Added support for <WarningsAsErrors>nullable</WarningsAsErrors>

CHANGELOG.md

@@ -1,7 +1,10 @@
 # Changelog
 All changes to the project will be documented in this file.
 
-## [1.39.0]
+## [1.39.1]
+* Added support for `<WarningsAsErrors>nullable</WarningsAsErrors>` ([#2292](https://github.com/OmniSharp/omnisharp-roslyn/issues/2292), PR: [#2406](https://github.com/OmniSharp/omnisharp-roslyn/pull/2406))
+
+## [1.39.0] - 2022-05-19
 * Update Roslyn to 4.3.0-2.22267.5 (PR: [#2401](https://github.com/OmniSharp/omnisharp-roslyn/pull/2401))
 * Fixed run script for Mono ([OmniSharp/omnisharp-vscode#5181](https://github.com/OmniSharp/omnisharp-vscode/issues/5181), [OmniSharp/omnisharp-vscode#5179](https://github.com/OmniSharp/omnisharp-vscode/issues/5179), PR: [#2398](https://github.com/OmniSharp/omnisharp-roslyn/pull/2398))
 * Fall back to /usr/lib/os-release if /etc/os-release doesn't exist (PR: [#2380](https://github.com/OmniSharp/omnisharp-roslyn/pull/2380))

