Add support for .editorconfig documents

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

@@ -1137,6 +1137,12 @@ protected virtual async Task<Project> CreateProjectImplAsync(EvaluatedProjectSta
                     var documentId = DocumentId.CreateNewId(additionalProjectId, debugName: newFileName);
                     solution = solution.AddAdditionalDocument(documentId, newFileName, source, filePath: newFileName);
                 }
+
+                foreach (var (newFileName, source) in projectState.AnalyzerConfigFiles)
+                {
+                    var documentId = DocumentId.CreateNewId(additionalProjectId, debugName: newFileName);
+                    solution = solution.AddAnalyzerConfigDocument(documentId, newFileName, source, filePath: newFileName);
+                }
             }
 
             solution = solution.AddMetadataReferences(projectId, primaryProject.AdditionalReferences);
@@ -1153,6 +1159,12 @@ protected virtual async Task<Project> CreateProjectImplAsync(EvaluatedProjectSta
                 solution = solution.AddAdditionalDocument(documentId, newFileName, source, filePath: newFileName);
             }
 
+            foreach (var (newFileName, source) in primaryProject.AnalyzerConfigFiles)
+            {
+                var documentId = DocumentId.CreateNewId(projectId, debugName: newFileName);
+                solution = solution.AddAnalyzerConfigDocument(documentId, newFileName, source, filePath: newFileName);
+            }
+
             solution = AddProjectReferences(solution, projectId, primaryProject.AdditionalProjectReferences.Select(name => projectIdMap[name]));
             foreach (var projectState in additionalProjects)
             {

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

@@ -65,13 +65,15 @@ protected static bool CodeActionExpected(SolutionState state)
                 || state.MarkupHandling != null
                 || state.Sources.Any()
                 || state.AdditionalFiles.Any()
+                || state.AnalyzerConfigFiles.Any()
                 || state.AdditionalFilesFactories.Any();
         }
 
         protected static bool HasAnyChange(SolutionState oldState, SolutionState newState)
         {
             return !oldState.Sources.SequenceEqual(newState.Sources, SourceFileEqualityComparer.Instance)
-                || !oldState.AdditionalFiles.SequenceEqual(newState.AdditionalFiles, SourceFileEqualityComparer.Instance);
+                || !oldState.AdditionalFiles.SequenceEqual(newState.AdditionalFiles, SourceFileEqualityComparer.Instance)
+                || !oldState.AnalyzerConfigFiles.SequenceEqual(newState.AnalyzerConfigFiles, SourceFileEqualityComparer.Instance);
         }
 
         protected static CodeAction? TryGetCodeActionToApply(ImmutableArray<CodeAction> actions, int? codeActionIndex, string? codeActionEquivalenceKey, Action<CodeAction, IVerifier>? codeActionVerifier, IVerifier verifier)

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

@@ -0,0 +1,39 @@
+// 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.Generic;
+using System.Reflection;
+
+namespace Microsoft.CodeAnalysis.Testing
+{
+    internal static class ProjectExtensions
+    {
+        private static readonly Func<Project, IEnumerable<TextDocument>> s_analyzerConfigDocuments;
+
+        static ProjectExtensions()
+        {
+            var analyzerConfigDocumentType = typeof(Project).GetTypeInfo().Assembly.GetType("Microsoft.CodeAnalysis.AnalyzerConfigDocument");
+            if (analyzerConfigDocumentType is { })
+            {
+                var analyzerConfigDocumentsProperty = typeof(Project).GetProperty(nameof(AnalyzerConfigDocuments), typeof(IEnumerable<>).MakeGenericType(analyzerConfigDocumentType));
+                if (analyzerConfigDocumentsProperty is { GetMethod: { } getMethod })
+                {
+                    s_analyzerConfigDocuments = (Func<Project, IEnumerable<TextDocument>>)getMethod.CreateDelegate(typeof(Func<Project, IEnumerable<TextDocument>>), target: null);
+                }
+                else
+                {
+                    s_analyzerConfigDocuments = project => throw new NotSupportedException();
+                }
+            }
+            else
+            {
+                s_analyzerConfigDocuments = project => throw new NotSupportedException();
+            }
+        }
+
+        public static IEnumerable<TextDocument> AnalyzerConfigDocuments(this Project project)
+            => s_analyzerConfigDocuments(project);
+    }
+}

