp1.0:2394")>]
+    [<Fact(Skip = "FSharp1.0:2394")>]
     member public this.``Single.DotNet.ParameterArray`` () = 
         this.TestSystematicParameterInfo("loc-2*),", [ ["format"; "args"];
                                                        ["format"; "arg0"];
@@ -567,69 +534,63 @@ type UsingMSBuild()  =
                                                        ["format"; "arg0"; "arg1"];
                                                        ["format"; "arg0"; "arg1"; "arg2"] ] )
     // Test on .NET indexers
-    [<Test>]
-    [<Ignore("FSharp1.0:5245")>]
+    [<Fact(Skip = "FSharp1.0:5245")>]
     member public this.``Single.DotNet.IndexerParameter`` () = 
         this.TestSystematicParameterInfo("alist.[", [ ["index: int"] ] )
     
     // Test on .NET parameters passed with 'out' keyword (byref)
-    [<Test>]
-    [<Ignore("FSharp1.0:2394")>]
+    [<Fact(Skip = "FSharp1.0:2394")>]
     member public this.``Single.DotNet.ParameterByReference`` () = 
         this.TestSystematicParameterInfo("Int32.TryParse(s,", [ ["s: string"; "result: int byref"]; ["s"; "style"; "provider"; "result"] ] )
         
     // Test on reference type and value type parameters (e.g. string & DateTime)
-    [<Test>]
+    [<Fact>]
     member public this.``Single.DotNet.RefTypeValueType`` () = 
         this.TestSystematicParameterInfo("loc-3*)Emp(", [ [];
                                                           ["name: string"; "dob: System.DateTime"];
                                                           ["name: string"; "salary: float"; "dob: System.DateTime"] ] )
                                                           
     // Test PI does not pop up at point of definition/declaration
-    [<Test>]
-    [<Ignore("FSharp1.0:5160")>]
+    [<Fact(Skip = "FSharp1.0:5160")>]
     member public this.``Single.Locations.PointOfDefinition`` () = 
         this.TestSystematicParameterInfo("loc-4*)new(", [ ] )
         this.TestSystematicParameterInfo("member ConvertToInt32 (", [ ] )
         this.TestSystematicParameterInfo("member this.IncreaseBy(", [ ] )
         
     // Test PI does not pop up on whitespace after type annotation
-    [<Test>]
-    [<Ignore("FSharp1.0:5244")>]
+    [<Fact(Skip = "FSharp1.0:5244")>]
     member public this.``Single.Locations.AfterTypeAnnotation`` () = 
         this.TestSystematicParameterInfo("(*loc-5*)", [], true)        
 
 
     // Test PI does not pop up after non-parameterized properties
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.AfterProperties`` () = 
         this.TestSystematicParameterInfo("System.DateTime.Today", [])
         //this.TestSystematicParameterInfo("(*loc-8*)", [], true)
 
     // Test PI does not pop up after non-function values
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.AfterValues`` () = 
         this.TestSystematicParameterInfo("(*loc-8*)", [], true)
     
     // Test PI does not pop up after non-parameterized properties and after values
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Locations.EndOfFile`` () = 
         this.TestSystematicParameterInfo("System.Console.ReadLine(", [ [] ])
         
     // Test PI pop up on parameter list for attributes
-    [<Test>]
-    [<Ignore("FSharp1.0:5242")>]
+    [<Fact(Skip = "FSharp1.0:5242")>]
     member public this.``Single.OnAttributes`` () = 
         this.TestSystematicParameterInfo("(*loc-6*)", [ []; [ "check: bool" ] ], true)
     
     // Test PI when quoted identifiers are used as parameter
-    [<Test>]
+    [<Fact>]
     member public this.``Single.QuotedIdentifier`` () = 
         this.TestSystematicParameterInfo("(*loc-7*)", [ []; [ "maxValue" ]; [ "minValue"; "maxValue" ] ], true)
         
     // Test PI with parameters of custom type 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.RecordAndUnionType`` () = 
         this.TestSystematicParameterInfo("(*loc-9*)", [ [ "Fruit"; "KeyValuePair" ] ], true)
 
@@ -643,65 +604,55 @@ type UsingMSBuild()  =
         MoveCursorToEndOfMarker(file, testLine)
         let methodGroup = GetParameterInfoAtCursor file
         if (methReq = []) then
-            Assert.IsTrue(methodGroup.IsNone, "expected no method group")
+            Assert.True(methodGroup.IsNone, "expected no method group")
         else
             AssertMethodGroup(methodGroup, methReq)
     
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Generics.Typeof``() =
         this.TestGenericParameterInfo("typeof<int>(", [])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.MathAbs``() =
         let sevenTimes l = [ l; l; l; l; l; l; l ]
         this.TestGenericParameterInfo("Math.Abs(", sevenTimes ["value"])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.ExchangeInt``() =
         let sevenTimes l = [ l; l; l; l; l; l; l ]
         this.TestGenericParameterInfo("Interlocked.Exchange<int>(", sevenTimes ["location1"; "value"])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.Exchange``() =
         let sevenTimes l = [ l; l; l; l; l; l; l ]
         this.TestGenericParameterInfo("Interlocked.Exchange(", sevenTimes ["location1"; "value"])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.ExchangeUnder``() =
         let sevenTimes l = [ l; l; l; l; l; l; l ]
         this.TestGenericParameterInfo("Interlocked.Exchange<_> (", sevenTimes ["location1"; "value"])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.Dictionary``() =
         this.TestGenericParameterInfo("System.Collections.Generic.Dictionary<_, option<int>>(", [ []; ["capacity"]; ["comparer"]; ["capacity"; "comparer"]; ["dictionary"]; ["dictionary"; "comparer"] ])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.List``() =
         this.TestGenericParameterInfo("new System.Collections.Generic.List< _ > ( ", [ []; ["capacity"]; ["collection"] ])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.ListInt``() =
         this.TestGenericParameterInfo("System.Collections.Generic.List<int>(", [ []; ["capacity"]; ["collection"] ])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.EventHandler``() =
         this.TestGenericParameterInfo("new System.EventHandler( ", [ [""] ]) // function arg doesn't have a name
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.EventHandlerEventArgs``() =
         this.TestGenericParameterInfo("System.EventHandler<EventArgs>(", [ [""] ]) // function arg doesn't have a name
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Generics.EventHandlerEventArgsNew``() =
         this.TestGenericParameterInfo("new System.EventHandler<EventArgs> ( ", [ [""] ]) // function arg doesn't have a name
 
@@ -727,7 +678,7 @@ type UsingMSBuild()  =
         let gpatcc = GlobalParseAndTypeCheckCounter.StartNew(this.VS)
         MoveCursorToEndOfMarker(file, cursorPrefix)
         let info = GetParameterInfoAtCursor file
-        Assert.IsTrue(info.IsNone, "expected no parameter info")
+        Assert.True(info.IsNone, "expected no parameter info")
         gpatcc.AssertExactly(0,0)
         
     member public this.TestParameterInfoLocation (testLine, expectedPos, ?addtlRefAssy : string list) =
@@ -740,7 +691,7 @@ type UsingMSBuild()  =
         let (_, _, file) = this.CreateSingleFileProject(code, ?references = addtlRefAssy)
         MoveCursorToEndOfMarker(file, cursorPrefix)
         let info = GetParameterInfoAtCursor file
-        Assert.IsTrue(info.IsSome, "expected parameter info")
+        Assert.True(info.IsSome, "expected parameter info")
         let info = info.Value
         AssertEqual(expectedPos, info.GetColumnOfStartOfLongId())
 
@@ -748,83 +699,72 @@ type UsingMSBuild()  =
     // There are more comments below that explain particular tricky cases
     
 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.Simple``() =
         this.TestParameterInfoLocation("let a = System.Math.Sin($", 8)
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.LineWithSpaces``() =
         this.TestParameterInfoLocation("let r =\n"+
                                        "   System.Math.Abs($0)", 3) // on the beginning of "System", not line!
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.FullCall``() =
         this.TestParameterInfoLocation("System.Math.Abs($0)", 0)
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.SpacesAfterParen``() =
         this.TestParameterInfoLocation("let a = Math.Sign( $-10  )", 8)
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.WithNamespace``() =
         this.TestParameterInfoLocation("let a = System.Threading.Interlocked.Exchange($", 8)
         
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterInfo.Locations.WithoutNamespace``() =
         this.TestParameterInfoLocation("let a = Interlocked.Exchange($", 8)
         
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Single.Locations.WithGenericArgs``() =
         this.TestParameterInfoLocation("Interlocked.Exchange<int>($", 0)
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.FunctionWithSpace``() =
         this.TestParameterInfoLocation("let a = sin 0$.0", 8) 
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.MethodCallWithoutParens``() =
         this.TestParameterInfoLocation("let n = Math.Sin 1$0.0", 8)
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.GenericCtorWithNamespace``() =
         this.TestParameterInfoLocation("let _ = new System.Collections.Generic.Dictionary<_, _>($)", 12) // on the beginning of "System" (not on "new")
         
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.GenericCtor``() =
         this.TestParameterInfoLocation("let _ = new Dictionary<_, _>($)", 12) // on the beginning of "System" (not on "new")
  
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     //This test verifies that ParamInfo location on a provided type with namespace that exposes static parameter that takes >1 argument works normally.
     member public this.``TypeProvider.Type.ParameterInfoLocation.WithNamespace`` () =
         this.TestParameterInfoLocation("type boo = N1.T<$",11,
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
  
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     //This test verifies that ParamInfo location on a provided type without the namespace that exposes static parameter that takes >1 argument works normally.
     member public this.``TypeProvider.Type.ParameterInfoLocation.WithOutNamespace`` () =
         this.TestParameterInfoLocation("open N1 \n"+"type boo = T<$",
             expectedPos = 11,
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
  
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact>]
     //This test verifies that no ParamInfo in a string for a provided type  that exposes static parameter that takes >1 argument works normally.
      //The intent here to make sure the ParamInfo is not shown when inside a string
     member public this.``TypeProvider.Type.Negative.InString`` () =
         this.TestParameterInfoNegative("type boo = \"N1.T<$\"",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact>]
     //This test verifies that no ParamInfo in a Comment for a provided type that exposes static parameter that takes >1 argument works normally.
     //The intent here to make sure the ParamInfo is not shown when inside a comment
     member public this.``TypeProvider.Type.Negative.InComment`` () =
@@ -837,35 +777,35 @@ type UsingMSBuild()  =
     // we *must* look at the previous line to find the location where NameRes info ends
     // so in these cases we can find the identifier and location of tooltip is beginning of it
     // (but in general, we don't search for it)
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.Multiline.IdentOnPrevLineWithGenerics``() =
         this.TestParameterInfoLocation("let d = Dictionary<_, option< int >>  \n" +
                                        "                ( $  )", 8) // on the "D" (line untestable)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.Multiline.IdentOnPrevLine``() =
         this.TestParameterInfoLocation("do Console.WriteLine\n" + 
                                        "        ($\"Multiline\")", 3)
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.Multiline.IdentOnPrevPrevLine``() =
         this.TestParameterInfoLocation("do Console.WriteLine\n" + 
                                        "        (  \n" +
                                        "          $ \"Multiline\")", 3)
              
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.GenericCtorWithoutNew``() =
         this.TestParameterInfoLocation("let d = System.Collections.Generic.Dictionary<_, option< int >>   ( $ )", 8) // on "S" - standard 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.Multiline.GenericTyargsOnTheSameLine``() =
         this.TestParameterInfoLocation("let dict3 = System.Collections.Generic.Dictionary<_, \n" +
                                        "                option< int>>( $ )", 12) // on "S" (beginning of "System")
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.Multiline.LongIdentSplit``() =
         this.TestParameterInfoLocation("let ll = new System.Collections.\n" +
                                        "                    Generic.List< _ > ($)", 13) // on "S" (beginning of "System")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Locations.OperatorTrick3``() =
         this.TestParameterInfoLocation
             ("let mutable n = null\n" + 
@@ -874,32 +814,31 @@ type UsingMSBuild()  =
     // A several cases that are tricky and we don't want to show anything
     // in the following cases, we may return a location of an operator (its ambiguous), but we don't want to show info about it!
     
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Negative.OperatorTrick1``() =
         this.TestParameterInfoNegative
             ("let fooo = 0\n" + 
              "             >($ 1 )") // this may be end of a generic args specification
                                        
-    [<Test>]
+    [<Fact>]
     member public this.``Single.Negative.OperatorTrick2``() =
         this.TestParameterInfoNegative
             ("let fooo = 0\n" + 
              "             <($ 1 )")
 
     /// No intellisense in comments/strings!
-    [<Test>]
+    [<Fact>]
     member public this.``Single.InString``() =        
         this.TestParameterInfoNegative
             ("let s = \"System.Console.WriteLine($)\"")
 
     /// No intellisense in comments/strings!
-    [<Test>]
+    [<Fact>]
     member public this.``Single.InComment``() =        
         this.TestParameterInfoNegative
             ("// System.Console.WriteLine($)")
   
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``Regression.LocationOfParams.AfterQuicklyTyping.Bug91373``() =        
         let code = [ "let f x = x   "
                      "let f1 y = y  "
@@ -917,14 +856,13 @@ type UsingMSBuild()  =
                      "let z = f(f1( " ] )
         MoveCursorToEndOfMarker(file, "f1(")
         let info = GetParameterInfoAtCursor file // this will fall back to using the name environment, which is stale, but sufficient to look up the call to 'f1'
-        Assert.IsTrue(info.IsSome, "expected parameter info")
+        Assert.True(info.IsSome, "expected parameter info")
         let info = info.Value
         AssertEqual("f1", info.GetName(0))
         // note about (5,0): service.fs adds three lines of empty text to the end of every file, so it reports the location of 'end of file' as first the char, 3 lines past the last line of the file
         AssertEqual([|(2,10);(2,12);(2,13);(3,0)|], info.GetParameterLocations())
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member this.``LocationOfParams.AfterQuicklyTyping.CallConstructor``() =        
         let code = [ "type Foo() = class end" ]
         let (_, _, file) = this.CreateSingleFileProject(code)
@@ -940,7 +878,7 @@ type UsingMSBuild()  =
         MoveCursorToEndOfMarker(file, "new Foo(")
         // Note: no TakeCoffeeBreak(this.VS)
         let info = GetParameterInfoAtCursor file // this will fall back to using the name environment, which is stale, but sufficient to look up the call to 'f1'
-        Assert.IsTrue(info.IsSome, "expected parameter info")
+        Assert.True(info.IsSome, "expected parameter info")
         let info = info.Value
         AssertEqual("Foo", info.GetName(0))
         // note about (4,0): service.fs adds three lines of empty text to the end of every file, so it reports the location of 'end of file' as first the char, 3 lines past the last line of the file
@@ -950,7 +888,7 @@ type UsingMSBuild()  =
 (*
 This does not currently work, because the 'fallback to name environment' does weird QuickParse-ing and mangled the long id "Bar.Foo".
 We really need to rewrite some code paths here to use the real parse tree rather than QuickParse-ing.
-    [<Test>]
+    [<Fact>]
     member this.``ParameterInfo.LocationOfParams.AfterQuicklyTyping.CallConstructorViaLongId.Bug94333``() =        
         let solution = CreateSolution(this.VS)
         let project = CreateProject(solution,"testproject")
@@ -974,7 +912,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         AssertEqual([|(1,14);(1,21);(1,21);(4,0)|], info.GetParameterLocations())
 *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterInfo.NamesOfParams``() =
         let testLines = [
             "type Foo ="
@@ -985,7 +923,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let (_, _, file) = this.CreateSingleFileProject(testLines)
         MoveCursorToStartOfMarker(file, "0")
         let info = GetParameterInfoAtCursor file
-        Assert.IsTrue(info.IsSome, "expected parameter info")
+        Assert.True(info.IsSome, "expected parameter info")
         let info = info.Value
         let names = info.GetParameterNames()
         AssertEqual([| null; null; "d"; "e"; "c" |], names)
@@ -1019,7 +957,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let (_, _, file) = this.CreateSingleFileProject(testLines, references = references)
         MoveCursorToEndOfMarker(file, cursorPrefix)
         let info = GetParameterInfoAtCursor file
-        Assert.IsTrue(info.IsSome, "expected parameter info")
+        Assert.True(info.IsSome, "expected parameter info")
         let info = info.Value
         AssertEqual(expectedLocs, info.GetParameterLocations()) 
 
@@ -1040,17 +978,17 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let (_, _, file) = this.CreateSingleFileProject(testLines, references = references)
         MoveCursorToEndOfMarker(file, cursorPrefix)
         let info = GetParameterInfoAtCursor file
-        Assert.IsTrue(info.IsNone, "expected no parameter info for this particular test, though it would be nice if this has started to work")
+        Assert.True(info.IsNone, "expected no parameter info for this particular test, though it would be nice if this has started to work")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Case1``() =        
         this.TestParameterInfoLocationOfParams("""^System.Console.WriteLine^(^"hel$lo"^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Case2``() =        
         this.TestParameterInfoLocationOfParams("""^System.Console.WriteLine^   (^  "hel$lo {0}"  ,^ "Brian" ^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Case3``() =        
         this.TestParameterInfoLocationOfParams(
             """^System.Console.WriteLine^  
@@ -1058,11 +996,11 @@ We really need to rewrite some code paths here to use the real parse tree rather
                         "hel$lo {0}"  ,^ 
                         "Brian" ^)  """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Case4``() =        
         this.TestParameterInfoLocationOfParams("""^System.Console.WriteLine^   (^  "hello {0}"  ,^ ("tuples","don't $ confuse it") ^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterInfo.LocationOfParams.Bug112688``() =
         let testLines = [
             "let f x y = ()"
@@ -1078,7 +1016,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let info = GetParameterInfoAtCursor file
         ()
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterInfo.LocationOfParams.Bug112340``() =
         let testLines = [
             """let a = typeof<N."""
@@ -1089,12 +1027,11 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let info = GetParameterInfoAtCursor file
         ()
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Regression.LocationOfParams.Bug91479``() =        
         this.TestParameterInfoLocationOfParams("""let z = fun x -> x + ^System.Int16.Parse^(^$ """, markAtEOF=true)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Attributes.Bug230393``() =        
         this.TestParameterInfoLocationOfParams("""
             let paramTest((strA : string),(strB : string)) =
@@ -1105,30 +1042,30 @@ We really need to rewrite some code paths here to use the real parse tree rather
             type RMB
         """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InfixOperators.Case1``() =        
         // infix operators like '+' do not give their own param info
         this.TestParameterInfoLocationOfParams("""^System.Console.WriteLine^(^"" + "$"^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InfixOperators.Case2``() =        
         // infix operators like '+' do give param info when used as prefix ops
         this.TestParameterInfoLocationOfParams("""System.Console.WriteLine((^+^)(^$3^)(4))""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.GenericMethodExplicitTypeArgs()``() =        
         this.TestParameterInfoLocationOfParams("""
             type T<'a> =
                 static member M(x:int, y:string) = x + y.Length
             let x = ^T<int>.M^(^1,^ $"test"^)    """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InsideAMemberOfAType``() =        
         this.TestParameterInfoLocationOfParams("""
             type Widget(z) = 
                 member x.a = (1 <> ^System.Int32.Parse^(^"$"^)) """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InsidePropertyGettersAndSetters.Case1``() =        
         this.TestParameterInfoLocationOfParams("""
             type Widget(z) = 
@@ -1138,7 +1075,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 member x.P2 with get() = System.Int32.Parse("")
                 member x.P2 with set(z) = System.Int32.Parse("") |> ignore """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InsidePropertyGettersAndSetters.Case2``() =        
         this.TestParameterInfoLocationOfParams("""
             type Widget(z) = 
@@ -1148,7 +1085,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 member x.P2 with get() = System.Int32.Parse("")
                 member x.P2 with set(z) = System.Int32.Parse("") |> ignore """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InsidePropertyGettersAndSetters.Case3``() =        
         this.TestParameterInfoLocationOfParams("""
             type Widget(z) = 
@@ -1158,7 +1095,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 member x.P2 with get() = ^System.Int32.Parse^(^"$"^)
                 member x.P2 with set(z) = System.Int32.Parse("") |> ignore """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InsidePropertyGettersAndSetters.Case4``() =        
         this.TestParameterInfoLocationOfParams("""
             type Widget(z) = 
@@ -1168,48 +1105,46 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 member x.P2 with get() = System.Int32.Parse("")
                 member x.P2 with set(z) = ^System.Int32.Parse^(^"$"^) |> ignore """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.InsideObjectExpression``() =        
         this.TestParameterInfoLocationOfParams("""
                 let _ = { new ^System.Object^(^$^) with member _.GetHashCode() = 2}""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Nested1``() =        
         this.TestParameterInfoLocationOfParams("""System.Console.WriteLine("hello {0}"  , ^sin^  (^4$2.0 ^) )""")
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.MatchGuard``() =        
         this.TestParameterInfoLocationOfParams("""match [1] with | [x] when ^box^(^$x^) <> null -> ()""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Nested2``() =        
         this.TestParameterInfoLocationOfParams("""System.Console.WriteLine("hello {0}"  , ^sin^  4^$2.0^ )""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Generics1``() =        
         this.TestParameterInfoLocationOfParams("""
             let f<'T,'U>(x:'T, y:'U) = (y,x)
             let r = ^f^<int,string>(^4$2,^""^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Generics2``() =        
         this.TestParameterInfoLocationOfParams("""let x = ^System.Collections.Generic.Dictionary^<int,int>(^42,^n$ull^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Unions1``() =        
         this.TestParameterInfoLocationOfParams("""
             type MyDU =
                 | FOO of int * string
             let r = ^FOO^(^42,^"$"^) """)
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.EvenWhenOverloadResolutionFails.Case1``() =        
         this.TestParameterInfoLocationOfParams("""let a = new ^System.IO.FileStream^(^$^)""")
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.EvenWhenOverloadResolutionFails.Case2``() =        
         this.TestParameterInfoLocationOfParams("""
             open System.Collections.Generic
@@ -1217,8 +1152,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let l = List<int>([||])
             ^l.Aggregate^(^$^) // was once a bug""")
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.BY_DESIGN.WayThatMismatchedParensFailOver.Case1``() =        
         // when only one 'statement' after the mismatched parens after a comma, the comma swallows it and it becomes a badly-indented
         // continuation of the expression from the previous line
@@ -1229,8 +1163,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             ^c.M^(^1,^2,^3,^ $
             c.M(1,2,3,4)""", markAtEOF=true)
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.BY_DESIGN.WayThatMismatchedParensFailOver.Case2``() =        
         // when multiple 'statements' after the mismatched parens after a comma, the parser sees a single argument to the method that
         // is a statement sequence, e.g. a bunch of discarded expressions.  That is, 
@@ -1253,18 +1186,17 @@ We really need to rewrite some code paths here to use the real parse tree rather
             c.M(1,2,3,4)
             c.M(1,2,3,4)""", markAtEOF=true)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Tuples.Bug91360.Case1``() =        
         this.TestParameterInfoLocationOfParams("""
             ^System.Console.WriteLine^(^ (4$2,43) ^) // oops""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.Tuples.Bug91360.Case2``() =        
         this.TestParameterInfoLocationOfParams("""
             ^System.Console.WriteLine^(^ $(42,43) ^) // oops""")
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.Tuples.Bug123219``() =
         this.TestParameterInfoLocationOfParams("""
             type Expr = | Num of int
@@ -1274,14 +1206,14 @@ We really need to rewrite some code paths here to use the real parse tree rather
  
             ^x.M1^(^(1,$ """, markAtEOF=true)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.UnmatchedParens.Bug91609.OtherCases.Open``() =        
         this.TestParameterInfoLocationOfParams("""
             let arr = Array.create 4 1
             arr.[1] <- ^System.Int32.Parse^(^$
             open^ System""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.UnmatchedParens.Bug91609.OtherCases.Module``() =        
         this.TestParameterInfoLocationOfParams("""
             let arr = Array.create 4 1
@@ -1289,7 +1221,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             ^module Foo =
                 let x = 42""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.UnmatchedParens.Bug91609.OtherCases.Namespace``() =        
         this.TestParameterInfoLocationOfParams("""
             namespace Foo
@@ -1298,7 +1230,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 arr.[1] <- ^System.Int32.Parse^(^$
             namespace^ Other""")
 
-    [<Test>]
+    [<Fact>]
     member this.``LocationOfParams.InheritsClause.Bug192134``() =        
         this.TestParameterInfoLocationOfParams("""
             type B(x : int) = 
@@ -1306,7 +1238,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             type A() =
                inherit ^B^(^1$,^2^)""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.ThisOnceAsserted``() =        
             this.TestNoParameterInfo("""
                 module CSVTypeProvider
@@ -1325,7 +1257,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
 
                 match types |> Array.tryFind (fun ty -> ty.Name = typeName^) with _ -> ()""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.ThisOnceAssertedToo``() =        
             this.TestNoParameterInfo("""
                 let readString() =
@@ -1337,7 +1269,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                             while true do
                                 ($)  """)
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.UnmatchedParensBeforeModuleKeyword.Bug245850.Case2a``() =        
         this.TestParameterInfoLocationOfParams("""
             module Repro =
@@ -1391,92 +1323,84 @@ We really need to rewrite some code paths here to use the real parse tree rather
             this.TestParameterInfoLocationOfParams (allText, markAtEOF=needMarkAtEnd, ?additionalReferenceAssemblies=additionalReferenceAssemblies)
         )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.TypeProviders.Basic``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ 42 ^>""", 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.TypeProviders.BasicNamed``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ ParamIgnored=42 ^>""", 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.TypeProviders.Prefix0``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ $ """, // missing all params, just have <
             markAtEnd = true,
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.TypeProviders.Prefix1``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ 42 """, // missing >
             markAtEnd = true,
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.TypeProviders.Prefix1Named``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ ParamIgnored=42 """, // missing >
             markAtEnd = true,
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.TypeProviders.Prefix2``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ """, // missing last param
             markAtEnd = true,
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.TypeProviders.Prefix2Named1``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ ParamIgnored= """, // missing last param after name with equals
             markAtEnd = true,
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``LocationOfParams.TypeProviders.Prefix2Named2``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ ParamIgnored """, // missing last param after name sans equals
             markAtEnd = true,
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.TypeProviders.Negative1``() =       
             this.TestNoParameterInfo("""
                 type D = ^System.Collections.Generic.Dictionary^<^ in$t, int ^>""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.TypeProviders.Negative2``() =       
             this.TestNoParameterInfo("""
                 type D = ^System.Collections.Generic.List^<^ in$t ^>""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.TypeProviders.Negative3``() =       
             this.TestNoParameterInfo("""
                 let i = 42
                 let b = ^i^<^ 4$2""")
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.TypeProviders.Negative4.Bug181000``() =       
             this.TestNoParameterInfo("""
                 type U = ^N1.T^<^ "foo",^ 42 ^>$  """,   // when the caret is right of the '>', we should not report any param info
                 additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
+    [<Fact>]
     member public this.``LocationOfParams.TypeProviders.BasicWithinExpr``() =
             this.TestNoParameterInfo("""
                 let f() =
@@ -1484,8 +1408,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                     r    """, 
                 additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.TypeProviders.BasicWithinExpr.DoesNotInterfereWithOuterFunction``() =        
         this.TestParameterInfoLocationOfParams("""
             let f() =
@@ -1493,36 +1416,31 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 r    """, 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.TypeProviders.Bug199744.ExcessCommasShouldNotAssertAndShouldGiveInfo.Case1``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ 42,^ ,^ ^>""", 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.TypeProviders.Bug199744.ExcessCommasShouldNotAssertAndShouldGiveInfo.Case2``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ "fo$o",^ ,^ ^>""", 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``LocationOfParams.TypeProviders.Bug199744.ExcessCommasShouldNotAssertAndShouldGiveInfo.Case3``() =        
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             type U = ^N1.T^<^ ,^$ ^>""", 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``LocationOfParams.TypeProviders.StaticParametersAtConstructorCallSite``() =
         this.TestParameterInfoLocationOfParamsWithVariousSurroundingContexts("""
             let x = new ^N1.T^<^ "fo$o",^ 42 ^>()""", 
             additionalReferenceAssemblies = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.FormatOfNamesOfSystemTypes``() =
         let code = ["""type TTT = N1.T< "foo", ParamIgnored=42 > """]
         let references = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")]
@@ -1530,7 +1448,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let gpatcc = GlobalParseAndTypeCheckCounter.StartNew(this.VS)
         MoveCursorToEndOfMarker(file,"foo")
         let methodGroup = GetParameterInfoAtCursor file
-        Assert.IsTrue(methodGroup.IsSome, "expected parameter info")
+        Assert.True(methodGroup.IsSome, "expected parameter info")
         let methodGroup = methodGroup.Value
         let actualDisplays =
             [ for i = 0 to methodGroup.GetCount() - 1 do
@@ -1541,7 +1459,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         AssertEqual(expected, actualDisplays)
         gpatcc.AssertExactly(0,0)
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterNamesInFunctionsDefinedByLetBindings``() = 
         let useCases = 
             [
@@ -1583,13 +1501,13 @@ We really need to rewrite some code paths here to use the real parse tree rather
             MoveCursorToEndOfMarker(file, marker)
             let methodGroup = GetParameterInfoAtCursor file
             
-            Assert.IsTrue(methodGroup.IsSome, "expected parameter info")
+            Assert.True(methodGroup.IsSome, "expected parameter info")
             let methodGroup = methodGroup.Value
 
-            Assert.AreEqual(1, methodGroup.GetCount(), "Only one function expected")            
+            Assert.Equal(1, methodGroup.GetCount())            
 
             let expectedParamsCount = List.length expectedParams
-            Assert.AreEqual(expectedParamsCount, methodGroup.GetParameterCount(0), sprintf "%d parameters expected" expectedParamsCount)
+            Assert.Equal(expectedParamsCount, methodGroup.GetParameterCount(0))
             
             let actualParams = [ for i = 0 to (expectedParamsCount - 1) do yield methodGroup.GetParameterInfo(0, i) ]               
             let ok = 
@@ -1600,15 +1518,15 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 printfn "==Parameters don't match=="
                 printfn "Expected parameters %A" expectedParams
                 printfn "Actual parameters %A" actualParams
-                Assert.Fail()
+                failwith "Parameters don't match"
                   
     (* Tests for multi-parameterinfos ------------------------------------------------------------------ *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterInfo.ArgumentsWithParamsArrayAttribute``() =
         let content = """let _ = System.String.Format("",(*MARK*))"""
         let methodTip = this.GetMethodListForAMethodTip(content, "(*MARK*)")
-        Assert.IsTrue(methodTip.IsSome, "expected parameter info")
+        Assert.True(methodTip.IsSome, "expected parameter info")
         let methodTip = methodTip.Value
 
         let overloadWithTwoParamsOpt = 
@@ -1627,16 +1545,16 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 )
             |> Seq.tryFind(fun (i, _) -> i = 2)
         match overloadWithTwoParamsOpt with
-        | Some(_, [_;(_name, display, _description)]) -> Assert.IsTrue(display.Contains("[<System.ParamArray>] args"))
+        | Some(_, [_;(_name, display, _description)]) -> Assert.True(display.Contains("[<System.ParamArray>] args"))
         | x -> Assert.Fail(sprintf "Expected overload not found, current result %A" x)
 
     (* DotNet functions for multi-parameterinfo tests -------------------------------------------------- *)
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.DotNet.StaticMethod``() =
         let fileContents = """System.Console.WriteLine("Today is {0:dd MMM yyyy}",(*Mark*)System.DateTime.Today)"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["string";"obj"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.DotNet.StaticMethod.WithinClassMember``() =
         let fileContents = """
             type Widget(z) = 
@@ -1646,18 +1564,17 @@ We really need to rewrite some code paths here to use the real parse tree rather
             45"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["string";"System.Globalization.NumberStyles"])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Multi.DotNet.StaticMethod.WithinLambda``() =
         let fileContents = """let z = fun x -> x + System.Int16.Parse("",(*Mark*)"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["string";"System.Globalization.NumberStyles"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.DotNet.StaticMethod.WithinLambda2``() = 
         let fileContents = "let _ = fun file -> new System.IO.FileInfo((*Mark*)"
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["string"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.DotNet.InstanceMethod``() = 
         let fileContents = """
             let s = "Hello"
@@ -1665,18 +1582,17 @@ We really need to rewrite some code paths here to use the real parse tree rather
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["int";"int"])
 
     (* Common functions for multi-parameterinfo tests -------------------------------------------------- *)
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Multi.DotNet.Constructor``() = 
         let fileContents = "let _ = new System.DateTime(2010,12,(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["int";"int";"int"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Constructor.WithinObjectExpression``() = 
         let fileContents = "let _ = { new System.Object((*Mark*)) with member _.GetHashCode() = 2}"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",[])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Function.InTheClassMember``() = 
         let fileContents = """
             type Foo() = 
@@ -1687,14 +1603,14 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 member this.A(a : string, b:int) = ()"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int";"int"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.ParamAsTupleType``() = 
         let fileContents = """
             let tuple((a : int, b : int), c : int) = a * b + c
             let result = tuple((1, 2)(*Mark*), 3)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int * int";"int"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.ParamAsCurryType``() = 
         let fileContents = """
             let multi (x : float) (y : float) = 0
@@ -1702,7 +1618,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let rtnValue = sum(multi (1.0(*Mark*)) 3.0, 5)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["float"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.MethodInMatchCause``() = 
         let fileContents = """
             let rec f l = 
@@ -1711,8 +1627,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                     | x :: xs -> f xs"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["string";"obj"])
 
-    [<Test>]
-    [<Ignore("93945 - No param info shown on the Indexer Property")>]
+    [<Fact(Skip = "93945 - No param info shown on the Indexer Property")>]
     member public this.``Regression.Multi.IndexerProperty.Bug93945``() = 
         let fileContents = """
             type Year2(year : int) =
@@ -1729,8 +1644,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let randomDay = O'seven.[12,(*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int";"int"]])
 
-    [<Test>]
-    [<Ignore("93188 - No param info shown in the Attribute method")>]
+    [<Fact(Skip = "93188 - No param info shown in the Attribute method")>]
     member public this.``Regression.Multi.ExplicitAnnotate.Bug93188``() = 
         let fileContents = """
             type LiveAnimalAttribute(a : int, b: string) =
@@ -1740,7 +1654,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             type Wombat() = class end"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int";"string"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Function.WithRecordType``() = 
         let fileContents = """
             type Vector =
@@ -1749,7 +1663,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             foo(12, { X = 10.0; Y = (*Mark*)20.0; Z = 30.0 })"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int";"Vector"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Function.AsParameter``() = 
         let fileContents = """
             let isLessThanZero x = (x < 0)
@@ -1761,15 +1675,14 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let _ = Option.get(containsNegativeNumbers [6; 20; (*Mark*)8; 45; 5])"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int list"]])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Multi.Function.WithOptionType``() = 
         let fileContents = """
             let foo( a : int option, b : string ref) = 0
             let _ = foo(Some(12),(*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int option";"string ref"]])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Function.WithOptionType2``() = 
         let fileContents = """
             let multi (x : float) (y : float) = x * y
@@ -1778,8 +1691,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let rtnOption = options(Some(sum(1, 3)), (*Mark*)Some(multi 3.1 5.0)) """
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int option";"float option"]])
 
-    [<Test>]
-    [<Ignore("https://github.com/dotnet/fsharp/issues/6166")>]
+    [<Fact(Skip = "https://github.com/dotnet/fsharp/issues/6166")>]
     member public this.``Multi.Function.WithRefType``() = 
         let fileContents = """
             let foo( a : int ref, b : string ref) = 0
@@ -1788,12 +1700,12 @@ We really need to rewrite some code paths here to use the real parse tree rather
 
     (* Overload list/Adjust method's param for multi-parameterinfo tests ------------------------------ *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.OverloadMethod.OrderedParameters``() = 
         let fileContents = "new System.DateTime(2000,12,(*Mark*)"
         this.VerifyParameterInfoOverloadMethodIndex(fileContents,"(*Mark*)",3(*The fourth method*),["int";"int";"int"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Overload.WithSameParameterCount``() = 
         let fileContents = """
             type Foo() = 
@@ -1803,7 +1715,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             foo.A1(1,1,(*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int";"int";"string";"bool"];["int";"string";"int";"bool"]])
         
-    [<Test>]
+    [<Fact>]
     member public this.``ExtensionMethod.Overloads``() = 
         let fileContents = """
             module MyCode =
@@ -1819,8 +1731,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             foo.Method((*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["string"];["int"]])
  
-    [<Test>]
-    [<Ignore("Parameterinfo not retrieved properly for indexed properties by test infra")>]
+    [<Fact(Skip = "Parameterinfo not retrieved properly for indexed properties by test infra")>]
     member public this.``ExtensionProperty.Overloads``() = 
         let fileContents = """
             module MyCode =
@@ -1838,68 +1749,66 @@ We really need to rewrite some code paths here to use the real parse tree rather
         
     (* Generic functions for multi-parameterinfo tests ------------------------------------------------ *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Generic.ExchangeInt``() = 
         let fileContents = "System.Threading.Interlocked.Exchange<int>(123,(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["byref<int>";"int"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Generic.Exchange.``() = 
         let fileContents = "System.Threading.Interlocked.Exchange(12.0,(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["byref<float>";"float"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Generic.ExchangeUnder``() = 
         let fileContents = "System.Threading.Interlocked.Exchange<_> (obj,(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["byref<obj>";"obj"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.Generic.Dictionary``() = 
         let fileContents = "System.Collections.Generic.Dictionary<_, option<int>>(12,(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["int";"System.Collections.Generic.IEqualityComparer<obj>"])
 
-    [<Test>]
-    [<Ignore("95862 - [Unittests] parseInfo(TypeCheckResult.TypeCheckInfo).GetMethods cannot get MethodOverloads")>]
+    [<Fact(Skip = "95862 - [Unittests] parseInfo(TypeCheckResult.TypeCheckInfo).GetMethods cannot get MethodOverloads")>]
     member public this.``Multi.Generic.HashSet``() = 
         let fileContents = "System.Collections.Generic.HashSet<int>({ 1 ..12 },(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["Seq<'a>";"System.Collections.Generic.IEqualityComparer<'a>"])
     
-    [<Test>]
-    [<Ignore("95862 - [Unittests] parseInfo(TypeCheckResult.TypeCheckInfo).GetMethods cannot get MethodOverloads")>]
+    [<Fact(Skip = "95862 - [Unittests] parseInfo(TypeCheckResult.TypeCheckInfo).GetMethods cannot get MethodOverloads")>]
     member public this.``Multi.Generic.SortedList``() = 
         let fileContents = "System.Collections.Generic.SortedList<_,option<int>> (12,(*Mark*)"
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["int";"System.Collections.Generic.IComparer<'TKey>"])
     
     (* No Param Info Shown for multi-parameterinfo tests ---------------------------------------------- *)
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParameterInfo.Multi.NoParameterInfo.InComments``() = 
         let fileContents = "//let _ = System.Object((*Mark*))"
         this.VerifyNoParameterInfoAtStartOfMarker(fileContents,"(*Mark*)")
     
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.NoParameterInfo.InComments2``() = 
         let fileContents = """(*System.Console.WriteLine((*Mark*)"Test on Fsharp style comments.")*)"""
         this.VerifyNoParameterInfoAtStartOfMarker(fileContents,"(*Mark*)")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.NoParameterInfo.OnFunctionDeclaration``() = 
         let fileContents = "let Foo(x : int, (*Mark*)b : string) = ()"
         this.VerifyNoParameterInfoAtStartOfMarker(fileContents,"(*Mark*)")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.NoParameterInfo.WithinString``() = 
         let fileContents = """let s = "new System.DateTime(2000,12(*Mark*)" """
         this.VerifyNoParameterInfoAtStartOfMarker(fileContents,"(*Mark*)")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.NoParameterInfo.OnProperty``() = 
         let fileContents = """
             let s = "Hello"
             let _ = s.Length(*Mark*)"""
         this.VerifyNoParameterInfoAtStartOfMarker(fileContents,"(*Mark*)")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multi.NoParameterInfo.OnValues``() = 
         let fileContents = """
             type Foo = class
@@ -1911,13 +1820,13 @@ We really need to rewrite some code paths here to use the real parse tree rather
 
     (* Regression tests/negative tests for multi-parameterinfos --------------------------------------- *) 
     // To be added when the bugs are fixed...
-    [<Test>]
+    [<Fact>]
     //[<Ignore("90832 - [ParameterInfo] No Parameter Info shown on string parameter with operator")>]
     member public this.``Regression.ParameterWithOperators.Bug90832``() = 
         let fileContents = """System.Console.WriteLine("This(*Mark*) is a" + " bug.")"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["string"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.OptionalArguments.Bug4042``() = 
         let fileContents = """
             module ParameterInfo
@@ -1932,7 +1841,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let tt = TT((*Mark*)"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["int";"int"]])
 