src/OmniSharp.MSBuild/Errors/Errors.cs

@@ -0,0 +1,77 @@
+using System.Collections.Immutable;
+
+namespace OmniSharp.MSBuild
+{
+    internal static class Errors
+    {
+        public static readonly ImmutableHashSet<string> NullableWarnings;
+
+        // sourced from https://github.com/dotnet/roslyn/blob/v4.2.0-3.22151.16/src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs#L27-L82 
+        static Errors()
+        {
+            ImmutableHashSet<string>.Builder nullableWarnings = ImmutableHashSet.CreateBuilder<string>();
+
+            nullableWarnings.Add("CS8601"); // WRN_NullReferenceAssignment
+            nullableWarnings.Add("CS8602"); // WRN_NullReferenceReceiver
+            nullableWarnings.Add("CS8603"); // WRN_NullReferenceReturn
+            nullableWarnings.Add("CS8604"); // WRN_NullReferenceArgument
+
+            nullableWarnings.Add("CS8618"); // WRN_UninitializedNonNullableField
+            nullableWarnings.Add("CS8619"); // WRN_NullabilityMismatchInAssignment
+            nullableWarnings.Add("CS8620"); // WRN_NullabilityMismatchInArgument
+            nullableWarnings.Add("CS8624"); // WRN_NullabilityMismatchInArgumentForOutput
+
+            nullableWarnings.Add("CS8621"); // WRN_NullabilityMismatchInReturnTypeOfTargetDelegate
+            nullableWarnings.Add("CS8622"); // WRN_NullabilityMismatchInParameterTypeOfTargetDelegate
+            nullableWarnings.Add("CS8625"); // WRN_NullAsNonNullable
+            nullableWarnings.Add("CS8629"); // WRN_NullableValueTypeMayBeNull
+            nullableWarnings.Add("CS8631"); // WRN_NullabilityMismatchInTypeParameterConstraint
+            nullableWarnings.Add("CS8634"); // WRN_NullabilityMismatchInTypeParameterReferenceTypeConstraint
+            nullableWarnings.Add("CS8714"); // WRN_NullabilityMismatchInTypeParameterNotNullConstraint
+
+            nullableWarnings.Add("CS8597"); // WRN_ThrowPossibleNull
+            nullableWarnings.Add("CS8605"); // WRN_UnboxPossibleNull
+            nullableWarnings.Add("CS8655"); // WRN_SwitchExpressionNotExhaustiveForNull
+            nullableWarnings.Add("CS8847"); // WRN_SwitchExpressionNotExhaustiveForNullWithWhen
+
+            nullableWarnings.Add("CS8600"); // WRN_ConvertingNullableToNonNullable
+            nullableWarnings.Add("CS8607"); // WRN_DisallowNullAttributeForbidsMaybeNullAssignment
+            nullableWarnings.Add("CS8762"); // WRN_ParameterConditionallyDisallowsNull
+            nullableWarnings.Add("CS8763"); // WRN_ShouldNotReturn
+
+
+            nullableWarnings.Add("CS8608"); // WRN_NullabilityMismatchInTypeOnOverride
+            nullableWarnings.Add("CS8609"); // WRN_NullabilityMismatchInReturnTypeOnOverride
+            nullableWarnings.Add("CS8819"); // WRN_NullabilityMismatchInReturnTypeOnPartial
+            nullableWarnings.Add("CS8610"); // WRN_NullabilityMismatchInParameterTypeOnOverride
+            nullableWarnings.Add("CS8611"); // WRN_NullabilityMismatchInParameterTypeOnPartial
+            nullableWarnings.Add("CS8612"); // WRN_NullabilityMismatchInTypeOnImplicitImplementation
+            nullableWarnings.Add("CS8613"); // WRN_NullabilityMismatchInReturnTypeOnImplicitImplementation
+            nullableWarnings.Add("CS8614"); // WRN_NullabilityMismatchInParameterTypeOnImplicitImplementation
+            nullableWarnings.Add("CS8615"); // WRN_NullabilityMismatchInTypeOnExplicitImplementation
+            nullableWarnings.Add("CS8616"); // WRN_NullabilityMismatchInReturnTypeOnExplicitImplementation
+            nullableWarnings.Add("CS8617"); // WRN_NullabilityMismatchInParameterTypeOnExplicitImplementation
+            nullableWarnings.Add("CS8633"); // WRN_NullabilityMismatchInConstraintsOnImplicitImplementation
+            nullableWarnings.Add("CS8643"); // WRN_NullabilityMismatchInExplicitlyImplementedInterface
+            nullableWarnings.Add("CS8644"); // WRN_NullabilityMismatchInInterfaceImplementedByBase
+            nullableWarnings.Add("CS8645"); // WRN_DuplicateInterfaceWithNullabilityMismatchInBaseList
+            nullableWarnings.Add("CS8667"); // WRN_NullabilityMismatchInConstraintsOnPartialImplementation
+            nullableWarnings.Add("CS8670"); // WRN_NullReferenceInitializer
+            nullableWarnings.Add("CS8770"); // WRN_DoesNotReturnMismatch
+            nullableWarnings.Add("CS8769"); // WRN_TopLevelNullabilityMismatchInParameterTypeOnExplicitImplementation
+            nullableWarnings.Add("CS8767"); // WRN_TopLevelNullabilityMismatchInParameterTypeOnImplicitImplementation
+            nullableWarnings.Add("CS8765"); // WRN_TopLevelNullabilityMismatchInParameterTypeOnOverride
+            nullableWarnings.Add("CS8768"); // WRN_TopLevelNullabilityMismatchInReturnTypeOnExplicitImplementation
+            nullableWarnings.Add("CS8766"); // WRN_TopLevelNullabilityMismatchInReturnTypeOnImplicitImplementation
+            nullableWarnings.Add("CS8764"); // WRN_TopLevelNullabilityMismatchInReturnTypeOnOverride
+            nullableWarnings.Add("CS8774"); // WRN_MemberNotNull
+            nullableWarnings.Add("CS8776"); // WRN_MemberNotNullBadMember
+            nullableWarnings.Add("CS8775"); // WRN_MemberNotNullWhen
+            nullableWarnings.Add("CS8777"); // WRN_ParameterDisallowsNull
+            nullableWarnings.Add("CS8824"); // WRN_ParameterNotNullIfNotNull
+            nullableWarnings.Add("CS8825"); // WRN_ReturnNotNullIfNotNull
+
+            NullableWarnings = nullableWarnings.ToImmutable();
+        }
+    }
+}

src/OmniSharp.MSBuild/ProjectFile/ProjectFileInfoExtensions.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Globalization;
 using System.IO;
@@ -64,27 +65,39 @@ public static ImmutableDictionary<string, ReportDiagnostic> GetDiagnosticOptions
             var specificRules = projectFileInfo.RuleSet?.SpecificDiagnosticOptions ?? ImmutableDictionary<string, ReportDiagnostic>.Empty;
 
