Ignore suppressed diagnostics unless produced by a DiagnosticSuppressor

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/AnalyzerTest`1.cs

@@ -1157,7 +1157,8 @@ namespace Microsoft.CodeAnalysis.Testing
             }
 
             diagnostics.AddRange(additionalDiagnostics);
-            var results = SortDistinctDiagnostics(diagnostics);
+            var filteredDiagnostics = FilterDiagnostics(diagnostics.ToImmutable());
+            var results = SortDistinctDiagnostics(filteredDiagnostics);
             return results;
 
             static async Task<ImmutableArray<Diagnostic>> GetCompilerDiagnosticsAsync(AnalyzerTest<TVerifier> self, Compilation compilation, ImmutableArray<DiagnosticAnalyzer> analyzers, AnalyzerOptions analyzerOptions, CancellationToken cancellationToken)
@@ -1677,13 +1678,28 @@ namespace Microsoft.CodeAnalysis.Testing
 
         protected abstract ParseOptions CreateParseOptions();
 
+        /// <summary>
+        /// Filter <see cref="Diagnostic"/>s to only include items of interest to testing. By default, this includes all
+        /// unsuppressed diagnostics, and all diagnostics suppressed by a
+        /// <see cref="T:Microsoft.CodeAnalysis.Diagnostics.DiagnosticSuppressor"/>.
+        /// </summary>
+        /// <param name="diagnostics">A collection of <see cref="Diagnostic"/>s to be filtered.</param>
+        /// <returns>A collection containing the input <paramref name="diagnostics"/>, filtered to only include
+        /// diagnostics relevant for testing.</returns>
+        protected virtual ImmutableArray<(Project project, Diagnostic diagnostic)> FilterDiagnostics(ImmutableArray<(Project project, Diagnostic diagnostic)> diagnostics)
+        {
+            return diagnostics
+                .Where(d => !d.diagnostic.IsSuppressed() || d.diagnostic.ProgrammaticSuppressionInfo() != null)
+                .ToImmutableArray();
+        }
+
         /// <summary>
         /// Sort <see cref="Diagnostic"/>s by location in source document.
         /// </summary>
         /// <param name="diagnostics">A collection of <see cref="Diagnostic"/>s to be sorted.</param>
         /// <returns>A collection containing the input <paramref name="diagnostics"/>, sorted by
         /// <see cref="Diagnostic.Location"/> and <see cref="Diagnostic.Id"/>.</returns>
-        protected virtual ImmutableArray<(Project project, Diagnostic diagnostic)> SortDistinctDiagnostics(IEnumerable<(Project project, Diagnostic diagnostic)> diagnostics)
+        protected virtual ImmutableArray<(Project project, Diagnostic diagnostic)> SortDistinctDiagnostics(ImmutableArray<(Project project, Diagnostic diagnostic)> diagnostics)
         {
             return diagnostics
                 .OrderBy(d => d.diagnostic.Location.GetLineSpan().Path, StringComparer.Ordinal)

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/Extensions/DiagnosticExtensions.cs

@@ -22,10 +22,19 @@ namespace Microsoft.CodeAnalysis.Testing.Extensions
                 nameof(IsSuppressed),
                 defaultValue: false);
 
+        private static readonly Func<Diagnostic, object?> s_grogrammaticSuppressionInfo =
+            LightupHelpers.CreatePropertyAccessor<Diagnostic, object?>(
+                typeof(Diagnostic),
+                nameof(ProgrammaticSuppressionInfo),
+                defaultValue: null);
+
         public static IReadOnlyList<object?> Arguments(this Diagnostic diagnostic)
             => s_arguments(diagnostic);
 
         public static bool IsSuppressed(this Diagnostic diagnostic)
             => s_isSuppressed(diagnostic);
+
+        public static ProgrammaticSuppressionInfoWrapper? ProgrammaticSuppressionInfo(this Diagnostic diagnostic)
+            => s_grogrammaticSuppressionInfo(diagnostic) is { } info ? ProgrammaticSuppressionInfoWrapper.FromInstance(info) : null;
     }
 }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/Lightup/ProgrammaticSuppressionInfoWrapper.cs

@@ -0,0 +1,61 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Immutable;
+using System.Reflection;
+
+namespace Microsoft.CodeAnalysis.Testing.Lightup
+{
+    internal readonly struct ProgrammaticSuppressionInfoWrapper
+    {
+        internal const string WrappedTypeName = "Microsoft.CodeAnalysis.Diagnostics.ProgrammaticSuppressionInfo";
+        internal static readonly Type? WrappedType = typeof(Diagnostic).GetTypeInfo().Assembly.GetType(WrappedTypeName);
+        private static readonly Func<object, ImmutableHashSet<(string id, LocalizableString justification)>> s_suppressions;
+
+        private readonly object _instance;
+
+        static ProgrammaticSuppressionInfoWrapper()
+        {
+            s_suppressions = LightupHelpers.CreatePropertyAccessor<object, ImmutableHashSet<(string id, LocalizableString justification)>>(WrappedType, nameof(Suppressions), ImmutableHashSet<(string id, LocalizableString justification)>.Empty);
+        }
+
+        private ProgrammaticSuppressionInfoWrapper(object instance)
+        {
+            _instance = instance;
+        }
+
+        public ImmutableHashSet<(string id, LocalizableString justification)> Suppressions => s_suppressions(_instance);
+
+        public static ProgrammaticSuppressionInfoWrapper FromInstance(object instance)
+        {
+            if (instance == null)
+            {
+                return default;
+            }
+
+            if (!IsInstance(instance))
+            {
+                throw new InvalidCastException($"Cannot cast '{instance.GetType().FullName}' to '{WrappedTypeName}'");
+            }
+
+            return new ProgrammaticSuppressionInfoWrapper(instance);
+        }
+
+        public static bool IsInstance(object value)
+        {
+            if (value is null)
+            {
+                return false;
+            }
+
+            if (WrappedType is null)
+            {
+                return false;
+            }
+
+            return WrappedType.IsAssignableFrom(value.GetType());
+        }
+    }
+}