-    [<Test>]
+    [<Fact>]
     //[<Ignore("90798 - [ParameterInfo] No param info when typing ( for the first time")>]
     member public this.``Regression.ParameterFirstTypeOpenParen.Bug90798``() = 
         let fileContents = """
@@ -1942,7 +1851,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let p = 10"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["'Arg -> Async<'T>"]])
 
-    [<Test>]   
+    [<Fact>]   
     // regression test for bug 3878: no parameter info triggered by "("
     member public this.``Regression.NoParameterInfoTriggeredByOpenBrace.Bug3878``() = 
         let fileContents = """
@@ -1954,7 +1863,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let y = 1"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",[""])
 
-    [<Test>]   
+    [<Fact>]   
     // regression test for bug 4495 : Should alway sort method lists in order of argument count
     member public this.``Regression.MethodSortedByArgumentCount.Bug4495.Case1``() = 
         let fileContents = """
@@ -1964,7 +1873,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
             let m = a1.GetType("System.Decimal").GetConstructor((*Mark*)null)"""
         this.VerifyParameterInfoOverloadMethodIndex(fileContents,"(*Mark*)",0,["System.Type array"])
 
-    [<Test>]   
+    [<Fact>]   
     member public this.``Regression.MethodSortedByArgumentCount.Bug4495.Case2``() = 
         let fileContents = """
             module ParameterInfo
@@ -1976,8 +1885,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
                                                                                 "System.Type array";
                                                                                 "System.Reflection.ParameterModifier array"])
 
-    [<Test>]   
-    [<Ignore("Bug 95862")>]
+    [<Fact(Skip = "Bug 95862")>]   
     member public this.``BasicBehavior.WithReference``() = 
         let fileContents = """
             open System.ServiceModel
@@ -1991,22 +1899,20 @@ We really need to rewrite some code paths here to use the real parse tree rather
         let expected = ["System.Type";"System.Uri []"]
         AssertMethodGroupContain(methodstr,expected)
 
-    [<Test>]   
+    [<Fact>]   
     member public this.``BasicBehavior.CommonFunction``() = 
         let fileContents = """
             let f(x) = 1
             f((*Mark*))"""
         this.VerifyParameterInfoAtStartOfMarker(fileContents,"(*Mark*)",[["'a"]])
 
-    [<Test>]   
+    [<Fact>]   
     member public this.``BasicBehavior.DotNet.Static``() = 
         let fileContents = """System.String.Format((*Mark*)"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Mark*)",["string";"obj array"])
 
 (*------------------------------------------IDE Query automation start -------------------------------------------------*)
-    [<Test>]   
-    [<Category("Query")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // ParamInfo works normally for calls as query operator arguments
     // works fine In nested queries
     member public this.``Query.InNestedQuery``() = 
@@ -2025,11 +1931,9 @@ We really need to rewrite some code paths here to use the real parse tree rather
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Marker1*)",["obj"],queryAssemblyRefs)
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Marker2*)",["string";"obj array"],queryAssemblyRefs)
 
-    [<Test>]   
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // ParamInfo works normally for calls as query operator arguments
     // ParamInfo Still works when an error exists
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.WithErrors``() = 
         let fileContents = """
         let tuples = [ (1, 8, 9); (56, 45, 3)] 
@@ -2041,10 +1945,8 @@ We really need to rewrite some code paths here to use the real parse tree rather
                 }"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Marker*)",["obj"],queryAssemblyRefs)
 
-    [<Test>]   
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // ParamInfo works normally for calls as query operator arguments
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.OperatorWithParentheses``() = 
         let fileContents = """
         type Product() =
@@ -2070,8 +1972,7 @@ We really need to rewrite some code paths here to use the real parse tree rather
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Marker1*)",[],queryAssemblyRefs)
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Marker2*)",[],queryAssemblyRefs)
 
-    [<Test>]   
-    [<Category("Query")>]
+    [<Fact>]   
     // ParamInfo works normally for calls as query operator arguments
     // ParamInfo Still works when there is an optional argument
     member public this.``Query.OptionalArgumentsInQuery``() = 
@@ -2094,11 +1995,9 @@ We really need to rewrite some code paths here to use the real parse tree rather
             }"""
         this.VerifyParameterInfoContainedAtStartOfMarker(fileContents,"(*Marker*)",["int";"int"],queryAssemblyRefs)
 
-    [<Test>]   
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // ParamInfo works normally for calls as query operator arguments
     // ParamInfo Still works when there are overload methods with the same param count
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.OverloadMethod.InQuery``() = 
         let fileContents = """
         let numbers = [ 1;2; 8; 9; 15; 23; 3; 42; 4;0; 55;]
@@ -2118,6 +2017,5 @@ We really need to rewrite some code paths here to use the real parse tree rather
 
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickInfo.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickInfo.fs
index 1d62dd3c399..1df4a6a6413 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickInfo.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickInfo.fs
@@ -3,21 +3,20 @@
 namespace Tests.LanguageService.QuickInfo
 
 open System
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
 open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
+open Xunit
 
 [<AutoOpen>]
 module QuickInfoStandardSettings = 
     let standard40AssemblyRefs  = [ "System"; "System.Core"; "System.Numerics" ]
     let queryAssemblyRefs = [ "System.Xml.Linq"; "System.Core" ]
 
-[<TestFixture>]
-[<Category "LanguageService">] 
 type UsingMSBuild() = 
     inherit LanguageServiceBaseTests()
 
@@ -41,8 +40,8 @@ type UsingMSBuild() =
     let checkTooltip expected ((tooltip, span : TextSpan), (row, col)) = 
         AssertContains(tooltip, expected)
         // cursor should be inside the span
-        Assert.IsTrue(row = (span.iStartLine + 1) && row = (span.iEndLine + 1), "Cursor should be one the same line with the tooltip span")
-        Assert.IsTrue(col >= span.iStartIndex && col <= span.iEndIndex, "Cursor should be located inside the span")
+        Assert.True(row = (span.iStartLine + 1) && row = (span.iEndLine + 1), "Cursor should be one the same line with the tooltip span")
+        Assert.True(col >= span.iStartIndex && col <= span.iEndIndex, "Cursor should be located inside the span")
 
 
 //    (* Tests for QuickInfos ---------------------------------------------------------------- *)
@@ -118,7 +117,7 @@ type UsingMSBuild() =
         let tooltip = time1 GetQuickInfoAtCursor file "Time of first tooltip"
         AssertContainsInOrder(tooltip, expectedExactOrder)
 
-    [<Test>]
+    [<Fact>]
     member public this.``NestedTypesOrder``() = 
         this.VerifyOrderOfNestedTypesInQuickInfo(
             source = "type t = System.Runtime.CompilerServices.RuntimeHelpers(*M*)",
@@ -126,7 +125,7 @@ type UsingMSBuild() =
             expectedExactOrder = ["GetHashCode"; "GetObjectValue"]
             )
     
-    [<Test>]
+    [<Fact>]
     member public this.``Operators.TopLevel``() =
         let source = """
             /// tooltip for operator
@@ -137,10 +136,10 @@ type UsingMSBuild() =
             code = source,
             marker = "== \"\"",
             atStart = true,
-            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.IsTrue(text.Contains "tooltip for operator"))
+            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.True(text.Contains "tooltip for operator"))
             )
             
-    [<Test>]
+    [<Fact>]
     member public this.``Operators.Member``() =
         let source = """
             type U = U
@@ -153,10 +152,10 @@ type UsingMSBuild() =
             code = source,
             marker = "++ U",
             atStart = true,
-            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.IsTrue(text.Contains "tooltip for operator"))
+            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.True(text.Contains "tooltip for operator"))
             )
     
-    [<Test>]
+    [<Fact>]
     member public this.``QuickInfo.HiddenMember``() =
         // Tooltips showed hidden members - #50
         let source = """
@@ -174,10 +173,10 @@ type UsingMSBuild() =
             code = source,
             marker = "ypeU =",
             atStart = true,
-            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.IsFalse(text.Contains "member _Print"))
+            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.False(text.Contains "member _Print"))
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``QuickInfo.ObsoleteMember``() =
         // Tooltips showed obsolete members - #50
         let source = """
@@ -193,11 +192,10 @@ type UsingMSBuild() =
             code = source,
             marker = "ypeU =",
             atStart = true,
-            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.IsFalse(text.Contains "member Print1"))
+            f = (fun ((text, _), _) -> printfn "actual %s" text; Assert.False(text.Contains "member Print1"))
             )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``QuickInfo.HideBaseClassMembersTP``() =
         let fileContents = "type foo = HiddenMembersInBaseClass.HiddenBaseMembersTP(*Marker*)"
         
@@ -207,7 +205,7 @@ type UsingMSBuild() =
             expected = "type HiddenBaseMembersTP =\n  inherit TPBaseTy",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
-    [<Test>]
+    [<Fact>]
     member public this.``QuickInfo.OverridenMethods``() =
         let source = """
             type A() =
@@ -231,10 +229,10 @@ type UsingMSBuild() =
                     code = source,
                     marker = marker,
                     atStart = false,
-                    f = (fun ((text : string, _), _) -> printfn "expected %s, actual %s" expected text; Assert.IsTrue (text.Contains(expected)))
+                    f = (fun ((text : string, _), _) -> printfn "expected %s, actual %s" expected text; Assert.True (text.Contains(expected)))
                 )
 
-    [<Test>]
+    [<Fact>]
     member public this.``QuickInfoForQuotedIdentifiers``() =
         let source = """
             /// The fff function
@@ -246,7 +244,7 @@ type UsingMSBuild() =
         for i = 1 to (identifier.Length - 1) do
             let marker = "+ " + (identifier.Substring(0, i))
             this.CheckTooltip (source, marker, false, checkTooltip "gg gg")
-    [<Test>]
+    [<Fact>]
     member public this.``QuickInfoSingleCharQuotedIdentifier``() = 
         let source = """
         let ``x`` = 10
@@ -254,7 +252,7 @@ type UsingMSBuild() =
         """
         this.CheckTooltip(source, "x``|>", true, checkTooltip "x")
 
-    [<Test>]
+    [<Fact>]
     member public this.QuickInfoForTypesWithHiddenRepresentation() =
         let source = """
             let x = Async.AsBeginEnd
@@ -277,9 +275,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
 
         this.CheckTooltip(source, "Asyn", false, checkTooltip expectedTooltip)
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProviders.NestedTypesOrder``() = 
         let code = "type t = N1.TypeWithNestedTypes(*M*)"
         let tpReference = PathRelativeToTestAssembly( @"DummyProviderForLanguageServiceTesting.dll")
@@ -290,7 +286,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             extraRefs = [tpReference]
             ) 
 
-    [<Test>]
+    [<Fact>]
     member public this.``GetterSetterInsideInterfaceImpl.ThisOnceAsserted``() =
         let fileContent ="""
             type IFoo =
@@ -304,7 +300,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.AssertQuickInfoContainsAtStartOfMarker(fileContent, "id", "Operators.id")
 
     //regression test for bug 3184 -- intellisense should normalize to ¡°int[]¡± so that [] is not mistaken for list.
-    [<Test>]
+    [<Fact>]
     member public this.IntArrayQuickInfo() = 
       
         let fileContents = """
@@ -315,7 +311,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContents, "y(*MInt[]*)", "int array")
         
     //Verify no quickinfo -- link name string have 
-    [<Test>]
+    [<Fact>]
     member public this.LinkNameStringQuickInfo() = 
       
         let fileContents = """
@@ -326,11 +322,8 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContents, "\"x\"(*Marker1*)", "")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContents, "\"y\"(*Marker2*)", "")
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the correct TypeProvider Type message is shown or not in the TypeProviderXmlDocAttribute
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.XmlDocAttribute.Type.Comment``() = 
         
         let fileContents = """
@@ -339,10 +332,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContents, "T(*Marker*)", "This is a synthetic type created by me!",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithAdequateComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test for long message in the TypeProviderXmlDocAttribute for TypeProvider Type
     member public this.``TypeProvider.XmlDocAttribute.Type.WithLongComment``() = 
         
@@ -353,10 +343,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic type created by me!. Which is used to test the tool tip of the typeprovider type to check if it shows the right message or not.",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLongComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("This is not outputting 'member', but 'event'.")>]
+    [<Fact(Skip = "This is not outputting 'member', but 'event'.")>]
     //This is to test when the message is null in the TypeProviderXmlDocAttribute for TypeProvider Type
     member public this.``TypeProvider.XmlDocAttribute.Type.WithNullComment``() = 
         
@@ -367,10 +354,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "type T =\n  new: unit -> T\n  static member M: unit -> int []\n  static member StaticProp: decimal\n  member Event1: EventHandler", 
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithNullComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]    
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("This is not outputting 'member', but 'event'.")>]
+    [<Fact(Skip = "This is not outputting 'member', but 'event'.")>]
     //This is to test when there is empty message from the TypeProviderXmlDocAttribute for TypeProvider Type
     member public this.``TypeProvider.XmlDocAttribute.Type.WithEmptyComment``() =
 
@@ -382,10 +366,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithEmptyComment.dll")])
          
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the multi-language in the TypeProviderXmlDocAttribute for TypeProvider Type
     member public this.``TypeProvider.XmlDocAttribute.Type.LocalizedComment``() = 
         
@@ -396,11 +377,8 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic type Localized! ኤፍ ሻርፕ",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLocalizedComment.dll")])
    
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the correct TypeProvider Constructor message is shown or not in the TypeProviderXmlDocAttribute
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.XmlDocAttribute.Constructor.Comment``() = 
         
         let fileContents = """
@@ -409,10 +387,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContents, "T(*Marker*)", "This is a synthetic .ctor created by me for N.T",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithAdequateComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test for long message in the TypeProviderXmlDocAttribute for TypeProvider Constructor
     member public this.``TypeProvider.XmlDocAttribute.Constructor.WithLongComment``() = 
         
@@ -423,10 +398,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic .ctor created by me for N.T. Which is used to test the tool tip of the typeprovider Constructor to check if it shows the right message or not.",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLongComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test when the message is null in the TypeProviderXmlDocAttribute for TypeProvider Constructor
     member public this.``TypeProvider.XmlDocAttribute.Constructor.WithNullComment``() = 
         
@@ -437,10 +409,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "N.T() : N.T", 
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithNullComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]    
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test when there is empty message from the TypeProviderXmlDocAttribute for TypeProvider Constructor
     member public this.``TypeProvider.XmlDocAttribute.Constructor.WithEmptyComment``() =
 
@@ -451,10 +420,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "N.T() : N.T",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithEmptyComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the multi-language in the TypeProviderXmlDocAttribute for TypeProvider Constructor
     member public this.``TypeProvider.XmlDocAttribute.Constructor.LocalizedComment``() = 
         
@@ -466,10 +432,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLocalizedComment.dll")])
         
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the correct TypeProvider event message is shown or not in the TypeProviderXmlDocAttribute
     member public this.``TypeProvider.XmlDocAttribute.Event.Comment``() = 
         
@@ -481,10 +444,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *event* created by me for N.T",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithAdequateComment.dll")])
     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the multi-language in the TypeProviderXmlDocAttribute for TypeProvider Event
     member public this.``TypeProvider.XmlDocAttribute.Event.LocalizedComment``() = 
         
@@ -496,8 +456,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *event* Localized! ኤፍ ሻርፕ for N.T",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLocalizedComment.dll")])
    
-    [<Test>]
-    [<Category("QuickInfo.ParamsAttribute")>]
+    [<Fact>]
     //This is to test the multi-language in the TypeProviderXmlDocAttribute for TypeProvider Event
     member public this.``TypeProvider.ParamsAttributeTest``() = 
         
@@ -506,10 +465,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
 
         this.AssertQuickInfoContainsAtEndOfMarker (fileContents, "Spl", "[<System.ParamArray>] separator")
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test for long message in the TypeProviderXmlDocAttribute for TypeProvider Event
     member public this.``TypeProvider.XmlDocAttribute.Event.WithLongComment``() = 
         
@@ -521,10 +477,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *event* created by me for N.T. Which is used to test the tool tip of the typeprovider Event to check if it shows the right message or not.!",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLongComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("This is not outputting 'member', but 'event'.")>]
+    [<Fact(Skip = "This is not outputting 'member', but 'event'.")>]
     //This is to test when the message is null in the TypeProviderXmlDocAttribute for TypeProvider Event
     member public this.``TypeProvider.XmlDocAttribute.Event.WithNullComment``() = 
         
@@ -536,10 +489,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "member N.T.Event1: IEvent<System.EventHandler,System.EventArgs>", 
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithNullComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]    
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("This is not outputting 'member', but 'event'.")>]
+    [<Fact(Skip = "This is not outputting 'member', but 'event'.")>]
     //This is to test when there is empty message from the TypeProviderXmlDocAttribute for TypeProvider Event
     member public this.``TypeProvider.XmlDocAttribute.Event.WithEmptyComment``() =
 
@@ -552,10 +502,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithEmptyComment.dll")])
     
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the correct TypeProvider Method message is shown or not in the TypeProviderXmlDocAttribute
     member public this.``TypeProvider.XmlDocAttribute.Method.Comment``() = 
         
@@ -566,10 +513,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *method* created by me!!",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithAdequateComment.dll")])
     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the multi-language in the TypeProviderXmlDocAttribute for TypeProvider Method
     member public this.``TypeProvider.XmlDocAttribute.Method.LocalizedComment``() = 
         
@@ -580,10 +524,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *method* Localized! ኤፍ ሻርፕ",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLocalizedComment.dll")])
    
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test for long message in the TypeProviderXmlDocAttribute for TypeProvider Method
     member public this.``TypeProvider.XmlDocAttribute.Method.WithLongComment``() = 
         
@@ -594,10 +535,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *method* created by me!!. Which is used to test the tool tip of the typeprovider Method to check if it shows the right message or not.!",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLongComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test when the message is null in the TypeProviderXmlDocAttribute for TypeProvider Method
     member public this.``TypeProvider.XmlDocAttribute.Method.WithNullComment``() = 
         
@@ -608,10 +546,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "N.T.M() : int array", 
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithNullComment.dll")])
     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]    
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test when there is empty message from the TypeProviderXmlDocAttribute for TypeProvider Method
     member public this.``TypeProvider.XmlDocAttribute.Method.WithEmptyComment``() =
 
@@ -623,10 +558,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithEmptyComment.dll")])
     
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the correct TypeProvider Property message is shown or not in the TypeProviderXmlDocAttribute
     member public this.``TypeProvider.XmlDocAttribute.Property.Comment``() = 
         
@@ -637,10 +569,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *property* created by me for N.T",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithAdequateComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test the multi-language in the TypeProviderXmlDocAttribute for TypeProvider Property
     member public this.``TypeProvider.XmlDocAttribute.Property.LocalizedComment``() = 
         
@@ -651,10 +580,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *property* Localized! ኤፍ ሻርፕ for N.T",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLocalizedComment.dll")])
    
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test for long message in the TypeProviderXmlDocAttribute for TypeProvider Property
     member public this.``TypeProvider.XmlDocAttribute.Property.WithLongComment``() = 
         
@@ -665,10 +591,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "This is a synthetic *property* created by me for N.T. Which is used to test the tool tip of the typeprovider Property to check if it shows the right message or not.!",
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithLongComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider.XmlDocAttribute")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test when the message is null in the TypeProviderXmlDocAttribute for TypeProvider Property
     member public this.``TypeProvider.XmlDocAttribute.Property.WithNullComment``() = 
         
@@ -679,10 +602,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          "property N.T.StaticProp: decimal", 
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithNullComment.dll")])
     
-    [<Test>]
-    [<Category("TypeProvider")>]    
-    [<Category("TypeProvider.XmlDocAttribute")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This is to test when there is empty message from the TypeProviderXmlDocAttribute for TypeProvider Property
     member public this.``TypeProvider.XmlDocAttribute.Property.WithEmptyComment``() =
 
@@ -694,10 +614,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
          addtlRefAssy = [PathRelativeToTestAssembly( @"XmlDocAttributeWithEmptyComment.dll")])
     
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     //This test case Verify that when Hover over foo the correct quickinfo is displayed for TypeProvider static parameter
     //Dummy Type Provider exposes a parametric type (N1.T) that takes 2 static params (string * int)
     member public this.``TypeProvider.StaticParameters.Correct``() =
@@ -711,9 +628,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             expected = "type foo = N1.T",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact>]
     //This test case Verify that when Hover over foo the correct quickinfo is displayed
     //Dummy Type Provider exposes a parametric type (N1.T) that takes 2 static params (string * int)
     //As you can see this is "Negative Case" to check that when given invalid static Parameter quickinfo shows "type foo = obj"
@@ -728,9 +643,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             expected = "type foo",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact>]
     //This test case Verify that when Hover over foo the XmlComment is shown in quickinfo
     //Dummy Type Provider exposes a parametric type (N1.T) that takes 2 static params (string * int)
     member public this.``TypeProvider.StaticParameters.XmlComment``() =
@@ -745,10 +658,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             expected = "XMLComment",
             addtlRefAssy = [PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.StaticParameters.QuickInfo.OnTheErasedType``() =
         let fileContents = """type TTT = Samples.FSharp.RegexTypeProvider.RegexTyped< @"(?<AreaCode>^\d{3})-(?<PhoneNumber>\d{3}-\d{7}$)">"""
         this.AssertQuickInfoContainsAtStartOfMarker( 
@@ -757,10 +667,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             expected = "type TTT = Samples.FSharp.RegexTypeProvider.RegexTyped<...>\nFull name: File1.TTT",
             addtlRefAssy = ["System"; PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("TypeProvider")>]
-    [<Category("TypeProvider.StaticParameters")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.StaticParameters.QuickInfo.OnNestedErasedTypeProperty``() =
         let fileContents = """
             type T = Samples.FSharp.RegexTypeProvider.RegexTyped< @"(?<AreaCode>^\d{3})-(?<PhoneNumber>\d{3}-\d{7}$)">
@@ -774,7 +681,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             addtlRefAssy = ["System"; PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")])
     
     // Regression for 2948
-    [<Test>]
+    [<Fact>]
     member public this.TypeRecordQuickInfo() = 
       
         let fileContents = """namespace NS
@@ -783,7 +690,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         
         this.InfoInDeclarationTestQuickInfoImplWithTrim fileContents "Re(*MarkerRecord*)" expectedQuickinfoTypeRecord
     
-    [<Test>]
+    [<Fact>]
     member public this.``QuickInfo.LetBindingsInTypes``() = 
         let code = 
             """
@@ -793,7 +700,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.AssertQuickInfoContainsAtEndOfMarker(code, "let ff", "val fff: n: int -> int")
 
     // Regression for 2494
-    [<Test>]
+    [<Fact>]
     member public this.TypeConstructorQuickInfo() = 
       
         let fileContents = """
@@ -827,7 +734,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.InfoInDeclarationTestQuickInfoImplWithTrim fileContents "pq(*MarkerVal*)" expectedquickinfoVal
         this.InfoInDeclarationTestQuickInfoImplWithTrim fileContents "singleton(*MarkerLastLine*)" expectedquickinfoLastLine
         
-    [<Test>]
+    [<Fact>]
     member public this.NamedDUFieldQuickInfo() = 
       
         let fileContents = """
@@ -851,60 +758,60 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
         this.InfoInDeclarationTestQuickInfoImplWithTrim fileContents "Case3(*MarkerCase3*)" expectedquickinfoCase3
         this.InfoInDeclarationTestQuickInfoImplWithTrim fileContents "NamedExn(*MarkerException*)" expectedquickinfoException
 
-    [<Test>]
+    [<Fact>]
     member public this.``EnsureNoAssertFromBadParserRangeOnAttribute``() = 
         let fileContents = """ 
                 [<System.Obsolete>]
                 Types foo = int"""
         this.AssertQuickInfoContainsAtEndOfMarker (fileContents, "ype", "")  // just want to ensure there is no assertion fired by the parse tree walker
    
-    [<Test>]
+    [<Fact>]
     member public this.``ShiftKeyDown``() =
         ShiftKeyDown(this.VS)
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""#light""","#ligh","")
 
-    [<Test>]
+    [<Fact>]
     member public this.``ActivePatterns.Declaration``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""let ( |One|Two| ) x = One(x+1)""","ne|Tw","int -> Choice")
 
-    [<Test>]
+    [<Fact>]
     member public this.``ActivePatterns.Result``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""let ( |One|Two| ) x = One(x+1)""","= On","active pattern result One: int -> Choice")
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``ActivePatterns.Value``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
          ("""let ( |One|Two| ) x = One(x+1)
              let patval = (|One|Two|) // use""","= (|On","int -> Choice")
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.InDeclaration.Bug3176a``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""type T<'a> = { aaaa : 'a; bbbb : int } ""","aa","aaaa")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.InDeclaration.Bug3176c``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""type C =
                 val aaaa: int""","aa","aaaa")
                       
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.InDeclaration.Bug3176d``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""type DU<'a> =
                 | DULabel of 'a""","DULab","DULabel")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Generic.3773a``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""let rec M2<'a>(a:'a) = M2(a)""","let rec M","val M2: a: 'a -> obj")
 
     // Before this fix, if the user hovered over 'cccccc' they would see 'Yield'
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ComputationExpressionMemberAppearingInQuickInfo``() =        
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker 
             """
@@ -921,7 +828,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
     // they would see a quickinfo for any available function named get or set.
     // The tests below define a get function with 'let' and then test to make sure that
     // this isn't the get seen in the tool tip.
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903a``() =        
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker 
             """namespace CountChocula
@@ -932,7 +839,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                        and set(value:int) : unit = ()""" 
             "with g" "string"
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903d``() =        
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker 
             """namespace CountChocula
@@ -943,7 +850,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                        and set(value:int) : unit = ()""" 
             "AMetho" "string"          
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903b``() =        
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker 
             """namespace CountChocula
@@ -954,7 +861,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                        and set(value:int) : unit = ()"""
             "and s" "seq"          
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903c``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
            ("""namespace CountChocula
@@ -966,7 +873,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
             "let g","string")
           
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParamsArrayArgument.OnType``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
            ("""
@@ -975,7 +882,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                 let r = A.Foo(42)""" ,
             "type A","[<ParamArray>] a:"    )
 
-    [<Test>]
+    [<Fact>]
     member public this.``ParamsArrayArgument.OnMethod``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
            ("""
@@ -984,7 +891,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                 let r = A.Foo(42)""" ,
             "A.Foo","[<System.ParamArray>] a:"    )
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903e``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
            ("""namespace CountChocula
@@ -995,7 +902,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                        and set(value:int) : unit = ()""" ,
             "member source.Pr","Prop"    )
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903f``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
            ("""namespace CountChocula
@@ -1006,7 +913,7 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                        and set(value:int) : unit = ()""" ,
             "member source.Pr","int"                   )
           
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.AccessorMutator.Bug4903g``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
            ("""namespace CountChocula
@@ -1017,13 +924,13 @@ Full name: Microsoft.FSharp.Control.Async""".TrimStart().Replace("\r\n", "\n")
                        and set(value:int) : unit = ()""" ,
             "member sou","source"                )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.RecursiveDefinition.Generic.3773b``() =        
         this.AssertQuickInfoContainsAtEndOfMarker 
           ("""let rec M1<'a>(a:'a) = M1(0)""","let rec M","val M1: a: int -> 'a")
           
         //regression test for bug Dev11:138110 - "F# language service hover tip for ITypeProvider does now show Invalidate event"
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ImportedEvent.138110``() =
         let fileContents = """
 open Microsoft.FSharp.Core.CompilerServices
@@ -1036,17 +943,17 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
 
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Declaration.CyclicalDeclarationDoesNotCrash``() =
         this.AssertQuickInfoContainsAtEndOfMarker
           ("""type (*1*)A = int * (*2*)A ""","(*2*)","type A")
 
-    [<Test>]
+    [<Fact>]
     member public this.``JustAfterIdentifier``() =
         this.AssertQuickInfoContainsAtEndOfMarker
           ("""let f x = x + 1 ""","let f","int")
         
-    [<Test; Ignore(".NET classes are treated differently now. Should this be revisited? Probably not.")>]
+    [<Fact(Skip =".NET classes are treated differently now. Should this be revisited? Probably not.")>]
     member public this.``FrameworkClass``() =
         let fileContent = """let l = new System.Collections.Generic.List<int>()"""
         let marker = "Generic.List"
@@ -1057,14 +964,14 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent marker "get_Count"
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent marker "set_Count"
           
-    [<Test>]
+    [<Fact>]
     member public this.``FrameworkClassNoMethodImpl``() =
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker
           """let l = new System.Collections.Generic.LinkedList<int>()"""
            "Generic.LinkedList" "System.Collections.ICollection.ISynchronized" // Bug 5092: A framework class contained a private method impl
 
     // Disabled due to issue #11752   ---  https://github.com/dotnet/fsharp/issues/11752
-    //[<Test>]
+    //[<Fact>]
     member public this.``Regression.ModulesFromExternalLibrariesBug5785``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1084,7 +991,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         SetConfigurationAndPlatform(projectLib, "Debug|AnyCPU")  // we must set config/platform when building with ProjectReferences
         AddProjectReference(project, projectLib)
         let br = BuildTarget(projectLib, "Build") // build the dependent library
-        Assert.IsTrue(br.BuildSucceeded, "build should succeed")
+        Assert.True(br.BuildSucceeded, "build should succeed")
         let file = OpenFile(project,"App.fs")
         TakeCoffeeBreak(this.VS) // Wait for the background compiler to catch up.
 
@@ -1109,13 +1016,13 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
 
 
     /// Even though we don't show squiggles, some types will still be known. For example, System.String.
-    [<Test>]
+    [<Fact>]
     member public this.``OrphanFs.BaselineIntellisenseStillWorks``() = 
         this.AssertQuickInfoContainsAtEndOfMarker
            ("""let astring = "Hello" ""","let astr","string")
 
     /// FEATURE: User may hover over a type or identifier and get basic information about it in a tooltip.
-    [<Test>]
+    [<Fact>]
     member public this.``Basic``() = 
         let fileContent = """type (*bob*)Bob() = 
                                   let x = 1"""
@@ -1123,7 +1030,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,marker,"Bob =")
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,marker,"Bob =")
 
-    [<Test>]
+    [<Fact>]
     member public this.``ModuleDefinition.ModuleNoNewLines``() = 
         let fileContent = """module XXX
                              type t = C3
@@ -1137,7 +1044,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"YY","module YYY\n\nfrom XXX")
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"ZZ","module ZZZ\n\nfrom XXX<summary>\n\nDoc</summary>")
 
-    [<Test>]
+    [<Fact>]
     member public this.``IdentifierWithTick``() = 
         let code = 
                                     ["#light"
@@ -1154,14 +1061,13 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         let tooltip = GetQuickInfoAtCursor file
         AssertContains(tooltip,"val x': string")
 
-    [<Test>]
+    [<Fact>]
     member public this.``NegativeTest.CharLiteralNotConfusedWithIdentifierWithTick``() = 
         let fileContent = """let x = 1"
                              let y = 'x' """
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"'x","")   // no tooltips for char literals
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``QueryExpression.QuickInfoSmokeTest1``() = 
         let fileContent = """let q = query { for x in ["1"] do select x }"""
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"selec","custom operation: select", addtlRefAssy=standard40AssemblyRefs)
@@ -1169,8 +1075,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"selec","Calls"   , addtlRefAssy=standard40AssemblyRefs)
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"selec","Linq.QueryBuilder.Select"  , addtlRefAssy=standard40AssemblyRefs )
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``QueryExpression.QuickInfoSmokeTest2``() = 
         let fileContent = """let q = query { for x in ["1"] do join y in ["2"] on (x = y); select (x,y) }"""
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"joi","custom operation: join"  , addtlRefAssy=standard40AssemblyRefs )
@@ -1178,8 +1083,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"joi","Calls"  , addtlRefAssy=standard40AssemblyRefs )
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"joi","Linq.QueryBuilder.Join"  , addtlRefAssy=standard40AssemblyRefs )
 
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Test>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``QueryExpression.QuickInfoSmokeTest3``() = 
         let fileContent = """let q = query { for x in ["1"] do groupJoin y in ["2"] on (x = y) into g; select (x,g) }"""
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"groupJoin","custom operation: groupJoin"  , addtlRefAssy=standard40AssemblyRefs )
@@ -1189,7 +1093,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
 
 
     /// Hovering over a literal string should not show data tips for variable names that appear in the string
-    [<Test>]
+    [<Fact>]
     member public this.``StringLiteralWithIdentifierLookALikes.Bug2360_A``() =
         let fileContent = """let y = 1
                              let f x = "x"
@@ -1197,13 +1101,13 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "f x = \"" "val"
 
     /// Hovering over a literal string should not show data tips for variable names that appear in the string
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.StringLiteralWithIdentifierLookALikes.Bug2360_B``() =
         let fileContent = """let y = 1"""
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"let ","int")
 
     /// FEATURE: Intellisense information from types in earlier files in the project is available in subsequent files.        
-    [<Test>]
+    [<Fact>]
     member public this.``AcrossMultipleFiles``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1231,7 +1135,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         AssertContains(tooltip,"File1.Bob")
 
     /// FEATURE: Linked files work
-    [<Test>]
+    [<Fact>]
     member public this.``AcrossLinkedFiles``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1258,7 +1162,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         printf "Second-%s\n" tooltip
         AssertContains(tooltip,"Link.Bob")
 
-    [<Test>]
+    [<Fact>]
     member public this.``TauStarter``() =
         let code =
                                     ["#light"
@@ -1278,12 +1182,12 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         MoveCursorToEndOfMarker(file,"(*Scenario021*)")
         let tooltip = time1 GetQuickInfoAtCursor file "Time of first tooltip"
         printf "First-%s\n" tooltip
-        Assert.IsTrue(tooltip.Contains("Bob ="))
+        Assert.True(tooltip.Contains("Bob ="))
         
         MoveCursorToEndOfMarker(file,"(*Scenario022*)")
         let tooltip = time1 GetQuickInfoAtCursor file "Time of first tooltip"
         printf "First-%s\n" tooltip
-        Assert.IsTrue(tooltip.Contains("Alice ="))
+        Assert.True(tooltip.Contains("Alice ="))
 
     member private this.QuickInfoResolutionTest lines queries =
         let code = [ yield "#light"
@@ -1299,7 +1203,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
                 MoveCursorToEndOfMarker(file,marker)
                 let tooltip = time1 GetQuickInfoAtCursor file "Time for tooltip"
                 printf "QuickInfo at marker '%s' is '%s', expect '%s'\n" marker tooltip expectedText
-                Assert.IsTrue(tooltip.Contains(expectedText))
+                Assert.True(tooltip.Contains(expectedText))
 
     member public this.GetLongPathsTestCases() =
             ["let test0 = System.Console.In"
@@ -1331,12 +1235,12 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
               ("type Test0e = System.Collections.Generic.","KeyNotFoundException","Generic.KeyNotFoundException");  // note resolves to type
              ]
         
-    [<Test>]
+    [<Fact>]
     member public this.``LongPaths``() =
         let text,cases = this.GetLongPathsTestCases()
         this.QuickInfoResolutionTest text cases
 
-    [<Test>]
+    [<Fact>]
     member public this.``Global.LongPaths``() =
         let text,cases = this.GetLongPathsTestCases()
         let replace (s:string) = s.Replace("System", "global.System")
@@ -1348,7 +1252,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
 
         this.QuickInfoResolutionTest text cases
         
-    [<Test>]
+    [<Fact>]
     member public this.``TypeAndModuleReferences``() =
         this.QuickInfoResolutionTest 
             ["let test1 = List.length"
@@ -1364,7 +1268,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ("let test3 = (\"1\").","Length"                                   ,"String.Length");
             ("let test3b = (id \"1\").","Length"                               ,"String.Length") ]
         
-    [<Test>]
+    [<Fact>]
     member public this.``ModuleNameAndMisc``() =
         this.QuickInfoResolutionTest 
             ["module (*test3q*)MM3 ="
@@ -1377,7 +1281,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ("let test4 = ","lock"                                             ,"lock");
             ("let (*test5*) ","ffff"                                           ,"ffff") ]
 
-    [<Test>]
+    [<Fact>]
     member public this.``MemberIdentifiers``() =
         this.QuickInfoResolutionTest 
             ["type TestType() ="
@@ -1393,7 +1297,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ("member (*test7*) xx.","QQQQ"                                     ,"float");
             ("let test8 = (TestType()).", "PPPP"                               , "PPPP") ]
         
-    [<Test>]
+    [<Fact>]
     member public this.``IdentifiersForFields``() =
         this.QuickInfoResolutionTest 
             ["type TestType9 = { XXX : int }"
@@ -1403,7 +1307,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
            [("type TestType9 = { ", "XXX"                                      , "XXX: int");
             ("let test11 = { ", "XXX"                                          , "XXX");] 
         
-    [<Test>]
+    [<Fact>]
     member public this.``IdentifiersForUnionCases``() =
         this.QuickInfoResolutionTest 
             ["type TestType10 = Case1 | Case2 of int"
@@ -1415,7 +1319,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ("let test12 = (", "Case1"                                         , "union case TestType10.Case1");
             ("let test12 = (Case1,", "Case2"                                   , "union case TestType10.Case2");] 
         
-    [<Test>]
+    [<Fact>]
     member public this.``IdentifiersInAttributes``() =
         this.QuickInfoResolutionTest 
             ["[<(*test13*)System.CLSCompliant(true)>]"
@@ -1429,7 +1333,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ("[<(*test13*)System.", "CLSCompliant"                             , "CLSCompliantAttribute");
             ("[<(*test14*)", "CLSCompliant"                                    , "CLSCompliantAttribute");] 
         
-    [<Test>]
+    [<Fact>]
     member public this.``ArgumentAndPropertyNames``() =
         this.QuickInfoResolutionTest 
             ["type R = { mutable AAA : int }"
@@ -1450,12 +1354,12 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ("let test16 = new System.Reflection.AssemblyName(", "assemblyName", "argument assemblyName")] 
         
     /// Quickinfo was throwing an exception when the mouse was over the end of a line.
-    [<Test>]
+    [<Fact>]
     member public this.``AtEndOfLine``() =
         let fileContent = """#light"""
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "#light" "Bug:"
         
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.FieldRepeatedInToolTip.Bug3538``() = 
         this.AssertIdentifierInToolTipExactlyOnce
           """#light
@@ -1466,7 +1370,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
                val mutable x : int"""
              "LayoutKind.Expl" "Explicit"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.FieldRepeatedInToolTip.Bug3818``() = 
         this.AssertIdentifierInToolTipExactlyOnce
           """#light
@@ -1475,7 +1379,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
                do ()"""
              "Inherite" "Inherited"  // Get the tooltip at "Inherite" & Verify that it contains the 'Inherited' field exactly once
         
-    [<Test>]
+    [<Fact>]
     member public this.``MethodAndPropTooltip``() = 
         let fileContent = """#light
                              open System
@@ -1485,7 +1389,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertIdentifierInToolTipExactlyOnce fileContent "Console.Cle" "Clear"
         this.AssertIdentifierInToolTipExactlyOnce fileContent "Console.Back" "BackgroundColor"
         
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.StaticVsInstance.Bug3626``() = 
         let fileContent = """
                              type Foo() =
@@ -1501,7 +1405,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"(*string*) Hoo.Ba","Foo.Bar")
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"(*string*) Hoo.Ba","-> string")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Class.OnlyClassInfo``() = 
         let fileContent = """type TT(x : int, ?y : int) = 
                                  class end"""
@@ -1509,7 +1413,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"type T","type TT")
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "type T" "---"
 
-    //KnownFail:  [<Test>]
+    //KnownFail:  [<Fact>]
     member public this.``Async.AsyncToolTips``() = 
         let fileContent = """let a = 
                              async {
@@ -1521,7 +1425,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"asy","AsyncBuilder")
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "asy" "---"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Exceptions.Bug3723``() = 
         let fileContent = """exception E3E of int * int
                              exception E4E of (int * int)
@@ -1533,7 +1437,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         // E5E is an alias - should contain name of the aliased exception
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"exception E5","E4E")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Classes.Bug4066``() = 
         let fileContent = """type Foo() as this =
                                  do this |> ignore
@@ -1550,7 +1454,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"Bar() = thi","this")
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "Bar() = thi" "ref"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Classes.Bug2362``() = 
         let fileContent = """let append mm nn = fun ac -> mm (nn ac)"""
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"let appen","mm: ('a -> 'b) -> nn: ('c -> 'a) -> ac: 'c -> 'b")
@@ -1558,14 +1462,14 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"let append m","'a -> 'b")
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"let append mm n","'c -> 'a")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ModuleAlias.Bug3790a``() = 
         let fileContent = """module ``Some`` = Microsoft.FSharp.Collections.List
                              module None = Microsoft.FSharp.Collections.List"""
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "module ``So" "Option"
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "module No" "Option"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ModuleAlias.Bug3790b``() = 
         let code =
                                     [ "#light"
@@ -1578,14 +1482,14 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         let tooltip = GetQuickInfoAtCursor file
         AssertNotContains(tooltip, "Option")
             
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ActivePatterns.Bug4100a``() = 
         let fileContent = """let (|Lazy|) x = x
                              match 0 with | Lazy y -> ()"""
         // Test quickinfo in place where the declaration is used
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "with | Laz" "'?"    // e.g. "Lazy: '?3107 -> '?3107", "Lazy: 'a -> 'a" will be fine
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ActivePatterns.Bug4100b``() = 
         let fileContent = """let Some (a:int) = a
                              match None with
@@ -1601,7 +1505,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         // This shouldn't find the function returning string but a pattern returning int
         this.VerifyQuickInfoDoesNotContainAnyAtEndOfMarker fileContent "| NSom" "int -> string"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ActivePatterns.Bug4103``() = 
         let fileContent = """let (|Lazy|) x = x
                              match 0 with | Lazy y -> ()"""
@@ -1611,7 +1515,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             
     // This test checks that we don't show any tooltips for operators
     // (which is currently not supported, but it used to collide with support for active patterns)
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.NoTooltipForOperators.Bug4567``() = 
         let fileContent = """let ( |+| ) a b = a + b
                              let n = 1 |+| 2
@@ -1622,7 +1526,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"true |","")
 
     // Check to see that two distinct projects can be present
-    [<Test>]
+    [<Fact>]
     member public this.``AcrossTwoProjects``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1643,16 +1547,16 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         MoveCursorToEndOfMarker(file1,"type (*bob*)Bob")
         let tooltip = time1 GetQuickInfoAtCursor file1 "Time of file1 tooltip"
         printf "Tooltip for file1:\n%s\n" tooltip
-        Assert.IsTrue(tooltip.Contains("Bob1 ="))
+        Assert.True(tooltip.Contains("Bob1 ="))
         
         // Check Bob2
         MoveCursorToEndOfMarker(file2,"type (*bob*)Bob")
         let tooltip = time1 GetQuickInfoAtCursor file2 "Time of file2 tooltip"
         printf "Tooltip for file2:\n%s\n" tooltip
-        Assert.IsTrue(tooltip.Contains("Bob2 ="))
+        Assert.True(tooltip.Contains("Bob2 ="))
         
     // In this bug, relative paths with .. in them weren't working.
-    [<Test>]
+    [<Fact>]
     member public this.``BugInRelativePaths``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1680,7 +1584,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         AssertContains(tooltip,"File1.Bob")
 
     // QuickInfo over a type that references types in an unreferenced assembly works.        
-    [<Test>]
+    [<Fact>]
     member public this.``MissingDependencyReferences.QuickInfo.Bug5409``() =     
         let code = 
                                     ["#light"
@@ -1697,7 +1601,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
     /// The fix--at the point in time it was fixed--was to modify the parser to send a limited number
     /// of additional EOF tokens to allow the recovery code to proceed up the change of productions
     /// in the grammar.
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Bug1605``() = 
         let fileContent = """let rec f l =
                                  match l with
@@ -1706,7 +1610,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
         // This string doesn't matter except that it should prove there is some datatip present.
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"| [] -> str","string")
         
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Bug4642``() =   
         let fileContent = """ "AA".Chars """
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"\"AA\".Ch","int -> char")
@@ -1724,11 +1628,10 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             let descr = descrFunc()
             AssertContainsInOrder(descr,rhsContainsOrder)
         | None -> 
-            Console.WriteLine("Could not find completion name '{0}'", completionName)
             ShowErrors(project)
-            Assert.Fail()
+            failwith $"Could not find completion name '{completionName}'"
 
-    [<Test>]
+    [<Fact>]
     //``CompletiongListItem.DocCommentsOnMembers`` and with //Regression 5856
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_1``() =
         this.AssertMemberDataTipContainsInOrder
@@ -1755,7 +1658,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_2``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1779,7 +1682,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_3``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1803,7 +1706,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_4``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1829,7 +1732,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_5``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1852,7 +1755,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_6``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1875,7 +1778,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_7``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1899,7 +1802,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_8``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1922,7 +1825,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_9``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1945,7 +1848,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_10``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1964,7 +1867,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_13``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -1983,7 +1886,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )   
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_14``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2002,7 +1905,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
              ]
             )    
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.MemberDefinition.DocComments.Bug5856_15``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2021,7 +1924,7 @@ let f (tp:ITypeProvider(*$$$*)) = tp.Invalidate
             ) 
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.ExtensionMethods.DocComments.Bug6028``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2042,7 +1945,7 @@ query."
              ]
             ) 
             
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.OnMscorlibMethodInScript.Bug6489``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2064,7 +1967,7 @@ query."
               
