Consolidate analyzer tests that verify no diagnostics are emitted

test/Microsoft.VisualStudio.Composition.Analyzers.Tests/Helpers/CSharpMultiAnalyzerVerifier+Test.cs

@@ -0,0 +1,70 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Reflection;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Text;
+using Microsoft.VisualStudio.Composition.Analyzers;
+
+public static partial class CSharpMultiAnalyzerVerifier
+{
+    /// <summary>
+    /// Test class that configures all VSMEF analyzers for simultaneous testing.
+    /// </summary>
+    public class Test : CSharpCodeFixTest<VSMEF001PropertyMustHaveSetter, EmptyCodeFixProvider, DefaultVerifier>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Test"/> class.
+        /// </summary>
+        public Test()
+        {
+            this.ReferenceAssemblies = ReferencesHelper.DefaultReferences;
+            this.TestBehaviors |= TestBehaviors.SkipGeneratedCodeCheck;
+
+            this.SolutionTransforms.Add((solution, projectId) =>
+            {
+                var parseOptions = (CSharpParseOptions)solution.GetProject(projectId)!.ParseOptions!;
+                solution = solution.WithProjectParseOptions(projectId, parseOptions.WithLanguageVersion(LanguageVersion.CSharp12));
+                return solution;
+            });
+
+            this.TestState.AdditionalFilesFactories.Add(() =>
+            {
+                const string additionalFilePrefix = "AdditionalFiles.";
+                return from resourceName in Assembly.GetExecutingAssembly().GetManifestResourceNames()
+                       where resourceName.StartsWith(additionalFilePrefix, StringComparison.Ordinal)
+                       let content = ReadManifestResource(Assembly.GetExecutingAssembly(), resourceName)
+                       select (filename: resourceName.Substring(additionalFilePrefix.Length), SourceText.From(content));
+            });
+        }
+
+        /// <inheritdoc/>
+        protected override IEnumerable<DiagnosticAnalyzer> GetDiagnosticAnalyzers()
+        {
+            return
+            [
+                new VSMEF001PropertyMustHaveSetter(),
+                new VSMEF002AvoidMixingAttributeVarietiesAnalyzer(),
+                new VSMEF003ExportTypeMismatchAnalyzer(),
+                new VSMEF004ExportWithoutImportingConstructorAnalyzer(),
+                new VSMEF005MultipleImportingConstructorsAnalyzer(),
+                new VSMEF006ImportNullabilityAnalyzer(),
+                new VSMEF007DuplicateImportAnalyzer(),
+                new VSMEF008ImportContractTypeMismatchAnalyzer(),
+                new VSMEF009ImportManyMemberCollectionTypeAnalyzer(),
+                new VSMEF010ImportManyParameterCollectionTypeAnalyzer(),
+                new VSMEF011BothImportAndImportManyAnalyzer(),
+                new VSMEF012DisallowMefAttributeVersionAnalyzer(),
+            ];
+        }
+
+        private static string ReadManifestResource(Assembly assembly, string resourceName)
+        {
+            using (var reader = new StreamReader(assembly.GetManifestResourceStream(resourceName) ?? throw new ArgumentException("No such resource stream", nameof(resourceName))))
+            {
+                return reader.ReadToEnd();
+            }
+        }
+    }
+}

test/Microsoft.VisualStudio.Composition.Analyzers.Tests/Helpers/CSharpMultiAnalyzerVerifier.cs

@@ -0,0 +1,40 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Microsoft.CodeAnalysis.Text;
+
+/// <summary>
+/// A verifier that tests source code against all VSMEF analyzers simultaneously.
+/// Used for tests that verify code produces no diagnostics from any analyzer.
+/// </summary>
+public static partial class CSharpMultiAnalyzerVerifier
+{
+    /// <summary>
+    /// Verifies that the given source code produces no diagnostics from any VSMEF analyzer.
+    /// </summary>
+    /// <param name="source">The source code to analyze.</param>
+    /// <returns>A task representing the asynchronous operation.</returns>
+    public static Task VerifyAnalyzerAsync(string source)
+    {
+        var test = new Test { TestCode = source };
+        return test.RunAsync();
+    }
+
+    /// <summary>
+    /// Verifies that the given source code produces no diagnostics from any VSMEF analyzer,
+    /// with optional editor configuration.
+    /// </summary>
+    /// <param name="source">The source code to analyze.</param>
+    /// <param name="editorConfig">Optional editor configuration content.</param>
+    /// <returns>A task representing the asynchronous operation.</returns>
+    public static Task VerifyAnalyzerAsync(string source, string? editorConfig)
+    {
+        var test = new Test { TestCode = source };
+        if (editorConfig is not null)
+        {
+            test.TestState.AnalyzerConfigFiles.Add(("/.editorconfig", SourceText.From(editorConfig)));
+        }
+
+        return test.RunAsync();
+    }
+}