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

@@ -0,0 +1,34 @@
+// 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.Generic;
+using System.Reflection;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.Testing
+{
+    internal static class SolutionExtensions
+    {
+        private static readonly Func<Solution, DocumentId, string, SourceText, IEnumerable<string>?, string?, Solution> s_addAnalyzerConfigDocument;
+
+        static SolutionExtensions()
+        {
+            var methodInfo = typeof(Solution).GetMethod(nameof(AddAnalyzerConfigDocument), new[] { typeof(DocumentId), typeof(string), typeof(SourceText), typeof(IEnumerable<string>), typeof(string) });
+            if (methodInfo is { })
+            {
+                s_addAnalyzerConfigDocument = (Func<Solution, DocumentId, string, SourceText, IEnumerable<string>?, string?, Solution>)methodInfo.CreateDelegate(typeof(Func<Solution, DocumentId, string, SourceText, IEnumerable<string>, string, Solution>), target: null);
+            }
+            else
+            {
+                s_addAnalyzerConfigDocument = (solution, documentId, name, text, folders, filePath) => throw new NotSupportedException();
+            }
+        }
+
+        public static Solution AddAnalyzerConfigDocument(this Solution solution, DocumentId documentId, string name, SourceText text, IEnumerable<string>? folders = null, string? filePath = null)
+        {
+            return s_addAnalyzerConfigDocument(solution, documentId, name, text, folders, filePath);
+        }
+    }
+}

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/Microsoft.CodeAnalysis.Analyzer.Testing.csproj

@@ -37,6 +37,7 @@
   </Choose>
 
   <ItemGroup>
+    <InternalsVisibleTo Include="Microsoft.CodeAnalysis.CodeFix.Testing" />
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.Testing.Verifiers.MSTest" />
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.Testing.Verifiers.NUnit" />
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.Testing.Verifiers.XUnit" />

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/Model/EvaluatedProjectState.cs

@@ -22,6 +22,7 @@ public EvaluatedProjectState(ProjectState state, ReferenceAssemblies defaultRefe
                 state.DocumentationMode ?? DocumentationMode.Diagnose,
                 state.Sources.ToImmutableArray(),
                 state.AdditionalFiles.ToImmutableArray(),
+                state.AnalyzerConfigFiles.ToImmutableArray(),
                 state.AdditionalProjectReferences.ToImmutableArray(),
                 state.AdditionalReferences.ToImmutableArray())
         {
@@ -36,6 +37,7 @@ private EvaluatedProjectState(
             DocumentationMode documentationMode,
             ImmutableArray<(string filename, SourceText content)> sources,
             ImmutableArray<(string filename, SourceText content)> additionalFiles,
+            ImmutableArray<(string filename, SourceText content)> analyzerConfigFiles,
             ImmutableArray<string> additionalProjectReferences,
             ImmutableArray<MetadataReference> additionalReferences)
         {
@@ -47,6 +49,7 @@ private EvaluatedProjectState(
             DocumentationMode = documentationMode;
             Sources = sources;
             AdditionalFiles = additionalFiles;
+            AnalyzerConfigFiles = analyzerConfigFiles;
             AdditionalProjectReferences = additionalProjectReferences;
             AdditionalReferences = additionalReferences;
         }
@@ -67,6 +70,8 @@ private EvaluatedProjectState(
 
         public ImmutableArray<(string filename, SourceText content)> AdditionalFiles { get; }
 
+        public ImmutableArray<(string filename, SourceText content)> AnalyzerConfigFiles { get; }
+
         public ImmutableArray<string> AdditionalProjectReferences { get; }
 
         public ImmutableArray<MetadataReference> AdditionalReferences { get; }
@@ -90,6 +95,7 @@ private EvaluatedProjectState With(
             Optional<DocumentationMode> documentationMode = default,
             Optional<ImmutableArray<(string filename, SourceText content)>> sources = default,
             Optional<ImmutableArray<(string filename, SourceText content)>> additionalFiles = default,
+            Optional<ImmutableArray<(string filename, SourceText content)>> analyzerConfigFiles = default,
             Optional<ImmutableArray<string>> additionalProjectReferences = default,
             Optional<ImmutableArray<MetadataReference>> additionalReferences = default)
         {
@@ -102,6 +108,7 @@ private EvaluatedProjectState With(
                 GetValueOrDefault(documentationMode, DocumentationMode),
                 GetValueOrDefault(sources, Sources),
                 GetValueOrDefault(additionalFiles, AdditionalFiles),
+                GetValueOrDefault(analyzerConfigFiles, AnalyzerConfigFiles),
                 GetValueOrDefault(additionalProjectReferences, AdditionalProjectReferences),
                 GetValueOrDefault(additionalReferences, AdditionalReferences));
         }