               
     /// BUG: intellisense on "self" parameter in implicit ctor classes is wrong
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.CompListItemInfo.Bug5694``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2085,7 +1988,7 @@ query."
 
 
     /// Bug 4592: Check that ctors are displayed from C# classes, i.e. the "new" lines below.
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Class.Printing.CSharp.Classes.Only.Bug4592``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2103,7 +2006,7 @@ query."
               "  member NextDouble: unit -> float"]
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.``GenericDotNetMethodShowsComment``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2119,7 +2022,7 @@ query."
             )
 
     /// Bug 4624: Check the order in which members are printed, C# classes
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Class.Printing.CSharp.Classes.Bug4624``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2143,7 +2046,7 @@ query."
              ])
 
     /// Bug 4624: Check the order in which members are printed, F# classes
-    [<Test>]
+    [<Fact>]
     member public this.``Regression.Class.Printing.FSharp.Classes.Bug4624``() =
         this.AssertMemberDataTipContainsInOrder
             ((*code *)
@@ -2191,7 +2094,7 @@ query."
              ])
 
 (*------------------------------------------IDE automation starts here -------------------------------------------------*)
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.AccessibilityOnTypeMembers.Bug4168``() =
         let fileContent = """module Test
                              type internal Foo2(*Marker*) () = 
@@ -2203,7 +2106,7 @@ query."
                                   private new(x:int,y:int,z:int) = new Foo2()"""
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker*)", "type internal Foo2")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.AccessorsAndMutators.Bug4276``() =
         let fileContent = """type TestType1(*Marker1*)( x : int , y : int ) =  
                                  let mutable x = x
@@ -2242,14 +2145,13 @@ query."
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker2*)" "get_Length"
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker2*)" "set_Length"
 
-    [<Test>]
-    [<Ignore("DocComment issue")>]
+    [<Fact(Skip = "DocComment issue")>]
     member public this.``Automation.AutoOpenMyNamespace``() =
         let fileContent ="""namespace System.Numerics
                             type t = BigInteger(*Marker1*)"""
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "r(*Marker1*)", "type BigInteger")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.BeforeAndAfterIdentifier.Bug4371``() =
         let fileContent = """module Test
                              let f arg1 (arg2, arg3, arg4) arg5 = 42
@@ -2262,7 +2164,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker2*)", "property System.Console.BufferWidth: int")
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"(*Marker3*)","Full name: Test.printer")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.ConstructorWithSameNameAsType.Bug2739``() =
         let fileContent = """namespace AA
                              module AA = 
@@ -2272,7 +2174,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker1*)", "AA.AA: AA")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker2*)", "BB.BB: string")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.EventImplementation.Bug5471``() =
         let fileContent = """namespace regressiontest
                              open System
@@ -2327,7 +2229,7 @@ query."
         AssertContains(tooltip, "override CommandReference.CanExecuteChanged: IEvent<EventHandler,EventArgs>") 
         AssertContains(tooltip, "regressiontest.CommandReference.CanExecuteChanged") 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.ExtensionMethod``() =
         let fileContent ="""namespace TestQuickinfo
 
@@ -2446,7 +2348,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker42*)", "FSStruct.ExtensionProperty: string")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker42*)", "fs struct extension property")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.GenericFunction.Bug2868``() =
         let fileContent ="""module Test
                             // Hovering over a generic function (generic argument decorated with [<Measure>] attribute yields a bad tooltip
@@ -2457,8 +2359,7 @@ query."
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker*)" "Exception"
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker*)" "thrown"
 
-    [<Test>]
-    [<Ignore("DocComment issue")>]
+    [<Fact(Skip = "DocComment issue")>]
     member public this.``Automation.IdentifierHaveDiffMeanings``() =
         let fileContent ="""namespace NS
                             module float(*Marker1_1*) =
@@ -2524,14 +2425,14 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker6_2*)", "member ValType.Value : int with set")
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker6_2*)" "Microsoft.FSharp.Core.ExtraTopLevelOperators.set"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.ModuleIdentifier.Bug2937``() =
         let fileContent ="""module XXX(*Marker*)
                             type t = C3"""
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker*)", "module XXX")
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker*)" "\n"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.NamesArgument.Bug3818``() =
         let fileContent ="""module m 
                             [<System.AttributeUsage(System.AttributeTargets.All, AllowMultiple(*Marker1*) = true)>]
@@ -2539,8 +2440,7 @@ query."
                                      end"""
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker1*)", "property System.AttributeUsageAttribute.AllowMultiple: bool")
 
-    [<Test>]
-    [<Ignore("DocComment issue")>]
+    [<Fact(Skip = "DocComment issue")>]
     member public this.``Automation.OnUnitsOfMeasure``() =
         let fileContent ="""namespace TestQuickinfo
 
@@ -2580,7 +2480,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker22*)", "from Microsoft.FSharp.Collections")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker22*)", "Functional programming operators related to the Set<_> type.")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.OverRiddenMembers``() =
         let fileContent ="""namespace QuickinfoGeneric
 
@@ -2602,7 +2502,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker11*)", "override ByteOutputSink.WriteChar: c: char -> unit")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker12*)", "override ByteOutputSink.WriteString: s: string -> unit")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.QuotedIdentifier.Bug3790``() =
         let fileContent ="""module Test
                             module ``Some``(*Marker1*) = Microsoft.FSharp.Collections.List
@@ -2612,8 +2512,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "``(*Marker2*)", "module List")
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "``(*Marker2*)" "Option.Some"
 
-    [<Test>]
-    [<Ignore("Cannot get QuickInfo tips")>]
+    [<Fact(Skip = "Cannot get QuickInfo tips")>]
     member public this.``Automation.Setter``() =
         let fileContent ="""type T() =
                                  member this.XX
@@ -2653,7 +2552,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker4*)", "T2.Foo: a: 'a * b: 'b -> string")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker5*)", "val foo: int -> int -> int")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.TupleException.Bug3723``() =
         let fileContent ="""namespace TestQuickinfo
                             exception E3(*Marker1*) of int * int
@@ -2665,7 +2564,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker2*)", "Full name: TestQuickinfo.E4")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker3*)", "exception E5 = E4")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.TypeAbbreviations``() =
         let fileContent ="""namespace NS
                             module TypeAbbreviation =
@@ -2716,7 +2615,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker5_1*)", "type AbAttrName = AbstractClassAttribute")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker5_2*)", "type AbAttrName = AbstractClassAttribute")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.TypeInferenceScenarios.Bug2362&3538``() =
         let fileContent ="""module Test.Module1
 
@@ -2751,7 +2650,7 @@ query."
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"(*Marker7*)","type A =")
         this.AssertQuickInfoContainsAtEndOfMarker(fileContent,"(*Marker7*)","val mutable x: int")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.TypemoduleConstructorLastLine.Bug2494``() =
         let fileContent ="""namespace NS
                             open System
@@ -2777,7 +2676,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*MarkerVal*)", "val pq: PriorityQueue<'a,'b>")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*MarkerLastLine*)", "val singleton: k: 'a -> a: 'b -> PriorityQueue<'a,'b>")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.WhereQuickInfoShouldNotShowUp``() =
         let fileContent ="""namespace Test
 
@@ -2825,7 +2724,7 @@ query."
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker7*)" "bigint"
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker8*)" "myString"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.XmlDocComments.Bug3157``() =
         let fileContent ="""namespace TestQuickinfo
                             module XmlComment =
@@ -2839,7 +2738,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker*)", "Full name: TestQuickinfo.XmlComment.func")
         this.VerifyQuickInfoDoesNotContainAnyAtStartOfMarker fileContent "(*Marker*)" "XmlComment K"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.Regression.XmlDocCommentsOnExtensionMembers.Bug138112``() =
         let fileContent ="""module Module1 =
                                 type T() = 
@@ -2862,8 +2761,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker2*)", "XmlComment M2")
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Marker3*)", "XmlComment M3")
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.XmlDocCommentsForArguments() =
         let fileContent = """
                              type bar() =
@@ -3059,7 +2957,7 @@ query."
             AssertContains(tooltip, expectedTip)
 
                 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.XDelegateDUStructfromOwnCode``() =
         let fileContent ="""module Test
 
@@ -3099,7 +2997,7 @@ query."
                          ("(*Marker4*)", "Gets and sets X")]
         this.VerifyUsingFsTestLib fileContent queries false
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.StructDelegateDUfromOwnCode``() =
         let fileContent ="""module Test
 
@@ -3141,7 +3039,7 @@ query."
                         ]
         this.VerifyUsingFsTestLib fileContent queries false
 
-    [<Test>]
+    [<Fact>]
     member public this.``Automation.TupleRecordClassfromOwnCode``() =
         let fileContent ="""module Test
 
@@ -3237,9 +3135,7 @@ query."
         gpatcc.AssertExactly(0,0)   
 
 
-    [<Test>]
-    [<Category("Query")>]
-    [<Ignore("bug196137:Wrong type quickinfo in the query with errors elsewhere")>]
+    [<Fact(Skip = "bug196137:Wrong type quickinfo in the query with errors elsewhere")>]
     // QuickInfo still works on valid operators in a query with errors elsewhere in it
     member public this.``Query.WithError1.Bug196137``() =
         let fileContent ="""
@@ -3255,10 +3151,8 @@ query."
                 }"""
         this.AssertQuickInfoInQuery (fileContent, "(*Mark*)", "Product.ProductName: string")
 
-    [<Test>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // QuickInfo still works on valid operators in a query with errors elsewhere in it
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.WithError2``() =
         let fileContent ="""
             open DataSource
@@ -3271,8 +3165,7 @@ query."
                     }"""
         this.AssertQuickInfoInQuery (fileContent, "(*Mark*)", "custom operation: minBy ('Value)")
 
-    [<Test; Ignore("Multiple failures due to CancellationTokenSource being disposed. Bad test")>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Multiple failures due to CancellationTokenSource being disposed. Bad test")>]
     // QuickInfo works in a large query (using many operators)
     member public this.``Query.WithinLargeQuery``() =
         let fileContent ="""
@@ -3303,9 +3196,7 @@ query."
         this.AssertQuickInfoInQuery (fileContent, "(*Mark3*)", "custom operation: where (bool)")
         this.AssertQuickInfoInQuery (fileContent, "(*Mark4*)", "custom operation: distinct")
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Arguments to query operators have correct QuickInfo
     // quickinfo should be correct including when the operator is causing an error
     member public this.``Query.ArgumentToQuery.OperatorError``() =
@@ -3319,9 +3210,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "n.GetType()", "val n: int",queryAssemblyRefs)
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "Type()", "System.Object.GetType() : System.Type",queryAssemblyRefs)
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // Arguments to query operators have correct QuickInfo
     // quickinfo should be correct In a nested query
     member public this.``Query.ArgumentToQuery.InNestedQuery``() =
@@ -3342,10 +3231,8 @@ query."
         this.AssertQuickInfoInQuery (fileContent, "(*Mark3*)", "custom operation: groupValBy ('Value) ('Key)")
         this.AssertQuickInfoInQuery (fileContent, "(*Mark4*)", "custom operation: select ('Result)")
 
-    [<Test>]
-    [<Category("Query")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     // A computation expression with its own custom operators has correct QuickInfo displayed
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.ComputationExpression.Method``() =
         let fileContent ="""
             open System.Collections.Generic
@@ -3387,8 +3274,7 @@ query."
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Mark1*)", "member WorkflowBuilder.Combine: f: 'b0 * g: 'c1 -> 'c1",queryAssemblyRefs)
         this.AssertQuickInfoContainsAtStartOfMarker (fileContent, "(*Mark2*)", "member WorkflowBuilder.Zero: unit -> unit",queryAssemblyRefs)
 
-    [<Test>]
-    [<Category("Query")>]
+    [<Fact>]
     // A computation expression with its own custom operators has correct QuickInfo displayed
     member public this.``Query.ComputationExpression.CustomOp``() =
         let fileContent ="""
@@ -3424,6 +3310,5 @@ query."
 
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickParse.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickParse.fs
index 4f2297a74e4..40efc4655a8 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickParse.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.QuickParse.fs
@@ -3,13 +3,9 @@
 namespace Tests.LanguageService
 
 open System
-open NUnit.Framework
+open Xunit
 open FSharp.Compiler.EditorServices
 
-[<TestFixture>]
-[<Category "LanguageService">] 
-[<Category("LanguageService.MSBuild")>]
-[<Category "ProjectSystem">]
 type QuickParse() = 
 
     let CheckIsland(tolerateJustAfter:bool, s : string, p : int, expected) =
@@ -17,9 +13,9 @@ type QuickParse() =
             match QuickParse.GetCompleteIdentifierIsland tolerateJustAfter s p with
             | Some (s, col, _) -> Some (s, col)
             | None -> None
-        Assert.AreEqual(expected, actual)
+        Assert.Equal(expected, actual)
         
-    [<Test>]
+    [<Fact>]
     member public qp.CheckGetPartialLongName() = 
         let CheckAt(line, index, expected) = 
             let actual = QuickParse.GetPartialLongNameEx(line, index)
@@ -53,118 +49,118 @@ type QuickParse() =
         Check("let y=SomeModule  .  ", (["SomeModule"], "", Some 18))
         
         
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland0() = CheckIsland(true, "", -1, None)       
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland1() = CheckIsland(false, "", -1, None)
         
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland2() = CheckIsland(true, "", 0, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland3() = CheckIsland(false, "", 0, None)
         
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland4() = CheckIsland(true, null, 0, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland5() = CheckIsland(false, null, 0, None)
         
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland6() = CheckIsland(false, "identifier", 0, Some("identifier",10))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland7() = CheckIsland(false, "identifier", 8, Some("identifier",10))
         
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland8() = CheckIsland(true, "identifier", 0, Some("identifier",10))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland9() = CheckIsland(true, "identifier", 8, Some("identifier",10))
 
     // A place where tolerateJustAfter matters
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland10() = CheckIsland(false, "identifier", 10, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland11() = CheckIsland(true, "identifier", 10, Some("identifier",10))
 
     // Index which overflows the line
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland12() = CheckIsland(true, "identifier", 11, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland13() = CheckIsland(false, "identifier", 11, None)
     
     // Match active pattern identifiers
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland14() = CheckIsland(false, "|Identifier|", 0, Some("|Identifier|",12))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland15() = CheckIsland(true, "|Identifier|", 0, Some("|Identifier|",12))        
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland16() = CheckIsland(false, "|Identifier|", 12, None)    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland17() = CheckIsland(true, "|Identifier|", 12, Some("|Identifier|",12))        
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland18() = CheckIsland(false, "|Identifier|", 13, None)    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland19() = CheckIsland(true, "|Identifier|", 13, None)        
     
     // ``Quoted`` identifiers
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland20() = CheckIsland(false, "``Space Man``", 0, Some("``Space Man``",13))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland21() = CheckIsland(true, "``Space Man``", 0, Some("``Space Man``",13))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland22() = CheckIsland(false, "``Space Man``", 10, Some("``Space Man``",13))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland23() = CheckIsland(true, "``Space Man``", 10, Some("``Space Man``",13))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland24() = CheckIsland(false, "``Space Man``", 11, Some("``Space Man``",13))    
-    // [<Test>]
+    // [<Fact>]
     // member public qp.CheckIsland25() = CheckIsland(true, "``Space Man``", 11, Some("Man",11))  // This is probably not what the user wanted. Not enforcing this test.
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland26() = CheckIsland(false, "``Space Man``", 12, Some("``Space Man``",13))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland27() = CheckIsland(true, "``Space Man``", 12, Some("``Space Man``",13))    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland28() = CheckIsland(false, "``Space Man``", 13, None)    
-    [<Test>]
+    [<Fact>]
     member public qp.CheckIsland29() = CheckIsland(true, "``Space Man``", 13, Some("``Space Man``",13))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland30() = CheckIsland(false, "``Space Man``", 14, None)    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland31() = CheckIsland(true, "``Space Man``", 14, None)    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland32() = CheckIsland(true, "``msft-prices.csv``", 14, Some("``msft-prices.csv``",19))    
     // handle extracting islands from arrays    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland33() = CheckIsland(true, "[|abc;def|]", 2, Some("abc",5))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland34() = CheckIsland(true, "[|abc;def|]", 4, Some("abc",5))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland35() = CheckIsland(true, "[|abc;def|]", 5, Some("abc",5))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland36() = CheckIsland(true, "[|abc;def|]", 6, Some("def",9))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland37() = CheckIsland(true, "[|abc;def|]", 8, Some("def",9))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland38() = CheckIsland(true, "[|abc;def|]", 9, Some("def",9))    
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland39() = CheckIsland(false, "identifier(*boo*)", 0, Some("identifier",10))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland40() = CheckIsland(true, "identifier(*boo*)", 0, Some("identifier",10))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland41() = CheckIsland(false, "identifier(*boo*)", 10, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland42() = CheckIsland(true, "identifier(*boo*)", 10, Some("identifier",10))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland43() = CheckIsland(false, "identifier(*boo*)", 11, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland44() = CheckIsland(true, "identifier(*boo*)", 11, None)
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland45() = CheckIsland(false, "``Space Man (*boo*)``", 13, Some("``Space Man (*boo*)``",21))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland46() = CheckIsland(true, "``Space Man (*boo*)``", 13, Some("``Space Man (*boo*)``",21))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland47() = CheckIsland(false, "(*boo*)identifier", 11, Some("identifier",17))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland48() = CheckIsland(true, "(*boo*)identifier", 11, Some("identifier",17))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland49() = CheckIsland(false, "identifier(*(*  *)boo*)", 0, Some("identifier",10))
-    [<Test>] 
+    [<Fact>] 
     member public qp.CheckIsland50() = CheckIsland(true, "identifier(*(*  *)boo*)", 0, Some("identifier",10))
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs
index 8a563a879dc..f6c6ce7fdb7 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs
@@ -5,7 +5,7 @@ namespace Tests.LanguageService.Script
 open System
 open System.IO
 open System.Reflection
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
@@ -13,8 +13,6 @@ open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 
-[<TestFixture>]
-[<Category "LanguageService">]
 type UsingMSBuild() as this = 
     inherit LanguageServiceBaseTests() 
 
@@ -59,7 +57,7 @@ type UsingMSBuild() as this =
             [ for i = 0 to errorList.Length - 1 do
                 yield errorList.[i].Message]
             
-        Assert.IsTrue(errorList
+        Assert.True(errorList
                           |> GetErrorMessages
                           |> Seq.exists (fun errorMessage ->
                                 errorMessage.Contains(expectedStr)))
@@ -92,7 +90,7 @@ type UsingMSBuild() as this =
             match squiggleOption with
             | None -> Assert.Fail("Expected a squiggle but none was seen.")
             | Some(severity,message) ->
-                Assert.IsTrue((severity=expectedSeverity), sprintf "Expected %s but saw %s: %s" nameOfExpected nameOfNotExpected message)
+                Assert.True((severity=expectedSeverity), sprintf "Expected %s but saw %s: %s" nameOfExpected nameOfNotExpected message)
                 assertf(message,containing)        
         AssertSquiggle Microsoft.VisualStudio.FSharp.LanguageService.Severity.Error    "Error"    "Warning" AssertContains,
         AssertSquiggle Microsoft.VisualStudio.FSharp.LanguageService.Severity.Warning  "Warning"  "Error"   AssertContains,
@@ -133,27 +131,26 @@ type UsingMSBuild() as this =
         AssertNotContains(tooltip, notexpected)
 
     /// There was a problem with Salsa that caused squiggles not to be shown for .fsx files.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.Squiggles.ShowInFsxFiles``() =  
         let fileContent = """open Thing1.Thing2"""
         this.VerifyFSXErrorListContainedExpectedString(fileContent,"Thing1")
         
     /// Regression test for FSharp1.0:4861 - #r to nonexistent file causes the first line to be squiggled
     /// There was a problem with Salsa that caused squiggles not to be shown for .fsx files.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.Hash.RProperSquiggleForNonExistentFile``() =  
         let fileContent = """#r "NonExistent" """
         this.VerifyFSXErrorListContainedExpectedString(fileContent,"was not found or is invalid") 
 
     /// Nonexistent hash. There was a problem with Salsa that caused squiggles not to be shown for .fsx files.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.Hash.RDoesNotExist.Bug3325``() =  
         let fileContent = """#r "ThisDLLDoesNotExist" """
         this.VerifyFSXErrorListContainedExpectedString(fileContent,"'ThisDLLDoesNotExist' was not found or is invalid") 
 
     // There was a spurious error message on the first line.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.Bug4861``() =  
         let code = 
                                       ["#light" // First line is important in this repro
@@ -162,7 +159,7 @@ type UsingMSBuild() as this =
         let (project, _) = createSingleFileFsxFromLines code
         AssertExactlyCountErrorSeenContaining(project, "Nonexistent", 1)   // ...and not an error on the first line.
         
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.InvalidHashLoad.ShouldBeASquiggle.Bug3012``() =  
         let fileContent = """
             #light
@@ -171,8 +168,7 @@ type UsingMSBuild() as this =
         this.VerifyFSXErrorListContainedExpectedString(fileContent,"Bar.fs") 
 
     // Transitive to existing property.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ScriptClosure.TransitiveLoad1``() = 
         use _guard = this.UsingNewVS() 
         let solution = this.CreateSolution()
@@ -196,8 +192,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)
 
     // Transitive to nonexisting property.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ScriptClosure.TransitiveLoad2``() = 
         use _guard = this.UsingNewVS()  
         let solution = this.CreateSolution()
@@ -219,8 +214,7 @@ type UsingMSBuild() as this =
         AssertExactlyOneErrorSeenContaining(project, "NonExistingProperty")
 
     /// FEATURE: Typing a #r into a file will cause it to be recognized by intellisense.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashR.AddedIn``() =  
         let code =
                                     ["#light"
@@ -240,7 +234,7 @@ type UsingMSBuild() as this =
         gpatcc.AssertExactly(notAA[file],notAA[file], true (* expectCreate, because dependent DLL set changed *))
 
     // FEATURE: Adding a #load to a file will cause types from that file to be visible in intellisense
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashLoad.Added``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -271,7 +265,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)
 
     // FEATURE: Removing a #load to a file will cause types from that file to no longer be visible in intellisense
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashLoad.Removed``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -301,7 +295,7 @@ type UsingMSBuild() as this =
         TakeCoffeeBreak(this.VS)
         VerifyErrorListContainedExpectedStr("MyNamespace",project)
     
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashLoad.Conditionals``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -330,14 +324,13 @@ type UsingMSBuild() as this =
         MoveCursorToEndOfMarker(fsx, "InDifferentFS.")
         let completion = AutoCompleteAtCursor fsx
         let completion = completion |> Array.map (fun (CompletionItem(name, _, _, _, _)) -> name) |> set
-        Assert.AreEqual(Set.count completion, 2, "Expected 2 elements in the completion list")
-        Assert.IsTrue(completion.Contains "x", "Completion list should contain x because INTERACTIVE is defined")
-        Assert.IsTrue(completion.Contains "B", "Completion list should contain B because DEBUG is not defined")
+        Assert.Equal(Set.count completion, 2)
+        Assert.True(completion.Contains "x", "Completion list should contain x because INTERACTIVE is defined")
+        Assert.True(completion.Contains "B", "Completion list should contain B because DEBUG is not defined")
         
 
     /// FEATURE: Removing a #r into a file will cause it to no longer be seen by intellisense.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashR.Removed``() =  
         let code =
                                     ["#light"
@@ -362,8 +355,7 @@ type UsingMSBuild() as this =
 
 
     // Corecursive load to existing property.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.ScriptClosure.TransitiveLoad3``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -387,8 +379,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)
         
     // #load of .fsi is respected (for non-hidden property)
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.ScriptClosure.TransitiveLoad9``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -416,8 +407,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project) 
 
     // #load of .fsi is respected at second #load level (for non-hidden property) 
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.ScriptClosure.TransitiveLoad10``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -448,8 +438,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project) 
 
     // #load of .fsi is respected when dispersed between two #load levels (for non-hidden property)
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.ScriptClosure.TransitiveLoad11``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -480,8 +469,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)  
         
     // #load of .fsi is respected when dispersed between two #load levels (the other way) (for non-hidden property)
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.ScriptClosure.TransitiveLoad12``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -512,8 +500,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)  
         
     // #nowarn seen in closed .fsx is global to the closure
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.ScriptClosure.TransitiveLoad16``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -534,7 +521,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)   
 
     /// FEATURE: #r in .fsx to a .dll name works.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.NoError.HashR.DllWithNoPath``() =  
         let fileContent = """
             #light
@@ -543,7 +530,7 @@ type UsingMSBuild() as this =
         this.VerifyFSXNoErrorList(fileContent)
 
 
-    [<Test>]
+    [<Fact>]
     // 'System' is in the default set. Make sure we can still resolve it.
     member public this.``Fsx.NoError.HashR.BugDefaultReferenceFileIsAlsoResolved``() =  
         let fileContent = """
@@ -552,8 +539,7 @@ type UsingMSBuild() as this =
             """
         this.VerifyFSXNoErrorList(fileContent)
 
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.HashR.DoubleReference``() =  
         let fileContent = """
             #light
@@ -562,8 +548,7 @@ type UsingMSBuild() as this =
             """
         this.VerifyFSXNoErrorList(fileContent)
 
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     // 'CustomMarshalers' is loaded from the GAC _and_ it is available on XP and above.
     member public this.``Fsx.NoError.HashR.ResolveFromGAC``() =  
         let fileContent = """
@@ -572,17 +557,14 @@ type UsingMSBuild() as this =
             """
         this.VerifyFSXNoErrorList(fileContent)
 
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoError.HashR.ResolveFromFullyQualifiedPath``() =
         let fullyqualifiepathtoddll = System.IO.Path.Combine( System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory(), "System.configuration.dll" )
         let code = ["#light";"#r @\"" + fullyqualifiepathtoddll + "\""]
         let (project, _) = createSingleFileFsxFromLines code
         AssertNoErrorsOrWarnings(project)
 
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Fsx.NoError.HashR.RelativePath1``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -618,8 +600,7 @@ type UsingMSBuild() as this =
         let ans = GetSquiggleAtCursor(script1)
         AssertNoSquiggle(ans)
 
-    [<Test; Category("fsx closure")>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Fsx.NoError.HashR.RelativePath2``() = 
         use _guard = this.UsingNewVS()  
         let solution = this.CreateSolution()
@@ -656,7 +637,7 @@ type UsingMSBuild() as this =
         AssertNoSquiggle(ans)
 
      /// FEATURE: #load in an .fsx file will include that file in the 'build' of the .fsx.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.NoError.HashLoad.Simple``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -678,8 +659,7 @@ type UsingMSBuild() as this =
         AssertNoErrorsOrWarnings(project)
 
     // In this bug the #loaded file contains a level-4 warning (copy to avoid mutation). This warning was reported at the #load in file2.fsx but shouldn't have been.s
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.NoWarn.OnLoadedFile.Bug4837``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -699,8 +679,7 @@ type UsingMSBuild() as this =
 
     /// FEATURE: .fsx files have automatic imports of certain system assemblies.
     //There is a test bug here. The actual scenario works. Need to revisit.
-    [<Test>]
-    [<Category("ReproX")>]  
+    [<Fact>]
     member public this.``Fsx.NoError.AutomaticImportsForFsxFiles``() =
         let fileContent = """
             #light
@@ -717,8 +696,7 @@ type UsingMSBuild() as this =
         this.VerifyFSXNoErrorList(fileContent) 
 
     // Corecursive load to nonexisting property.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.ScriptClosure.TransitiveLoad4``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -741,8 +719,7 @@ type UsingMSBuild() as this =
         AssertExactlyOneErrorSeenContaining(project, "NonExistingProperty")  
 
     // #load of .fsi is respected
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.ScriptClosure.TransitiveLoad5``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -770,8 +747,7 @@ type UsingMSBuild() as this =
         AssertExactlyOneErrorSeenContaining(project, "HiddenProperty")   
 
     // #load of .fsi is respected at second #load level
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.ScriptClosure.TransitiveLoad6``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -802,8 +778,7 @@ type UsingMSBuild() as this =
         AssertExactlyOneErrorSeenContaining(project, "HiddenProperty") 
         
     // #load of .fsi is respected when dispersed between two #load levels
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.ScriptClosure.TransitiveLoad7``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -834,8 +809,7 @@ type UsingMSBuild() as this =
         AssertExactlyOneErrorSeenContaining(project, "HiddenProperty")    
         
     // #load of .fsi is respected when dispersed between two #load levels (the other way)
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.ScriptClosure.TransitiveLoad8``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -866,8 +840,7 @@ type UsingMSBuild() as this =
         AssertExactlyOneErrorSeenContaining(project, "HiddenProperty")   
         
     // Bug seen during development: A #load in an .fs would be followed.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ExactlyOneError.ScriptClosure.TransitiveLoad15``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -890,7 +863,7 @@ type UsingMSBuild() as this =
         TakeCoffeeBreak(this.VS)
         AssertExactlyOneErrorSeenContaining(project, "Namespace")  
 
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.Bug4311HoverOverReferenceInFirstLine``() =
         let fileContent = """#r "PresentationFramework.dll"
                              
@@ -899,7 +872,7 @@ type UsingMSBuild() as this =
         this.AssertQuickInfoContainsAtEndOfMarkerInFsxFile fileContent marker "PresentationFramework.dll"
         this.AssertQuickInfoNotContainsAtEndOfMarkerInFsxFile fileContent marker "multiple results"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.QuickInfo.Bug4979``() =
         let code = 
                 ["System.ConsoleModifiers.Shift |> ignore "
@@ -925,7 +898,7 @@ type UsingMSBuild() as this =
     // they may be metadata-only assemblies.
     //
     // "Reference Assemblies" was only introduced in 3.5sp1, so not all 2.0 F# boxes will have it, so only run on 4.0
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.Bug5073``() =
         let fileContent = """#r "System" """
         let marker = "#r \"System"
@@ -933,35 +906,32 @@ type UsingMSBuild() as this =
         this.AssertQuickInfoContainsAtEndOfMarkerInFsxFile fileContent marker ".NET Framework"
 
     /// FEATURE: Hovering over a resolved #r file will show a data tip with the fully qualified path to that file.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashR_QuickInfo.ShowFilenameOfResolvedAssembly``() =
         this.AssertQuickInfoContainsAtEndOfMarkerInFsxFile
             """#r "System.Transactions" """ // Pick anything that isn't in the standard set of assemblies.
             "#r \"System.Tra" "System.Transactions.dll"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashR_QuickInfo.BugDefaultReferenceFileIsAlsoResolved``() =
         this.AssertQuickInfoContainsAtEndOfMarkerInFsxFile
             """#r "System" """  // 'System' is in the default set. Make sure we can still resolve it.
             "#r \"Syst" "System.dll"
         
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashR_QuickInfo.DoubleReference``() =
         let fileContent = """#r "System" // Mark1
                              #r "System" // Mark2 """   // The same reference repeated twice. 
         this.AssertQuickInfoContainsAtStartOfMarkerInFsxFile fileContent "tem\" // Mark1" "System.dll"
         this.AssertQuickInfoContainsAtStartOfMarkerInFsxFile fileContent "tem\" // Mark2" "System.dll"
         
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashR_QuickInfo.ResolveFromGAC``() = 
         this.AssertQuickInfoContainsAtEndOfMarkerInFsxFile
             """#r "CustomMarshalers" """        // 'mscorcfg' is loaded from the GAC _and_ it is available on XP and above.
             "#r \"Custo" ".NET Framework"
 
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashR_QuickInfo.ResolveFromFullyQualifiedPath``() = 
         let fullyqualifiepathtoddll = System.IO.Path.Combine( System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory(), "System.configuration.dll" ) // Can be any fully qualified path to an assembly
         let expectedtooltip = System.Reflection.Assembly.ReflectionOnlyLoadFrom(fullyqualifiepathtoddll).FullName
@@ -970,7 +940,7 @@ type UsingMSBuild() as this =
         this.AssertQuickInfoContainsAtEndOfMarkerInFsxFile fileContent marker expectedtooltip
         //this.AssertQuickInfoNotContainsAtEndOfMarkerInFsxFile fileContent marker ".dll"
 
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.InvalidHashReference.ShouldBeASquiggle.Bug3012``() =  
         let code = 
             ["#light"
@@ -979,11 +949,10 @@ type UsingMSBuild() as this =
         MoveCursorToEndOfMarker(file,"#r \"Ba") 
         let squiggle = GetSquiggleAtCursor(file)
         TakeCoffeeBreak(this.VS)
-        Assert.IsTrue(snd squiggle.Value |> fun str -> str.Contains("Bar.dll"))
+        Assert.True(snd squiggle.Value |> fun str -> str.Contains("Bar.dll"))
 
     // Bug seen during development: The unresolved reference error would x-ray through to the root.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ScriptClosure.TransitiveLoad14``() =  
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1016,23 +985,23 @@ type UsingMSBuild() as this =
         | Some(sev,msg) -> 
             AssertEqual(Microsoft.VisualStudio.FSharp.LanguageService.Severity.Error, sev)
             AssertContains(msg, expectedStr)
-        | _ -> Assert.Fail() 
+        | _ -> failwith ""
 
     /// FEATURE: #r, #I, #load are all errors when running under the language service
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashDirectivesAreErrors.InNonScriptFiles.Case1``() =  
         this.TestFsxHashDirectivesAreErrors("#r \"Joe", "may only be used in F# script files")
      
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashDirectivesAreErrors.InNonScriptFiles.Case2``() =  
         this.TestFsxHashDirectivesAreErrors("#I \"", "may only be used in F# script files")
         
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashDirectivesAreErrors.InNonScriptFiles.Case3``() =  
         this.TestFsxHashDirectivesAreErrors("#load \"Doo", "may only be used in F# script files")
 
     /// FEATURE: #reference against a non-assembly .EXE gives a reasonable error message
-    //[<Test>]
+    //[<Fact>]
     member public this.``Fsx.HashReferenceAgainstNonAssemblyExe``() = 
         let windows = System.Environment.GetEnvironmentVariable("windir")
         let code =
@@ -1048,8 +1017,7 @@ type UsingMSBuild() as this =
     (* ---------------------------------------------------------------------------------- *)
 
      // FEATURE: A #loaded file is squiggled with an error if there are errors in that file.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashLoadedFileWithErrors.Bug3149``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1074,8 +1042,7 @@ type UsingMSBuild() as this =
         
         
      // FEATURE: A #loaded file is squiggled with a warning if there are warning that file.
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashLoadedFileWithWarnings.Bug3149``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1098,8 +1065,7 @@ type UsingMSBuild() as this =
         AssertSquiggleIsWarningContaining(ans, "WarningHere")  
 
      // Bug: #load should report the first error message from a file
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.HashLoadedFileWithErrors.Bug3652``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1125,7 +1091,7 @@ type UsingMSBuild() as this =
         AssertSquiggleIsErrorNotContaining(ans, "foo")
 
     // In this bug the .fsx project directory was wrong so it couldn't reference a relative file.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.ScriptCanReferenceBinDirectoryOutput.Bug3151``() =
         use _guard = this.UsingNewVS()
         let stopWatch = new System.Diagnostics.Stopwatch()
@@ -1155,8 +1121,7 @@ type UsingMSBuild() as this =
                
 
     /// In this bug, multiple references to mscorlib .dll were causing problem in load closure
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.BugAllowExplicitReferenceToMsCorlib``() =  
         let code =
                                     ["#r \"mscorlib\""
@@ -1169,8 +1134,7 @@ type UsingMSBuild() as this =
         AssertCompListContains(completions,"CommandLineArgs")        
         
     /// FEATURE: There is a global fsi module that should be in scope for script files.        
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.Bug2530FsiObject``() =  
         let code = 
                                     ["#light"
@@ -1183,8 +1147,7 @@ type UsingMSBuild() as this =
         AssertCompListContains(completions,"CommandLineArgs")
   
     // Ensure that the script closure algorithm gets the right order of hash directives
-    [<Test>]
-    [<Category("fsx closure")>]
+    [<Fact>]
     member public this.``Fsx.ScriptClosure.SurfaceOrderOfHashes``() =  
         let code = 
                                     ["#r \"System.Runtime.Remoting\""
@@ -1199,12 +1162,12 @@ type UsingMSBuild() as this =
         AssertArrayContainsPartialMatchOf(fas.OtherOptions, "System.Runtime.Remoting.dll")
         AssertArrayContainsPartialMatchOf(fas.OtherOptions, "System.Transactions.dll")
         AssertArrayContainsPartialMatchOf(fas.OtherOptions, "FSharp.Compiler.Interactive.Settings.dll")
-        Assert.AreEqual(Path.Combine(projectFolder,"File1.fsx"), fas.SourceFiles.[0])
-        Assert.AreEqual(1, fas.SourceFiles.Length)
+        Assert.Equal(Path.Combine(projectFolder,"File1.fsx"), fas.SourceFiles.[0])
+        Assert.Equal(1, fas.SourceFiles.Length)
 
 
     /// FEATURE: #reference against a strong name should work.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.HashReferenceAgainstStrongName``() = 
         let code =
                                             ["#light"
@@ -1217,7 +1180,7 @@ type UsingMSBuild() as this =
 
 
     /// Try out some bogus file names in #r, #I and #load.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.InvalidMetaCommandFilenames``() =
         let code = 
                                     [
@@ -1236,7 +1199,7 @@ type UsingMSBuild() as this =
         TakeCoffeeBreak(this.VS) // This used to assert
 
     /// FEATURE: .fsx files have INTERACTIVE #defined
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.INTERACTIVEIsDefinedInFsxFiles``() =
         let code =
                                     [
@@ -1249,9 +1212,7 @@ type UsingMSBuild() as this =
         AssertEqual(TokenType.Identifier ,GetTokenTypeAtCursor(file))  
 
     // Ensure that basic compile of an .fsx works        
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_1``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1260,14 +1221,12 @@ type UsingMSBuild() as this =
         let file1 = AddFileFromTextEx(project,"Script.fsx","Script.fsx",BuildAction.Compile,
                                       ["printfn \"Hello world\""])
         let build = time1 Build project "Time to build project"
-        Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed")
+        Assert.True(build.BuildSucceeded, "Expected build to succeed")
         ShowErrors(project)
         
 
     // Compile a script which #loads a source file. The build can't succeed without the loaded file.      
-    [<Test; Category("Expensive")>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_2``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1285,12 +1244,10 @@ type UsingMSBuild() as this =
             let lines = GetOutputWindowPaneLines(this.VS)
             for line in lines do printfn "%s" line
             ()
-        Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed")
+        Assert.True(build.BuildSucceeded, "Expected build to succeed")
         
     // Compile a script which #loads a source file. The build can't succeed without 
-    [<Test; Category("Expensive")>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_3``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1308,12 +1265,10 @@ type UsingMSBuild() as this =
             let lines = GetOutputWindowPaneLines(this.VS)
             for line in lines do printfn "%s" line
             ()
-        Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed")        
+        Assert.True(build.BuildSucceeded, "Expected build to succeed")        
         
     // Must be explicitly referenced by compile.
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_Bug5416_1``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1325,13 +1280,10 @@ type UsingMSBuild() as this =
             let lines = GetOutputWindowPaneLines(this.VS)
             for line in lines do printfn "%s" line
             ()
-        Assert.IsTrue(not(build.BuildSucceeded), "Expected build to fail")    
+        Assert.True(not(build.BuildSucceeded), "Expected build to fail")    
         
     // Must be explicitly referenced by compile.
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Fsx.CompileFsx_Bug5416_2``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1357,13 +1309,11 @@ type UsingMSBuild() as this =
             for line in lines do printfn "%s" line
             ()
         if not(SupportsOutputWindowPane(this.VS)) then  
-            Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed")                
+            Assert.True(build.BuildSucceeded, "Expected build to succeed")                
         
         
     // Ensure that #load order is preserved when #loading multiple files. 
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_5``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1388,13 +1338,11 @@ type UsingMSBuild() as this =
             let lines = GetOutputWindowPaneLines(this.VS)
             for line in lines do printfn "%s" line
             ()
-        Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed")          
+        Assert.True(build.BuildSucceeded, "Expected build to succeed")          
         
     // If an fs file is explicitly passed in to the compiler and also #loaded then 
     // the command-line order is respected rather than the #load order
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_6``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1419,14 +1367,12 @@ type UsingMSBuild() as this =
             let lines = GetOutputWindowPaneLines(this.VS)
             for line in lines do printfn "%s" line
             ()
-        Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed") 
+        Assert.True(build.BuildSucceeded, "Expected build to succeed") 
 
         
         
     // If a #loaded file does not exist, there should be an error
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_7``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1441,13 +1387,11 @@ type UsingMSBuild() as this =
             for line in lines do printfn "%s" line
             AssertListContainsInOrder(lines, ["error FS0079: Could not load file"; "NonexistentFile.fs"; "because it does not exist or is inaccessible"])            
             
-        Assert.IsTrue(not(build.BuildSucceeded), "Expected build to fail")       
+        Assert.True(not(build.BuildSucceeded), "Expected build to fail")       
         
         
     // #r references should be respected.
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_8``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1462,13 +1406,11 @@ type UsingMSBuild() as this =
             let lines = GetOutputWindowPaneLines(this.VS)
             for line in lines do printfn "%s" line
             
-        Assert.IsTrue(build.BuildSucceeded, "Expected build to succeed")          
+        Assert.True(build.BuildSucceeded, "Expected build to succeed")          
         
         
     // Missing script file should be a reasonable failure, not a callstack.
-    [<Test>]
-    [<Category("fsx closure")>]
-    [<Category("fsx compile")>]
+    [<Fact>]
     member public this.``Fsx.CompileFsx_Bug5414``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -1486,11 +1428,11 @@ type UsingMSBuild() as this =
                 printfn "%s" line
                 AssertNotContains(line,"error MSB") // Microsoft.FSharp.Targets(135,9): error MSB6006: "fsc.exe" exited with code -532462766.
 
