Fix StyleCopTester not running disabled rules even with /id

Author: sharwell

StyleCop.Analyzers/StyleCopTester/Program.cs

@@ -77,7 +77,7 @@ private static async Task MainAsync(string[] args, CancellationToken cancellatio
 
                 MSBuildWorkspace workspace = MSBuildWorkspace.Create();
                 string solutionPath = args.SingleOrDefault(i => !i.StartsWith("/", StringComparison.Ordinal));
-                Solution solution = workspace.OpenSolutionAsync(solutionPath, cancellationToken).Result;
+                Solution solution = await workspace.OpenSolutionAsync(solutionPath, cancellationToken).ConfigureAwait(false);
 
                 Console.WriteLine($"Loaded solution in {stopwatch.ElapsedMilliseconds}ms");
 
@@ -373,7 +373,22 @@ private static async Task<ImmutableDictionary<ProjectId, ImmutableArray<Diagnost
         /// <returns>A list of diagnostics inside the project</returns>
         private static async Task<ImmutableArray<Diagnostic>> GetProjectAnalyzerDiagnosticsAsync(ImmutableArray<DiagnosticAnalyzer> analyzers, Project project, CancellationToken cancellationToken)
         {
-            Compilation compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
+            var supportedDiagnosticsSpecificOptions = new Dictionary<string, ReportDiagnostic>();
+            foreach (var analyzer in analyzers)
+            {
+                foreach (var diagnostic in analyzer.SupportedDiagnostics)
+                {
+                    // make sure the analyzers we are testing are enabled
+                    supportedDiagnosticsSpecificOptions[diagnostic.Id] = ReportDiagnostic.Default;
+                }
+            }
+
+            // update the project compilation options
+            var modifiedSpecificDiagnosticOptions = supportedDiagnosticsSpecificOptions.ToImmutableDictionary().SetItems(project.CompilationOptions.SpecificDiagnosticOptions);
+            var modifiedCompilationOptions = project.CompilationOptions.WithSpecificDiagnosticOptions(modifiedSpecificDiagnosticOptions);
+            var processedProject = project.WithCompilationOptions(modifiedCompilationOptions);
+
+            Compilation compilation = await processedProject.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
             CompilationWithAnalyzers compilationWithAnalyzers = compilation.WithAnalyzers(analyzers, cancellationToken: cancellationToken);
 
             var allDiagnostics = await compilationWithAnalyzers.GetAllDiagnosticsAsync().ConfigureAwait(false);