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ProjectState.cs

@@ -33,6 +33,7 @@ internal ProjectState(ProjectState sourceState)
 
             Sources.AddRange(sourceState.Sources);
             AdditionalFiles.AddRange(sourceState.AdditionalFiles);
+            AnalyzerConfigFiles.AddRange(sourceState.AnalyzerConfigFiles);
             AdditionalFilesFactories.AddRange(sourceState.AdditionalFilesFactories);
             AdditionalProjectReferences.AddRange(sourceState.AdditionalProjectReferences);
         }
@@ -65,6 +66,8 @@ internal ProjectState(ProjectState sourceState)
 
         public SourceFileCollection AdditionalFiles { get; } = new SourceFileCollection();
 
+        public SourceFileCollection AnalyzerConfigFiles { get; } = new SourceFileCollection();
+
         public List<Func<IEnumerable<(string filename, SourceText content)>>> AdditionalFilesFactories { get; } = new List<Func<IEnumerable<(string filename, SourceText content)>>>();
 
         public List<string> AdditionalProjectReferences { get; } = new List<string>();

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

@@ -122,6 +122,7 @@ Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState
 Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.AdditionalFiles.get -> System.Collections.Immutable.ImmutableArray<(string filename, Microsoft.CodeAnalysis.Text.SourceText content)>
 Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.AdditionalProjectReferences.get -> System.Collections.Immutable.ImmutableArray<string>
 Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.AdditionalReferences.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.MetadataReference>
+Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.AnalyzerConfigFiles.get -> System.Collections.Immutable.ImmutableArray<(string filename, Microsoft.CodeAnalysis.Text.SourceText content)>
 Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.AssemblyName.get -> string
 Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.DocumentationMode.get -> Microsoft.CodeAnalysis.DocumentationMode
 Microsoft.CodeAnalysis.Testing.Model.EvaluatedProjectState.EvaluatedProjectState(Microsoft.CodeAnalysis.Testing.ProjectState state, Microsoft.CodeAnalysis.Testing.ReferenceAssemblies defaultReferenceAssemblies) -> void
@@ -144,6 +145,7 @@ Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalFiles.get -> Microsoft.Cod
 Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalFilesFactories.get -> System.Collections.Generic.List<System.Func<System.Collections.Generic.IEnumerable<(string filename, Microsoft.CodeAnalysis.Text.SourceText content)>>>
 Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalProjectReferences.get -> System.Collections.Generic.List<string>
 Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalReferences.get -> Microsoft.CodeAnalysis.Testing.MetadataReferenceCollection
+Microsoft.CodeAnalysis.Testing.ProjectState.AnalyzerConfigFiles.get -> Microsoft.CodeAnalysis.Testing.SourceFileCollection
 Microsoft.CodeAnalysis.Testing.ProjectState.AssemblyName.get -> string
 Microsoft.CodeAnalysis.Testing.ProjectState.DocumentationMode.get -> Microsoft.CodeAnalysis.DocumentationMode?
 Microsoft.CodeAnalysis.Testing.ProjectState.DocumentationMode.set -> void

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/SolutionState.cs

@@ -140,6 +140,11 @@ public SolutionState WithInheritedValuesApplied(SolutionState? baseState, Immuta
                     result.AdditionalFiles.AddRange(baseState.AdditionalFiles);
                 }
 
+                if (AnalyzerConfigFiles.Count == 0)
+                {
+                    result.AnalyzerConfigFiles.AddRange(baseState.AnalyzerConfigFiles);
+                }
+
                 if (AdditionalProjects.Count == 0)
                 {
                     result.AdditionalProjects.AddRange(baseState.AdditionalProjects);
@@ -172,6 +177,7 @@ public SolutionState WithInheritedValuesApplied(SolutionState? baseState, Immuta
             result.InheritanceMode = StateInheritanceMode.Explicit;
             result.Sources.AddRange(Sources);
             result.AdditionalFiles.AddRange(AdditionalFiles);
+            result.AnalyzerConfigFiles.AddRange(AnalyzerConfigFiles);
             result.AdditionalProjects.AddRange(AdditionalProjects);
             result.AdditionalProjectReferences.AddRange(AdditionalProjectReferences);
             result.AdditionalReferences.AddRange(AdditionalReferences);
@@ -202,6 +208,11 @@ private static bool HasAnyContentChanges(bool willInherit, SolutionState state,
                 return true;
             }
 