-        Assert.IsTrue(not(build.BuildSucceeded), "Expected build to fail")                                  
+        Assert.True(not(build.BuildSucceeded), "Expected build to fail")                                  
         
         
     /// There was a problem in which synthetic tokens like #load were causing asserts
-    [<Test; Category("Expensive")>]
+    [<Fact>]
     member public this.``Fsx.SyntheticTokens``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -1503,7 +1445,7 @@ type UsingMSBuild() as this =
             )
                                  
     /// There was a problem where an unclosed reference picked up the text of the reference on the next line.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.ShouldBeAbleToReference30Assemblies.Bug2050``() =     
         let code = 
                                     ["#light"
@@ -1516,7 +1458,7 @@ type UsingMSBuild() as this =
         AssertCompListContains(completions,"Linq")
 
     /// There was a problem where an unclosed reference picked up the text of the reference on the next line.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.UnclosedHashReference.Case1``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -1524,7 +1466,7 @@ type UsingMSBuild() as this =
             "#reference \"" // Unclosed
             "#reference \"Hello There\""]    
             )
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.UnclosedHashReference.Case2``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner,
@@ -1534,7 +1476,7 @@ type UsingMSBuild() as this =
            )
                                      
     /// There was a problem where an unclosed reference picked up the text of the reference on the next line.
-    [<Test>]
+    [<Fact>]
     member public this.``Fsx.UnclosedHashLoad``() =     
         Helper.ExhaustivelyScrutinize(
             this.TestRunner, 
@@ -1543,9 +1485,7 @@ type UsingMSBuild() as this =
               "#load \"Hello There\""]
             ) 
 
-    [<Test>]
-    [<Category("TypeProvider")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``TypeProvider.UnitsOfMeasure.SmokeTest1``() =
         let code =
                                     ["open Microsoft.FSharp.Data.UnitSystems.SI.UnitNames"
@@ -1565,22 +1505,22 @@ type UsingMSBuild() as this =
         use _guard = this.UsingNewVS()
         let providerAssemblyName = PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")
         let providerAssembly = System.Reflection.Assembly.LoadFrom providerAssemblyName
-        Assert.IsNotNull(providerAssembly, "provider assembly should not be null")
+        Assert.NotNull(providerAssembly, "provider assembly should not be null")
         let providerCounters = providerAssembly.GetType("DummyProviderForLanguageServiceTesting.GlobalCounters")
-        Assert.IsNotNull(providerCounters, "provider counters module should not be null")
+        Assert.NotNull(providerCounters, "provider counters module should not be null")
         let totalCreationsMeth = providerCounters.GetMethod("GetTotalCreations")
-        Assert.IsNotNull(totalCreationsMeth, "totalCreationsMeth should not be null")
+        Assert.NotNull(totalCreationsMeth, "totalCreationsMeth should not be null")
         let totalDisposalsMeth = providerCounters.GetMethod("GetTotalDisposals")
-        Assert.IsNotNull(totalDisposalsMeth, "totalDisposalsMeth should not be null")
+        Assert.NotNull(totalDisposalsMeth, "totalDisposalsMeth should not be null")
         let checkConfigsMeth = providerCounters.GetMethod("CheckAllConfigsDisposed")
-        Assert.IsNotNull(checkConfigsMeth, "checkConfigsMeth should not be null")
+        Assert.NotNull(checkConfigsMeth, "checkConfigsMeth should not be null")
 
         let providerCounters2 = providerAssembly.GetType("ProviderImplementation.ProvidedTypes.GlobalCountersForInvalidation")
-        Assert.IsNotNull(providerCounters2, "provider counters #2 module should not be null")
+        Assert.NotNull(providerCounters2, "provider counters #2 module should not be null")
         let totalInvalidationHandlersAddedMeth = providerCounters2.GetMethod("GetInvalidationHandlersAdded")
-        Assert.IsNotNull(totalInvalidationHandlersAddedMeth, "totalInvalidationHandlersAddedMeth should not be null")
+        Assert.NotNull(totalInvalidationHandlersAddedMeth, "totalInvalidationHandlersAddedMeth should not be null")
         let totalInvalidationHandlersRemovedMeth = providerCounters2.GetMethod("GetInvalidationHandlersRemoved")
-        Assert.IsNotNull(totalInvalidationHandlersRemovedMeth, "totalInvalidationHandlersRemovedMeth should not be null")
+        Assert.NotNull(totalInvalidationHandlersRemovedMeth, "totalInvalidationHandlersRemovedMeth should not be null")
 
         let totalCreations() = totalCreationsMeth.Invoke(null, [| |]) :?> int
         let totalDisposals() = totalDisposalsMeth.Invoke(null, [| |]) :?> int
@@ -1598,8 +1538,8 @@ type UsingMSBuild() as this =
         let countInvalidationHandlersAdded() = totalInvalidationHandlersAdded() - startInvalidationHandlersAdded
         let countInvalidationHandlersRemoved() = totalInvalidationHandlersRemoved() - startInvalidationHandlersRemoved
 
-        Assert.IsTrue(startCreations >= startDisposals, "Check0")
-        Assert.IsTrue(startInvalidationHandlersAdded >= startInvalidationHandlersRemoved, "Check0")
+        Assert.True(startCreations >= startDisposals, "Check0")
+        Assert.True(startInvalidationHandlersAdded >= startInvalidationHandlersRemoved, "Check0")
         for i in 1 .. 50 do 
             let solution = this.CreateSolution()
             let project = CreateProject(solution,"testproject" + string (i % 20))    
@@ -1624,17 +1564,17 @@ type UsingMSBuild() as this =
             let d = countDisposals()
 
             // Creations should always be greater or equal to disposals
-            Assert.IsTrue(c >= d, "Check2, countCreations() >= countDisposals(), iteration " + string i + ", countCreations() = " + string c + ", countDisposals() = " + string d)
+            Assert.True(c >= d, "Check2, countCreations() >= countDisposals(), iteration " + string i + ", countCreations() = " + string c + ", countDisposals() = " + string d)
 
             // Creations can run ahead of iterations if the background checker resurrects the builder for a project
             // even after we've moved on from it.
-            Assert.IsTrue((c >= i), "Check3, countCreations() >= i, iteration " + string i + ", countCreations() = " + string c)
+            Assert.True((c >= i), "Check3, countCreations() >= i, iteration " + string i + ", countCreations() = " + string c)
 
             if not clearing then 
                 // By default we hold 3 build incrementalBuilderCache entries and 5 typeCheckInfo entries, so if we're not clearing
                 // there should be some roots to project builds still present
                 if i >= 3 then 
-                    Assert.IsTrue(c >= d + 3, "Check4a, c >= countDisposals() + 3, iteration " + string i + ", i = " + string i + ", countDisposals() = " + string d)
+                    Assert.True(c >= d + 3, "Check4a, c >= countDisposals() + 3, iteration " + string i + ", i = " + string i + ", countDisposals() = " + string d)
                     printfn "Check4a2, i = %d, countInvalidationHandlersRemoved() = %d" i (countInvalidationHandlersRemoved())
 
             // If we forcefully clear out caches and force a collection, then we can say much stronger things...
@@ -1644,31 +1584,30 @@ type UsingMSBuild() as this =
                 let d = countDisposals()
 
                 // Creations should be equal to disposals after a `ClearLanguageServiceRootCachesAndCollectAndFinalizeAllTransients`
-                Assert.IsTrue((c = d), "Check4b, countCreations() = countDisposals(), iteration " + string i)
-                Assert.IsTrue((countInvalidationHandlersAdded() = countInvalidationHandlersRemoved()), "Check4b2, all invalidation handlers removed, iteration " + string i)
+                Assert.True((c = d), "Check4b, countCreations() = countDisposals(), iteration " + string i)
+                Assert.True((countInvalidationHandlersAdded() = countInvalidationHandlersRemoved()), "Check4b2, all invalidation handlers removed, iteration " + string i)
         
         let c = countCreations()
         let d = countDisposals()
-        Assert.IsTrue(c >= 50, "Check5, at end, countCreations() >= 50")
+        Assert.True(c >= 50, "Check5, at end, countCreations() >= 50")
 
         ClearLanguageServiceRootCachesAndCollectAndFinalizeAllTransients(this.VS)
 
         let c = countCreations()
         let d = countDisposals()
         // Creations should be equal to disposals after a `ClearLanguageServiceRootCachesAndCollectAndFinalizeAllTransients`
-        Assert.IsTrue((c = d), "Check6b, at end, countCreations() = countDisposals() after explicit clearing")
-        Assert.IsTrue((countInvalidationHandlersAdded() = countInvalidationHandlersRemoved()), "Check6b2, at end, all invalidation handlers removed after explicit clearing")
+        Assert.True((c = d), "Check6b, at end, countCreations() = countDisposals() after explicit clearing")
+        Assert.True((countInvalidationHandlersAdded() = countInvalidationHandlersRemoved()), "Check6b2, at end, all invalidation handlers removed after explicit clearing")
         checkConfigsDisposed()
 
-    [<Test;Category("TypeProvider"); Category("Expensive"); Ignore("Flaky test, unclear if it is valuable")>]
+    [<Fact(Skip = "Flaky test, unclear if it is valuable")>]
     member public this.``TypeProvider.Disposal.SmokeTest1``() = this.TypeProviderDisposalSmokeTest(true)
 
-    [<Test;Category("TypeProvider"); Ignore("Flaky test, unclear if it is valuable")>]
+    [<Fact(Skip ="Flaky test, unclear if it is valuable")>]
     member public this.``TypeProvider.Disposal.SmokeTest2``() = this.TypeProviderDisposalSmokeTest(false)
 
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
 
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.TimeStamp.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.TimeStamp.fs
index 76c6d663df2..530260a0d5f 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.TimeStamp.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.TimeStamp.fs
@@ -4,15 +4,13 @@ namespace Tests.LanguageService.TimeStamp
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
 open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 
-[<TestFixture>]
-[<Category "LanguageService">] 
 type UsingMSBuild()  = 
     inherit LanguageServiceBaseTests()
 
@@ -46,7 +44,7 @@ type UsingMSBuild()  =
     // In this bug, if you clean the dependent project, the dependee started getting errors again about the unresolved assembly.
     // The desired behavior is like C#, which is if the assembly disappears from disk, we use cached results of last time it was there.
     // Disabled due to issue #11752   ---  https://github.com/dotnet/fsharp/issues/11752
-    //[<Test>]
+    //[<Fact>]
     member public this.``Regression.NoError.Timestamps.Bug3368b``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -88,8 +86,7 @@ type UsingMSBuild()  =
         AssertNoErrorsOrWarnings(project2)  // this is key, project2 remembers what used to be on disk, does not fail due to missing assembly
 
     // In this bug, the referenced project output didn't exist yet. Building dependee should cause update in dependent
-    [<Test>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Regression.NoContainedString.Timestamps.Bug3368a``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -121,7 +118,7 @@ type UsingMSBuild()  =
         AssertNoErrorSeenContaining(project2, "project1")
 
    // FEATURE: OnIdle() will reprocess open dirty files, even if those file do not currently have editor focus
-    // [<Test>] TODO This test does not work because the unit tests do not cover product code that implements this feature
+    // [<Fact>] TODO This test does not work because the unit tests do not cover product code that implements this feature
     member public this.``Timestamps.Bug3368c``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -147,7 +144,7 @@ type UsingMSBuild()  =
         TakeCoffeeBreak(this.VS)
         
         let errs = GetErrors(project2)
-        Assert.IsTrue(List.length errs > 0, "There should be errors (unresolved reference)")
+        Assert.True(List.length errs > 0, "There should be errors (unresolved reference)")
 
         // switch focus to a different file (to turn off 'focus' idle processing for file2)
         let file1 = OpenFile(project1,"File1.fs")
@@ -156,7 +153,7 @@ type UsingMSBuild()  =
         printfn "building dependent project..."
         Build project1 |> ignore
         let errs = GetErrors(project2)
-        Assert.IsTrue(List.length errs > 0, "There should be errors (unresolved reference)")
+        Assert.True(List.length errs > 0, "There should be errors (unresolved reference)")
         
         TakeCoffeeBreak(this.VS) // the code that should clear out the errors is in LanguageService.cs:LanguageService.OnIdle(), 
                           // but unit tests do not call this FSharp.LanguageService.Base code; TakeCoffeeBreak(this.VS) just simulates
@@ -165,8 +162,7 @@ type UsingMSBuild()  =
         AssertNoErrorsOrWarnings(project2)
 
    // FEATURE: When a referenced assembly's timestamp changes the reference is reread.
-    [<Test; Category("Expensive")>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Timestamps.ReferenceAssemblyChangeAbsolute``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -194,7 +190,7 @@ type UsingMSBuild()  =
         SwitchToFile this.VS file2
         MoveCursorToEndOfMarker(file2,"File1.File1.")
         let completions = AutoCompleteAtCursor(file2)
-        Assert.AreEqual(0, completions.Length)
+        Assert.Equal(0, completions.Length)
         
         // Now modify project1's file and rebuild.
         ReplaceFileInMemory file1 
@@ -208,12 +204,11 @@ type UsingMSBuild()  =
         MoveCursorToEndOfMarker(file2,"File1.File1.")
         TakeCoffeeBreak(this.VS) // Give enough time to catch up
         let completions = AutoCompleteAtCursor(file2)
-        Assert.AreNotEqual(0, completions.Length)
+        Assert.NotEqual(0, completions.Length)
         printfn "Completions=%A\n" completions
 
     // In this bug, relative paths to referenced assemblies weren't seen.
-    [<Test; Category("Expensive")>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Timestamps.ReferenceAssemblyChangeRelative``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -249,7 +244,7 @@ type UsingMSBuild()  =
         SwitchToFile this.VS file2
         MoveCursorToEndOfMarker(file2,"File1.File1.")
         let completions = AutoCompleteAtCursor(file2)
-        Assert.AreEqual(0, completions.Length)
+        Assert.Equal(0, completions.Length)
 
         // Now modify project1's file and rebuild.
         ReplaceFileInMemory file1 
@@ -263,12 +258,11 @@ type UsingMSBuild()  =
         MoveCursorToEndOfMarker(file2,"File1.File1.")
         TakeCoffeeBreak(this.VS) // Give enough time to catch up
         let completions = AutoCompleteAtCursor(file2)
-        Assert.AreNotEqual(0, completions.Length)
+        Assert.NotEqual(0, completions.Length)
         printfn "Completions=%A\n" completions
 
     // FEATURE: When a referenced project's assembly timestamp changes the reference is reread.
-    [<Test; Category("Expensive")>]
-    [<Ignore("Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
+    [<Fact(Skip = "Re-enable this test --- https://github.com/dotnet/fsharp/issues/5238")>]
     member public this.``Timestamps.ProjectReferenceAssemblyChange``() =
         use _guard = this.UsingNewVS()
         let solution = this.CreateSolution()
@@ -302,7 +296,7 @@ type UsingMSBuild()  =
         SwitchToFile this.VS file2
         MoveCursorToEndOfMarker(file2,"File1.File1.")
         let completions = AutoCompleteAtCursor(file2)
-        Assert.AreEqual(0, completions.Length)
+        Assert.Equal(0, completions.Length)
         
         // Now modify project1's file and rebuild.
         ReplaceFileInMemory file1 
@@ -316,7 +310,7 @@ type UsingMSBuild()  =
         MoveCursorToEndOfMarker(file2,"File1.File1.")
         TakeCoffeeBreak(this.VS) // Give enough time to catch up             
         let completions = AutoCompleteAtCursor(file2)
-        Assert.AreNotEqual(0, completions.Length)
+        Assert.NotEqual(0, completions.Length)
         printfn "Completions=%A\n" completions            
 
 
@@ -325,10 +319,9 @@ namespace Tests.LanguageService.TimeStamp
 open Tests.LanguageService
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 
 // Context project system
-[<TestFixture>] 
 type UsingProjectSystem() = 
     inherit UsingMSBuild(VsOpts = LanguageServiceExtension.ProjectSystemTestFlavour)
\ No newline at end of file
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs
index faf186f8cef..d484b81f8b8 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs
@@ -8,7 +8,7 @@ open System.Collections.Generic
 open System.IO
 open System.Text.RegularExpressions
 open System.Xml.Linq
-open NUnit.Framework
+open Xunit
 
 // VS namespaces 
 open Microsoft.VisualStudio
@@ -23,13 +23,10 @@ open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
 
 
-[<SetUpFixture>]
 type public AssemblyResolverTestFixture () =
 
-    [<OneTimeSetUp>]
     member public _.Init () = AssemblyResolver.addResolver ()
 
-[<TestFixture>][<Category "ProjectSystem">]
 type Config() = 
     inherit TheTests()
 
@@ -38,7 +35,7 @@ type Config() =
     static let SaveProject(project : UnitTestingFSharpProjectNode) =
         project.Save(null, 1, 0u) |> ignore
 
-    [<Test>]
+    [<Fact>]
     member this.TargetPlatform () =
         this.MakeProjectAndDoWithProjectFileAndConfigChangeNotifier(["foo.fs"], [], 
             this.MSBuildProjectMultiPlatformBoilerplate "Library",  
@@ -46,32 +43,32 @@ type Config() =
                 ccn((project :> IVsHierarchy), "Debug|x86")
                 project.ComputeSourcesAndFlags()
                 let flags = project.CompilationOptions |> List.ofArray
-                Assert.IsTrue(List.exists (fun s -> s = "--platform:x86") flags)
+                Assert.True(List.exists (fun s -> s = "--platform:x86") flags)
                 ()
         ))
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.EnsureAtLeastOneConfiguration`` () =
         this.HelperEnsureAtLeastOne 
             @"<PropertyGroup Condition="" '$(Platform)' == 'x86' "" />" 
             [|"Debug"|]  // the goal of the test - when no configs, "Debug" should magically appear
             [|"x86"|]
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.EnsureAtLeastOnePlatform`` () =
         this.HelperEnsureAtLeastOne 
             @"<PropertyGroup Condition="" '$(Configuration)' == 'Release' "" />"
             [|"Release"|]
             [|"Any CPU"|] // the goal of the test - when no platforms, "AnyCPU" should magically appear
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.EnsureAtLeastOneConfigurationAndPlatform`` () =
         this.HelperEnsureAtLeastOne 
             ""
             [|"Debug"|] // first goal of the test - when no configs, "Debug" should magically appear
             [|"Any CPU"|] // second goal of the test - when no platforms, "AnyCPU" should magically appear
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.EnsureAtLeastOneConfiguration.Imported`` () =
         // Take advantage of the fact that we always create projects one directory below TempPath
         let tmpTargets = Path.Combine(Path.GetTempPath(), "foo.targets")
@@ -88,7 +85,7 @@ type Config() =
         finally
             File.Delete tmpTargets
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.EnsureAtLeastOnePlatform.Imported`` () =
         // Take advantage of the fact that we always create projects one directory below TempPath
         // The unit test failed due to the previous test use the same target name "foo.targets". 
@@ -106,7 +103,7 @@ type Config() =
         finally
             File.Delete tmpTargets
     
-    [<Test>]
+    [<Fact>]
     member this.``Configs.Renaming`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiConfigBoilerplate ["Debug",""; "Release",""],
@@ -122,7 +119,7 @@ type Config() =
                 TheTests.AssertSimilarXml(expectedXDoc.Root, xDoc.Root)                
             ))
             
-    [<Test>]
+    [<Fact>]
     member this.``Configs.Deleting`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiConfigBoilerplate ["Debug",""; "Release",""],
@@ -137,7 +134,7 @@ type Config() =
                 let expectedXDoc = XDocument.Load(new StringReader(TheTests.SimpleFsprojText(["foo.fs"],[],expected)))
                 TheTests.AssertSimilarXml(expectedXDoc.Root, xDoc.Root)                
             ))
-    [<Test>]
+    [<Fact>]
     member this.``Configs.Adding`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiConfigBoilerplate ["Debug","<Foo/>"; "Release",""],
@@ -152,7 +149,7 @@ type Config() =
                 let expectedXDoc = XDocument.Load(new StringReader(TheTests.SimpleFsprojText(["foo.fs"],[],expected)))
                 TheTests.AssertSimilarXml(expectedXDoc.Root, xDoc.Root)                
             ))
-    [<Test>]
+    [<Fact>]
     member this.``Configs.AddingBaseless`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiConfigBoilerplate ["Debug","<Foo/>"; "Release",""],
@@ -168,7 +165,7 @@ type Config() =
                 TheTests.AssertSimilarXml(expectedXDoc.Root, xDoc.Root)                
             ))
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.Platforms.Deleting`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiPlatform ["Any CPU",""; "x86",""],
@@ -185,7 +182,7 @@ type Config() =
 
         ))
         
-    [<Test>]
+    [<Fact>]
     member this.``Configs.Platforms.Adding`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiPlatform ["Any CPU",""; "x86","<Custom/>"],
@@ -202,7 +199,7 @@ type Config() =
 
         ))
 
-    [<Test>]
+    [<Fact>]
     member this.``Configs.Platforms.AddingBaseless`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiPlatform ["Any CPU",""; "x86",""],
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
index 7aa25427e2d..d820b86a842 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
@@ -18,13 +18,12 @@ open Microsoft.VisualStudio.FSharp.ProjectSystem
 open Microsoft.VisualStudio.FSharp.Editor
 
 // Internal unittest namespaces
-open NUnit.Framework
+open Xunit
 open Salsa
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
 
-[<TestFixture>][<Category "ProjectSystem">]
 type Miscellaneous() = 
     inherit TheTests()
 
@@ -34,7 +33,7 @@ type Miscellaneous() =
     static let SaveProject(project : UnitTestingFSharpProjectNode) =
         project.Save(null, 1, 0u) |> ignore
 
-    //[<Test>]   // keep disabled unless trying to prove that UnhandledExceptionHandler is working 
+    //[<Fact>]   // keep disabled unless trying to prove that UnhandledExceptionHandler is working 
     member public this.EnsureThatUnhandledExceptionsCauseAnAssert() =
         this.MakeProjectAndDo([], ["System"], "", (fun proj ->
             let t = new System.Threading.Thread(new System.Threading.ThreadStart(fun () -> failwith "foo"))
@@ -42,16 +41,16 @@ type Miscellaneous() =
             System.Threading.Thread.Sleep(1000)
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Miscellaneous.CreatePropertiesObject`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             File.AppendAllText(projFile, TheTests.SimpleFsprojText([], [], ""))
             use project = TheTests.CreateProject(projFile) 
             let prop = project.CreatePropertiesObject()
-            Assert.AreEqual(typeof<FSharpProjectNodeProperties>, prop.GetType())
+            Assert.Equal(typeof<FSharpProjectNodeProperties>, prop.GetType())
             )
             
-    [<Test>]
+    [<Fact>]
     member public this.``Miscellaneous.TestProperties`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             File.AppendAllText(projFile, TheTests.SimpleFsprojText([], [], ""))
@@ -59,63 +58,63 @@ type Miscellaneous() =
             let prop = new FSharpProjectNodeProperties(project)
             
             prop.AssemblyName <- "a"
-            Assert.AreEqual("a", prop.AssemblyName)            
+            Assert.Equal("a", prop.AssemblyName)            
             
             // Output type and output file name
             prop.OutputType <- OutputType.Exe
-            Assert.AreEqual(OutputType.Exe, prop.OutputType)
-            Assert.AreEqual("a.exe", prop.OutputFileName)
+            Assert.Equal(OutputType.Exe, prop.OutputType)
+            Assert.Equal("a.exe", prop.OutputFileName)
             
             prop.OutputType <- OutputType.Library
-            Assert.AreEqual(OutputType.Library, prop.OutputType)
-            Assert.AreEqual("a.dll", prop.OutputFileName)
+            Assert.Equal(OutputType.Library, prop.OutputType)
+            Assert.Equal("a.dll", prop.OutputFileName)
             
             prop.OutputType <- OutputType.WinExe
-            Assert.AreEqual(OutputType.WinExe, prop.OutputType)
-            Assert.AreEqual("a.exe", prop.OutputFileName)
+            Assert.Equal(OutputType.WinExe, prop.OutputType)
+            Assert.Equal("a.exe", prop.OutputFileName)
             )            
             
-    [<Test>]
+    [<Fact>]
     member public this.``Miscellaneous.CreateServices`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             File.AppendAllText(projFile, TheTests.SimpleFsprojText([], [], ""))
             use project = TheTests.CreateProject(projFile) 
             let proj = project.CreateServices(typeof<VSLangProj.VSProject>)
-            Assert.AreEqual(typeof<Microsoft.VisualStudio.FSharp.ProjectSystem.Automation.OAVSProject>, proj.GetType())
+            Assert.Equal(typeof<Microsoft.VisualStudio.FSharp.ProjectSystem.Automation.OAVSProject>, proj.GetType())
             let eproj = project.CreateServices(typeof<EnvDTE.Project>)
-            Assert.AreEqual(typeof<Microsoft.VisualStudio.FSharp.ProjectSystem.Automation.OAProject>, eproj.GetType())
+            Assert.Equal(typeof<Microsoft.VisualStudio.FSharp.ProjectSystem.Automation.OAProject>, eproj.GetType())
             let badservice = project.CreateServices(typeof<string>)
-            Assert.IsNull(badservice)
+            Assert.Null(badservice)
             )
             
-    [<Test>]
+    [<Fact>]
     member public this.``Miscellaneous.FSharpFileNode.RelativeFilePath`` () =
         this.MakeProjectAndDo(["orig1.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "orig1.fs")
             let files = new List<FSharpFileNode>()
             project.FindNodesOfType(files)
-            Assert.AreEqual(1, files.Count)
+            Assert.Equal(1, files.Count)
             let file = files.[0]
             let path = file.RelativeFilePath
-            Assert.AreEqual("orig1.fs", path)
+            Assert.Equal("orig1.fs", path)
             ))
            
-    [<Test>]
+    [<Fact>]
     member public this.``Miscellaneous.FSharpFileNode.CreateServices`` () =
         this.MakeProjectAndDo(["orig1.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "orig1.fs")
             let files = new List<FSharpFileNode>()
             project.FindNodesOfType(files)
-            Assert.AreEqual(1, files.Count)
+            Assert.Equal(1, files.Count)
             let file = files.[0]
             let badservice = file.CreateServices(typeof<string>)
-            Assert.IsNull(badservice)
+            Assert.Null(badservice)
             let eproj = file.CreateServices(typeof<EnvDTE.ProjectItem>)
-            Assert.AreEqual(typeof<Microsoft.VisualStudio.FSharp.ProjectSystem.Automation.OAFileItem>, eproj.GetType())
+            Assert.Equal(typeof<Microsoft.VisualStudio.FSharp.ProjectSystem.Automation.OAFileItem>, eproj.GetType())
             ))
 
     
-    //[<Test>]    
+    //[<Fact>]    
     member public this.AttemptDragAndDrop() =
         printfn "starting..."
         let fsproj = "D:\Depot\staging\Test.fsproj"
@@ -159,15 +158,14 @@ type Miscellaneous() =
                 node <- node.NextSibling 
                 if node = null then
                     finished <- true
-        Assert.AreNotEqual(node, null)
+        Assert.NotEqual(node, null)
         let itemId = node.ID
         
         project.DragEnter(iOleDataObject, keyboardState, itemId, &dwEffect) |> ignore
         ()
 
     
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Automation.OutputGroup.OUTPUTLOC``() =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], [],
             this.MSBuildProjectMultiPlatform(["x86",""],"x86"),
@@ -184,8 +182,7 @@ type Miscellaneous() =
             )
          )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Automation.OutputGroups``() =
         DoWithTempFile "Test.fsproj" (fun file ->
             let text = TheTests.FsprojTextWithProjectReferences([],[],[],@"
@@ -247,7 +244,7 @@ type Miscellaneous() =
             AssertEqual expected ogInfos
         )
 
-    [<Test>]
+    [<Fact>]
     member public this.``LoadProject.x86`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], ["System"],
             this.MSBuildProjectMultiPlatform(["x86",""],"x86"),
@@ -262,8 +259,7 @@ type Miscellaneous() =
                 AssertEqual 1 l.Count
         ))
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``BuildAndClean``() =
         this.MakeProjectAndDoWithProjectFileAndConfigChangeNotifier(["foo.fs"], [], 
              this.MSBuildProjectBoilerplate "Library", 
@@ -291,7 +287,7 @@ type Miscellaneous() =
                                 success <- fSuccess <> 0
                                 printfn "Build %s, code %i, phase: %s." (if success then "succeeded" else "failed") fSuccess (if isCleaning then "Cleaning" else "Build")
 
-                                event.Set() |> Assert.IsTrue
+                                event.Set() |> Assert.True
                                 VSConstants.S_OK
                             member this.Tick pfContinue = pfContinue <- 1; VSConstants.S_OK
                         }
@@ -301,10 +297,10 @@ type Miscellaneous() =
                     let output = VsMocks.vsOutputWindowPane(ref [])
                     let doBuild target =
                         success <- false
-                        event.Reset() |> Assert.IsTrue
+                        event.Reset() |> Assert.True
                         buildMgrAccessor.BeginDesignTimeBuild() |> ValidateOK // this is not a design-time build, but our mock does all the right initialization of the build manager for us, similar to what the system would do in VS for real
                         buildableCfg.Build(0u, output, target)
-                        event.WaitOne() |> Assert.IsTrue
+                        event.WaitOne() |> Assert.True
                         buildMgrAccessor.EndDesignTimeBuild() |> ValidateOK // this is not a design-time build, but our mock does all the right initialization of the build manager for us, similar to what the system would do in VS for real
                         AssertEqual true success
 
@@ -324,7 +320,7 @@ type Miscellaneous() =
         ))
         
         
-    //KnownFail: [<Test>]
+    //KnownFail: [<Fact>]
     member public this.``ErrorReporting.EmptyModuleReportedAtTheLastLine``() =
         let (outputWindowPaneErrors : string list ref) = ref [] // output window pane errors
         let vso = VsMocks.vsOutputWindowPane(outputWindowPaneErrors)
@@ -358,16 +354,15 @@ type Miscellaneous() =
                ))
 
 #if NUNIT_V2
-    [<Test>][<ExpectedException (typeof<ClassLibraryCannotBeStartedDirectlyException>)>]
+    [<Fact>][<ExpectedException (typeof<ClassLibraryCannotBeStartedDirectlyException>)>]
     member public this.``DebuggingDLLFails``() = this.``DebuggingDLLFailsFunc``()
 #else
-    [<Test>]
+    [<Fact>]
     member public this.``DebuggingDLLFails``() =
-        Assert.That((fun () -> this.``DebuggingDLLFailsFunc``()), NUnit.Framework.Throws.TypeOf(typeof<ClassLibraryCannotBeStartedDirectlyException>))
+        Assert.Throws<ClassLibraryCannotBeStartedDirectlyException>((fun () -> this.``DebuggingDLLFailsFunc``()))
 #endif
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``DebuggingEXESucceeds``() =
         this.MakeProjectAndDoWithProjectFileAndConfigChangeNotifier(["foo.fs"], [], 
             this.MSBuildProjectBoilerplate "Exe",  
@@ -376,7 +371,7 @@ type Miscellaneous() =
                 let fooPath = Path.Combine(project.ProjectFolder, "foo.fs")
                 File.AppendAllText(fooPath, "#light")                
                 let buildResult = project.Build("Build")
-                Assert.IsTrue buildResult.IsSuccessful
+                Assert.True buildResult.IsSuccessful
                 AssertEqual true (File.Exists (Path.Combine(project.ProjectFolder, "bin\\Debug\\Blah.exe")))
 
                 let mutable configurationInterface : IVsCfg = null
@@ -387,11 +382,11 @@ type Miscellaneous() =
                     config.DebugLaunch(0ul) |> ignore
                 with
                 | :? ClassLibraryCannotBeStartedDirectlyException -> Assert.Fail("Exe should be debuggable")
-                | _ -> Assert.Fail() // DmiLom: Currently DebugLaunch() swallows most exceptions, in future if we improve DebugLaunch() we will expect it to throw a particular exception here
+                | _ -> failwith "" // DmiLom: Currently DebugLaunch() swallows most exceptions, in future if we improve DebugLaunch() we will expect it to throw a particular exception here
                 ()
         ))
         
-    [<Test>]
+    [<Fact>]
     member public this.``IsDocumentInProject`` () =
         DoWithTempFile "Test.fsproj" (fun file ->
             let fakeCsLibProjectFile = @"..\CsLib\CsLib.csproj"            
@@ -414,7 +409,7 @@ type Miscellaneous() =
             checkInProject false "System.dll"
         )
 
-    //Known Fail:  [<Test>]
+    //Known Fail:  [<Fact>]
     member public this.``PreBuildEvent`` () =
         this.MakeProjectAndDoWithProjectFile(["foo.fs"], ["System"], "",
             (fun project projFileName ->
@@ -434,10 +429,10 @@ type Miscellaneous() =
                 printfn "Build output:"
                 !outputWindowPaneErrors |> Seq.iter (printfn "%s")
                 let expectedRegex = new Regex("\\s*ProjectExt\\[.fsproj\\]")                
-                Assert.IsTrue(!outputWindowPaneErrors |> List.exists (fun s -> expectedRegex.IsMatch(s)), "did not see expected value in build output")
+                Assert.True(!outputWindowPaneErrors |> List.exists (fun s -> expectedRegex.IsMatch(s)), "did not see expected value in build output")
             ))
         
-    [<Test>]
+    [<Fact>]
     member public this.``BuildMacroValues`` () = 
         let logger (message:string) = System.IO.File.AppendAllText(@"c:\temp\logfile.txt", (message + Environment.NewLine))
 
@@ -455,23 +450,23 @@ type Miscellaneous() =
 
             // Verify Solution values
             let solutionDir = project.GetBuildMacroValue("SolutionDir")
-            Assert.IsNotNull (solutionDir, "SolutionDir is NULL")
-            Assert.IsFalse ( (solutionDir = "*Undefined*"), "SolutionDir not defined")
+            Assert.NotNull (solutionDir, "SolutionDir is NULL")
+            Assert.False ( (solutionDir = "*Undefined*"), "SolutionDir not defined")
 
             let solutionFileName = project.GetBuildMacroValue("SolutionFileName")
-            Assert.IsNotNull (solutionFileName, "SolutionFileName is null")
-            Assert.IsFalse ( (solutionFileName = "*Undefined*"), "SolutionFileName not defined")
+            Assert.NotNull (solutionFileName, "SolutionFileName is null")
+            Assert.False ( (solutionFileName = "*Undefined*"), "SolutionFileName not defined")
 
             let solutionName = project.GetBuildMacroValue("SolutionName")
-            Assert.IsNotNull (solutionName, "SolutionName is null")
-            Assert.IsFalse ( (solutionName = "*Undefined*"), "SolutionName not defined")
+            Assert.NotNull (solutionName, "SolutionName is null")
+            Assert.False ( (solutionName = "*Undefined*"), "SolutionName not defined")
 
             let solutionExt = project.GetBuildMacroValue("SolutionExt")
-            Assert.IsNotNull (solutionExt, "SolutionExt is null")
-            Assert.IsFalse ( (solutionExt = "*Undefined*"), "SolutionExt not defined")
+            Assert.NotNull (solutionExt, "SolutionExt is null")
+            Assert.False ( (solutionExt = "*Undefined*"), "SolutionExt not defined")
         )
      
