Add test related to .NET 9.0.200 difficulties

Author: tdg5

Tdg5.StandardConventions.Tests/MinimalReproductionTest.cs

@@ -0,0 +1,78 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.MSBuild;
+using System.Collections.Immutable;
+using Tdg5.StandardConventions.Tests.TestHelpers;
+using Xunit.Abstractions;
+
+namespace Tdg5.StandardConventions.Tests;
+
+/// <summary>
+/// Test case demonstrating a minimal reproduction of a diagnostic issue that
+/// arose in .NET 9.0.200.
+/// </summary>
+public class MinimalReproductionTest : BaseTestProjectAnalysisVerifierTest
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="MinimalReproductionTest"/> class.
+    /// </summary>
+    /// <param name="testOutputHelper">The test output helper.</param>
+    public MinimalReproductionTest(ITestOutputHelper testOutputHelper)
+        : base(testOutputHelper)
+    {
+    }
+
+    /// <summary>
+    /// Gets a version of the project path that can be used as member data.
+    /// </summary>
+    public static List<object[]> TheProjectPath { get; } = [["Data/StyleCopRules/StyleCopRules.csproj"]];
+
+    /// <inheritdoc/>
+    public override string ProjectPath => (TheProjectPath[0][0] as string)!;
+
+    /// <summary>
+    /// The minimum reproduction.
+    /// </summary>
+    /// <param name="projectPath">The project to run diagnostics on.</param>
+    /// <returns>A task representing the completion of the test.</returns>
+    [Theory]
+    [MemberData(nameof(TheProjectPath))]
+    public async Task MinimumReproduction(string projectPath)
+    {
+        var workspace = MSBuildWorkspace.Create();
+        var project = await workspace.OpenProjectAsync(projectPath);
+        var analyzers = project
+            .AnalyzerReferences
+            .SelectMany(r => r.GetAnalyzers(project.Language))
+            .ToImmutableArray();
+        Dictionary<string, List<string>> diagnosticIdsByAnalyzer = [];
+        foreach (var analyzerReference in project.AnalyzerReferences)
+        {
+            var analyzerId = analyzerReference.Id.ToString() ?? "NO_ANALYZER_ID";
+            var analyzerName = analyzerId[..analyzerId.IndexOf(',')];
+            List<string> ids;
+            if (!diagnosticIdsByAnalyzer.TryGetValue(analyzerName, out ids!))
+            {
+                ids = [];
+                diagnosticIdsByAnalyzer[analyzerName] = ids;
+            }
+
+            foreach (var analyzer in analyzerReference.GetAnalyzers(project.Language))
+            {
+                foreach (var diagnostic in analyzer.SupportedDiagnostics)
+                {
+                    ids.Add(diagnostic.Id);
+                }
+            }
+        }
+
+        var cSharpCodeStyleDiagnosticIds =
+            Assert.Contains("Microsoft.CodeAnalysis.CSharp.CodeStyle", diagnosticIdsByAnalyzer);
+        var codeStyleDiagnosticIds =
+            Assert.Contains("Microsoft.CodeAnalysis.CodeStyle", diagnosticIdsByAnalyzer);
+
+        Assert.Contains("IDE0040", cSharpCodeStyleDiagnosticIds);
+        Assert.Contains("IDE0055", cSharpCodeStyleDiagnosticIds);
+        Assert.Contains("IDE0033", codeStyleDiagnosticIds);
+        Assert.Contains("IDE0070", codeStyleDiagnosticIds);
+    }
+}