+            if ((!willInherit || state.AnalyzerConfigFiles.Any()) && !ContentEqual(state.AnalyzerConfigFiles, baseState.AnalyzerConfigFiles))
+            {
+                return true;
+            }
+
             if ((!willInherit || state.AdditionalReferences.Any()) && !state.AdditionalReferences.SequenceEqual(baseState.AdditionalReferences))
             {
                 return true;
@@ -241,8 +252,8 @@ private static bool ContentEqual(SourceFileCollection x, SourceFileCollection y)
         /// <summary>
         /// Processes the markup syntax for this <see cref="SolutionState"/> according to the current
         /// <see cref="MarkupHandling"/>, and returns a new <see cref="SolutionState"/> with the
-        /// <see cref="ProjectState.Sources"/>, <see cref="ProjectState.AdditionalFiles"/>, and
-        /// <see cref="ExpectedDiagnostics"/> updated accordingly.
+        /// <see cref="ProjectState.Sources"/>, <see cref="ProjectState.AdditionalFiles"/>,
+        /// <see cref="ProjectState.AnalyzerConfigFiles"/>, and <see cref="ExpectedDiagnostics"/> updated accordingly.
         /// </summary>
         /// <param name="markupOptions">Additional options to apply during markup processing.</param>
         /// <param name="defaultDiagnostic">The diagnostic descriptor to use for markup spans without an explicit name,
@@ -265,7 +276,8 @@ public SolutionState WithProcessedMarkup(MarkupOptions markupOptions, Diagnostic
 
             var markupLocations = ImmutableDictionary<string, FileLinePositionSpan>.Empty;
             (var expected, var testSources) = ProcessMarkupSources(Sources, ExpectedDiagnostics, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
-            var (additionalExpected, additionalFiles) = ProcessMarkupSources(AdditionalFiles.Concat(AdditionalFilesFactories.SelectMany(factory => factory())), expected, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
+            var (additionalExpected1, additionalFiles) = ProcessMarkupSources(AdditionalFiles.Concat(AdditionalFilesFactories.SelectMany(factory => factory())), expected, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
+            var (additionalExpected, analyzerConfigFiles) = ProcessMarkupSources(AnalyzerConfigFiles, additionalExpected1, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
 
             var result = new SolutionState(Name, Language, DefaultPrefix, DefaultExtension);
             result.MarkupHandling = MarkupMode.None;
@@ -275,18 +287,22 @@ public SolutionState WithProcessedMarkup(MarkupOptions markupOptions, Diagnostic
             result.DocumentationMode = DocumentationMode;
             result.Sources.AddRange(testSources);
             result.AdditionalFiles.AddRange(additionalFiles);
+            result.AnalyzerConfigFiles.AddRange(analyzerConfigFiles);
 
             foreach (var (projectName, projectState) in AdditionalProjects)
             {
                 var (correctedIntermediateDiagnostics, additionalProjectSources) = ProcessMarkupSources(projectState.Sources, additionalExpected, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
-                var (correctedDiagnostics, additionalProjectAdditionalFiles) = ProcessMarkupSources(projectState.AdditionalFiles.Concat(projectState.AdditionalFilesFactories.SelectMany(factory => factory())), correctedIntermediateDiagnostics, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
+                var (correctedDiagnostics1, additionalProjectAdditionalFiles) = ProcessMarkupSources(projectState.AdditionalFiles.Concat(projectState.AdditionalFilesFactories.SelectMany(factory => factory())), correctedIntermediateDiagnostics, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
+                var (correctedDiagnostics, additionalProjectAnalyzerConfigFiles) = ProcessMarkupSources(projectState.AnalyzerConfigFiles, correctedDiagnostics1, ref markupLocations, markupOptions, defaultDiagnostic, supportedDiagnostics, fixableDiagnostics, defaultPath);
 
                 var processedProjectState = new ProjectState(projectState);
                 processedProjectState.Sources.Clear();
                 processedProjectState.Sources.AddRange(additionalProjectSources);
                 processedProjectState.AdditionalFiles.Clear();
                 processedProjectState.AdditionalFilesFactories.Clear();
                 processedProjectState.AdditionalFiles.AddRange(additionalProjectAdditionalFiles);
+                processedProjectState.AnalyzerConfigFiles.Clear();
+                processedProjectState.AnalyzerConfigFiles.AddRange(additionalProjectAnalyzerConfigFiles);
 
                 result.AdditionalProjects.Add(projectName, processedProjectState);
                 additionalExpected = correctedDiagnostics;