-    [<Test>]
+    [<Fact>]
     member public this.CreateFSharpManifestResourceName () =
         DoWithTempFile "Test.fsproj" (fun file ->
             let text = TheTests.FsprojTextWithProjectReferences(["foo.fs";"Bar.resx"; "Bar.de.resx"; "Xyz\Baz.ru.resx"; "Abc.resources"],[],[],"")
@@ -491,14 +486,14 @@ type Miscellaneous() =
         let buildMgr = project.Site.GetService(typeof<SVsSolutionBuildManager>) :?> IVsSolutionBuildManager
         let cfgs = Array.create 1 (null : IVsProjectCfg)
         let hr = buildMgr.FindActiveProjectCfg(System.IntPtr.Zero, System.IntPtr.Zero, project, cfgs)
-        Assert.AreEqual(VSConstants.S_OK, hr)
-        Assert.IsNotNull(cfgs.[0])
+        Assert.Equal(VSConstants.S_OK, hr)
+        Assert.NotNull(cfgs.[0])
         let mutable cfgName = ""
         let hr = cfgs.[0].get_CanonicalName(&cfgName)
-        Assert.AreEqual(VSConstants.S_OK, hr)
+        Assert.Equal(VSConstants.S_OK, hr)
         cfgName
 
-    [<Test>]
+    [<Fact>]
     member this.``MSBuildExtensibility.BrokenCompileDependsOn.WithRecovery`` () =
         this.MakeProjectAndDoWithProjectFileAndConfigChangeNotifier(
             ["foo.fs";"bar.fs"],
@@ -529,7 +524,7 @@ type Miscellaneous() =
                 project.Reload()
                 // Ensure we are not in 'Foo' config, and thus expect failure
                 let curCfgCanonicalName = this.GetCurrentConfigCanonicalName(project)
-                Assert.IsFalse(curCfgCanonicalName.StartsWith("Foo"), sprintf "default config should not be 'Foo'! in fact it had canonical name '%s'" curCfgCanonicalName)
+                Assert.False(curCfgCanonicalName.StartsWith("Foo"), sprintf "default config should not be 'Foo'! in fact it had canonical name '%s'" curCfgCanonicalName)
                 // Now the project system is in a state where ComputeSourcesAndFlags will fail.
                 // Our goal is to at least be able to open individual source files and treat them like 'files outside a project' with regards to intellisense, etc.
                 // Also, if the user does 'Build', he will get an error which will help diagnose the problem.
@@ -537,10 +532,10 @@ type Miscellaneous() =
                 let ips = ipps.GetProjectSite()
                 let expected = [| |] // Ideal behavior is [|"foo.fs";"bar.fs"|], and we could choose to improve this in the future.  For now we are just happy to now throw/crash.
                 let actual = ips.CompilationSourceFiles
-                Assert.AreEqual(expected, actual, "project site did not report expected set of source files")
+                Assert.Equal<string array>(expected, actual)
             )
 
-    [<Test>]
+    [<Fact>]
     member public this.TestBuildActions () =
         DoWithTempFile "Test.fsproj" (fun file ->
             let text = TheTests.FsprojTextWithProjectReferences(["foo.fs";"Bar.resx"; "Bar.de.resx"; "Xyz\Baz.ru.resx"; "Abc.resources"],[],[],"<Import Project=\"My.targets\" />")
@@ -571,7 +566,7 @@ type Miscellaneous() =
             ()
         )
 
-    [<Test>]
+    [<Fact>]
     member public this.TestBuildActionConversions () =
 
         let replace (pattern:string) (replacement:string) (input:string) = Regex.Replace(input, pattern, replacement)
@@ -582,10 +577,10 @@ type Miscellaneous() =
             props :?> BuildableNodeProperties
 
         let checkNotStandardBuildAction buildAction = 
-            Assert.IsFalse(VSLangProj.prjBuildAction.prjBuildActionNone = buildAction, "Unexpected None match")
-            Assert.IsFalse(VSLangProj.prjBuildAction.prjBuildActionCompile = buildAction, "Unexpected Compile match")
-            Assert.IsFalse(VSLangProj.prjBuildAction.prjBuildActionContent = buildAction, "Unexpected Content match")
-            Assert.IsFalse(VSLangProj.prjBuildAction.prjBuildActionEmbeddedResource = buildAction, "Unexpected EmbeddedResource match")
+            Assert.False(VSLangProj.prjBuildAction.prjBuildActionNone = buildAction, "Unexpected None match")
+            Assert.False(VSLangProj.prjBuildAction.prjBuildActionCompile = buildAction, "Unexpected Compile match")
+            Assert.False(VSLangProj.prjBuildAction.prjBuildActionContent = buildAction, "Unexpected Content match")
+            Assert.False(VSLangProj.prjBuildAction.prjBuildActionEmbeddedResource = buildAction, "Unexpected EmbeddedResource match")
 
         DoWithTempFile "Test.fsproj" (fun file ->
             let text =
@@ -598,32 +593,32 @@ type Miscellaneous() =
 
             // test proper behavior from project file
             let node = getBuildableNodeProps project "Compile.fs"
-            Assert.IsTrue(node.BuildAction = VSLangProj.prjBuildAction.prjBuildActionCompile, "Compile build action failed")
-            Assert.IsTrue(node.ItemType = "Compile", "Compile item type failed")
+            Assert.True(node.BuildAction = VSLangProj.prjBuildAction.prjBuildActionCompile, "Compile build action failed")
+            Assert.True(node.ItemType = "Compile", "Compile item type failed")
 
             let node = getBuildableNodeProps project "None.fs"
-            Assert.IsTrue(node.BuildAction = VSLangProj.prjBuildAction.prjBuildActionNone, "None build action failed")
-            Assert.IsTrue(node.ItemType = "None", "None item type failed")
+            Assert.True(node.BuildAction = VSLangProj.prjBuildAction.prjBuildActionNone, "None build action failed")
+            Assert.True(node.ItemType = "None", "None item type failed")
 
             let node = getBuildableNodeProps project "Resource.fs"
             checkNotStandardBuildAction node.BuildAction
-            Assert.IsTrue(node.ItemType = "Resource", "Resource item type failed")
+            Assert.True(node.ItemType = "Resource", "Resource item type failed")
 
             let node = getBuildableNodeProps project "Dude.fs"
             checkNotStandardBuildAction node.BuildAction
-            Assert.IsTrue(node.ItemType = "Dude", "Dude item type failed")
+            Assert.True(node.ItemType = "Dude", "Dude item type failed")
 
             // test handling of bogus values
             node.BuildAction <- enum 100
-            Assert.IsTrue(node.BuildAction = VSLangProj.prjBuildAction.prjBuildActionNone, "Bogus build action not mapped to None")
+            Assert.True(node.BuildAction = VSLangProj.prjBuildAction.prjBuildActionNone, "Bogus build action not mapped to None")
 
             node.ItemType <- "Wibble"
-            Assert.IsTrue(node.ItemType = "None", "Bogus item type not mapped to None")
+            Assert.True(node.ItemType = "None", "Bogus item type not mapped to None")
 
             ()
         )
 
-    [<Test>]
+    [<Fact>]
     member this.``WildcardsInProjectFile.ThrowingCase`` () =
         DoWithTempFile "Test.fsproj"(fun file ->
             let text = TheTests.FsprojTextWithProjectReferences(["*.fs"],[],[],"")
@@ -639,10 +634,10 @@ type Miscellaneous() =
                     exceptionThrown <- true
                     AssertEqual "*.fs" e.ItemSpecification
                     AssertEqual "Compile" e.ItemType
-            Assert.IsTrue(exceptionThrown)
+            Assert.True(exceptionThrown)
         )
         
-    [<Test>]
+    [<Fact>]
     member this.``WildcardsInProjectFile.OkCase`` () =
         DoWithTempFile "Test.fsproj"(fun file ->
             let text = TheTests.FsprojTextWithProjectReferences(["*.fs"],[],[],"")
@@ -665,7 +660,6 @@ type Miscellaneous() =
                 project.Close() |> ignore
         )
 
-[<TestFixture>]
 type Utilities() = 
     (*
         Simulation of the code found in Xaml editor that we were crashing. The relevent code is pasted below.
@@ -733,24 +727,24 @@ type Utilities() =
 
     let CheckPublicKeyToString(bytes,expect) =
         let actual = KeyToken.ToHexString(bytes)
-        Assert.AreEqual(expect, actual)
+        Assert.Equal(expect, actual)
         SimulateXamlEditorReceivingThroughDTE(actual)
 
-    [<Test>]
+    [<Fact>]
     member public this.``PublicKeyToken.0000000000000000``() = CheckPublicKeyToString([|0uy;0uy;0uy;0uy;0uy;0uy;0uy;0uy|], "0000000000000000")
         
-    [<Test>]
+    [<Fact>]
     member public this.``PublicKeyToken.0000000000000001``() = CheckPublicKeyToString([|0uy;0uy;0uy;0uy;0uy;0uy;0uy;1uy|], "0000000000000001")
 
-    [<Test>]
+    [<Fact>]
     member public this.``PublicKeyToken.0a00000000000001``() = CheckPublicKeyToString([|0xauy;0uy;0uy;0uy;0uy;0uy;0uy;1uy|], "0a00000000000001")
 
-    [<Test>]
+    [<Fact>]
     member public this.``Parse MSBuild property of type Int64`` () = 
-        Assert.AreEqual(123L, ProjectNode.ParsePropertyValueToInt64("123"))
-        Assert.AreEqual(255L, ProjectNode.ParsePropertyValueToInt64("0xFF"))
-        Assert.AreEqual(null, ProjectNode.ParsePropertyValueToInt64(""))
-        Assert.AreEqual(null, ProjectNode.ParsePropertyValueToInt64(null))
+        Assert.Equal(123L, ProjectNode.ParsePropertyValueToInt64("123").Value)
+        Assert.Equal(255L, ProjectNode.ParsePropertyValueToInt64("0xFF").Value)
+        Assert.Null(ProjectNode.ParsePropertyValueToInt64(""))
+        Assert.Null(ProjectNode.ParsePropertyValueToInt64(null))
         Throws<Exception>(fun () -> ignore (ProjectNode.ParsePropertyValueToInt64("abc")))
         Throws<Exception>(fun () -> ignore (ProjectNode.ParsePropertyValueToInt64("12333333333333333333333333")))
 
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.MultiTargeting.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.MultiTargeting.fs
index f1b699a428c..1e393f7ceed 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.MultiTargeting.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.MultiTargeting.fs
@@ -8,7 +8,7 @@ open System.IO
 open System.Reflection
 open System.Text.RegularExpressions
 open System.Xml.Linq
-open NUnit.Framework
+open Xunit
 open Salsa
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.Utils.FilesystemHelpers
@@ -16,7 +16,6 @@ open UnitTests.TestLib.ProjectSystem
 open Microsoft.VisualStudio.FSharp.ProjectSystem
 
 
-[<TestFixture>][<Category "ProjectSystem">]
 type MultiTargeting() = 
     inherit TheTests()
     
@@ -35,7 +34,7 @@ type MultiTargeting() =
         File.AppendAllText(projFile, TheTests.FsprojTextWithProjectReferencesAndOtherFlags([], [refLibPath], [], null, "", "v4.0"))
         refLibPath
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.CheckIconForMismatchedAssemblyReference`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             let sp, ccn = VsMocks.MakeMockServiceProviderAndConfigChangeNotifier40()
@@ -43,14 +42,14 @@ type MultiTargeting() =
             use project = TheTests.CreateProject(projFile, "true", ccn, sp)
             let l = new List<AssemblyReferenceNode>()
             project.FindNodesOfType(l)
-            Assert.AreEqual(1, l.Count)
-            Assert.AreEqual(refLibPath, l.[0].Url)
-            Assert.AreEqual(refLibPath, l.[0].Caption)
+            Assert.Equal(1, l.Count)
+            Assert.Equal(refLibPath, l.[0].Url)
+            Assert.Equal(refLibPath, l.[0].Caption)
             let ref = l.[0]
-            Assert.AreEqual(true, ref.CanShowDefaultIcon())
+            Assert.Equal(true, ref.CanShowDefaultIcon())
         )
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.CheckIconForMatchedAssemblyReference20`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             let sp, ccn = VsMocks.MakeMockServiceProviderAndConfigChangeNotifier20()
@@ -58,14 +57,14 @@ type MultiTargeting() =
             use project = TheTests.CreateProject(projFile, "true", ccn, sp)
             let l = new List<AssemblyReferenceNode>()
             project.FindNodesOfType(l)
-            Assert.AreEqual(1, l.Count)
-            Assert.AreEqual(refLibPath, l.[0].Url)
-            Assert.AreEqual(refLibPath, l.[0].Caption)
+            Assert.Equal(1, l.Count)
+            Assert.Equal(refLibPath, l.[0].Url)
+            Assert.Equal(refLibPath, l.[0].Caption)
             let ref = l.[0]
-            Assert.AreEqual(true, ref.CanShowDefaultIcon())
+            Assert.Equal(true, ref.CanShowDefaultIcon())
         )
         
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.DetermineRuntimeAndSKU`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             let sp, ccn = VsMocks.MakeMockServiceProviderAndConfigChangeNotifier40()
@@ -74,62 +73,62 @@ type MultiTargeting() =
             
             let validate (fn : System.Runtime.Versioning.FrameworkName) eR eS =
                 let (runtime, sku) = project.DetermineRuntimeAndSKU(fn.ToString())
-                Assert.AreEqual(eR, runtime)
-                Assert.AreEqual(eS, sku)
+                Assert.Equal(eR, runtime)
+                Assert.Equal(eS, sku)
             validate (new System.Runtime.Versioning.FrameworkName(".NETFramework", new System.Version(4, 0))) "v4.0" ".NETFramework,Version=v4.0"
             validate (new System.Runtime.Versioning.FrameworkName(".NETFramework", new System.Version(2, 0))) "v2.0.50727" null
         )
         
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AppConfigNoStartupNode`` () =
         let root = XElement.Parse("<Configuration></Configuration>")
         let dirty = LangConfigFile.PatchUpXml(root, "version", "sku")
-        Assert.IsTrue(dirty)
-        Assert.IsTrue(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
+        Assert.True(dirty)
+        Assert.True(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AppConfigVersionExistsAddNewSku`` () =
         let root = XElement.Parse("<Configuration><startup><supportedRuntime version=\"version\" /></startup></Configuration>")
         let dirty = LangConfigFile.PatchUpXml(root, "version", "sku")
-        Assert.IsTrue(dirty)
-        Assert.IsTrue(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
+        Assert.True(dirty)
+        Assert.True(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AppConfigVersionExistsReplaceSku`` () =
         let root = XElement.Parse("<Configuration><startup><supportedRuntime version=\"version\" sku=\"oldsku\" /></startup></Configuration>")
         let dirty = LangConfigFile.PatchUpXml(root, "version", "sku")
-        Assert.IsTrue(dirty)
-        Assert.IsTrue(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
+        Assert.True(dirty)
+        Assert.True(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AppConfigVersionExistsRemoveSku`` () =
         let root = XElement.Parse("<Configuration><startup><supportedRuntime version=\"version\" sku=\"oldsku\" /></startup></Configuration>")
         let dirty = LangConfigFile.PatchUpXml(root, "version", null) 
-        Assert.IsTrue(dirty)
-        Assert.IsTrue(root.ToString().Contains("<supportedRuntime version=\"version\" />"))
+        Assert.True(dirty)
+        Assert.True(root.ToString().Contains("<supportedRuntime version=\"version\" />"))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AppConfigVersionReplaceOldRuntime`` () =
         let root = XElement.Parse("<Configuration><startup><supportedRuntime version=\"versionold\" sku=\"oldsku\" /></startup></Configuration>")
         let dirty = LangConfigFile.PatchUpXml(root, "version", "sku")
-        Assert.IsTrue(dirty)
-        Assert.IsTrue(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
-        Assert.IsFalse(root.ToString().Contains("<supportedRuntime version=\"versionold\" sku=\"oldsku\" />"))
+        Assert.True(dirty)
+        Assert.True(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
+        Assert.False(root.ToString().Contains("<supportedRuntime version=\"versionold\" sku=\"oldsku\" />"))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AppConfigVersionReplaceOldRuntimes`` () =
         let root = XElement.Parse("<Configuration><startup><supportedRuntime version=\"versionold\" sku=\"oldsku\" /><supportedRuntime version=\"versionold2\" /></startup></Configuration>")
         let dirty = LangConfigFile.PatchUpXml(root, "version", "sku")
-        Assert.IsTrue(dirty)
-        Assert.IsTrue(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
-        Assert.IsFalse(root.ToString().Contains("<supportedRuntime version=\"versionold\" sku=\"oldsku\" />"))
-        Assert.IsFalse(root.ToString().Contains("<supportedRuntime version=\"versionold2\" />"))
+        Assert.True(dirty)
+        Assert.True(root.ToString().Contains("<supportedRuntime version=\"version\" sku=\"sku\" />"))
+        Assert.False(root.ToString().Contains("<supportedRuntime version=\"versionold\" sku=\"oldsku\" />"))
+        Assert.False(root.ToString().Contains("<supportedRuntime version=\"versionold2\" />"))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.TestFrameworkNameToVersionString`` () =
         let validatePair name str =
             let res = HierarchyNode.GetFrameworkVersionString(name)
-            Assert.AreEqual(str, res)
+            Assert.Equal(str, res)
 
         validatePair (new System.Runtime.Versioning.FrameworkName(".NETFramework", new System.Version(4,0))) "v4.0"
         validatePair (new System.Runtime.Versioning.FrameworkName(".NETFramework", new System.Version(4,0,5))) "v4.0.5"
@@ -143,7 +142,7 @@ type MultiTargeting() =
         validatePair (new System.Runtime.Versioning.FrameworkName(".NETFramework", new System.Version(2,0,0,1))) "v2.0"
 
         (*
-    [<Test>]
+    [<Fact>]
     member public this.``Multitargeting.AddAppConfigIfRetargetTo40Full`` () =
         DoWithTempFile "Test.fsproj" (fun projFile ->
             let sp, ccn = VsMocks.MakeMockServiceProviderAndConfigChangeNotifier20()
@@ -157,10 +156,10 @@ type MultiTargeting() =
             project.FixupAppConfigOnTargetFXChange(fn.ToString(), "4.3.0.0", false) |> ignore
             let appFile = Path.Combine((Path.GetDirectoryName projFile), "app.config")
             let appText = System.IO.File.ReadAllText(appFile)
-            Assert.IsTrue(appText.Contains("<supportedRuntime version=\"v4.0\" sku=\".NETFramework,Version=v4.0\" />"))
-            //Assert.IsTrue(appText.Contains("<supportedRuntime version=\"v4.0\" sku=\".NETFramework,Version=v4.0,Profile=Client\" />"))
-            //Assert.IsTrue(appText.Contains("<supportedRuntime version=\"v2.0.50727\" sku=\"Client\" />"))
-            //Assert.IsTrue(appText.Contains("<supportedRuntime version=\"v2.0.50727\" />"))
+            Assert.True(appText.Contains("<supportedRuntime version=\"v4.0\" sku=\".NETFramework,Version=v4.0\" />"))
+            //Assert.True(appText.Contains("<supportedRuntime version=\"v4.0\" sku=\".NETFramework,Version=v4.0,Profile=Client\" />"))
+            //Assert.True(appText.Contains("<supportedRuntime version=\"v2.0.50727\" sku=\"Client\" />"))
+            //Assert.True(appText.Contains("<supportedRuntime version=\"v2.0.50727\" />"))
             ()
         )
         *)
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs
index ac6b083a0cb..df148dbac14 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs
@@ -8,7 +8,7 @@ open System.Collections.Generic
 open System.IO
 open System.Text.RegularExpressions
 open System.Xml.Linq
-open NUnit.Framework
+open Xunit
 
 // VS namespaces 
 open Microsoft.VisualStudio
@@ -22,7 +22,6 @@ open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
 
 
-[<TestFixture>][<Category "ProjectSystem">]
 type Project() = 
     inherit TheTests()
 
@@ -34,7 +33,7 @@ type Project() =
     static let SaveProject(project : UnitTestingFSharpProjectNode) =
         project.Save(null, 1, 0u) |> ignore
 
-    [<Test>]    
+    [<Fact>]    
     member public _.NewFolderOnProjectMenu() =
         printfn "starting..."
         let package = new FSharpProjectPackage()
@@ -51,7 +50,7 @@ type Project() =
             Assert.Fail("Unexpected: New Folder was not enabled")
         ()    
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileOrderInFsprojIsRespected.Case1``() =
         let compileItems = ["one.fs"; "two.fs"; "three.fs"]
         let expect = Tree("References", ANYTREE,
@@ -63,7 +62,7 @@ type Project() =
         // "one" "three" "two"
         this.``FsprojFileToSolutionExplorer.PositiveTest``(compileItems, "", expect)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileOrderInFsprojIsRespected.Case2``() =
         let compileItems = [@"A\B\D\foo.fs"; @"A\B\C\bar.fs"]
         let expect = Tree("References", ANYTREE,
@@ -79,7 +78,7 @@ type Project() =
         // no alphabetization of files or folders
         this.``FsprojFileToSolutionExplorer.PositiveTest``(compileItems, "", expect)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileOrderInFsprojIsRespected.Case3``() =
         let compileItems = [@"B\foo.fs"; @"A\bar.fs"]
         let other = @"
@@ -99,7 +98,7 @@ type Project() =
         // Including folder should not put folder at front of other folders
         this.``FsprojFileToSolutionExplorer.PositiveTest``(compileItems, other, expect)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileOrderInFsprojIsRespected.Case4``() =
         let compileItems = [@"foo.fs"; @"A\bar.fs"]
         let other = @"
@@ -119,7 +118,7 @@ type Project() =
         this.``FsprojFileToSolutionExplorer.PositiveTest``(compileItems, other, expect)
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.LinksIntoFoldersAreRespected``() =
         let compileItems = []
         let other = @"
@@ -144,7 +143,7 @@ type Project() =
         this.``FsprojFileToSolutionExplorer.PositiveTest``(compileItems, other, expect)
 
 
-    [<Test>]
+    [<Fact>]
     member public this.``Links.AddLinkToRootWorks``() =
         let compileItems = [@"Folder\foo.fs"; @"bar.fs"; ]
         this.MakeProjectAndDoWithProjectFile(compileItems, [], "", (fun project fileName ->
@@ -168,7 +167,7 @@ type Project() =
             TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Links.AddLinkToSubfolderWorks``() =
         let compileItems = [@"bar.fs"; @"Folder\foo.fs"; ]
         this.MakeProjectAndDoWithProjectFile(compileItems, [], "", (fun project fileName ->
@@ -190,7 +189,7 @@ type Project() =
             TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Links.AddLinkToRootWorksForNonFsFile``() =
         let compileItems = [@"Folder\foo.fs"; @"bar.fs"; ]
         this.MakeProjectAndDoWithProjectFile(compileItems, [], "", (fun project fileName ->
@@ -214,7 +213,7 @@ type Project() =
             TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
         ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``Removal.ExcludeFileShouldDirtyProjectFileAndBeSeenOnDiskAfterSave``() =
         let items = MSBuildItems([CompileItem "foo.fs"; CompileItem "bar.fs"])
         this.MakeProjectAndDoWithProjectFile([], [], items.ToString(), (fun project fileName ->
@@ -235,7 +234,7 @@ type Project() =
             AssertEqualMsg false (fsprojFileText.Contains(toVerify)) "it was not removed from the .fsproj on disk"
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``Removal.RemoveReferenceShouldDirtyProjectFileAndBeSeenOnDiskAfterSave``() =
         let items = MSBuildItems([CompileItem "foo.fs"; CompileItem "bar.fs"])
         this.MakeProjectAndDoWithProjectFile([], ["System"], items.ToString(), (fun project fileName ->
@@ -256,7 +255,7 @@ type Project() =
             AssertEqualMsg false (fsprojFileText.Contains(toVerify)) "it was not removed from the .fsproj on disk"
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.MoveUpShouldDirtyProject``() =
         let items = MSBuildItems([CompileItem "foo.fs"; CompileItem "bar.fs"])
         this.MakeProjectAndDoWithProjectFile([], [], items.ToString(), (fun project fileName ->
@@ -273,7 +272,7 @@ type Project() =
             TheTests.AssertSameTree(expect, project.FirstChild)
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.MoveDownShouldDirtyProject``() =
         let items = MSBuildItems([CompileItem "foo.fs"; CompileItem "bar.fs"])
         this.MakeProjectAndDoWithProjectFile([], [], items.ToString(), (fun project fileName ->
@@ -299,7 +298,7 @@ type Project() =
     member private this.SampleFolderWithItemsEntity = ([CompileItem @"MyFolder\x1.fs"; CompileItem @"MyFolder\Sub\x2.fs"; CompileItem @"MyFolder\x3.fs"], 
                                                        fun t -> Tree("MyFolder",Tree("x1.fs", Nil, Tree("Sub", Tree("x2.fs", Nil, Nil), Tree("x3.fs", Nil, Nil))), t))
 
-    [<Test>]
+    [<Fact>]
     member public this.``SpecificVersion.OptionsSavedToFsprojFile``() =
         let items = MSBuildItems( [CompileItem "foo.fs"] )
         this.MakeProjectAndDoWithProjectFile([], ["System"], items.ToString(), (fun project fileName ->
@@ -314,12 +313,12 @@ type Project() =
                             let expected = XDocument.Load(new StringReader(@"<Reference Include=""ANY""><SpecificVersion>True</SpecificVersion></Reference>")).Root
                             TheTests.AssertSimilarXml(expected, e)
                             let inc = e.Attributes() |> WithAttrName "Include" |> Seq.head
-                            Assert.IsTrue(inc.Value.StartsWith("System, Version", StringComparison.Ordinal), "assembly reference lacks version"))
+                            Assert.True(inc.Value.StartsWith("System, Version", StringComparison.Ordinal), "assembly reference lacks version"))
                        false, (fun (e:XElement) -> 
                             let expected = XDocument.Load(new StringReader(@"<Reference Include=""ANY""><SpecificVersion>False</SpecificVersion></Reference>")).Root
                             TheTests.AssertSimilarXml(expected, e)
                             let inc = e.Attributes() |> WithAttrName "Include" |> Seq.head
-                            Assert.IsTrue(inc.Value.StartsWith("System, Version", StringComparison.Ordinal), "assembly reference lacks version")) 
+                            Assert.True(inc.Value.StartsWith("System, Version", StringComparison.Ordinal), "assembly reference lacks version")) 
                     |]
             let props = system.NodeProperties :?> AssemblyReferenceProperties
             for v, f in a do
@@ -333,7 +332,7 @@ type Project() =
                 f refNode
         ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileRenaming.RenamingAFileDoesNotChangeOrderInSolutionExplorerOrMSBuild``() =
         for entity, treeMaker in [this.SampleFileEntity; this.SampleEmptyFolderEntity] do
             let items = MSBuildItems( [CompileItem "foo.fs"] @ entity )
@@ -390,15 +389,15 @@ type Project() =
                 TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedUpAboveFile``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedUpAbove``(this.SampleFileEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedUpAboveEmptyFolder``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedUpAbove``(this.SampleEmptyFolderEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedUpAboveFolderWithItems``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedUpAbove``(this.SampleFolderWithItemsEntity)
 
@@ -431,15 +430,15 @@ type Project() =
                 TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedDownBelowFile``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedDownBelow``(this.SampleFileEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedDownBelowEmptyFolder``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedDownBelow``(this.SampleEmptyFolderEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedDownBelowFolderWithItems``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.EntityCanBeMovedDownBelow``(this.SampleFolderWithItemsEntity)
 
@@ -484,15 +483,15 @@ type Project() =
             TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedUpAboveFile``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedUpAbove``(this.SampleFileEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedUpAboveEmptyFolder``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedUpAbove``(this.SampleEmptyFolderEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedUpAboveFolderWithItems``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedUpAbove``(this.SampleFolderWithItemsEntity)
 
@@ -537,19 +536,19 @@ type Project() =
             TheTests.HelpfulAssertMatches '<' regexStr fsprojFileText
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedDownBelowFile``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedDownBelow``(this.SampleFileEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedDownBelowEmptyFolder``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedDownBelow``(this.SampleEmptyFolderEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedDownBelowFolderWithItems``() =
         this.``FsprojFileToSolutionExplorer.FileMovement.FolderWithItemsCanBeMovedDownBelow``(this.SampleFolderWithItemsEntity)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.NegativeTests.EntityCannotBeMovedAboveReferences``() =
         for entity in this.SampleEntities do
             printfn "=========> testing moving %s" (entity.ToString())
@@ -562,7 +561,7 @@ type Project() =
             let foo = TheTests.FindNodeWithCaption(project, entity.Caption())
             TheTests.EnsureMoveUpDisabled(foo)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.NegativeTests.EntityCannotBeMovedUpWhenTopOfFolder``() =
         for entity in this.SampleEntities |> List.map (fun e -> e.IntoFolder(@"Folder\")) do
             printfn "=========> testing moving %s" (entity.ToString())
@@ -575,7 +574,7 @@ type Project() =
             let bar = TheTests.FindNodeWithCaption(project, entity.Caption())
             TheTests.EnsureMoveUpDisabled(bar)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojFileToSolutionExplorer.FileMovement.NegativeTests.EntityCannotBeMovedDownWhenBottomOfFolder``() =
         for entity in this.SampleEntities |> List.map (fun e -> e.IntoFolder(@"Folder\")) do
             printfn "=========> testing moving %s" (entity.ToString())
@@ -588,7 +587,7 @@ type Project() =
             let bar = TheTests.FindNodeWithCaption(project, entity.Caption())
             TheTests.EnsureMoveDownDisabled(bar)
 
-    [<Test>]
+    [<Fact>]
     member public this.``RenameFile.FailureToRenameInRDT.Bug616680.EnsureRevertToKnownConsistentState``() =
         this.MakeProjectAndDo(["orig1.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "orig1.fs")
@@ -615,7 +614,7 @@ type Project() =
                 File.Delete(absFilePath)
             ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``RenameFile.FailureToRenameInRDT.Bug616680.EnsureThatFileOrderDidNotChange``() =
         this.MakeProjectAndDo(["a.fs";"b.fs";"orig1.fs";"c.fs";"d.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "orig1.fs")
@@ -646,7 +645,7 @@ type Project() =
                 File.Delete(absFilePath)
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``RenameFile.VerifyItemIdsRemainsTheSame``() =
         let name1 = "orig.fs"
         let name2 = "orig2.fs"
@@ -668,7 +667,7 @@ type Project() =
                 File.Delete(absFilePath)
             ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``RenameFile.MainlineSuccessCase``() =
         this.MakeProjectAndDo(["orig1.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "orig1.fs")
@@ -694,7 +693,7 @@ type Project() =
                 File.Delete(absFilePath)
             ))
     
-    [<Test>] //ref bug https://github.com/dotnet/fsharp/issues/259
+    [<Fact>] //ref bug https://github.com/dotnet/fsharp/issues/259
     member public this.``RenameFile.InFolder``() =
         this.MakeProjectAndDo(["file1.fs"; @"Folder1\file2.fs"; @"Folder1\nested1.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "Folder1", "nested1.fs")
@@ -757,7 +756,7 @@ type Project() =
     
 (* Disabled for now - see https://github.com/dotnet/fsharp/pull/3071 - this is testing old project system features
 
-    [<Test>]
+    [<Fact>]
     member public this.``RenameFile.BuildActionIsResetBasedOnFilenameExtension``() =
         let GetTextFromBuildAction (action:VSLangProj.prjBuildAction) =
             match action with
@@ -832,8 +831,7 @@ type Project() =
 *)
 
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``FsprojOutputWindow.ErrorOriginColumnsAreBase1``() =
         let (outputWindowPaneErrors : string list ref) = ref [] // output window pane errors
         let vso = VsMocks.vsOutputWindowPane(outputWindowPaneErrors)
@@ -856,8 +854,7 @@ type Project() =
             AssertEqual (List.length errors) 1
         )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``FsprojOutputWindow.HighUnicodeCharactersAreProperlyDisplayed``() =
         let (outputWindowPaneErrors : string list ref) = ref [] // output window pane errors
         let vso = VsMocks.vsOutputWindowPane(outputWindowPaneErrors)
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.ProjectItems.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.ProjectItems.fs
index 3e1e26c8f22..26c25a7edf6 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.ProjectItems.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.ProjectItems.fs
@@ -4,20 +4,19 @@ namespace Tests.ProjectSystem
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.ProjectSystem
 open Microsoft.VisualStudio.FSharp.ProjectSystem
 
 
-[<TestFixture>][<Category "ProjectSystem">]
 type ProjectItems() = 
     inherit TheTests()
     
     //TODO: look for a way to remove the helper functions
     static let ANYTREE = Tree("",Nil,Nil)
 
-    [<Test>]
+    [<Fact>]
     member public this.``RemoveAssemblyReference.NoIVsTrackProjectDocuments2Events``() =
         this.MakeProjectAndDo(["file.fs"], ["System.Numerics"],"", (fun project ->
             let listener = project.Site.GetService(typeof<Salsa.VsMocks.IVsTrackProjectDocuments2Listener>) :?> Salsa.VsMocks.IVsTrackProjectDocuments2Listener
@@ -28,7 +27,7 @@ type ProjectItems() =
                 |> Array.exists (fun f -> f.IndexOf("System.Numerics") <> -1)
 
             let mutable wasCalled = false
-            Assert.IsTrue(containsSystemNumerics (), "Project should contains reference to System.Numerics")
+            Assert.True(containsSystemNumerics (), "Project should contains reference to System.Numerics")
 
             let refContainer = project.GetReferenceContainer()
             let reference = 
@@ -39,11 +38,11 @@ type ProjectItems() =
                 reference.Remove(false)
             )
 
-            Assert.IsFalse(wasCalled, "No events from IVsTrackProjectDocuments2 are expected")
-            Assert.IsFalse(containsSystemNumerics(), "Project should not contains reference to System.Numerics")            
+            Assert.False(wasCalled, "No events from IVsTrackProjectDocuments2 are expected")
+            Assert.False(containsSystemNumerics(), "Project should not contains reference to System.Numerics")            
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``AddNewItem.ItemAppearsAtBottomOfFsprojFile``() =
         this.MakeProjectAndDo(["orig.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "a.fs")
@@ -58,7 +57,7 @@ type ProjectItems() =
                 File.Delete(absFilePath)
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``AddNewItem.ToAFolder.ItemAppearsAtBottomOfFolder``() =
         this.MakeProjectAndDo(["orig.fs"; "Folder\\f1.fs"; "Folder\\f2.fs"; "final.fs"], [], "", (fun project ->
             let dir = Path.Combine(project.ProjectFolder, "Folder")
@@ -75,7 +74,7 @@ type ProjectItems() =
                 File.Delete(absFilePath)
             ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``AddNewItemBelow.ItemAppearsInRightSpot``() =
         this.MakeProjectAndDo(["orig1.fs"; "orig2.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "new.fs")
@@ -98,7 +97,7 @@ type ProjectItems() =
                 File.Delete(absFilePath)
             ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``AddNewItemAbove.ItemAppearsInRightSpot.Case1``() =
         this.MakeProjectAndDo(["orig1.fs"; "orig2.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "new.fs")
@@ -121,7 +120,7 @@ type ProjectItems() =
                 File.Delete(absFilePath)
             ))
     
-    [<Test>]
+    [<Fact>]
     member public this.``AddNewItemAbove.ItemAppearsInRightSpot.Case2``() =
         this.MakeProjectAndDo(["orig1.fs"; "orig2.fs"], [], "", (fun project ->
             let absFilePath = Path.Combine(project.ProjectFolder, "new.fs")
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
index f64efebaefe..f22381e1c76 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
@@ -7,7 +7,7 @@ open System.Collections.Generic
 open System.IO
 open System.Reflection
 
-open NUnit.Framework
+open Xunit
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
@@ -16,7 +16,6 @@ open Microsoft.VisualStudio.FSharp.ProjectSystem
 open Microsoft.VisualStudio.Shell.Interop
 open System.Xml.Linq
 
-[<TestFixture>][<Category "ProjectSystem">]
 type References() = 
     inherit TheTests()
 
@@ -41,25 +40,25 @@ type References() =
         let fooPath = Path.Combine(project.ProjectFolder, "foo.fs")
         File.AppendAllText(fooPath, "namespace Foo\nmodule Bar =\n  let x = 42")
         let buildResult = project.Build("Build")
-        Assert.IsTrue buildResult.IsSuccessful
+        Assert.True buildResult.IsSuccessful
         let exe = Path.Combine(project.ProjectFolder, "bin\\Debug\\Test.exe")
         k exe))
 
-    [<Test>]
+    [<Fact>]
     member this.``BasicAssemblyReferences1``() =
         this.MakeProjectAndDo([], ["System"], "", (fun proj ->
             let systemRef = proj.FirstChild.FirstChild :?> AssemblyReferenceNode
-            Assert.IsTrue(systemRef.CanShowDefaultIcon())
+            Assert.True(systemRef.CanShowDefaultIcon())
         ))
 
-    [<Test>]
+    [<Fact>]
     member this.``BasicAssemblyReferences2``() =
         this.MakeProjectAndDo([], ["System.Net"], "", (fun proj ->
             let systemRef = proj.FirstChild.FirstChild :?> AssemblyReferenceNode
-            Assert.IsTrue(systemRef.CanShowDefaultIcon())
+            Assert.True(systemRef.CanShowDefaultIcon())
         ))
             
-    [<Test>]
+    [<Fact>]
     member this.``AddReference.StarredAssemblyName`` () = 
         DoWithTempFile "Test.fsproj" (fun projFile ->
             File.AppendAllText(projFile, TheTests.SimpleFsprojText([], [], ""))
@@ -67,11 +66,11 @@ type References() =
             let assemblyName = new AssemblyName(typeof<System.Windows.Forms.Form>.Assembly.FullName)
             let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_ComPlus, bstrFile = "*" + assemblyName.FullName)
             let refContainer = GetReferenceContainerNode(project)
-            refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.IsNotNull
+            refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.NotNull
             let l = new List<AssemblyReferenceNode>()
             project.FindNodesOfType(l)
-            Assert.AreEqual(1, l.Count)
-            Assert.AreEqual("System.Windows.Forms", l.[0].Caption)            
+            Assert.Equal(1, l.Count)
+            Assert.Equal("System.Windows.Forms", l.[0].Caption)            
             SaveProject(project)
             let fsprojFileText = File.ReadAllText(project.FileName)
             printfn "%s" fsprojFileText
@@ -79,34 +78,32 @@ type References() =
             TheTests.HelpfulAssertMatches '<' expectedFsprojRegex fsprojFileText
             )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``References.Bug787899.AddDuplicateUnresolved``() =
         // Let's create a run-of-the-mill project just to have a spare assembly around
         this.CreateDummyTestProjectBuildItAndDo(fun exe ->
-            Assert.IsTrue(File.Exists exe, "failed to build exe")
+            Assert.True(File.Exists exe, "failed to build exe")
             this.MakeProjectAndDoWithProjectFile(["doesNotMatter.fs"], ["mscorlib"; "System"; "System.Core"; "System.Net"], 
                                                     "<ItemGroup><Reference Include=\"Test\"><HintPath>.\\Test.dll</HintPath></Reference></ItemGroup>", "v4.0", (fun project file ->
                 let assemRef = TheTests.FindNodeWithCaption(project, "Test") :?> AssemblyReferenceNode
-                Assert.IsFalse(assemRef.CanShowDefaultIcon(), "reference should be banged out, does not resolve")
+                Assert.False(assemRef.CanShowDefaultIcon(), "reference should be banged out, does not resolve")
                 // add reference to Test.exe
                 let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_File, bstrFile = exe)
                 let refContainer = GetReferenceContainerNode(project)
-                refContainer.AddReferenceFromSelectorData(selectorData) |> (fun x -> Assert.IsNotNull(x, "expected AddReference to succeed"))
+                refContainer.AddReferenceFromSelectorData(selectorData) |> (fun x -> Assert.NotNull(x, "expected AddReference to succeed"))
                 // it should have succeeded (no throw)
                 ))
             )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``References.Bug787899.AddDuplicateResolved``() =
         // Let's create a run-of-the-mill project just to have a spare assembly around
         this.CreateDummyTestProjectBuildItAndDo(fun exe ->
-            Assert.IsTrue(File.Exists exe, "failed to build exe")
+            Assert.True(File.Exists exe, "failed to build exe")
             this.MakeProjectAndDoWithProjectFile(["doesNotMatter.fs"], ["mscorlib"; "System"; "System.Core"; "System.Net"], 
                                                     sprintf "<ItemGroup><Reference Include=\"Test\"><HintPath>%s</HintPath></Reference></ItemGroup>" exe, "v4.0", (fun project file ->
                 let assemRef = TheTests.FindNodeWithCaption(project, "Test") :?> AssemblyReferenceNode
-                Assert.IsTrue(assemRef.CanShowDefaultIcon(), "reference should not be banged out, does resolve")
+                Assert.True(assemRef.CanShowDefaultIcon(), "reference should not be banged out, does resolve")
                 // add reference to Test.exe
                 let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_File, bstrFile = exe)
                 let refContainer = GetReferenceContainerNode(project)
@@ -114,11 +111,11 @@ type References() =
                     refContainer.AddReferenceFromSelectorData(selectorData) |> ignore
                     Assert.Fail("expected AddReference to Fail")
                 with :? InvalidOperationException as e ->
-                    Assert.AreEqual("A reference to 'Test' (with assembly name 'Test') could not be added. A reference to the component 'Test' with the same assembly name already exists in the project.", e.Message)
+                    Assert.Equal("A reference to 'Test' (with assembly name 'Test') could not be added. A reference to the component 'Test' with the same assembly name already exists in the project.", e.Message)
                 ))
             )
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.LoadedFsProj.Works``() =
         this.MakeProjectAndDo(["doesNotMatter.fs"], ["mscorlib"; "System"; "System.Core"; "System.Net"], "", "v4.0", (fun project ->
             let expectedRefInfo = [ "mscorlib", true
@@ -136,7 +133,7 @@ type References() =
             ))
 
