Add MakeDeclarationMutable code fix

src/fsharp/service/ServiceUntypedParse.fs

@@ -122,6 +122,32 @@ type FSharpParseFileResults(errors: FSharpErrorInfo[], input: ParsedInput option
         match input with
         | Some input -> FSharpNoteworthyParamInfoLocations.Find(pos, input)
         | _ -> None
+
+    member scope.IsPositionContainedInACurriedParameter pos =
+        match input with
+        | Some input ->
+            let result =
+                AstTraversal.Traverse(pos, input, { new AstTraversal.AstVisitorBase<_>() with 
+                    member __.VisitExpr(_path, traverseSynExpr, defaultTraverse, expr) =
+                        defaultTraverse(expr)
+
+                    override __.VisitBinding (_, binding) =
+                        match binding with
+                        | Binding(_, _, _, _, _, _, valData, _, _, _, range, _) when rangeContainsPos range pos ->
+                            let info = valData.SynValInfo.CurriedArgInfos
+                            let mutable found = false
+                            for group in info do
+                                for arg in group do
+                                    match arg.Ident with
+                                    | Some ident when rangeContainsPos ident.idRange pos ->
+                                        found <- true
+                                    | _ -> ()
+                            if found then Some range else None
+                        | _ ->
+                            None
+                })
+            result.IsSome
+        | _ -> false
 
     /// Get declared items and the selected item at the specified location
     member private scope.GetNavigationItemsImpl() =

src/fsharp/service/ServiceUntypedParse.fsi

@@ -29,6 +29,9 @@ type public FSharpParseFileResults =
     /// Notable parse info for ParameterInfo at a given location
     member FindNoteworthyParamInfoLocations : pos:pos -> FSharpNoteworthyParamInfoLocations option
 
+    /// Determines if the given position is contained within a curried parameter in a binding.
+    member IsPositionContainedInACurriedParameter: pos: pos -> bool
+
     /// Name of the file for which this information were created
     member FileName                       : string
 

tests/FSharp.Compiler.Service.Tests/SurfaceArea.netstandard.fs

@@ -22754,6 +22754,7 @@ FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: FSharp.Compiler.Sourc
 FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Range+range] TryRangeOfRefCellDereferenceContainingPos(pos)
 FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Range+range] ValidateBreakpointLocation(pos)
 FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.SourceCodeServices.FSharpNoteworthyParamInfoLocations] FindNoteworthyParamInfoLocations(pos)
+FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: Boolean IsPositionContainedInACurriedParameter(pos)
 FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.SyntaxTree+ParsedInput] ParseTree
 FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.SyntaxTree+ParsedInput] get_ParseTree()
 FSharp.Compiler.SourceCodeServices.FSharpParseFileResults: System.String FileName

vsintegration/src/FSharp.Editor/CodeFix/MakeDeclarationMutable.fs

@@ -0,0 +1,73 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace Microsoft.VisualStudio.FSharp.Editor
+
+open System.Composition
+open System.Threading
+open System.Threading.Tasks
+
+open Microsoft.CodeAnalysis.Text
+open Microsoft.CodeAnalysis.CodeFixes
+
+open FSharp.Compiler.Range
+open FSharp.Compiler.SourceCodeServices
+open FSharp.Compiler.AbstractIL.Internal.Library 
+
+[<ExportCodeFixProvider(FSharpConstants.FSharpLanguageName, Name = "MakeDeclarationMutable"); Shared>]
+type internal FSharpMakeDeclarationMutableFixProvider
+    [<ImportingConstructor>]
+    (
+        checkerProvider: FSharpCheckerProvider, 
+        projectInfoManager: FSharpProjectOptionsManager
+    ) =
+    inherit CodeFixProvider()
+
+    static let userOpName = "MakeDeclarationMutable"
+
+    let fixableDiagnosticIds = set ["FS0027"]
+
+    override _.FixableDiagnosticIds = Seq.toImmutableArray fixableDiagnosticIds
+
+    override _.RegisterCodeFixesAsync context : Task =
+        asyncMaybe {
+            let diagnostics =
+                context.Diagnostics
+                |> Seq.filter (fun x -> fixableDiagnosticIds |> Set.contains x.Id)
+                |> Seq.toImmutableArray
+
+            let document = context.Document
+            do! Option.guard (not(isSignatureFile document.FilePath))
+            let position = context.Span.Start
+            let checker = checkerProvider.Checker
+            let! parsingOptions, projectOptions = projectInfoManager.TryGetOptionsForEditingDocumentOrProject(document, CancellationToken.None, userOpName)
+            let! sourceText = document.GetTextAsync () |> liftTaskAsync
+            let defines = CompilerEnvironment.GetCompilationDefinesForEditing parsingOptions
+            let textLine = sourceText.Lines.GetLineFromPosition position
+            let textLinePos = sourceText.Lines.GetLinePosition position
+            let fcsTextLineNumber = Line.fromZ textLinePos.Line
+            let! parseFileResults, _, checkFileResults = checker.ParseAndCheckDocument (document, projectOptions, sourceText=sourceText, userOpName=userOpName)
+            let! lexerSymbol = Tokenizer.getSymbolAtPosition (document.Id, sourceText, position, document.FilePath, defines, SymbolLookupKind.Greedy, false, false)
+            let decl = checkFileResults.GetDeclarationLocation (fcsTextLineNumber, lexerSymbol.Ident.idRange.EndColumn, textLine.ToString(), lexerSymbol.FullIsland, false)
+
+            match decl with
+            // Only do this for symbols in the same file. That covers almost all cases anyways.
+            // We really shouldn't encourage making values mutable outside of local scopes anyways.
+            | FSharpFindDeclResult.DeclFound declRange when declRange.FileName = document.FilePath ->
+                let! span = RoslynHelpers.TryFSharpRangeToTextSpan(sourceText, declRange)
+
+                // Bail if it's a parameter, because like, that ain't allowed
+                do! Option.guard (not (parseFileResults.IsPositionContainedInACurriedParameter declRange.Start))
+
+                let title = SR.MakeDeclarationMutable()
+                let codeFix =
+                    CodeFixHelpers.createTextChangeCodeFix(
+                        title,
+                        context,
+                        (fun () -> asyncMaybe.Return [| TextChange(TextSpan(span.Start, 0), "mutable ") |]))
+
+                context.RegisterCodeFix(codeFix, diagnostics)
+            | _ ->
+                ()
+        }
+        |> Async.Ignore
+        |> RoslynHelpers.StartAsyncUnitAsTask(context.CancellationToken) 

vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj

@@ -89,6 +89,7 @@
     <Compile Include="Commands\FsiCommandService.fs" />
     <Compile Include="Commands\XmlDocCommandService.fs" />
     <Compile Include="CodeFix\CodeFixHelpers.fs" />
+    <Compile Include="CodeFix\MakeDeclarationMutable.fs" />
     <Compile Include="CodeFix\ChangeToUpcast.fs" />
     <Compile Include="CodeFix\AddMissingEqualsToTypeDefinition.fs" />
     <Compile Include="CodeFix\ConvertToSingleEqualsEqualityExpression.fs" />

vsintegration/src/FSharp.Editor/FSharp.Editor.resx

@@ -219,6 +219,9 @@
   <data name="FSharpDisposableTopLevelValuesClassificationType" xml:space="preserve">
     <value>F# Dispostable Values (top-level)</value>
   </data>
+  <data name="MakeDeclarationMutable" xml:space="preserve">
+    <value>Make declaration 'mutable'</value>
+  </data>
   <data name="UseUpcastKeyword" xml:space="preserve">
     <value>Use 'upcast'</value>
   </data>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.cs.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Implementujte rozhraní bez anotace typu.</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Před {0} vložte podtržítko.</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.de.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Schnittstelle ohne Typanmerkung implementieren</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">"{0}" einen Unterstrich voranstellen</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.es.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Implementar interfaz sin anotación de tipos</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Colocar un carácter de subrayado delante de "{0}"</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.fr.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Implémenter l'interface sans annotation de type</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Faire précéder '{0}' d'un trait de soulignement</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.it.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Implementa l'interfaccia senza annotazione di tipo</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Anteponi a '{0}' un carattere di sottolineatura</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.ja.xlf

@@ -52,6 +52,11 @@
         <target state="translated">型の注釈を指定しないでインターフェイスを実装する</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">アンダースコアが含まれているプレフィックス '{0}'</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.ko.xlf

@@ -52,6 +52,11 @@
         <target state="translated">형식 주석 없이 인터페이스 구현</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">밑줄이 있는 '{0}' 접두사</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.pl.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Zaimplementuj interfejs bez adnotacji typu</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Prefiks „{0}” ze znakiem podkreślenia</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.pt-BR.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Implementar a interface sem a anotação de tipo</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Prefixo '{0}' sem sublinhado</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.ru.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Реализовать интерфейс без заметки с типом</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">Добавить символ подчеркивания как префикс "{0}"</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.tr.xlf

@@ -52,6 +52,11 @@
         <target state="translated">Tür ek açıklaması olmadan arabirim uygulama</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">'{0}' öğesinin önüne alt çizgi ekleme</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.zh-Hans.xlf

@@ -52,6 +52,11 @@
         <target state="translated">无类型批注的实现接口</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">带下划线的前缀“{0}”</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.zh-Hant.xlf

@@ -52,6 +52,11 @@
         <target state="translated">實作沒有類型註釋的介面</target>
         <note />
       </trans-unit>
+      <trans-unit id="MakeDeclarationMutable">
+        <source>Make declaration 'mutable'</source>
+        <target state="new">Make declaration 'mutable'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="PrefixValueNameWithUnderscore">
         <source>Prefix '{0}' with underscore</source>
         <target state="translated">有底線的前置詞 '{0}'</target>