             // suppressions capture NoWarn and they have the highest priority
-            var combinedRules = specificRules.Concat(suppressions.Where(x => !specificRules.Keys.Contains(x.Key))).ToDictionary(x => x.Key, x => x.Value);
+            var combinedRules = specificRules.Concat(suppressions.Where(x => !specificRules.ContainsKey(x.Key))).ToDictionary(x => x.Key, x => x.Value);
 
             // then handle WarningsAsErrors
             foreach (var warningAsError in projectFileInfo.WarningsAsErrors)
             {
-                if (!suppressions.ContainsKey(warningAsError))
+                if (string.Equals(warningAsError, "nullable", StringComparison.OrdinalIgnoreCase))
                 {
-                    combinedRules[warningAsError] = ReportDiagnostic.Error;
+                    foreach (var id in Errors.NullableWarnings)
+                    {
+                        AddIfNotSuppressed(id, ReportDiagnostic.Error);
+                    }
+                }
+                else 
+                {
+                    AddIfNotSuppressed(warningAsError, ReportDiagnostic.Error);
                 }
             }
 
             // WarningsNotAsErrors can overwrite WarningsAsErrors
             foreach (var warningNotAsError in projectFileInfo.WarningsNotAsErrors)
             {
-                if (!suppressions.ContainsKey(warningNotAsError))
-                {
-                    combinedRules[warningNotAsError] = ReportDiagnostic.Warn;
-                }
+                AddIfNotSuppressed(warningNotAsError, ReportDiagnostic.Warn);
             }
 
             return combinedRules.ToImmutableDictionary();
+
+            void AddIfNotSuppressed(string code, ReportDiagnostic diagnostic)
+            {
+                if (!suppressions.ContainsKey(code))
+                {
+                    combinedRules[code] = diagnostic;
+                }
+            }
         }
 
         public static ProjectInfo CreateProjectInfo(this ProjectFileInfo projectFileInfo, IAnalyzerAssemblyLoader analyzerAssemblyLoader)

test-assets/test-projects/WarningsAsErrors/Program.cs

@@ -7,6 +7,7 @@ public class Program
     {
         public static async Task Main(string[] args)
         {
+            string bar = null;
             Console.WriteLine("Hello World!");
         }
     }

test-assets/test-projects/WarningsAsErrors/WarningsAsErrors.csproj

@@ -4,8 +4,9 @@
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp3.1</TargetFramework>
     <NoWarn>CS7081</NoWarn>
-    <WarningsAsErrors>CS1998,CS7080,CS7081</WarningsAsErrors>
+    <WarningsAsErrors>nullable,CS1998,CS7080,CS7081</WarningsAsErrors>
     <WarningsNotAsErrors>CS7080,CS7082</WarningsNotAsErrors>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
 </Project>

tests/OmniSharp.MSBuild.Tests/ProjectFileInfoTests.cs

@@ -225,6 +225,9 @@ public async Task WarningsAsErrors()
                 Assert.Equal(ReportDiagnostic.Warn, compilationOptions.SpecificDiagnosticOptions["CS7082"]);
                 // CS7081 is both WarningsAsErrors and NoWarn, but NoWarn are higher priority
                 Assert.Equal(ReportDiagnostic.Suppress, compilationOptions.SpecificDiagnosticOptions["CS7081"]);
+
+                // nullable warning as error
+                Assert.Equal(ReportDiagnostic.Error, compilationOptions.SpecificDiagnosticOptions["CS8600"]);
             }
         }