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.LoadedFsProj.WithExactDuplicates``() =
         this.MakeProjectAndDo(["doesNotMatter.fs"], ["System"; "System"], "", "v4.0", (fun project ->
             let expectedRefInfo = [ "System", true  // In C#, one will be banged out, whereas
@@ -151,7 +148,7 @@ type References() =
             AssertEqual expectedRefInfo actualRefInfo
             ))
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.LoadedFsProj.WithBadDuplicates``() =
         this.MakeProjectAndDo(["doesNotMatter.fs"], ["System"; "System.dll"], "", "v4.0", (fun project ->
             let expectedRefInfo = [ "System", false     // one will be banged out
@@ -166,7 +163,7 @@ type References() =
             AssertEqual expectedRefInfo actualRefInfo
             ))
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.LoadedFsProj.WorksWithFilenames``() =
             let netDir = currentFrameworkDirectory
             let ssmw = Path.Combine(netDir, "System.ServiceModel.Web.dll")
@@ -182,7 +179,7 @@ type References() =
             AssertEqual expectedRefInfo actualRefInfo
             ))
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.LoadedFsProj.WeirdCases``() =
         this.MakeProjectAndDo(["doesNotMatter.fs"], ["mscorlib, Version=4.0.0.0"; "System, Version=4.0.0.0"; "System.Core, Version=4.0.0.0"; "System.Net, Version=4.0.0.0"], "", "v4.0", (fun project ->
             let expectedRefInfo = [ "mscorlib", true
@@ -212,14 +209,14 @@ type References() =
                 | _ -> failwith "unexpected"
             let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = cType, bstrFile = fullPath)
             let refContainer = GetReferenceContainerNode(project)
-            refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.IsNotNull
+            refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.NotNull
             SaveProject(project)
             let fsprojFileText = File.ReadAllText(project.FileName)
             printfn "%s" fsprojFileText
             TheTests.HelpfulAssertMatches '<' expectedFsprojRegex fsprojFileText
             ))
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.FxAssembly.NetTab.AddDuplicate1``() =
         let netDir = currentFrameworkDirectory
         try
@@ -232,7 +229,7 @@ type References() =
         with e ->                                           
             TheTests.HelpfulAssertMatches ' ' "A reference to '.*' \\(with assembly name '.*'\\) could not be added. A reference to the component '.*' with the same assembly name already exists in the project." e.Message
 
-// see 5491 [<Test>]
+// see 5491 [<Fact>]
     member this.``ReferenceResolution.Bug4423.FxAssembly.NetTab.AddDuplicate2``() =
         let netDir = currentFrameworkDirectory
         try
@@ -245,12 +242,11 @@ type References() =
         with e ->
             TheTests.HelpfulAssertMatches ' ' "A reference to '.*' could not be added. A reference to the component '.*' already exists in the project." e.Message
 
-    [<Test; Category("Expensive")>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``ReferenceResolution.Bug4423.NonFxAssembly.BrowseTab.RelativeHintPath.InsideProjectDir``() =
         // Let's create a run-of-the-mill project just to have a spare assembly around
         this.CreateDummyTestProjectBuildItAndDo(fun exe ->
-            Assert.IsTrue(File.Exists exe, "failed to build exe")
+            Assert.True(File.Exists exe, "failed to build exe")
             // Now let's create an assembly reference to it and ensure we get expected relative HintPath
             let expectedFsprojRegex = @"<Reference Include=""Test"">"
                                          + @"\s*<HintPath>Test.exe</HintPath>"  // in this directory
@@ -258,10 +254,10 @@ type References() =
             this.MakeProjectAndDo(["bar.fs"], [], "", "v4.5", (fun project ->
                 let exeCopy = Path.Combine(project.ProjectFolder, "Test.exe")
                 File.Copy(exe, exeCopy, true)                
-                Assert.IsTrue(File.Exists exeCopy, "failed to build exe")
+                Assert.True(File.Exists exeCopy, "failed to build exe")
                 let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_File, bstrFile = exeCopy)
                 let refContainer = GetReferenceContainerNode(project)
-                refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.IsNotNull
+                refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.NotNull
                 SaveProject(project)
                 let fsprojFileText = File.ReadAllText(project.FileName)
                 printfn "%s" fsprojFileText
@@ -269,26 +265,25 @@ type References() =
                 // Finally, ensure that the reference works as expected
                 project.Reload()
                 let assemRef = TheTests.FindNodeWithCaption(project, "Test") :?> AssemblyReferenceNode
-                Assert.IsTrue(assemRef.CanShowDefaultIcon(), "the reference could not be resolved")  
+                Assert.True(assemRef.CanShowDefaultIcon(), "the reference could not be resolved")  
                 // Use the referenced DLL as a double-check
                 let barPath = Path.Combine(project.ProjectFolder, "bar.fs")
                 File.AppendAllText(barPath, "printfn \"%d\" Foo.Bar.x")  // code that requires the referenced assembly to successfully compile
                 let buildResult = project.Build("Build")
-                Assert.IsTrue buildResult.IsSuccessful
+                Assert.True buildResult.IsSuccessful
                 ))
         )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member this.``ReferenceResolution.Bug4423.NonFxAssembly.BrowseTab.RelativeHintPath.OutsideProjectDir``() =
         this.MakeProjectAndDo(["foo.fs"], [], "", (fun project ->
             // Let's create a run-of-the-mill 
             let fooPath = Path.Combine(project.ProjectFolder, "foo.fs")
             File.AppendAllText(fooPath, "namespace Foo\nmodule Bar =\n  let x = 42")
             let buildResult = project.Build("Build")
-            Assert.IsTrue buildResult.IsSuccessful
+            Assert.True buildResult.IsSuccessful
             let exe = Path.Combine(project.ProjectFolder, "bin\\Debug\\Test.exe")
-            Assert.IsTrue(File.Exists exe, "failed to build exe")
+            Assert.True(File.Exists exe, "failed to build exe")
             // Now let's create an assembly reference to it and ensure we get expected relative HintPath
             let expectedFsprojRegex = @"<Reference Include=""Test"">"
                                          + @"\s*<HintPath>\.\.\\.*?</HintPath>"  // the point is, some path start with "..\", since both projects are rooted somewhere in the temp directory (where unit tests create them)
@@ -296,7 +291,7 @@ type References() =
             this.MakeProjectAndDo(["bar.fs"], [], "", "v4.5", (fun project ->
                 let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_File, bstrFile = exe)
                 let refContainer = GetReferenceContainerNode(project)
-                refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.IsNotNull
+                refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.NotNull
                 SaveProject(project)
                 let fsprojFileText = File.ReadAllText(project.FileName)
                 printfn "%s" fsprojFileText
@@ -304,16 +299,16 @@ type References() =
                 // Finally, ensure that the reference works as expected
                 project.Reload()
                 let assemRef = TheTests.FindNodeWithCaption(project, "Test") :?> AssemblyReferenceNode
-                Assert.IsTrue(assemRef.CanShowDefaultIcon(), "the reference could not be resolved")  
+                Assert.True(assemRef.CanShowDefaultIcon(), "the reference could not be resolved")  
                 // Use the referenced DLL as a double-check
                 let barPath = Path.Combine(project.ProjectFolder, "bar.fs")
                 File.AppendAllText(barPath, "printfn \"%d\" Foo.Bar.x")  // code that requires the referenced assembly to successfully compile
                 let buildResult = project.Build("Build")
-                Assert.IsTrue buildResult.IsSuccessful
+                Assert.True buildResult.IsSuccessful
                 ))
         ))
 
-    [<Test>]
+    [<Fact>]
     member this.``ReferenceResolution.Bug4423.NotAValidDll.BrowseTab``() =
         let dirName = Path.GetTempPath()
         let dll = Path.Combine(dirName, "Foo.dll")
@@ -323,7 +318,7 @@ type References() =
                 let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_File, bstrFile = dll)
                 let refContainer = GetReferenceContainerNode(project)
                 try
-                    refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.IsNotNull
+                    refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.NotNull
                     Assert.Fail("this should not have succeeded")
                 with e ->
                     AssertContains e.Message "could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component."
@@ -331,7 +326,7 @@ type References() =
         finally
             File.Delete(dll)
 
-    [<Test>]
+    [<Fact>]
     member this.``PathReferences.Existing`` () =
         DoWithTempFile "Test.fsproj"(fun projFile ->
             let dirName = Path.GetDirectoryName(projFile)
@@ -346,14 +341,14 @@ type References() =
             AssertEqual 1 l.Count
             AssertEqual refLibPath l.[0].Url
             AssertEqual refLibPath l.[0].Caption  // when Include is a filename, entirety is caption
-            Assert.IsNotNull(l.[0].ResolvedAssembly)
+            Assert.NotNull(l.[0].ResolvedAssembly)
             let refContainer =
                 let l = new List<ReferenceContainerNode>()
                 project.FindNodesOfType(l)
                 l.[0]
             let mscorlibPath = (new Uri("".GetType().Assembly.EscapedCodeBase)).LocalPath
             let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_ComPlus, bstrFile = mscorlibPath)
-            refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.IsNotNull
+            refContainer.AddReferenceFromSelectorData(selectorData) |> Assert.NotNull
             let l = new List<AssemblyReferenceNode>()
             project.FindNodesOfType(l)
             AssertEqual 2 l.Count
@@ -362,7 +357,7 @@ type References() =
             AssertEqual "mscorlib" l.[1].Caption
         )
 
-    [<Test>]
+    [<Fact>]
     member this.``PathReferences.Existing.Captions`` () =
         DoWithTempFile "Test.fsproj"(fun projFile ->
             File.AppendAllText(projFile, TheTests.FsprojTextWithProjectReferences(
@@ -375,12 +370,12 @@ type References() =
             project.FindNodesOfType(l)
             AssertEqual 2 l.Count
             AssertEqual "System.dll" l.[0].Caption
-            Assert.IsNotNull(l.[0].ResolvedAssembly)
+            Assert.NotNull(l.[0].ResolvedAssembly)
             AssertEqual "System.Net.dll" l.[1].Caption
-            Assert.IsNotNull(l.[1].ResolvedAssembly)
+            Assert.NotNull(l.[1].ResolvedAssembly)
         )
         
-    [<Test>]
+    [<Fact>]
     member this.``PathReferences.NonExistent`` () =
         DoWithTempFile "Test.fsproj"(fun projFile ->
             let refLibPath = @"c:\foo\baz\blahblah.dll"
@@ -390,11 +385,11 @@ type References() =
             project.FindNodesOfType(l)
             AssertEqual 1 l.Count
             AssertEqual refLibPath l.[0].Caption
-            Assert.IsNull(l.[0].ResolvedAssembly)
+            Assert.Null(l.[0].ResolvedAssembly)
         )
 
         
-    [<Test>]
+    [<Fact>]
     member this.``FsprojPreferencePage.ProjSupportsPrefReadWrite``() =
         let testProp = "AssemblyName"
         let compileItem = [@"foo.fs"]
@@ -431,7 +426,7 @@ type References() =
     // Disabled due to: https://github.com/dotnet/fsharp/issues/1460
     // On DEV 15 Preview 4 the VS IDE Test fails with :
     //     System.InvalidOperationException : Operation is not valid due to the current state of the object.
-    // [<Test>]     // Disabled due to: https://github.com/dotnet/fsharp/issues/1460
+    // [<Fact>]     // Disabled due to: https://github.com/dotnet/fsharp/issues/1460
     member this.``AddReference.COM`` () = 
         DoWithTempFile "Test.fsproj" (fun projFile ->
             File.AppendAllText(projFile, TheTests.SimpleFsprojText([], [], ""))
@@ -450,23 +445,23 @@ type References() =
             let comReference = refContainer.AddReferenceFromSelectorData(selectorData)
 
             // check reference node properties
-            Assert.IsNotNull comReference
-            Assert.IsTrue(comReference :? ComReferenceNode)
+            Assert.NotNull comReference
+            Assert.True(comReference :? ComReferenceNode)
             let comRef = comReference :?> ComReferenceNode
-            Assert.AreEqual(1, comRef.MajorVersionNumber)
-            Assert.AreEqual(0, comRef.MinorVersionNumber)
-            Assert.AreEqual(guid, comRef.TypeGuid)
-            Assert.AreEqual("Microsoft Shell Controls And Automation", comRef.Caption)
+            Assert.Equal(1, comRef.MajorVersionNumber)
+            Assert.Equal(0, comRef.MinorVersionNumber)
+            Assert.Equal(guid, comRef.TypeGuid)
+            Assert.Equal("Microsoft Shell Controls And Automation", comRef.Caption)
             let sysDirectory = Environment.GetFolderPath(Environment.SpecialFolder.SystemX86)
-            Assert.IsTrue(String.Compare(Path.Combine(sysDirectory, "shell32.dll"), comRef.InstalledFilePath, StringComparison.OrdinalIgnoreCase) = 0)
+            Assert.True(String.Compare(Path.Combine(sysDirectory, "shell32.dll"), comRef.InstalledFilePath, StringComparison.OrdinalIgnoreCase) = 0)
 
             // check node exists under references
             let l = new List<ComReferenceNode>()
             project.FindNodesOfType(l)
 
-            Assert.AreEqual(1, l.Count)
+            Assert.Equal(1, l.Count)
             let referenceNode = l.[0]
-            Assert.AreSame(comRef, referenceNode)
+            Assert.Same(comRef, referenceNode)
 
             // check saved msbuild item
             SaveProject(project)
@@ -475,13 +470,13 @@ type References() =
             let xn s = fsproj.Root.GetDefaultNamespace().GetName(s)
             let comReferencesXml = fsproj.Descendants(xn "COMReference") |> Seq.toList
             
-            Assert.AreEqual(1, comReferencesXml |> List.length)
+            Assert.Equal(1, comReferencesXml |> List.length)
 
             let comRefXml = comReferencesXml |> List.head
 
-            Assert.AreEqual("Microsoft Shell Controls And Automation", comRefXml.Attribute(XName.Get("Include")).Value)
-            Assert.AreEqual(guid, Guid(comRefXml.Element(xn "Guid").Value))
-            Assert.AreEqual("1", comRefXml.Element(xn "VersionMajor").Value)
-            Assert.AreEqual("0", comRefXml.Element(xn "VersionMinor").Value)
-            Assert.AreEqual("0", comRefXml.Element(xn "Lcid").Value)
+            Assert.Equal("Microsoft Shell Controls And Automation", comRefXml.Attribute(XName.Get("Include")).Value)
+            Assert.Equal(guid, Guid(comRefXml.Element(xn "Guid").Value))
+            Assert.Equal("1", comRefXml.Element(xn "VersionMajor").Value)
+            Assert.Equal("0", comRefXml.Element(xn "VersionMinor").Value)
+            Assert.Equal("0", comRefXml.Element(xn "Lcid").Value)
             )
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.RoundTrip.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.RoundTrip.fs
index 1aad389737d..56aaf84d713 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.RoundTrip.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.RoundTrip.fs
@@ -5,14 +5,13 @@ namespace Tests.ProjectSystem
 open System
 open System.IO
 open System.Text.RegularExpressions
-open NUnit.Framework
+open Xunit
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
 open Microsoft.VisualStudio.FSharp.ProjectSystem
 
 
-[<TestFixture>][<Category "ProjectSystem">]
 type RoundTrip() = 
     inherit TheTests()
     
@@ -43,7 +42,7 @@ type RoundTrip() =
                 Assert.Fail("did not remove empty ItemGroups")
         ))
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.Basic.NonemptyFoldersRemoved.Case1``() =
         this.``FsprojRoundtrip.PositiveTest``(
             MSBuildItems [CompileItem @"bar.fs"
@@ -52,7 +51,7 @@ type RoundTrip() =
             MSBuildItems [CompileItem @"bar.fs"
                           CompileItem @"Folder\foo.fs"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.Basic.NonemptyFoldersRemoved.Case2``() =
         this.``FsprojRoundtrip.PositiveTest``(
             MSBuildItems [CompileItem @"bar.fs"
@@ -65,7 +64,7 @@ type RoundTrip() =
                           CompileItem @"A\B\C\foo.fs"
                           CompileItem @"A\qux.fs"])
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.ComplexButLegalCase``() =
         let items = MSBuildItems [CompileItem @"A\B\foo.fs"
                                   CompileItem @"A\bar.fs"
@@ -76,7 +75,7 @@ type RoundTrip() =
                                   ]
         this.``FsprojRoundtrip.PositiveTest``(items, items)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.EmptyFoldersArePreservedWhenRestIsIdempotent``() =
         let items = MSBuildItems [CompileItem @"bar.fs"
                                   FolderItem @"A\Empty1\"
@@ -85,7 +84,7 @@ type RoundTrip() =
                                   CompileItem @"A\qux.fs"]
         this.``FsprojRoundtrip.PositiveTest``(items, items)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.EmptyFoldersArePreservedWhenRestIsLegalButNotIdempotent``() =
         let origItems = [CompileItem @"bar.fs"
                          FolderItem @"A\Empty1\"        
@@ -100,13 +99,13 @@ type RoundTrip() =
                              CompileItem @"A\qux.fs"]
         this.``FsprojRoundtrip.PositiveTest``(MSBuildItems origItems, MSBuildItems expectedItems)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.Regression.FoldersWithSameName``() =
         let items = MSBuildItems [CompileItem @"First\Second\bar.fs"
                                   CompileItem @"Second\qux.fs"]
         this.``FsprojRoundtrip.PositiveTest``(items, items)
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.Regression.FoldersWithSameName2``() =
         let items = MSBuildItems [CompileItem @"First\First\bar.fs"]
         this.``FsprojRoundtrip.PositiveTest``(items, items)
@@ -128,21 +127,21 @@ type RoundTrip() =
             ()
         )
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.Basic.Invalid.Case1``() =
         let items = MSBuildItems [CompileItem @"A\B\C\foo.fs"
                                   CompileItem @"B\bar.fs"
                                   CompileItem @"A\B\D\qux.fs"]  // would cause A to be rendered twice
         this.``Fsproj.NegativeTest`` items
 
-    [<Test>]
+    [<Fact>]
     member public this.``FsprojRoundTrip.Basic.Invalid.Case2``() =
         let items = MSBuildItems [CompileItem @"A\foo.fs"
                                   CompileItem @"bar.fs"
                                   CompileItem @"A\qux.fs"]  // would cause A to be rendered twice
         this.``Fsproj.NegativeTest`` items
 
-    // REVIEW NYI: [<Test>]
+    // REVIEW NYI: [<Fact>]
     member public this.``FsprojRoundTrip.Basic.Invalid.Case3``() =
         let items = MSBuildItems [CompileItem @"A\foo.fs"
                                   FolderItem @"A\"           // <Folder> must be before anything below it
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs
index d21681de617..8d1b2795224 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs
@@ -18,21 +18,18 @@ open Microsoft.VisualStudio.FSharp
 open Microsoft.VisualStudio.FSharp.ProjectSystem
 
 // Internal unittest namespaces
-open NUnit.Framework
+open Xunit
 open Salsa
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
 
-[<TestFixture>][<Category "ProjectSystem">]
 type UpToDate() = 
     inherit TheTests()
 
-    [<OneTimeSetUp>]
     member public _.Init () = AssemblyResolver.addResolver ()
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.ItemInputs () =
         this.MakeProjectAndDo(["file1.fs"], [], @"
                 <ItemGroup>
@@ -64,36 +61,35 @@ type UpToDate() =
             File.AppendAllText(nonePath, "none")
             File.AppendAllText(embedPath, "some embedded resource")
 
-            Assert.IsFalse(config.IsUpToDate(logger, true))
+            Assert.False(config.IsUpToDate(logger, true))
             project.Build(configNameDebug, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(config.IsUpToDate(logger, true))
+            Assert.True(config.IsUpToDate(logger, true))
 
             // None items should not affect up-to-date (unless captured by well-known items, e.g. App.config)
             File.SetLastWriteTime(nonePath, DateTime.UtcNow.AddMinutes(5.))
-            Assert.IsTrue(config.IsUpToDate(logger, true))
+            Assert.True(config.IsUpToDate(logger, true))
 
             for path in [sourcePath; contentPath; resourcePath; embedPath; configPath] do
                 printfn "Testing path %s" path
 
                 // touch file
                 File.SetLastWriteTime(path, DateTime.UtcNow.AddMinutes(5.))
-                Assert.IsFalse(config.IsUpToDate(logger, true))
+                Assert.False(config.IsUpToDate(logger, true))
 
                 File.SetLastWriteTime(path, startTime)
-                Assert.IsTrue(config.IsUpToDate(logger, true))
+                Assert.True(config.IsUpToDate(logger, true))
 
                 // delete file
                 let originalContent = File.ReadAllText(path)
                 File.Delete(path)
-                Assert.IsFalse(config.IsUpToDate(logger, true))
+                Assert.False(config.IsUpToDate(logger, true))
 
                 File.AppendAllText(path, originalContent)
                 File.SetLastWriteTime(path, startTime)
-                Assert.IsTrue(config.IsUpToDate(logger, true))
+                Assert.True(config.IsUpToDate(logger, true))
             ))
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.PropertyInputs () =
         this.MakeProjectAndDo(["file1.fs"], [], @"
                 <PropertyGroup>
@@ -117,32 +113,31 @@ type UpToDate() =
             File.AppendAllText(keyPath, "a key")
 
             project.SetConfiguration(config.ConfigCanonicalName);
-            Assert.IsFalse(config.IsUpToDate(logger, true))
+            Assert.False(config.IsUpToDate(logger, true))
             project.Build(configNameDebug, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(config.IsUpToDate(logger, true))
+            Assert.True(config.IsUpToDate(logger, true))
 
             for path in [verPath; keyPath] do
                 printfn "Testing path %s" path
 
                 // touch file
                 File.SetLastWriteTime(path, DateTime.UtcNow.AddMinutes(5.))
-                Assert.IsFalse(config.IsUpToDate(logger, true))
+                Assert.False(config.IsUpToDate(logger, true))
 
                 File.SetLastWriteTime(path, startTime)
-                Assert.IsTrue(config.IsUpToDate(logger, true))
+                Assert.True(config.IsUpToDate(logger, true))
 
                 // delete file
                 let originalContent = File.ReadAllText(path)
                 File.Delete(path)
-                Assert.IsFalse(config.IsUpToDate(logger, true))
+                Assert.False(config.IsUpToDate(logger, true))
 
                 File.AppendAllText(path, originalContent)
                 File.SetLastWriteTime(path, startTime)
-                Assert.IsTrue(config.IsUpToDate(logger, true))
+                Assert.True(config.IsUpToDate(logger, true))
             ))
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.ProjectFile () =
         this.MakeProjectAndDoWithProjectFile(["file1.fs"], [], "", (fun project projFileName ->
             let configNameDebug = ConfigCanonicalName("Debug", "x86")
@@ -153,20 +148,19 @@ type UpToDate() =
             let startTime = DateTime.UtcNow
             File.AppendAllText(absFilePath, "printfn \"hello\"")
 
-            Assert.IsFalse(config.IsUpToDate(logger, true))
+            Assert.False(config.IsUpToDate(logger, true))
             project.Build(configNameDebug, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(config.IsUpToDate(logger, true))
+            Assert.True(config.IsUpToDate(logger, true))
 
             // touch proj file
             File.SetLastWriteTime(projFileName, DateTime.UtcNow.AddMinutes(5.))
-            Assert.IsFalse(config.IsUpToDate(logger, true))
+            Assert.False(config.IsUpToDate(logger, true))
 
             File.SetLastWriteTime(projFileName, startTime)
-            Assert.IsTrue(config.IsUpToDate(logger, true))
+            Assert.True(config.IsUpToDate(logger, true))
             ))
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.References () =
         let configNameDebug = ConfigCanonicalName("Debug", "x86")
         let output = VsMocks.vsOutputWindowPane(ref [])
@@ -185,9 +179,9 @@ type UpToDate() =
 
             let config1 = project1.ConfigProvider.GetProjectConfiguration(configNameDebug)
 
-            Assert.IsFalse(config1.IsUpToDate(logger, true))
+            Assert.False(config1.IsUpToDate(logger, true))
             project1.Build(configNameDebug, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(config1.IsUpToDate(logger, true))
+            Assert.True(config1.IsUpToDate(logger, true))
 
             let output1 = Path.Combine(project1.ProjectFolder, "bin\\debug", project1.OutputFileName)
 
@@ -204,24 +198,23 @@ type UpToDate() =
                 let config2 = project2.ConfigProvider.GetProjectConfiguration(configNameDebug)
                 let startTime = DateTime.UtcNow
 
-                Assert.IsFalse(config2.IsUpToDate(logger, true))
+                Assert.False(config2.IsUpToDate(logger, true))
                 project2.Build(configNameDebug, output, "Build", null) |> AssertBuildSuccessful
-                Assert.IsTrue(config2.IsUpToDate(logger, true))
+                Assert.True(config2.IsUpToDate(logger, true))
 
                 // reference is updated
                 File.SetLastWriteTime(output1, DateTime.UtcNow.AddMinutes(5.))
-                Assert.IsFalse(config2.IsUpToDate(logger, true))
+                Assert.False(config2.IsUpToDate(logger, true))
                 File.SetLastWriteTime(output1, startTime)
-                Assert.IsTrue(config2.IsUpToDate(logger, true))
+                Assert.True(config2.IsUpToDate(logger, true))
 
                 // reference is missing
                 File.Delete(output1)
-                Assert.IsFalse(config2.IsUpToDate(logger, true))
+                Assert.False(config2.IsUpToDate(logger, true))
             )
        )
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.OutputFiles () =
         this.MakeProjectAndDo(["file1.fs"], [], @"
                <ItemGroup>
@@ -249,9 +242,9 @@ type UpToDate() =
             File.AppendAllText(sourcePath, "printfn \"hello\"")
             File.AppendAllText(appConfigPath, """<?xml version="1.0" encoding="utf-8" ?><configuration></configuration>""")
 
-            Assert.IsFalse(config.IsUpToDate(logger, true))
+            Assert.False(config.IsUpToDate(logger, true))
             project.Build(configNameDebug, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(config.IsUpToDate(logger, true))
+            Assert.True(config.IsUpToDate(logger, true))
 
             let startTime = DateTime.UtcNow
 
@@ -260,23 +253,22 @@ type UpToDate() =
 
                 // touch file
                 File.SetLastWriteTime(path, DateTime.UtcNow.AddMinutes(-5.))
-                Assert.IsFalse(config.IsUpToDate(logger, true))
+                Assert.False(config.IsUpToDate(logger, true))
 
                 File.SetLastWriteTime(path, startTime)
-                Assert.IsTrue(config.IsUpToDate(logger, true))
+                Assert.True(config.IsUpToDate(logger, true))
 
                 // delete file
                 let originalContent = File.ReadAllBytes(path)
                 File.Delete(path)
-                Assert.IsFalse(config.IsUpToDate(logger, true))
+                Assert.False(config.IsUpToDate(logger, true))
 
                 File.WriteAllBytes(path, originalContent)
                 File.SetLastWriteTime(path, startTime)
-                Assert.IsTrue(config.IsUpToDate(logger, true))
+                Assert.True(config.IsUpToDate(logger, true))
             ))
 
-    [<Test>]
-    [<Ignore("Bug https://github.com/dotnet/fsharp/issues/17330")>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.ConfigChanges () =
         this.MakeProjectAndDo(["file1.fs"], [], "", (fun project ->
             let configNameDebugx86 = ConfigCanonicalName("Debug", "x86")
@@ -295,37 +287,37 @@ type UpToDate() =
             let sourcePath = Path.Combine(project.ProjectFolder, "file1.fs")
             File.AppendAllText(sourcePath, "printfn \"hello\"")
 
-            Assert.IsFalse(debugConfigx86.IsUpToDate(logger, true))
-            Assert.IsFalse(releaseConfigx86.IsUpToDate(logger, true))
-            Assert.IsFalse(debugConfigAnyCPU.IsUpToDate(logger, true))
-            Assert.IsFalse(releaseConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.False(debugConfigx86.IsUpToDate(logger, true))
+            Assert.False(releaseConfigx86.IsUpToDate(logger, true))
+            Assert.False(debugConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.False(releaseConfigAnyCPU.IsUpToDate(logger, true))
 
             project.Build(configNameDebugx86, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(debugConfigx86.IsUpToDate(logger, true))
-            Assert.IsFalse(releaseConfigx86.IsUpToDate(logger, true))
-            Assert.IsFalse(debugConfigAnyCPU.IsUpToDate(logger, true))
-            Assert.IsFalse(releaseConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.True(debugConfigx86.IsUpToDate(logger, true))
+            Assert.False(releaseConfigx86.IsUpToDate(logger, true))
+            Assert.False(debugConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.False(releaseConfigAnyCPU.IsUpToDate(logger, true))
 
             project.Build(configNameReleasex86, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(debugConfigx86.IsUpToDate(logger, true))
-            Assert.IsTrue(releaseConfigx86.IsUpToDate(logger, true))
-            Assert.IsFalse(debugConfigAnyCPU.IsUpToDate(logger, true))
-            Assert.IsFalse(releaseConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.True(debugConfigx86.IsUpToDate(logger, true))
+            Assert.True(releaseConfigx86.IsUpToDate(logger, true))
+            Assert.False(debugConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.False(releaseConfigAnyCPU.IsUpToDate(logger, true))
 
             project.Build(configNameDebugAnyCPU, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(debugConfigx86.IsUpToDate(logger, true))
-            Assert.IsTrue(releaseConfigx86.IsUpToDate(logger, true))
-            Assert.IsTrue(debugConfigAnyCPU.IsUpToDate(logger, true))
-            Assert.IsFalse(releaseConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.True(debugConfigx86.IsUpToDate(logger, true))
+            Assert.True(releaseConfigx86.IsUpToDate(logger, true))
+            Assert.True(debugConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.False(releaseConfigAnyCPU.IsUpToDate(logger, true))
 
             project.Build(configNameReleaseAnyCPU, output, "Build", null) |> AssertBuildSuccessful
-            Assert.IsTrue(debugConfigx86.IsUpToDate(logger, true))
-            Assert.IsTrue(releaseConfigx86.IsUpToDate(logger, true))
-            Assert.IsTrue(debugConfigAnyCPU.IsUpToDate(logger, true))
-            Assert.IsTrue(releaseConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.True(debugConfigx86.IsUpToDate(logger, true))
+            Assert.True(releaseConfigx86.IsUpToDate(logger, true))
+            Assert.True(debugConfigAnyCPU.IsUpToDate(logger, true))
+            Assert.True(releaseConfigAnyCPU.IsUpToDate(logger, true))
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.UTDCheckEnabled () =
         this.MakeProjectAndDo(["file1.fs"], [], @"
                 <PropertyGroup>
@@ -335,10 +327,10 @@ type UpToDate() =
             let configNameDebug = ConfigCanonicalName("Debug", "x86")
             let config = project.ConfigProvider.GetProjectConfiguration(configNameDebug)
 
-            Assert.IsFalse(config.IsFastUpToDateCheckEnabled())
+            Assert.False(config.IsFastUpToDateCheckEnabled())
             ))
 
-    [<Test>]
+    [<Fact>]
     member public this.UTDOptionsFlags () =
         this.MakeProjectAndDo(["file1.fs"], [], "", (fun project ->
             let configNameDebugx86 = ConfigCanonicalName("Debug", "x86")
@@ -352,8 +344,8 @@ type UpToDate() =
                 let supported = Array.zeroCreate<int> 1
                 let ready = Array.zeroCreate<int> 1
                 buildableConfig.QueryStartUpToDateCheck(flag, supported, ready) |> ignore
-                Assert.IsTrue(supported.[0] = expected)
-                Assert.IsTrue(ready.[0] = expected)
+                Assert.True(supported.[0] = expected)
+                Assert.True(ready.[0] = expected)
 
             [ VSConstants.VSUTDCF_DTEEONLY, 1
               VSConstants.VSUTDCF_PACKAGE, 0
@@ -362,7 +354,7 @@ type UpToDate() =
             |> List.iter (fun (flag, expected) -> testFlag flag expected)
           ))
 
-    [<Test>]
+    [<Fact>]
     member public this.UTDOptionsFlagsUTDDisabled () =
         this.MakeProjectAndDo(["file1.fs"], [],  @"
                 <PropertyGroup>
@@ -380,8 +372,8 @@ type UpToDate() =
                 let supported = Array.zeroCreate<int> 1
                 let ready = Array.zeroCreate<int> 1
                 buildableConfig.QueryStartUpToDateCheck(flag, supported, ready) |> ignore
-                Assert.AreEqual(supported.[0], expected)
-                Assert.AreEqual(ready.[0], expected)
+                Assert.Equal(supported.[0], expected)
+                Assert.Equal(ready.[0], expected)
 
             [ VSConstants.VSUTDCF_DTEEONLY, 1
               VSConstants.VSUTDCF_PACKAGE, 0
@@ -390,10 +382,9 @@ type UpToDate() =
             |> List.iter (fun (flag, expected) -> testFlag flag expected)
           ))
 
-[<TestFixture>]
 type ``UpToDate PreserveNewest`` () = 
 
-    [<Test>]
+    [<Fact>]
     member public this.IsUpToDatePreserveNewest () =
 
         let test (input, inputTimestamp) (output, outputTimestamp) =
@@ -416,28 +407,28 @@ type ``UpToDate PreserveNewest`` () =
 
         let ``no input -> not up-to-date and log`` =
             let u, logs = test ("readme.md", None) ("leggimi.md", None)
-            Assert.IsFalse(u)
+            Assert.False(u)
             logs
             |> List.exists (fun s -> s.Contains("readme.md") && s.Contains("can't find expected input"))
-            |> Assert.IsTrue
+            |> Assert.True
 
         let ``no output -> not up-to-date and log`` =
             let u, logs = test ("from.txt", Some now) ("to.txt", None)
-            Assert.IsFalse(u)
+            Assert.False(u)
             logs
             |> List.exists (fun s -> s.Contains("to.txt") && s.Contains("can't find expected output"))
-            |> Assert.IsTrue
+            |> Assert.True
 
         let ``a newer version of output file is ok`` =
             let u, logs = test ("before.doc", Some before) ("after.doc", Some now)
-            Assert.IsTrue(u)
+            Assert.True(u)
             logs |> AssertEqual []
 
         let ``stale output file -> not up-to-date and log`` =
             let u, logs = test ("logo.png", Some now) ("animatedlogo.gif", Some before)
-            Assert.IsFalse(u)
+            Assert.False(u)
             logs
             |> List.exists (fun s -> s.Contains("animatedlogo.gif") && s.Contains("stale"))
-            |> Assert.IsTrue
+            |> Assert.True
             
         ()        
diff --git a/vsintegration/tests/UnitTests/TestLib.Utils.fs b/vsintegration/tests/UnitTests/TestLib.Utils.fs
index 3a74b0c0e94..8072604ca2b 100644
--- a/vsintegration/tests/UnitTests/TestLib.Utils.fs
+++ b/vsintegration/tests/UnitTests/TestLib.Utils.fs
@@ -47,7 +47,7 @@ module Asserts =
         | None -> ()
 
     let AssertBuildSuccessful (result: Microsoft.VisualStudio.FSharp.ProjectSystem.BuildResult) =
-        Assert.IsTrue(result.IsSuccessful, "Expected build to succeed")
+        Assert.True(result.IsSuccessful, "Expected build to succeed")
 
 module UIStuff =
     let SetupSynchronizationContext() =
diff --git a/vsintegration/tests/UnitTests/Tests.Build.fs b/vsintegration/tests/UnitTests/Tests.Build.fs
index 78e4559d358..59ebf5baa83 100644
--- a/vsintegration/tests/UnitTests/Tests.Build.fs
+++ b/vsintegration/tests/UnitTests/Tests.Build.fs
@@ -2,7 +2,7 @@
 
 namespace Tests
 
-open NUnit.Framework
+open Xunit
 open System
 open System.IO
 open System.Diagnostics
@@ -19,8 +19,7 @@ module HandyExtensions =
             if not (s.MatchesPattern p) then
                 let up = System.Text.RegularExpressions.Regex.Unescape p
                 let message = sprintf "Expected\n%A\nto match pattern\n%A" s up
-                printfn "%s" message
-                Assert.Fail()
+                failwith message
 open HandyExtensions
 
 type MyLogger(f : string -> unit) =
@@ -49,7 +48,6 @@ type FauxHostObject() =
     interface ITaskHost
         // no members
 
-[<TestFixture>]
 type Build() = 
     (* Asserts ----------------------------------------------------------------------------- *)
     let AssertEqual expected actual =
@@ -60,16 +58,7 @@ type Build() =
 
     let MakeTaskItem (itemSpec : string) = new TaskItem(itemSpec) :> ITaskItem
 
-    /// Called per test
-    [<SetUp>]
-    member this.Setup() =
-        ()
-        
-    [<TearDown>]
-    member this.TearDown() =
-        ()
-
-    [<Test>]
+    [<Fact>]
     member public this.TestCodePage() =
         let tool = new FSharp.Build.Fsc()
         printfn "By the way, the registry or app.config tool path is %s" tool.ToolPath
@@ -85,7 +74,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestDebugSymbols() =
         let tool = new FSharp.Build.Fsc()
         tool.DebugSymbols <- true
@@ -100,7 +89,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestDebugType() =
         let tool = new FSharp.Build.Fsc()
         tool.DebugType <- "pdbONly"
@@ -115,7 +104,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestDefineConstants() =
         let tool = new FSharp.Build.Fsc()
         tool.DefineConstants <- [| MakeTaskItem "FOO=3"
@@ -132,7 +121,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestDisabledWarnings1() =
         let tool = new FSharp.Build.Fsc()
         tool.DisabledWarnings <- "52;109"
@@ -147,7 +136,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestDisabledWarnings2() =
         let tool = new FSharp.Build.Fsc()
         tool.DisabledWarnings <- ";"  // e.g. someone may have <NoWarn>$(NoWarn);$(SomeOtherVar)</NoWarn> and both vars are empty
@@ -161,7 +150,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestWarningsNotAsErrors() =
         let tool = new FSharp.Build.Fsc()
         tool.WarningsNotAsErrors <- "52;109"
@@ -176,7 +165,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestVersionFile() =
         let tool = new FSharp.Build.Fsc()
         tool.VersionFile <- "src/version"
@@ -191,7 +180,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestDocumentationFile() =
         let tool = new FSharp.Build.Fsc()
         tool.DocumentationFile <- "foo.xml"
@@ -206,7 +195,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestGenerateInterfaceFile() =
         let tool = new FSharp.Build.Fsc()
         tool.GenerateInterfaceFile <- "foo.fsi"
@@ -221,7 +210,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestKeyFile() =
         let tool = new FSharp.Build.Fsc()
         tool.KeyFile <- "key.txt"
@@ -236,7 +225,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestNoFramework() =
         let tool = new FSharp.Build.Fsc()
         tool.NoFramework <- true
@@ -251,7 +240,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestOptimize() =
         let tool = new FSharp.Build.Fsc()
         tool.Optimize <- false
@@ -265,7 +254,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestTailcalls() =
         let tool = new FSharp.Build.Fsc()
         tool.Tailcalls <- true
@@ -280,7 +269,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestOtherFlags() =
         let tool = new FSharp.Build.Fsc()
         tool.OtherFlags <- "--yadda yadda"
@@ -296,7 +285,7 @@ type Build() =
                      "yadda")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestOutputAssembly() =
         let tool = new FSharp.Build.Fsc()
         tool.OutputAssembly <- "oUt.dll"
@@ -311,7 +300,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestPdbFile() =
         let tool = new FSharp.Build.Fsc()
         tool.PdbFile <- "out.pdb"
@@ -326,7 +315,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestPlatform1() =
         let tool = new FSharp.Build.Fsc()
         tool.Platform <- "x64"
@@ -341,7 +330,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestPlatform3() =
         let tool = new FSharp.Build.Fsc()
         tool.Platform <- "x86"
@@ -356,7 +345,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestReferences() =
         let tool = new FSharp.Build.Fsc()
         let dll = "c:\\sd\\staging\\tools\\nunit\\nunit.framework.dll"
@@ -372,7 +361,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestReferencePath() =
         let tool = new FSharp.Build.Fsc()
         let path = "c:\\sd\\staging\\tools\\nunit\\;c:\\Foo"
@@ -388,7 +377,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestReferencePathWithSpaces() =
         let tool = new FSharp.Build.Fsc()
         let path = "c:\\program files;c:\\sd\\staging\\tools\\nunit;c:\\Foo"
@@ -404,7 +393,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestResources() =
         let tool = new FSharp.Build.Fsc()
         tool.Resources <- [| MakeTaskItem "Foo.resources" |]
@@ -419,7 +408,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestSources() =
         let tool = new FSharp.Build.Fsc()
         let src = "foo.fs"
@@ -438,7 +427,7 @@ type Build() =
                     cmd
         ()
 