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/PublicAPI.Unshipped.txt

@@ -350,13 +350,14 @@ virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.CreateWorkspaceIm
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.DefaultFilePath.get -> string
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.DefaultFilePathPrefix.get -> string
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.DefaultTestProjectName.get -> string
+virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.FilterDiagnostics(System.Collections.Immutable.ImmutableArray<(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Diagnostic diagnostic)> diagnostics) -> System.Collections.Immutable.ImmutableArray<(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Diagnostic diagnostic)>
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.GetAnalyzerOptions(Microsoft.CodeAnalysis.Project project) -> Microsoft.CodeAnalysis.Diagnostics.AnalyzerOptions
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.GetDefaultDiagnostic(Microsoft.CodeAnalysis.Diagnostics.DiagnosticAnalyzer[] analyzers) -> Microsoft.CodeAnalysis.DiagnosticDescriptor
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.GetProjectCompilationAsync(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Testing.IVerifier verifier, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<(Microsoft.CodeAnalysis.Compilation compilation, System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Diagnostic> generatorDiagnostics)>
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.GetSourceGenerators() -> System.Collections.Generic.IEnumerable<System.Type>
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.IsCompilerDiagnosticIncluded(Microsoft.CodeAnalysis.Diagnostic diagnostic, Microsoft.CodeAnalysis.Testing.CompilerDiagnostics compilerDiagnostics) -> bool
 virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.RunImplAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task
-virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.SortDistinctDiagnostics(System.Collections.Generic.IEnumerable<(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Diagnostic diagnostic)> diagnostics) -> System.Collections.Immutable.ImmutableArray<(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Diagnostic diagnostic)>
+virtual Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.SortDistinctDiagnostics(System.Collections.Immutable.ImmutableArray<(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Diagnostic diagnostic)> diagnostics) -> System.Collections.Immutable.ImmutableArray<(Microsoft.CodeAnalysis.Project project, Microsoft.CodeAnalysis.Diagnostic diagnostic)>
 virtual Microsoft.CodeAnalysis.Testing.CodeActionTest<TVerifier>.FilterCodeActions(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.CodeActions.CodeAction> actions) -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.CodeActions.CodeAction>
 virtual Microsoft.CodeAnalysis.Testing.DefaultVerifier.CreateMessage(string message) -> string
 virtual Microsoft.CodeAnalysis.Testing.DefaultVerifier.Empty<T>(string collectionName, System.Collections.Generic.IEnumerable<T> collection) -> void

tests/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing.UnitTests/AutoExclusionTests.cs

@@ -220,6 +220,54 @@ End Class
             }.RunAsync();
         }
 
+        [Fact]
+        public async Task TestCSharpTestIgnoresPragmaSuppressedWarnings()
+        {
+            var testCode = @"class TestClass {|#0:{|} }";
+
+            // A diagnostic is produced in the original code
+            await new CSharpAnalyzerTest<HighlightBraceSpanAnalyzer>
+            {
+                TestCode = testCode,
+                ExpectedDiagnostics =
+                {
+                    new DiagnosticResult("Brace", DiagnosticSeverity.Warning).WithLocation(0),
+                },
+            }.RunAsync();
+
+            // The same diagnostic is ignored when suppressed using '#pragma warning disable'
+            await new CSharpAnalyzerTest<HighlightBraceSpanAnalyzer>
+            {
+                TestCode = $@"#pragma warning disable Brace
+{testCode}",
+            }.RunAsync();
+        }
+
+        [Fact]
+        public async Task TestVisualBasicTestIgnoresPragmaSuppressedWarnings()
+        {
+            var testCode = @"Class TestClass
+    Dim Field As Integer() = {|#0:{|} }
+End Class";
+
+            // A diagnostic is produced in the original code
+            await new VisualBasicAnalyzerTest<HighlightBraceSpanAnalyzer>
+            {
+                TestCode = testCode,
+                ExpectedDiagnostics =
+                {
+                    new DiagnosticResult("Brace", DiagnosticSeverity.Warning).WithLocation(0),
+                },
+            }.RunAsync();
+
+            // The same diagnostic is ignored when suppressed using '#Disable Warning'
+            await new VisualBasicAnalyzerTest<HighlightBraceSpanAnalyzer>
+            {
+                TestCode = $@"#Disable Warning Brace
+{testCode}",
+            }.RunAsync();
+        }
+
         [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
         private class ReplaceThisWithBaseAnalyzer : DiagnosticAnalyzer
         {
@@ -314,6 +362,15 @@ End Class
             }
         }
 
+        [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
+        private class HighlightBraceSpanAnalyzer : AbstractHighlightBracesAnalyzer
+        {
+            protected override Diagnostic CreateDiagnostic(SyntaxToken token)
+            {
+                return Diagnostic.Create(Descriptor, token.GetLocation());
+            }
+        }
+
         private class CSharpReplaceThisWithBaseTest : CSharpAnalyzerTest<EmptyDiagnosticAnalyzer>
         {
             private readonly GeneratedCodeAnalysisFlags? _generatedCodeAnalysisFlags;