-    [<Test>]
+    [<Fact>]
     member public this.TestTargetType1() =
         let tool = new FSharp.Build.Fsc()
         tool.TargetType <- "Library"
@@ -453,7 +442,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestTargetType2() =
         let tool = new FSharp.Build.Fsc()
         tool.TargetType <- "Winexe"
@@ -468,7 +457,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestTargetType3() =
         let tool = new FSharp.Build.Fsc()
         tool.TargetType <- "Module"
@@ -483,7 +472,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestUtf8Output() =
         let tool = new FSharp.Build.Fsc()
         tool.Utf8Output <- true
@@ -497,7 +486,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestWin32Res() =
         let tool = new FSharp.Build.Fsc()
         tool.Win32ResourceFile <- "foo.res"
@@ -511,7 +500,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd
 
-    [<Test>]
+    [<Fact>]
     member public this.TestWin32Manifest() =
         let tool = new FSharp.Build.Fsc()
         tool.Win32ManifestFile <- "foo.manifest"
@@ -525,7 +514,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd 
 
-    [<Test>]
+    [<Fact>]
     member public this.TestHighEntropyVA() =
         let tool = new FSharp.Build.Fsc()
         tool.HighEntropyVA <- true
@@ -538,7 +527,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd 
 
-    [<Test>]
+    [<Fact>]
     member public this.TestSubsystemVersion() =
         let tool = new FSharp.Build.Fsc()
         tool.SubsystemVersion <- "6.02"
@@ -552,7 +541,7 @@ type Build() =
                      "--nocopyfsharpcore")
                     cmd 
 
-    [<Test>]
+    [<Fact>]
     member public this.TestAllCombo() =
         let tool = new FSharp.Build.Fsc()
         tool.CodePage <- "65001"
@@ -668,7 +657,7 @@ type Build() =
         let expectedSources = [| "foo.fs"; "C:\\Program Files\\spaces.fs" |]
         AssertEqual expectedSources hostObject.Sources
 
-    [<Test>]
+    [<Fact>]
     member public this.``DisabledWarnings build property``() =
         let tool = new FSharp.Build.Fsc()
         tool.DisabledWarnings <- "
diff --git a/vsintegration/tests/UnitTests/Tests.InternalCollections.fs b/vsintegration/tests/UnitTests/Tests.InternalCollections.fs
index 55a4bb1f34e..835eebcd771 100644
--- a/vsintegration/tests/UnitTests/Tests.InternalCollections.fs
+++ b/vsintegration/tests/UnitTests/Tests.InternalCollections.fs
@@ -4,11 +4,10 @@ namespace Tests.Compiler.InternalCollections
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open Internal.Utilities.Collections
        
                 
-[<TestFixture>] 
 type MruCache = 
     new() = { }        
 
@@ -23,23 +22,23 @@ type MruCache =
     member private rb.NumToStringBox n = box (rb.NumToString n)
 
 #if DISABLED_OLD_UNITTESTS
-    [<Test>]
+    [<Fact>]
     member public rb.Basic() = 
         let m = new MruCache<int,string>(3, (fun (x,y) -> x = y))
         let s = m.Get(5)
-        Assert.IsTrue("Five"=s)
+        Assert.True("Five"=s)
         let s = m.Get(6)
-        Assert.IsTrue("Six"=s)
+        Assert.True("Six"=s)
         let s = m.Get(7)
-        Assert.IsTrue("Seven"=s)
+        Assert.True("Seven"=s)
         let s = m.Get(8)
-        Assert.IsTrue("Eight"=s)
+        Assert.True("Eight"=s)
         let (i,s) = Option.get m.MostRecent
-        Assert.AreEqual(8,i)
-        Assert.IsTrue("Eight"=s)
+        Assert.Equal(8,i)
+        Assert.True("Eight"=s)
         ()
 
-    [<Test>]
+    [<Fact>]
     member public rb.MostRecentOfEmpty() = 
         let m = new MruCache<int,string>(3, rb.NumToString, (fun (x,y) -> x = y))
         match m.MostRecent with
@@ -47,21 +46,21 @@ type MruCache =
             | None->()
 
 
-    [<Test>]
+    [<Fact>]
     member public rb.SetAlternate() = 
         let m = new MruCache<int,string>(3, rb.NumToString, (fun (x,y) -> x = y))
         m.SetAlternate(2,"Banana")
         let (i,s) = Option.get m.MostRecent
-        Assert.AreEqual(2,i)
-        Assert.IsTrue("Banana"=s)
+        Assert.Equal(2,i)
+        Assert.True("Banana"=s)
             
     member private rb.AddBanana(m:MruCache<int,obj>) = 
         let banana = new obj()
         m.SetAlternate(2,banana)
         let s = m.Get(2)
-        Assert.AreEqual(banana,s)                    
+        Assert.Equal(banana,s)                    
             
-    [<Test>]
+    [<Fact>]
     member public rb.CacheDepthIsHonored() = 
         let m = new MruCache<int,obj>(3, rb.NumToStringBox, (fun (x,y) -> x = y))
         rb.AddBanana(m) // Separate function to keep 'banana' out of registers
@@ -70,9 +69,9 @@ type MruCache =
         let _ = m.Get(5)
         GC.Collect()
         let s = m.Get(2)
-        Assert.IsTrue("Two"=downcast s)
+        Assert.True("Two"=downcast s)
             
-    [<Test>]
+    [<Fact>]
     member public rb.SubsumptionIsHonored() = 
         let PairToString (s,n) = rb.NumToString n
         let AreSameForSubsumption((s1,n1),(s2,n2)) = n1=n2
@@ -80,13 +79,13 @@ type MruCache =
         let m = new MruCache<string*int,string>(3, PairToString, (fun (x,y) -> x = y), areSimilar=AreSameForSubsumption)
         m.SetAlternate(("x",2),"Banana")
         let s = m.Get (("x",2))
-        Assert.IsTrue("Banana"=s, "Check1")                                      
+        Assert.True("Banana"=s, "Check1")                                      
         let s = m.Get (("y",2))
-        Assert.IsTrue("Two"=s, "Check2")                                      
+        Assert.True("Two"=s, "Check2")                                      
         let s = m.Get (("x",2))
-        Assert.IsTrue("Two"=s, "Check3") // Not banana because it was subsumed
+        Assert.True("Two"=s, "Check3") // Not banana because it was subsumed
 
-    [<Test>]
+    [<Fact>]
     member public rb.OnDiscardIsHonored() = 
         
         let AreSameForSubsumption((s1,n1),(s2,n2)) = s1=s2
@@ -95,27 +94,26 @@ type MruCache =
         let m = new MruCache<string*int,string>(compute=fst, areSimilar=(fun (x,y) -> x = y), areSimilar=AreSameForSubsumption, keepStrongly=2, keepMax=2, onDiscard=(fun s -> discarded := s :: !discarded))
         m.SetAlternate(("x",1),"Banana") // no discard
         printfn "discarded = %A" discarded.Value
-        Assert.IsTrue(discarded.Value = [], "Check1")                                      
+        Assert.True(discarded.Value = [], "Check1")                                      
         m.SetAlternate(("x",2),"Apple") // forces discard of x --> Banana
         printfn "discarded = %A" discarded.Value
-        Assert.IsTrue(discarded.Value = ["Banana"], "Check2")                                      
+        Assert.True(discarded.Value = ["Banana"], "Check2")                                      
         let s = m.Get (("x",3))
         printfn "discarded = %A" discarded.Value
-        Assert.IsTrue(discarded.Value = ["Apple"; "Banana"], "Check3")                                      
+        Assert.True(discarded.Value = ["Apple"; "Banana"], "Check3")                                      
         let s = m.Get (("y",4))
         printfn "discarded = %A" discarded.Value
-        Assert.IsTrue(discarded.Value = ["Apple"; "Banana"], "Check4")                                      
+        Assert.True(discarded.Value = ["Apple"; "Banana"], "Check4")                                      
         let s = m.Get (("z",5)) // forces discard of x --> Bananas
         printfn "discarded = %A" discarded.Value
-        Assert.IsTrue(discarded.Value = ["x"; "Apple";"Banana"], "Check5")                                      
+        Assert.True(discarded.Value = ["x"; "Apple";"Banana"], "Check5")                                      
         let s = m.Get (("w",6)) // forces discard of y
         printfn "discarded = %A" discarded.Value
-        Assert.IsTrue(discarded.Value = ["y";"x";"Apple";"Banana"], "Check6")                                      
+        Assert.True(discarded.Value = ["y";"x";"Apple";"Banana"], "Check6")                                      
 #endif
 
 type AccessToken() = class end
             
-[<TestFixture>] 
 type AgedLookup() = 
     let mutable hold197 : byte [] = null
     let mutable hold198 : byte [] = null
@@ -127,17 +125,17 @@ type AgedLookup() =
             
         let AssertCached(i,o:byte array) = 
             match al.TryPeekKeyValue(atok,i) with
-            | Some(_,x) -> Assert.IsTrue(obj.ReferenceEquals(o,x), sprintf "Object in cache (%d) does not agree with expectation (%d)" x.[0] i)
-            | None -> Assert.IsTrue(false, "Object fell out of cache")
+            | Some(_,x) -> Assert.True(obj.ReferenceEquals(o,x), sprintf "Object in cache (%d) does not agree with expectation (%d)" x.[0] i)
+            | None -> Assert.True(false, "Object fell out of cache")
                 
         let AssertExistsInCached(i) = 
             match al.TryPeekKeyValue(atok,i) with
             | Some _ -> ()
-            | None -> Assert.IsTrue(false, "Object fell out of cache")                
+            | None -> Assert.True(false, "Object fell out of cache")                
                 
         let AssertNotCached(i) = 
             match al.TryPeekKeyValue(atok,i) with
-            | Some _ -> Assert.IsTrue(false, "Expected key to have fallen out of cache")     
+            | Some _ -> Assert.True(false, "Expected key to have fallen out of cache")     
             | None -> ()         
             
         let f() =
@@ -215,7 +213,7 @@ type AgedLookup() =
         GC.Collect()
         
         
-    [<Test>] member public rb.WeakRef0() = WeakRefTest 0
-    [<Test>] member public rb.WeakRef1() = WeakRefTest 1
-    [<Test>] member public rb.WeakRef2() = WeakRefTest 2
-    [<Test>] member public rb.WeakRef3() = WeakRefTest 3
+    [<Fact>] member public rb.WeakRef0() = WeakRefTest 0
+    [<Fact>] member public rb.WeakRef1() = WeakRefTest 1
+    [<Fact>] member public rb.WeakRef2() = WeakRefTest 2
+    [<Fact>] member public rb.WeakRef3() = WeakRefTest 3
diff --git a/vsintegration/tests/UnitTests/Tests.TaskReporter.fs b/vsintegration/tests/UnitTests/Tests.TaskReporter.fs
index fb5e57bb446..d644a6c3237 100644
--- a/vsintegration/tests/UnitTests/Tests.TaskReporter.fs
+++ b/vsintegration/tests/UnitTests/Tests.TaskReporter.fs
@@ -2,7 +2,7 @@
 
 namespace Tests.LanguageService.ErrorList
 
-open NUnit.Framework
+open Xunit
 open System
 open System.IO
 open System.Diagnostics
@@ -20,7 +20,6 @@ open Salsa.VsMocks
 type TextSpan = Microsoft.VisualStudio.TextManager.Interop.TextSpan
 type DocumentTask = Microsoft.VisualStudio.FSharp.LanguageService.DocumentTask
 
-[<TestFixture>]
 type TaskReporterTests() = 
     static let err(line) : 'a = 
         printfn "err() called on line %s with %s" line System.Environment.StackTrace 
@@ -94,7 +93,7 @@ type TaskReporterTests() =
 // One File Tests
     // For the next two, add tasks to the task list more than once to ensure that
     // hashing is occurring correctly   
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.LanguageServiceErrorsProperlyCoalesced``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -114,7 +113,7 @@ type TaskReporterTests() =
         
         
         
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.ProjectSystemErrorsProperlyCoalesced``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -134,7 +133,7 @@ type TaskReporterTests() =
         ()
         
     /// Test for multiple identical errors being properly coalesced in the error list (bug 2151)
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.ErrorsProperlyCoalesced``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -153,7 +152,7 @@ type TaskReporterTests() =
         ()
     
     // modify the span, and check to see if we have two tasks now instead of one    
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.ProjectSystemErrorsProperlyCoalesced2``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -175,7 +174,7 @@ type TaskReporterTests() =
         ()
         
     /// Ensure that text line markers are only created when a task is output to the task list
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.TextLineMarkersCreatedOnce``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -212,7 +211,7 @@ type TaskReporterTests() =
  
     // both files open
     // errors in each file, build - no duplicates  
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.TwoFilesBothOpen``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -238,7 +237,7 @@ type TaskReporterTests() =
  
      // file open, one file closed
      // - error in closed file
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.TwoFilesOneOpenErrorInOpen``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -268,7 +267,7 @@ type TaskReporterTests() =
         ()           
  
     // all files open - build, then fix - no errors left
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.TwoFilesCorrectError``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -314,7 +313,7 @@ type TaskReporterTests() =
         
         
     // Make sure a 'typecheck' is treated as a background task
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.BackgroundTaskIsClassified``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
@@ -342,7 +341,7 @@ type TaskReporterTests() =
         
         
     // Make sure a 'ilxgen' is treated as a build task
-    [<Test>]
+    [<Fact>]
     member public this.``ErrorList.BuildTaskIsClassified``() =  
         use errorReporter = CreateErrorReporter()
         let mutable span = new TextSpan(iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 2)
diff --git a/vsintegration/tests/UnitTests/Tests.Watson.fs b/vsintegration/tests/UnitTests/Tests.Watson.fs
index 35ccf0f4d03..e5c19d5e22d 100644
--- a/vsintegration/tests/UnitTests/Tests.Watson.fs
+++ b/vsintegration/tests/UnitTests/Tests.Watson.fs
@@ -11,7 +11,7 @@ open FSharp.Compiler.CodeAnalysis
 open Internal.Utilities.Library 
 open FSharp.Compiler.CompilerConfig
 open FSharp.Compiler.Driver
-open NUnit.Framework
+open Xunit
 open System.IO
 
 type Check = 
@@ -51,122 +51,121 @@ type Check =
         FileSystem.FileDeleteShim("watson-test.fs")
 
 
-[<TestFixture>] 
 module WatsonTests = 
 
-    [<Test>]
+    [<Fact>]
     let FscOutOfMemory() = Check.FscLevelException<System.OutOfMemoryException>("fsc-oom")
 
-    [<Test>]
+    [<Fact>]
     let FscArgumentNull() = Check.FscLevelException<System.ArgumentNullException>("fsc-an")        
     
-    [<Test>]
+    [<Fact>]
     let FscInvalidOperation() = Check.FscLevelException<System.InvalidOperationException>("fsc-invop")        
 
 // As of .NET 4.0 some exception types cannot be caught. As a result, we cannot test this case. I did visually confirm a Watson report is sent, though.
-//    [<Test>]
+//    [<Fact>]
 //    let FscAccessViolation() = Check.FscLevelException<System.AccessViolationException>("fsc-ac")        
 
-    [<Test>]
+    [<Fact>]
     let FscArgumentOutOfRange() = Check.FscLevelException<System.ArgumentOutOfRangeException>("fsc-aor")        
 
-    [<Test>]
+    [<Fact>]
     let FscDivideByZero() = Check.FscLevelException<System.DivideByZeroException>("fsc-dv0")        
 
-    [<Test>]
+    [<Fact>]
     let FscNotFiniteNumber() = Check.FscLevelException<System.NotFiniteNumberException>("fsc-nfn")        
 
-    [<Test>]
+    [<Fact>]
     let FscOverflow() = Check.FscLevelException<System.OverflowException>("fsc-oe")        
 
-    [<Test>]
+    [<Fact>]
     let FscArrayTypeMismatch() = Check.FscLevelException<System.ArrayTypeMismatchException>("fsc-atmm")        
 
-    [<Test>]
+    [<Fact>]
     let FscBadImageFormat() = Check.FscLevelException<System.BadImageFormatException>("fsc-bif")        
 
-    [<Test>]
+    [<Fact>]
     let FscKeyNotFound() = Check.FscLevelException<System.Collections.Generic.KeyNotFoundException>("fsc-knf")        
 
-    [<Test>]
+    [<Fact>]
     let FscIndexOutOfRange() = Check.FscLevelException<System.IndexOutOfRangeException>("fsc-ior")        
 
-    [<Test>]
+    [<Fact>]
     let FscInvalidCast() = Check.FscLevelException<System.InvalidCastException>("fsc-ic")        
 
-    [<Test>]
+    [<Fact>]
     let FscInvalidProgram() = Check.FscLevelException<System.InvalidProgramException>("fsc-ip")        
 
-    [<Test>]
+    [<Fact>]
     let FscMemberAccess() = Check.FscLevelException<System.MemberAccessException>("fsc-ma")        
 
-    [<Test>]
+    [<Fact>]
     let FscNotImplemented() = Check.FscLevelException<System.NotImplementedException>("fsc-ni")        
 
-    [<Test>]
+    [<Fact>]
     let FscNullReference() = Check.FscLevelException<System.NullReferenceException>("fsc-nr")        
 
-    [<Test>]
+    [<Fact>]
     let FscOperationCancelled() = Check.FscLevelException<System.OperationCanceledException>("fsc-oc")        
     
-    //[<Test>]
+    //[<Fact>]
     //let FscFailure() = Check.FscLevelException<Microsoft.FSharp.Core.FailureException>("fsc-fail")            
       
-    [<Test>]
+    [<Fact>]
     let TypeCheckOutOfMemory() = Check.FscLevelException<System.OutOfMemoryException>("tc-oom")
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckArgumentNull() = Check.FscLevelException<System.ArgumentNullException>("tc-an")        
     
-    [<Test>]
+    [<Fact>]
     let TypeCheckInvalidOperation() = Check.FscLevelException<System.InvalidOperationException>("tc-invop")        
 
 // As of .NET 4.0 some exception types cannot be caught. As a result, we cannot test this case. I did visually confirm a Watson report is sent, though.
-//    [<Test>]
+//    [<Fact>]
 //    let TypeCheckAccessViolation() = Check.FscLevelException<System.AccessViolationException>("tc-ac")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckArgumentOutOfRange() = Check.FscLevelException<System.ArgumentOutOfRangeException>("tc-aor")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckDivideByZero() = Check.FscLevelException<System.DivideByZeroException>("tc-dv0")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckNotFiniteNumber() = Check.FscLevelException<System.NotFiniteNumberException>("tc-nfn")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckOverflow() = Check.FscLevelException<System.OverflowException>("tc-oe")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckArrayTypeMismatch() = Check.FscLevelException<System.ArrayTypeMismatchException>("tc-atmm")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckBadImageFormat() = Check.FscLevelException<System.BadImageFormatException>("tc-bif")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckKeyNotFound() = Check.FscLevelException<System.Collections.Generic.KeyNotFoundException>("tc-knf")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckIndexOutOfRange() = Check.FscLevelException<System.IndexOutOfRangeException>("tc-ior")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckInvalidCast() = Check.FscLevelException<System.InvalidCastException>("tc-ic")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckInvalidProgram() = Check.FscLevelException<System.InvalidProgramException>("tc-ip")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckMemberAccess() = Check.FscLevelException<System.MemberAccessException>("tc-ma")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckNotImplemented() = Check.FscLevelException<System.NotImplementedException>("tc-ni")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckNullReference() = Check.FscLevelException<System.NullReferenceException>("tc-nr")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckOperationCancelled() = Check.FscLevelException<System.OperationCanceledException>("tc-oc")        
 
-    [<Test>]
+    [<Fact>]
     let TypeCheckFailure() = Check.FscLevelException<System.Exception>("tc-fail")            
 
diff --git a/vsintegration/tests/UnitTests/Tests.XmlDocComments.fs b/vsintegration/tests/UnitTests/Tests.XmlDocComments.fs
index 432d72ec018..b11bdd9ef8c 100644
--- a/vsintegration/tests/UnitTests/Tests.XmlDocComments.fs
+++ b/vsintegration/tests/UnitTests/Tests.XmlDocComments.fs
@@ -3,13 +3,12 @@
 namespace Tests.LanguageService
 
 open System
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open UnitTests.TestLib.Salsa
 open UnitTests.TestLib.Utils
 
-[<TestFixture>]
 type XmlDocComments() =
     inherit UnitTests.TestLib.LanguageService.LanguageServiceBaseTests(VsOpts = InstalledMSBuildTestFlavour())
 
@@ -58,31 +57,28 @@ type XmlDocComments() =
         let project2 = CreateProject(solution, "FSClient")
         let file1 = AddFileFromTextBlob(project1,"File1.fs", fileContent1)
         AddProjectReference(project2,project1)       
-        Build(project1) |> fun result -> Assert.IsTrue(result.BuildSucceeded)
+        Build(project1) |> fun result -> Assert.True(result.BuildSucceeded)
 
         let file2 = AddFileFromTextBlob(project2,"File2.fs", fileContent2)
         let file = OpenFile(project2, "File2.fs")
         MoveCursorToStartOfMarker(file, marker)
         GetQuickInfoAtCursor file
 
-    [<Test>]
-    [<Ignore("GetQuickInfoAtCursor miss XMLDoc analyzing")>]
+    [<Fact(Skip = "GetQuickInfoAtCursor miss XMLDoc analyzing")>]
     member this.``MalFormedXML.FromXMLDoc``() = 
         let expected = "XML comment"
         let tooltip = this.TestMalFormedXML("(*Marker1*)")
         printfn "%A" tooltip
         AssertContains(trimnewlines tooltip, trimnewlines expected) 
 
-    [<Test>]
-    [<Ignore("GetQuickInfoAtCursor miss XMLDoc analyzing")>]
+    [<Fact(Skip = "GetQuickInfoAtCursor miss XMLDoc analyzing")>]
     member this.``MalFormedXML.FromCurrentProject``() = 
         let expected = "'summary'"
         let tooltip = this.TestMalFormedXML("(*Marker2*)")
         printfn "%A" tooltip
         AssertContains(trimnewlines tooltip, trimnewlines expected) 
 
-    [<Test>]
-    [<Ignore("GetQuickInfoAtCursor miss XMLDoc analyzing")>]
+    [<Fact(Skip = "GetQuickInfoAtCursor miss XMLDoc analyzing")>]
     member this.``MalFormedXML.NoXMLComment.Bug5858``() = 
         let notexpected = "summary"
         let notexpected2 = "param name="
@@ -91,8 +87,7 @@ type XmlDocComments() =
         AssertNotContains(tooltip, notexpected)   
         AssertNotContains(tooltip, notexpected2)   
 
-    [<Test>]
-    [<Ignore("GetQuickInfoAtCursor miss XMLDoc analyzing")>]
+    [<Fact(Skip = "GetQuickInfoAtCursor miss XMLDoc analyzing")>]
     member this.Test() = 
         let fileContent = """
             //local custom type value
diff --git a/vsintegration/tests/UnitTests/UnusedOpensTests.fs b/vsintegration/tests/UnitTests/UnusedOpensTests.fs
index e47b38b46e6..e1a52c562bf 100644
--- a/vsintegration/tests/UnitTests/UnusedOpensTests.fs
+++ b/vsintegration/tests/UnitTests/UnusedOpensTests.fs
@@ -3,15 +3,12 @@
 module Tests.ServiceAnalysis.UnusedOpens
 
 open System
-open NUnit.Framework
+open Xunit
 open FSharp.Compiler.CodeAnalysis
 open FSharp.Compiler.CodeAnalysis
 open FSharp.Compiler.EditorServices
 open FSharp.Compiler.Text
 
-/// like "should equal", but validates same-type
-let shouldEqual (x: 'a) (y: 'a) = Assert.AreEqual(x, y, sprintf "Expected: %A\nActual: %A" x y)
-
 let private filePath = "C:\\test.fs"
 
 let private projectOptions : FSharpProjectOptions = 
@@ -43,9 +40,9 @@ let (=>) (source: string) (expectedRanges: ((*line*)int * ((*start column*)int *
     
     unusedOpenRanges 
     |> List.map (fun x -> x.StartLine, (x.StartColumn, x.EndColumn))
-    |> shouldEqual expectedRanges
+    |> fun actual -> Assert.Equal<(int * (int * int)) list>(expectedRanges, actual)
 
-[<Test>]
+[<Fact>]
 let ``unused open declaration in top level module``() =
     """
 module TopModule
@@ -55,7 +52,7 @@ let _ = DateTime.Now
 """
     => [ 4, (5, 14) ]
 
-[<Test>]
+[<Fact>]
 let ``unused open declaration in namespace``() =
     """
 namespace TopNamespace
@@ -66,7 +63,7 @@ module Nested =
 """
     => [ 4, (5, 14) ]
 
-[<Test>]
+[<Fact>]
 let ``unused open declaration in nested module``() =
     """
 namespace TopNamespace
@@ -77,7 +74,7 @@ module Nested =
 """
     => [ 5, (9, 18) ]
 
-[<Test>] 
+[<Fact>] 
 let ``unused open declaration due to partially qualified symbol``() =
     """
 module TopModule
@@ -87,7 +84,7 @@ let _ = IO.File.Create ""
 """
     => [ 4, (5, 14) ]
 
-[<Test>]
+[<Fact>]
 let ``unused parent open declaration due to partially qualified symbol``() =
     """
 module TopModule
@@ -97,7 +94,7 @@ let _ = File.Create ""
 """
     => [ 3, (5, 11) ]
 
-[<Test>]
+[<Fact>]
 let ``open statement duplication in parent module is unused``() =
     """
 module TopModule
@@ -108,7 +105,7 @@ module Nested =
 """
     => [ 5, (9, 18) ]
 
-[<Test>]
+[<Fact>]
 let ``open statement duplication in parent module is marked as unused even though it seems to be used in its scope``() =
     """
 module TopModule
@@ -120,14 +117,14 @@ let _ = File.Create ""
 """
     => [ 5, (9, 18) ]
 
-[<Test>]
+[<Fact>]
 let ``multiple open declaration in the same line``() =
     """
 open System.IO; let _ = File.Create "";; open System.IO
 """
     => [ 2, (46, 55) ]
 
-[<Test>]
+[<Fact>]
 let ``open a nested module inside another one is not unused``() =
     """
 module Top
@@ -139,7 +136,7 @@ module M2 =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open a nested module inside another one is not unused, complex hierarchy``() =
     """
 module Top =
@@ -153,7 +150,7 @@ module Top =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open a nested module inside another one is not unused, even more complex hierarchy``() =
     """
 module Top =
@@ -169,7 +166,7 @@ module Top =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``opening auto open module after it's parent module was opened should be marked as unused``() =
     """
 module NormalModule =
@@ -188,7 +185,7 @@ let _ = Class()
 """
     => [ 13, (5, 68) ]
 
-[<Test>]
+[<Fact>]
 let ``opening parent module after one of its auto open module was opened should be marked as unused``() =
     """
 module NormalModule =
@@ -207,7 +204,7 @@ let _ = Class()
 """
     => [ 13, (5, 52) ]
     
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if there is a shortened attribute symbol from it``() =
     """
 open System
@@ -216,7 +213,7 @@ type Class() = class end
 """
     => []
     
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if an extension property is used``() =
     """
 module Module =
@@ -227,7 +224,7 @@ let _ = "a long string".ExtensionProperty
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is marked as unused if an extension property is not used``() =
     """
 module Module =
@@ -238,7 +235,7 @@ let _ = "a long string".Trim()
 """
     => [ 5, (5, 11) ]
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if an extension method is used``() =
     """
 type Class() = class end
@@ -251,7 +248,7 @@ let _ = x.ExtensionMethod()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is marked as unused if an extension method is not used``() =
     """
 type Class() = class end
@@ -263,7 +260,7 @@ let x = Class()
 """
     => [ 6, (5, 11) ]
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if one of its types is used in a constructor signature``() =
     """
 module M =
@@ -273,7 +270,7 @@ type Site (x: Class -> unit) = class end
 """
     => []   
 
-[<Test>]
+[<Fact>]
 let ``open declaration is marked as unused if nothing from it is used``() =
     """
 module M =
@@ -283,7 +280,7 @@ type Site (x: int -> unit) = class end
 """
     => [ 4, (5, 6) ]
 
-[<Test>]
+[<Fact>]
 let ``static extension method applied to a type results that both namespaces /where the type is declared and where the extension is declared/ is not marked as unused``() =
     """
 module Extensions =
@@ -295,7 +292,7 @@ let _ = DateTime.ExtensionMethod
 """
     => []
     
-[<Test>]
+[<Fact>]
 let ``static extension property applied to a type results that both namespaces /where the type is declared and where the extension is declared/ is not marked as unused``() =
     """
 module Extensions =
@@ -307,7 +304,7 @@ let _ = DateTime.ExtensionProperty
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``accessing property on a variable should not force the namespace in which the type is declared to be marked as used``() =
     """
 let dt = System.DateTime.Now
@@ -317,7 +314,7 @@ module M =
 """
     => [4, (9, 15) ]
 
-[<Test>]
+[<Fact>]
 let ``either of two open declarations are not marked as unused if symbols from both of them are used``() =
     """
 module M1 =
@@ -332,7 +329,7 @@ let _ = func2()
 """
     => []
         
-[<Test>]
+[<Fact>]
 let ``open module with ModuleSuffix attribute value applied is not marked as unused if a symbol declared in it is used``() =
     """
 [<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
@@ -343,7 +340,7 @@ let _ = func()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open module all of which symbols are used by qualifier is marked as unused``() =
     """
 module M =
@@ -353,7 +350,7 @@ let _ = M.func 1
 """
     => [4, (5, 6) ]
 
-[<Test>]
+[<Fact>]
 let ``open module is not marked as unused if a symbol defined in it is used in OCaml-style type annotation``() =
     """
 module M =
@@ -363,7 +360,7 @@ let func (arg: Class list) = ()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``auto open module``() =
     """
 module Top =
@@ -375,7 +372,7 @@ let _ = func()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``auto open module with namespace``() =
     """
 namespace Module1Namespace
@@ -390,7 +387,7 @@ module Module3 =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``auto open module in the middle of hierarchy``() =
     """
 namespace Ns
@@ -404,7 +401,7 @@ module M2 =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if a delegate defined in it is used``() =
     """
 open System
@@ -412,7 +409,7 @@ let _ = Func<int, int>(fun _ -> 1)
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if a unit of measure defined in it is used``() =
     """
 module M = 
@@ -423,7 +420,7 @@ module N =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if an attribute defined in it is applied on an interface member argument``() =
     """
 open System.Runtime.InteropServices
@@ -431,7 +428,7 @@ type T = abstract M: [<DefaultParameterValue(null)>] ?x: int -> unit
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``relative module open declaration``() =
     """
 module Top =
@@ -443,7 +440,7 @@ let _ = x
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is used if a symbol defined in it is used in a module top-level do expression``() =
     """
 module Top
@@ -453,7 +450,7 @@ File.ReadAllLines ""
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``redundant opening a module with ModuleSuffix attribute value is marks as unused``() =
     """
 [<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
@@ -465,7 +462,7 @@ module M =
 """
     => [ 6, (9, 33) ]
     
-[<Test>]
+[<Fact>]
 let ``redundant opening a module is marks as unused``() =
     """
 module InternalModuleWithSuffix =
@@ -476,7 +473,7 @@ module M =
 """
     => [ 5, (9, 33) ]
 
-[<Test>]
+[<Fact>]
 let ``usage of an unqualified union case doesn't make an opening module where it's defined to be marked as unused``() =
     """
 module M =
@@ -486,7 +483,7 @@ let _ = Case1
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``usage of qualified union case doesn't make an opening module where it's defined to be marked as unused``() =
     """
 module M =
@@ -496,7 +493,7 @@ let _ = DU.Case1
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``type with different DisplayName``() =
     """
 open Microsoft.FSharp.Quotations
@@ -504,7 +501,7 @@ let _ = Expr.Coerce (<@@ 1 @@>, typeof<int>)
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``auto open module with ModuleSuffix attribute value``() =
     """
 module Top =
@@ -517,7 +514,7 @@ module Module1 =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``a type which has more than one DisplayName causes the namespace it's defined in to be not marked as unused``() =
     """
 open System
@@ -525,7 +522,7 @@ let _ = IntPtr.Zero
 """ 
     => []
 
-[<Test>]
+[<Fact>]
 let ``usage of an operator makes the module it's defined in to be not marked as unused``() =
     """
 module M =
@@ -535,7 +532,7 @@ let _ = 1 ++| 2
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``usage of an operator makes the module /with Module suffix/ it's defined in to be not marked as unused``() =
     """
 [<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
@@ -546,7 +543,7 @@ let _ = 1 ++| 2
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``type used in pattern matching with "as" keyword causes the module in which the type is defined to be not marked as unused``() =
     """
 module M = 
@@ -558,7 +555,7 @@ let _ = match obj() with
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``a function from printf family prevents Printf module from marking as unused``() =
     """
 open Microsoft.FSharp.Core.Printf
@@ -567,7 +564,7 @@ let _ = bprintf (StringBuilder()) "%A" 1
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``assembly level attribute prevents namespace in which it's defined to be marked as unused``() =
     """
 open System
@@ -576,7 +573,7 @@ open System
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if a related type extension is used``() =
     """
 module Module =
@@ -586,7 +583,7 @@ module Module =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``open declaration is not marked as unused if a symbol defined in it is used in type do block``() =
     """
 open System.IO.Compression
@@ -597,7 +594,7 @@ type OutliningHint() as self =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``should not mark open declaration with global prefix``() =
     """
 module Module =
@@ -606,7 +603,7 @@ module Module =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``record fields should be taken into account``() = 
     """
 module M1 =
@@ -617,7 +614,7 @@ module M2 =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``handle type alias``() = 
     """
 module TypeAlias =
@@ -628,7 +625,7 @@ module Usage =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``handle override members``() = 
     """
 type IInterface =
@@ -642,7 +639,7 @@ let f (x: IClass) = (x :> IInterface).Property
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``active pattern cases should be taken into account``() =
     """
 module M = 
@@ -652,7 +649,7 @@ let f (Pattern _) = ()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``active patterns applied as a function should be taken into account``() =
     """
 module M = 
@@ -662,7 +659,7 @@ let _ = (|Pattern|_|) ()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``not used active pattern does not make the module in which it's defined to not mark as unused``() =
     """
 module M = 
@@ -672,7 +669,7 @@ let _ = 1
 """
     => [ 4, (5, 6) ]
     
-[<Test>]
+[<Fact>]
 let ``type in type parameter constraint should be taken into account``() =
     """
 open System
@@ -680,7 +677,7 @@ let f (x: 'a when 'a :> IDisposable) = ()
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``namespace declaration should never be marked as unused``() =
     """
 namespace Library2
@@ -688,7 +685,7 @@ type T() = class end
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``auto open module opened before enclosing one is handled correctly``() =
     """
 module M =
@@ -703,7 +700,7 @@ let _ = y
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``single relative open declaration opens two independent modules in different parent modules``() =
     """
 module M =
@@ -722,7 +719,7 @@ let _ = x
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``C# extension methods are taken into account``() =
     """
 open System.Linq
@@ -733,7 +730,7 @@ module Test =
 """ 
     => []      
 
-[<Test>]
+[<Fact>]
 let ``namespace which contains types with C# extension methods is marked as unused if no extension is used``() =
     """
 open System.Linq
@@ -743,7 +740,7 @@ module Test =
 """ 
     => [ 2, (5, 16) ]      
 
-[<Test>]
+[<Fact>]
 let ``a type from an auto open module is taken into account``() =
     """
 module M1 =
@@ -757,7 +754,7 @@ module M2 =
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``unused open declaration in top level rec module``() =
     """
 module rec TopModule
@@ -767,7 +764,7 @@ let _ = DateTime.Now
 """
     => [ 4, (5, 14) ]
 
-[<Test>]
+[<Fact>]
 let ``unused open declaration in rec namespace``() =
     """
 namespace rec TopNamespace
@@ -778,7 +775,7 @@ module Nested =
 """
     => [ 4, (5, 14) ]
 
-[<Test>]
+[<Fact>]
 let ``unused inner module open declaration in rec module``() =
     """
 module rec TopModule
@@ -793,7 +790,7 @@ open Nested
 """
     => [ 10, (5, 11) ]
 
-[<Test>]
+[<Fact>]
 let ``used inner module open declaration in rec module``() =
     """
 module rec TopModule
@@ -810,7 +807,7 @@ let _ = f 1
 """
     => []
 
-[<Test>]
+[<Fact>]
 let ``used open C# type``() =
     """
 open type System.Console
@@ -819,7 +816,7 @@ WriteLine("Hello World")
     """
     => []
     
-[<Test>]
+[<Fact>]
 let ``unused open C# type``() =
     """
 open type System.Console
@@ -828,7 +825,7 @@ printfn "%s" "Hello World"
     """
     => [2, (10, 24)]
     
-[<Test>]
+[<Fact>]
 let ``used open type from module``() =
     """
 module MyModule =
@@ -841,7 +838,7 @@ printfn "%A" Thing
     """
     => []
         
-[<Test>]
+[<Fact>]
 let ``unused open type from module``() =
     """
 module MyModule =
diff --git a/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj b/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj
index f99bd68ec58..7989c2b6d9b 100644
--- a/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj
+++ b/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj
@@ -11,12 +11,16 @@
     <UsePackageTargetFallbackHack>true</UsePackageTargetFallbackHack>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <EnableDefaultEmbeddedResourceItems>false</EnableDefaultEmbeddedResourceItems>
-    <UnitTestType>nunit</UnitTestType>
+    <UnitTestType>xunit</UnitTestType>
     <IsTestProject>true</IsTestProject>
   </PropertyGroup>
+  
+  <ItemGroup>
+    <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
+  </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="$(FSharpSourcesRoot)\Compiler\Utilities\NullnessShims.fs"/>
+    <Compile Include="$(FSharpSourcesRoot)\Compiler\Utilities\NullnessShims.fs" />
     <Compile Include="AssemblyResolver.fs" />
     <Compile Include="$(FSharpSourcesRoot)\Compiler\Utilities\InternalCollections.fsi">
       <Link>Internal.Utilities.Collections.fsi</Link>
@@ -68,7 +72,6 @@
       <Pattern1>{{FSCoreVersion}}</Pattern1>
       <Replacement1>$(FSCoreVersion)</Replacement1>
     </NoneSubstituteText>
-    <None Include="app.runsettings" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(FSharpSourcesRoot)\fsc\fscProject\fsc.fsproj" />
diff --git a/vsintegration/tests/UnitTests/Workspace/WorkspaceTests.fs b/vsintegration/tests/UnitTests/Workspace/WorkspaceTests.fs
index f411cfa973e..684ae3a6c84 100644
--- a/vsintegration/tests/UnitTests/Workspace/WorkspaceTests.fs
+++ b/vsintegration/tests/UnitTests/Workspace/WorkspaceTests.fs
@@ -19,10 +19,9 @@ open Microsoft.CodeAnalysis.Host.Mef
 open Microsoft.VisualStudio.LanguageServices
 open Microsoft.VisualStudio.Shell
 open VisualFSharp.UnitTests.Editor
-open NUnit.Framework
+open Xunit
 open Microsoft.VisualStudio.FSharp.Editor.CancellableTasks
 
-[<TestFixture>]
 module WorkspaceTests =
 
     let compileFileAsDll (workspace: Workspace) filePath outputFilePath =
@@ -170,15 +169,15 @@ module WorkspaceTests =
         let doc = getDocument workspace filePath
         let parseResults, checkResults = doc.GetFSharpParseAndCheckResultsAsync("assertEmptyDocumentDiagnostics") |> CancellableTask.runSynchronouslyWithoutCancellation
         
-        Assert.IsEmpty(parseResults.Diagnostics)
-        Assert.IsEmpty(checkResults.Diagnostics)
+        Assert.Empty(parseResults.Diagnostics)
+        Assert.Empty(checkResults.Diagnostics)
 
     let assertHasDocumentDiagnostics (workspace: Workspace) (filePath: string) =
         let doc = getDocument workspace filePath
         let parseResults, checkResults = doc.GetFSharpParseAndCheckResultsAsync("assertHasDocumentDiagnostics") |> CancellableTask.runSynchronouslyWithoutCancellation
         
-        Assert.IsEmpty(parseResults.Diagnostics)
-        Assert.IsNotEmpty(checkResults.Diagnostics)
+        Assert.Empty(parseResults.Diagnostics)
+        Assert.NotEmpty(checkResults.Diagnostics)
 
     type TestFSharpWorkspaceProjectContext(mainProj: Project) =
 
@@ -286,7 +285,7 @@ module WorkspaceTests =
 //                let proj = workspace.CurrentSolution.GetProject(projInfo.Id)
 //                new TestFSharpWorkspaceProjectContext(proj) :> IFSharpWorkspaceProjectContext
 
-//    [<Test>]
+//    [<Fact>]
 //    let ``Script file opened in misc files workspace will get transferred to normal workspace``() =
 //        use workspace = createWorkspace()
 //        use miscFilesWorkspace = createMiscFileWorkspace()
@@ -306,25 +305,25 @@ module WorkspaceTests =
 //            let projInfo = createProjectInfoWithFileOnDisk filePath
 //            addProject miscFilesWorkspace projInfo
 
-//            Assert.IsTrue(hasDocument miscFilesWorkspace filePath)
-//            Assert.IsFalse(hasDocument workspace filePath)
+//            Assert.True(hasDocument miscFilesWorkspace filePath)
+//            Assert.False(hasDocument workspace filePath)
 
-//            Assert.IsFalse(isDocumentOpen miscFilesWorkspace filePath)
+//            Assert.False(isDocumentOpen miscFilesWorkspace filePath)
 //            openDocument miscFilesWorkspace filePath
 
 //            // Although we opened the document, it has been transferred to the other workspace.
-//            Assert.IsFalse(hasDocument miscFilesWorkspace filePath)
-//            Assert.IsTrue(hasDocument workspace filePath)
+//            Assert.False(hasDocument miscFilesWorkspace filePath)
+//            Assert.True(hasDocument workspace filePath)
 
 //            // Should not be automatically opened when transferred.
-//            Assert.IsFalse(isDocumentOpen workspace filePath)
+//            Assert.False(isDocumentOpen workspace filePath)
 
 //            assertEmptyDocumentDiagnostics workspace filePath
 
 //        finally
 //            try File.Delete(filePath) with | _ -> ()
 
-//    [<Test>]
+//    [<Fact>]
 //    let ``Script file referencing another script should have no diagnostics``() =
 //        use workspace = createWorkspace()
 //        use miscFilesWorkspace = createMiscFileWorkspace()
@@ -359,7 +358,7 @@ module WorkspaceTests =
 //            try File.Delete(filePath1) with | _ -> ()
 //            try File.Delete(filePath2) with | _ -> ()
 
-//    [<Test>]
+//    [<Fact>]
 //    let ``Script file referencing another script will correctly update when the referenced script file changes``() =
 //        use workspace = createWorkspace()
 //        use miscFilesWorkspace = createMiscFileWorkspace()
@@ -408,7 +407,7 @@ module WorkspaceTests =
 //            try File.Delete(filePath1) with | _ -> ()
 //            try File.Delete(filePath2) with | _ -> ()
 
-//    [<Test>]
+//    [<Fact>]
 //    let ``Script file referencing another script will correctly update when the referenced script file changes with opening in reverse order``() =
 //        use workspace = createWorkspace()
 //        use miscFilesWorkspace = createMiscFileWorkspace()
@@ -457,7 +456,7 @@ module WorkspaceTests =
 //            try File.Delete(filePath1) with | _ -> ()
 //            try File.Delete(filePath2) with | _ -> ()
 
-//    [<Test>]
+//    [<Fact>]
 //    let ``Script file referencing a DLL will correctly update when the referenced DLL file changes``() =
 //        use workspace = createWorkspace()
 //        use miscFilesWorkspace = createMiscFileWorkspace()
diff --git a/vsintegration/tests/UnitTests/app.runsettings b/vsintegration/tests/UnitTests/app.runsettings
deleted file mode 100644
index 009d9b69776..00000000000
--- a/vsintegration/tests/UnitTests/app.runsettings
+++ /dev/null
@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<RunSettings>
-  <!-- Configurations that affect the Test Framework -->
-  <RunConfiguration>
-    <MaxCpuCount>1</MaxCpuCount>
-  </RunConfiguration>
-
-</RunSettings>
diff --git a/vsintegration/tests/UnitTests/xunit.runner.json b/vsintegration/tests/UnitTests/xunit.runner.json
new file mode 100644
index 00000000000..533ef25c19c
--- /dev/null
+++ b/vsintegration/tests/UnitTests/xunit.runner.json
@@ -0,0 +1,4 @@
+{
+  "$schema": "https://xunit.net/schema/current/xunit.runner.schema.json",
+  "shadowCopy": false
+}
\ No newline at end of file

From d22973d2b1ab231e8cfee6e6d035ca4c9fb4cd14 Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Tue, 17 Sep 2024 15:13:34 +0200
Subject: [PATCH 02/11] up

---
 .../Tests.LanguageService.GotoDefinition.fs      |  2 +-
 .../Tests.LanguageService.Script.fs              | 16 ++++++++--------
 .../Tests.ProjectSystem.Miscellaneous.fs         | 10 +++++-----
 .../Tests.ProjectSystem.References.fs            |  2 +-
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs
index 4c43e7f92c1..8c2d8613c7c 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.GotoDefinition.fs
@@ -204,7 +204,7 @@ type UsingMSBuild()  =
 
             match result.ToOption() with 
             | Some(span,_) -> Assert.Equal(column',span.iStartIndex) 
-            | None ->  Assert.Fail <| sprintf "Expected to find the definition at column '%d' but GotoDefn failed." column'
+            | None -> failwithf "Expected to find the definition at column '%d' but GotoDefn failed." column'
 
         // Basic scenario on a provided Type
         let ``Type.BasicScenario``() = 
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs
index f6c6ce7fdb7..852758363c5 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.Script.fs
@@ -1505,22 +1505,22 @@ type UsingMSBuild() as this =
         use _guard = this.UsingNewVS()
         let providerAssemblyName = PathRelativeToTestAssembly(@"DummyProviderForLanguageServiceTesting.dll")
         let providerAssembly = System.Reflection.Assembly.LoadFrom providerAssemblyName
-        Assert.NotNull(providerAssembly, "provider assembly should not be null")
+        Assert.NotNull(providerAssembly)
         let providerCounters = providerAssembly.GetType("DummyProviderForLanguageServiceTesting.GlobalCounters")
-        Assert.NotNull(providerCounters, "provider counters module should not be null")
+        Assert.NotNull(providerCounters)
         let totalCreationsMeth = providerCounters.GetMethod("GetTotalCreations")
-        Assert.NotNull(totalCreationsMeth, "totalCreationsMeth should not be null")
+        Assert.NotNull(totalCreationsMeth)
         let totalDisposalsMeth = providerCounters.GetMethod("GetTotalDisposals")
-        Assert.NotNull(totalDisposalsMeth, "totalDisposalsMeth should not be null")
+        Assert.NotNull(totalDisposalsMeth)
         let checkConfigsMeth = providerCounters.GetMethod("CheckAllConfigsDisposed")
-        Assert.NotNull(checkConfigsMeth, "checkConfigsMeth should not be null")
+        Assert.NotNull(checkConfigsMeth)
 
         let providerCounters2 = providerAssembly.GetType("ProviderImplementation.ProvidedTypes.GlobalCountersForInvalidation")
-        Assert.NotNull(providerCounters2, "provider counters #2 module should not be null")
+        Assert.NotNull(providerCounters2)
         let totalInvalidationHandlersAddedMeth = providerCounters2.GetMethod("GetInvalidationHandlersAdded")
-        Assert.NotNull(totalInvalidationHandlersAddedMeth, "totalInvalidationHandlersAddedMeth should not be null")
+        Assert.NotNull(totalInvalidationHandlersAddedMeth)
         let totalInvalidationHandlersRemovedMeth = providerCounters2.GetMethod("GetInvalidationHandlersRemoved")
-        Assert.NotNull(totalInvalidationHandlersRemovedMeth, "totalInvalidationHandlersRemovedMeth should not be null")
+        Assert.NotNull(totalInvalidationHandlersRemovedMeth)
 
         let totalCreations() = totalCreationsMeth.Invoke(null, [| |]) :?> int
         let totalDisposals() = totalDisposalsMeth.Invoke(null, [| |]) :?> int
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
index d820b86a842..659964b836f 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
@@ -450,19 +450,19 @@ type Miscellaneous() =
 
             // Verify Solution values
             let solutionDir = project.GetBuildMacroValue("SolutionDir")
-            Assert.NotNull (solutionDir, "SolutionDir is NULL")
+            Assert.NotNull(solutionDir)
             Assert.False ( (solutionDir = "*Undefined*"), "SolutionDir not defined")
 
             let solutionFileName = project.GetBuildMacroValue("SolutionFileName")
-            Assert.NotNull (solutionFileName, "SolutionFileName is null")
+            Assert.NotNull(solutionFileName)
             Assert.False ( (solutionFileName = "*Undefined*"), "SolutionFileName not defined")
 
             let solutionName = project.GetBuildMacroValue("SolutionName")
-            Assert.NotNull (solutionName, "SolutionName is null")
+            Assert.NotNull(solutionName)
             Assert.False ( (solutionName = "*Undefined*"), "SolutionName not defined")
 
             let solutionExt = project.GetBuildMacroValue("SolutionExt")
-            Assert.NotNull (solutionExt, "SolutionExt is null")
+            Assert.NotNull(solutionExt)
             Assert.False ( (solutionExt = "*Undefined*"), "SolutionExt not defined")
         )
      
@@ -654,7 +654,7 @@ type Miscellaneous() =
                 | [ _; fn ] -> // first file is AssemblyAttributes.fs
                     AssertEqual fileName fn
                 | _ ->
-                    sprintf "wring set of compile items %A" items |> Assert.Fail
+                    failwithf "wring set of compile items %A" items
                 ()
             finally
                 project.Close() |> ignore
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
index f22381e1c76..911d97993fa 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
@@ -90,7 +90,7 @@ type References() =
                 // add reference to Test.exe
                 let selectorData = new VSCOMPONENTSELECTORDATA(``type`` = VSCOMPONENTTYPE.VSCOMPONENTTYPE_File, bstrFile = exe)
                 let refContainer = GetReferenceContainerNode(project)
-                refContainer.AddReferenceFromSelectorData(selectorData) |> (fun x -> Assert.NotNull(x, "expected AddReference to succeed"))
+                refContainer.AddReferenceFromSelectorData(selectorData) |> (fun x -> Assert.NotNull(x))
                 // it should have succeeded (no throw)
                 ))
             )

From ff9ba24fe531dfbb6f4ce7bb1028a5013f4c901d Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Tue, 17 Sep 2024 15:48:00 +0200
Subject: [PATCH 03/11] up

---
 .../tests/UnitTests/AssemblyResolver.fs       |  3 ---
 .../UnitTests/DocCommentIdParserTests.fs      |  5 +----
 .../Tests.ProjectSystem.Miscellaneous.fs      |  5 -----
 .../UnitTests/TestLib.LanguageService.fs      | 19 +------------------
 .../tests/UnitTests/TestLib.ProjectSystem.fs  | 16 +---------------
 .../tests/UnitTests/TestLib.Salsa.fs          |  4 ++--
 .../tests/UnitTests/TestLib.Utils.fs          |  2 +-
 7 files changed, 6 insertions(+), 48 deletions(-)

diff --git a/vsintegration/tests/UnitTests/AssemblyResolver.fs b/vsintegration/tests/UnitTests/AssemblyResolver.fs
index 65e717f2618..9097059f5b9 100644
--- a/vsintegration/tests/UnitTests/AssemblyResolver.fs
+++ b/vsintegration/tests/UnitTests/AssemblyResolver.fs
@@ -1,6 +1,5 @@
 namespace Microsoft.VisualStudio.FSharp
 
-open NUnit.Framework
 open System
 open System.IO
 open System.Reflection
@@ -47,8 +46,6 @@ module AssemblyResolver =
             | None -> Unchecked.defaultof<Assembly>
             | Some name -> Assembly.Load(name) )
 
-[<SetUpFixture>]
 type public AssemblyResolverTestFixture () =
 
-    [<OneTimeSetUp>]
     member public _.Init () = AssemblyResolver.addResolver ()
diff --git a/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs b/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs
index 3541c14043e..a20cc3381a9 100644
--- a/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs
+++ b/vsintegration/tests/UnitTests/DocCommentIdParserTests.fs
@@ -1,13 +1,10 @@
 // Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
-[<NUnit.Framework.TestFixture>]
+
 module Tests.ServiceAnalysis.DocCommentIdParser
 
 open Xunit
 open Microsoft.VisualStudio.FSharp.Editor
 
-
-
-
 [<Fact>]
 let ``Test DocCommentId parser``() =
     let testData = dict [
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
index 659964b836f..800411f1bd7 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Miscellaneous.fs
@@ -353,14 +353,9 @@ type Miscellaneous() =
                    ()
                ))
 
-#if NUNIT_V2
-    [<Fact>][<ExpectedException (typeof<ClassLibraryCannotBeStartedDirectlyException>)>]
-    member public this.``DebuggingDLLFails``() = this.``DebuggingDLLFailsFunc``()
-#else
     [<Fact>]
     member public this.``DebuggingDLLFails``() =
         Assert.Throws<ClassLibraryCannotBeStartedDirectlyException>((fun () -> this.``DebuggingDLLFailsFunc``()))
-#endif
 
     [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``DebuggingEXESucceeds``() =
diff --git a/vsintegration/tests/UnitTests/TestLib.LanguageService.fs b/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
index b4e055b036b..17bac22c2c1 100644
--- a/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
+++ b/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
@@ -4,7 +4,7 @@ namespace UnitTests.TestLib.LanguageService
 
 open System
 open System.Reflection
-open NUnit.Framework
+open Xunit
 open System.Diagnostics
 open System.IO
 open Salsa.Salsa
@@ -367,14 +367,7 @@ type LanguageServiceBaseTests() =
 
         GlobalFunctions.AddAssemblyReference(proj, ref)
 
-    /// Called per test run
-#if NUNIT_V2
-    [<TestFixtureSetUp>]
-    member this.TestFixtureSetUp() =
-#else
-    [<OneTimeSetUp>]
     member this.Init() =
-#endif
         let AssertNotAssemblyNameContains(a:System.Reflection.Assembly, text1:string, text2:string) = 
             let fullname = sprintf "%A" a
             if fullname.Contains(text1) && fullname.Contains(text2) then
@@ -399,13 +392,7 @@ type LanguageServiceBaseTests() =
         defaultSolution <- GlobalFunctions.CreateSolution(defaultVS)
         cache.Clear()
 
-#if NUNIT_V2
-    [<TestFixtureTearDown>]
-    member this.Shutdown() =
-#else
-    [<OneTimeTearDown>]
     member this.Cleanup() =
-#endif
         if box currentVS <> box defaultVS then
             failwith "LanguageServiceBaseTests.Shutdown was called when 'active' instance of VS is not 'default' one - this may denote that tests contains errors"
         
@@ -424,8 +411,6 @@ type LanguageServiceBaseTests() =
                 currentVS <- defaultVS }
 
 
-    /// Called per test
-    [<SetUp>]
     member this.Setup() =
         if box currentVS <> box defaultVS then
             failwith "LanguageServiceBaseTests.Setup was called when 'active' instance of VS is not 'default' one - this may denote that tests contains errors"
@@ -439,8 +424,6 @@ type LanguageServiceBaseTests() =
         testStopwatch.Start()
         ()
         
-    /// Called per test
-    [<TearDown>]
     member this.TearDown() =
 
 
diff --git a/vsintegration/tests/UnitTests/TestLib.ProjectSystem.fs b/vsintegration/tests/UnitTests/TestLib.ProjectSystem.fs
index d1e554f4e8c..5f9095ff4d9 100644
--- a/vsintegration/tests/UnitTests/TestLib.ProjectSystem.fs
+++ b/vsintegration/tests/UnitTests/TestLib.ProjectSystem.fs
@@ -25,7 +25,7 @@ open Microsoft.Build.Execution
 open Microsoft.Build.Framework
         
 #nowarn "52" // The value has been copied to ensure the original is not mutated
-open NUnit.Framework
+open Xunit
 open UnitTests.TestLib.Utils
 open UnitTests.TestLib.Utils.Asserts
 open UnitTests.TestLib.Utils.FilesystemHelpers
@@ -76,20 +76,6 @@ type TheTests() =
         project.FindNodesOfType(l)
         l.[0]            
         
-    /////////////////////////////////
-    /// Called per test
-    [<SetUp>]
-    member this.Setup() =
-        ()
-
-        
-    [<TearDown>]
-    member this.TearDown() =
-        // help find leaks per-test
-        System.GC.Collect()  
-        System.GC.WaitForPendingFinalizers()
-        ()
-
     /////////////////////////////////
     /// helpers
     static member AssertMatches (r : Regex) (s:string) =
diff --git a/vsintegration/tests/UnitTests/TestLib.Salsa.fs b/vsintegration/tests/UnitTests/TestLib.Salsa.fs
index c9dcbbb115a..ac3636723eb 100644
--- a/vsintegration/tests/UnitTests/TestLib.Salsa.fs
+++ b/vsintegration/tests/UnitTests/TestLib.Salsa.fs
@@ -4,7 +4,7 @@ module UnitTests.TestLib.Salsa
 
 open System
 open System.IO
-open NUnit.Framework
+open Xunit
 open Salsa.Salsa
 open Salsa.VsOpsUtils
 open System.Text.RegularExpressions
@@ -36,7 +36,7 @@ let AssertContainsInOrder(s:string,cs:string list) =
     containsInOrderFrom 0 cs
     
 let AssertContains(value: string, substring: string) =
-    Assert.That(value, Contains.Substring substring)
+    Assert.Contains(substring, value)
         
 let AssertArrayContainsPartialMatchOf(a:string array,c) =
     let found = ref false
diff --git a/vsintegration/tests/UnitTests/TestLib.Utils.fs b/vsintegration/tests/UnitTests/TestLib.Utils.fs
index 8072604ca2b..18d8cf98560 100644
--- a/vsintegration/tests/UnitTests/TestLib.Utils.fs
+++ b/vsintegration/tests/UnitTests/TestLib.Utils.fs
@@ -4,7 +4,7 @@ namespace UnitTests.TestLib.Utils
 
 open System
 open System.IO
-open NUnit.Framework
+open NUnit
 open Microsoft.VisualStudio
 
 module Asserts =

From c3114cb37e2152efc26f347d5343bff56a539edc Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Tue, 17 Sep 2024 15:51:50 +0200
Subject: [PATCH 04/11] up

---
 vsintegration/tests/UnitTests/TestLib.Utils.fs    | 2 +-
 vsintegration/tests/UnitTests/UnusedOpensTests.fs | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/vsintegration/tests/UnitTests/TestLib.Utils.fs b/vsintegration/tests/UnitTests/TestLib.Utils.fs
index 18d8cf98560..8072604ca2b 100644
--- a/vsintegration/tests/UnitTests/TestLib.Utils.fs
+++ b/vsintegration/tests/UnitTests/TestLib.Utils.fs
@@ -4,7 +4,7 @@ namespace UnitTests.TestLib.Utils
 
 open System
 open System.IO
-open NUnit
+open NUnit.Framework
 open Microsoft.VisualStudio
 
 module Asserts =
diff --git a/vsintegration/tests/UnitTests/UnusedOpensTests.fs b/vsintegration/tests/UnitTests/UnusedOpensTests.fs
index e1a52c562bf..b77d7e257ef 100644
--- a/vsintegration/tests/UnitTests/UnusedOpensTests.fs
+++ b/vsintegration/tests/UnitTests/UnusedOpensTests.fs
@@ -1,5 +1,5 @@
 // Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
-[<NUnit.Framework.TestFixture>]
+
 module Tests.ServiceAnalysis.UnusedOpens
 
 open System

From 03ac691c22e373e3681f071049b1bb532b63e292 Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Tue, 17 Sep 2024 18:27:28 +0200
Subject: [PATCH 05/11] Update TestLib.LanguageService.fs

---
 .../UnitTests/TestLib.LanguageService.fs      | 92 ++++++++++---------
 1 file changed, 48 insertions(+), 44 deletions(-)

diff --git a/vsintegration/tests/UnitTests/TestLib.LanguageService.fs b/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
index 17bac22c2c1..f000475f702 100644
--- a/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
+++ b/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
@@ -261,7 +261,48 @@ type LanguageServiceBaseTests() =
     // Timings ----------------------------------------------------------------------------- 
     let stopWatch = new Stopwatch()
     let ResetStopWatch() = stopWatch.Reset(); stopWatch.Start()
-               
+      
+
+    let Init() =
+        let AssertNotAssemblyNameContains(a:System.Reflection.Assembly, text1:string, text2:string) = 
+            let fullname = sprintf "%A" a
+            if fullname.Contains(text1) && fullname.Contains(text2) then
+                // Can't throw an exception here because its in an event handler.
+                System.Diagnostics.Debug.Assert(false, sprintf "Unexpected: loaded assembly '%s' to not contain '%s' and '%s'" fullname text1 text2)
+
+        // Under .NET 4.0 we don't allow 3.5.0.0 assemblies
+        let AssertNotBackVersionAssembly(args:AssemblyLoadEventArgs) =
+
+            // We're worried about loading these when running against .NET 4.0:
+            // Microsoft.Build.Tasks.v3.5, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
+            // Microsoft.Build.Utilities.v3.5, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
+            AssertNotAssemblyNameContains(args.LoadedAssembly,"Microsoft.Build", "Version=3.5.0.0") 
+            ()
+        AppDomain.CurrentDomain.AssemblyLoad.Add AssertNotBackVersionAssembly
+
+        UIStuff.SetupSynchronizationContext()
+
+        defaultVS <- ops.CreateVisualStudio()
+        currentVS <- defaultVS
+        
+        defaultSolution <- GlobalFunctions.CreateSolution(defaultVS)
+        cache.Clear()
+
+    do
+        Init()
+
+        if box currentVS <> box defaultVS then
+            failwith "LanguageServiceBaseTests.Setup was called when 'active' instance of VS is not 'default' one - this may denote that tests contains errors"
+        
+        // reset state of default VS instance that can be shared among the tests
+        ShiftKeyUp(currentVS)
+        ops.CleanInvisibleProject(currentVS)
+
+        ResetStopWatch()
+        testStopwatch.Reset()
+        testStopwatch.Start()
+        ()
+
     member internal _.VsOpts
         with set op = ops <- op
     
@@ -367,37 +408,13 @@ type LanguageServiceBaseTests() =
 
         GlobalFunctions.AddAssemblyReference(proj, ref)
 
-    member this.Init() =
-        let AssertNotAssemblyNameContains(a:System.Reflection.Assembly, text1:string, text2:string) = 
-            let fullname = sprintf "%A" a
-            if fullname.Contains(text1) && fullname.Contains(text2) then
-                // Can't throw an exception here because its in an event handler.
-                System.Diagnostics.Debug.Assert(false, sprintf "Unexpected: loaded assembly '%s' to not contain '%s' and '%s'" fullname text1 text2)
-
-        // Under .NET 4.0 we don't allow 3.5.0.0 assemblies
-        let AssertNotBackVersionAssembly(args:AssemblyLoadEventArgs) =
-
-            // We're worried about loading these when running against .NET 4.0:
-            // Microsoft.Build.Tasks.v3.5, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
-            // Microsoft.Build.Utilities.v3.5, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
-            AssertNotAssemblyNameContains(args.LoadedAssembly,"Microsoft.Build", "Version=3.5.0.0") 
-            ()
-        AppDomain.CurrentDomain.AssemblyLoad.Add AssertNotBackVersionAssembly
-
-        UIStuff.SetupSynchronizationContext()
-
-        defaultVS <- ops.CreateVisualStudio()
-        currentVS <- defaultVS
-        
-        defaultSolution <- GlobalFunctions.CreateSolution(defaultVS)
-        cache.Clear()
-
-    member this.Cleanup() =
-        if box currentVS <> box defaultVS then
-            failwith "LanguageServiceBaseTests.Shutdown was called when 'active' instance of VS is not 'default' one - this may denote that tests contains errors"
+    interface IDisposable with
+        member _.Dispose() =
+            if box currentVS <> box defaultVS then
+                failwith "LanguageServiceBaseTests.Shutdown was called when 'active' instance of VS is not 'default' one - this may denote that tests contains errors"
         
-        GlobalFunctions.Cleanup(defaultVS)
-        cache.Clear()
+            GlobalFunctions.Cleanup(defaultVS)
+            cache.Clear()
 
     member this.UsingNewVS() = 
         if box currentVS <> box defaultVS then
@@ -410,19 +427,6 @@ type LanguageServiceBaseTests() =
                 GlobalFunctions.Cleanup(currentVS)
                 currentVS <- defaultVS }
 
-
-    member this.Setup() =
-        if box currentVS <> box defaultVS then
-            failwith "LanguageServiceBaseTests.Setup was called when 'active' instance of VS is not 'default' one - this may denote that tests contains errors"
-        
-        // reset state of default VS instance that can be shared among the tests
-        ShiftKeyUp(currentVS)
-        ops.CleanInvisibleProject(currentVS)
-
-        ResetStopWatch()
-        testStopwatch.Reset()
-        testStopwatch.Start()
-        ()
         
     member this.TearDown() =
 

From 715ff7c9feb397b43d73f8f3776ac5e57c665e29 Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Wed, 18 Sep 2024 13:51:05 +0200
Subject: [PATCH 06/11] up

---
 vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj | 5 +----
 vsintegration/tests/UnitTests/xunit.runner.json             | 3 ++-
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj b/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj
index 7989c2b6d9b..2a764378864 100644
--- a/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj
+++ b/vsintegration/tests/UnitTests/VisualFSharp.UnitTests.fsproj
@@ -14,10 +14,6 @@
     <UnitTestType>xunit</UnitTestType>
     <IsTestProject>true</IsTestProject>
   </PropertyGroup>
-  
-  <ItemGroup>
-    <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
-  </ItemGroup>
 
   <ItemGroup>
     <Compile Include="$(FSharpSourcesRoot)\Compiler\Utilities\NullnessShims.fs" />
@@ -72,6 +68,7 @@
       <Pattern1>{{FSCoreVersion}}</Pattern1>
       <Replacement1>$(FSCoreVersion)</Replacement1>
     </NoneSubstituteText>
+    <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(FSharpSourcesRoot)\fsc\fscProject\fsc.fsproj" />
diff --git a/vsintegration/tests/UnitTests/xunit.runner.json b/vsintegration/tests/UnitTests/xunit.runner.json
index 533ef25c19c..dc9bc36c8a8 100644
--- a/vsintegration/tests/UnitTests/xunit.runner.json
+++ b/vsintegration/tests/UnitTests/xunit.runner.json
@@ -1,4 +1,5 @@
 {
   "$schema": "https://xunit.net/schema/current/xunit.runner.schema.json",
-  "shadowCopy": false
+  "shadowCopy": false,
+  "maxParallelThreads": 1
 }
\ No newline at end of file

From ba5108b9690b193d05c36ab955cfda6f1c754e3b Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Wed, 18 Sep 2024 15:46:47 +0200
Subject: [PATCH 07/11] up

---
 .../Tests.LanguageService.ErrorList.fs                    | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
index 758d9344c91..d217366f194 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
@@ -200,7 +200,7 @@ let g (t : T) = t.Count()
         CheckErrorList content (assertExpectedErrorMessages expectedMessages)
             
 
-    [<Fact>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.InvalidJoinRelation.GroupJoin``() = 
         let content = """
 let x = query { 
@@ -216,7 +216,7 @@ let x = query {
                 | errs -> 
                     Assert.Fail("Unexpected content of error list")
 
-    [<Fact>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.NonOpenedNullableModule.Join``() = 
         let content = """
 let t = 
@@ -233,7 +233,7 @@ let t =
                 | errs -> 
                     Assert.Fail("Unexpected content of error list")
 
-    [<Fact>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.NonOpenedNullableModule.GroupJoin``() = 
         let content = """
 let t = 
@@ -251,7 +251,7 @@ let t =
                     Assert.Fail("Unexpected content of error list")
 
 
-    [<Fact>]
+    [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.``Query.InvalidJoinRelation.Join``() = 
         let content = """
 let x = 

From ac7b0fbd9169d7d7ba40e042d04c9855de303034 Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Thu, 19 Sep 2024 14:20:45 +0200
Subject: [PATCH 08/11] up

---
 vsintegration/tests/UnitTests/AssemblyResolver.fs             | 4 ----
 .../LegacyLanguageService/Tests.LanguageService.ErrorList.fs  | 4 ----
 .../LegacyProjectSystem/Tests.ProjectSystem.Configs.fs        | 4 ----
 .../LegacyProjectSystem/Tests.ProjectSystem.Project.fs        | 3 +++
 .../LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs       | 2 --
 vsintegration/tests/UnitTests/TestLib.LanguageService.fs      | 2 --
 6 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/vsintegration/tests/UnitTests/AssemblyResolver.fs b/vsintegration/tests/UnitTests/AssemblyResolver.fs
index 9097059f5b9..aab95cc46fc 100644
--- a/vsintegration/tests/UnitTests/AssemblyResolver.fs
+++ b/vsintegration/tests/UnitTests/AssemblyResolver.fs
@@ -45,7 +45,3 @@ module AssemblyResolver =
             match found() with
             | None -> Unchecked.defaultof<Assembly>
             | Some name -> Assembly.Load(name) )
-
-type public AssemblyResolverTestFixture () =
-
-    member public _.Init () = AssemblyResolver.addResolver ()
diff --git a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
index d217366f194..b5cc13f4501 100644
--- a/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
+++ b/vsintegration/tests/UnitTests/LegacyLanguageService/Tests.LanguageService.ErrorList.fs
@@ -13,10 +13,6 @@ open UnitTests.TestLib.Utils
 open UnitTests.TestLib.LanguageService
 open UnitTests.TestLib.ProjectSystem
 
-type public AssemblyResolverTestFixture () =
-
-    member public _.Init () = AssemblyResolver.addResolver ()
-
 type UsingMSBuild() as this = 
     inherit LanguageServiceBaseTests()
 
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs
index d484b81f8b8..a0cedaf030f 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Configs.fs
@@ -23,10 +23,6 @@ open UnitTests.TestLib.Utils.FilesystemHelpers
 open UnitTests.TestLib.ProjectSystem
 
 
-type public AssemblyResolverTestFixture () =
-
-    member public _.Init () = AssemblyResolver.addResolver ()
-
 type Config() = 
     inherit TheTests()
 
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs
index df148dbac14..993a3590e6c 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.Project.fs
@@ -13,6 +13,7 @@ open Xunit
 // VS namespaces 
 open Microsoft.VisualStudio
 open Microsoft.VisualStudio.Shell.Interop
+open Microsoft.VisualStudio.FSharp
 open Microsoft.VisualStudio.FSharp.ProjectSystem
 
 // Internal unittest namespaces
@@ -25,6 +26,8 @@ open UnitTests.TestLib.ProjectSystem
 type Project() = 
     inherit TheTests()
 
+    do
+        AssemblyResolver.addResolver ()
 
     //TODO: look for a way to remove the helper functions
     static let ANYTREE = Tree("",Nil,Nil)
diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs
index 8d1b2795224..b63ec3eed8e 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.UpToDate.fs
@@ -27,8 +27,6 @@ open UnitTests.TestLib.ProjectSystem
 type UpToDate() = 
     inherit TheTests()
 
-    member public _.Init () = AssemblyResolver.addResolver ()
-
     [<Fact(Skip = "Bug https://github.com/dotnet/fsharp/issues/17330")>]
     member public this.ItemInputs () =
         this.MakeProjectAndDo(["file1.fs"], [], @"
diff --git a/vsintegration/tests/UnitTests/TestLib.LanguageService.fs b/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
index f000475f702..ecc8cc1479f 100644
--- a/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
+++ b/vsintegration/tests/UnitTests/TestLib.LanguageService.fs
@@ -246,8 +246,6 @@ type internal GlobalParseAndTypeCheckCounter private(initialParseCount:int, init
 /// various functions that abstract actions over vs.
 type LanguageServiceBaseTests() =  
 
-    let _resolver = AssemblyResolver.addResolver ()
-
     let mutable defaultSolution : OpenSolution = Unchecked.defaultof<_>
     let cache = System.Collections.Generic.Dictionary()
 

From 1e4d34acde5a17ea884f7680f06719243bcd53dc Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Fri, 20 Sep 2024 13:42:25 +0200
Subject: [PATCH 09/11] Remove unused tests

---
 .../tests/UnitTests/Tests.Powerpack.fs        | 87 -------------------
 1 file changed, 87 deletions(-)
 delete mode 100644 vsintegration/tests/UnitTests/Tests.Powerpack.fs

diff --git a/vsintegration/tests/UnitTests/Tests.Powerpack.fs b/vsintegration/tests/UnitTests/Tests.Powerpack.fs
deleted file mode 100644
index 7ea87328bc4..00000000000
--- a/vsintegration/tests/UnitTests/Tests.Powerpack.fs
+++ /dev/null
@@ -1,87 +0,0 @@
-// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
-
-namespace UnitTests.Tests.PowerPack
-
-open NUnit.Framework
-open System
-open System.IO
-open System.Diagnostics
-open FSharp.Build
-open Microsoft.Build.Framework
-open Microsoft.Build.Utilities
-open UnitTests.TestLib.Utils.FilesystemHelpers
-
-[<TestFixture>]
-type FsLexTests() = 
-    
-    [<SetUp>]
-    member this.Setup() = ()
-        
-    [<TearDown>]
-    member this.TearDown() = ()
-        
-    [<Test>]
-    member public this.TestCodePage() =
-        let tool = new FSharp.Build.FsLex()
-        tool.CodePage <- "65001"
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("--codepage 65001 ", cmd)
-
-    [<Test>]
-    member public this.TestOutputFile() =
-        let tool = new FSharp.Build.FsLex()
-        tool.OutputFile <- "result.fs"
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("-o result.fs ", cmd)
-
-    [<Test>]
-    member public this.TestUnicode() =
-        let tool = new FSharp.Build.FsLex()
-        tool.Unicode <- true
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("--unicode ", cmd)
-
-    [<Test>]
-    member public this.TestUnicodeNegCase() =
-        let tool = new FSharp.Build.FsLex()
-        tool.Unicode <- false
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        // Verify Unicode flag not specified
-        Assert.AreEqual("", cmd)
-
-[<TestFixture>]
-type FsYaccTests() = 
-    
-    [<SetUp>]
-    member this.Setup() = ()
-        
-    [<TearDown>]
-    member this.TearDown() = ()
-        
-    [<Test>]
-    member public this.TestCodePage() =
-        let tool = new FSharp.Build.FsYacc()
-        tool.CodePage <- "65001"
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("--codepage 65001", cmd)
-
-    [<Test>]
-    member public this.TestOutputFile() =
-        let tool = new FSharp.Build.FsYacc()
-        tool.OutputFile <- "result.fs"
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("-o result.fs", cmd)
-
-    [<Test>]
-    member public this.TestMLCompatibility() =
-        let tool = new FSharp.Build.FsYacc()
-        tool.MLCompatibility <- true
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("--ml-compatibility", cmd)
-        
-    [<Test>]
-    member public this.TestMLCompatibilityFalse() =
-        let tool = new FSharp.Build.FsYacc()
-        tool.MLCompatibility <- false
-        let cmd = tool.InternalGenerateCommandLineCommands()
-        Assert.AreEqual("", cmd)
\ No newline at end of file

From 49ed74b8201e434490abf65eeb7bfffa735f7d2f Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Fri, 20 Sep 2024 13:51:46 +0200
Subject: [PATCH 10/11] one more

---
 .../LegacyProjectSystem/Tests.ProjectSystem.References.fs     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
index 911d97993fa..5d9e702cfe9 100644
--- a/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
+++ b/vsintegration/tests/UnitTests/LegacyProjectSystem/Tests.ProjectSystem.References.fs
@@ -332,8 +332,8 @@ type References() =
             let dirName = Path.GetDirectoryName(projFile)
             let libDirName = Directory.CreateDirectory(Path.Combine(dirName, "lib")).FullName
             let codeBase = (new Uri(Assembly.GetExecutingAssembly().EscapedCodeBase)).LocalPath |> Path.GetDirectoryName
-            let refLibPath = Path.Combine(libDirName, "nunit.framework.dll")
-            File.Copy(Path.Combine(codeBase, "nunit.framework.dll"), refLibPath)
+            let refLibPath = Path.Combine(libDirName, "xunit.core.dll")
+            File.Copy(Path.Combine(codeBase, "xunit.core.dll"), refLibPath)
             File.AppendAllText(projFile, TheTests.SimpleFsprojText([], [refLibPath], ""))
             use project = TheTests.CreateProject(projFile) 
             let l = new List<AssemblyReferenceNode>()

From 5aec65f1e3125818dc5e89552cdbd03e2618bd59 Mon Sep 17 00:00:00 2001
From: Petr <psfinaki@users.noreply.github.com>
Date: Fri, 20 Sep 2024 13:56:38 +0200
Subject: [PATCH 11/11] up

---
 vsintegration/tests/UnitTests/Tests.Build.fs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/vsintegration/tests/UnitTests/Tests.Build.fs b/vsintegration/tests/UnitTests/Tests.Build.fs
index 59ebf5baa83..6f87164333f 100644
--- a/vsintegration/tests/UnitTests/Tests.Build.fs
+++ b/vsintegration/tests/UnitTests/Tests.Build.fs
@@ -348,7 +348,7 @@ type Build() =
     [<Fact>]
     member public this.TestReferences() =
         let tool = new FSharp.Build.Fsc()
-        let dll = "c:\\sd\\staging\\tools\\nunit\\nunit.framework.dll"
+        let dll = "c:\\sd\\staging\\tools\\xunit\\xunit.core.dll"
         tool.References <- [| MakeTaskItem dll |]
         AssertEqual 1 tool.References.Length 
         let cmd = tool.InternalGenerateResponseFileCommands()
@@ -364,13 +364,13 @@ type Build() =
     [<Fact>]
     member public this.TestReferencePath() =
         let tool = new FSharp.Build.Fsc()
-        let path = "c:\\sd\\staging\\tools\\nunit\\;c:\\Foo"
+        let path = "c:\\sd\\staging\\tools\\xunit\\;c:\\Foo"
         tool.ReferencePath <- path
         AssertEqual path tool.ReferencePath 
         let cmd = tool.InternalGenerateResponseFileCommands()
         printfn "cmd=\"%s\"" cmd
         AssertEqual ("--optimize+" + Environment.NewLine +
-                     "--lib:c:\\sd\\staging\\tools\\nunit\\,c:\\Foo" + Environment.NewLine +
+                     "--lib:c:\\sd\\staging\\tools\\xunit\\,c:\\Foo" + Environment.NewLine +
                      "--fullpaths" + Environment.NewLine +
                      "--flaterrors" + Environment.NewLine +
                      "--highentropyva-" + Environment.NewLine +
@@ -380,13 +380,13 @@ type Build() =
     [<Fact>]
     member public this.TestReferencePathWithSpaces() =
         let tool = new FSharp.Build.Fsc()
-        let path = "c:\\program files;c:\\sd\\staging\\tools\\nunit;c:\\Foo"
+        let path = "c:\\program files;c:\\sd\\staging\\tools\\xunit;c:\\Foo"
         tool.ReferencePath <- path
         AssertEqual path tool.ReferencePath 
         let cmd = tool.InternalGenerateResponseFileCommands()
         printfn "cmd=\"%s\"" cmd
         AssertEqual ("--optimize+" + Environment.NewLine +
-                     "--lib:c:\\program files,c:\\sd\\staging\\tools\\nunit,c:\\Foo" + Environment.NewLine +
+                     "--lib:c:\\program files,c:\\sd\\staging\\tools\\xunit,c:\\Foo" + Environment.NewLine +
                      "--fullpaths" + Environment.NewLine +
                      "--flaterrors" + Environment.NewLine +
                      "--highentropyva-" + Environment.NewLine +