Report deduplicated reference count, deflake EventSource schema tests

TypeSystemInitStop now reports the size of the final reference set passed
to Init() instead of the raw resolve count, which included same-name
duplicates that the version dedup later drops. The schema smoke tests
asserted exact global event counts, but the providers are process-wide
and the decompiler fixtures run in parallel, so unrelated decompilations
could inflate the counts; every string payload now carries a unique
marker (and the string-less snapshot events a sentinel count) that the
assertions filter on.

Assisted-by: Claude:claude-fable-5:Claude Code

ICSharpCode.Decompiler.Tests/Instrumentation/DecompilerEventSourceTests.cs

@@ -121,22 +121,25 @@ namespace ICSharpCode.Decompiler.Tests.Instrumentation
 		[Test]
 		public void FiringEveryEventProducesNoEventSourceErrors()
 		{
+			// The provider is process-wide and other fixtures decompile in parallel, so every
+			// string payload carries this marker and the count assertions filter on it.
+			const string marker = "SchemaSmokeTest.";
 			using var listener = new RecordingListener(EventLevel.Verbose, EventKeywords.All);
 			var log = DecompilerEventSource.Log;
-			log.DecompileTypeStart("T");
-			log.DecompileTypeStop("T");
-			log.DecompileMemberStart("T.M", 0x06000001, (int)DecompiledMemberKind.Method, 42);
-			log.DecompileMemberStop("T.M", 0x06000001, (int)DecompiledMemberKind.Method);
-			log.TypeSystemInitStart("module");
-			log.TypeSystemInitStop("module", 3);
-			log.AssemblyResolveStart("System.Runtime");
-			log.AssemblyResolveStop("System.Runtime", "/path/System.Runtime.dll", true);
-			log.ProjectDecompilationStart("module");
-			log.ProjectDecompilationStop("module", 10, 2);
-			log.ProjectFileStart("File.cs", 5);
-			log.ProjectFileStop("File.cs");
-			log.ILTransformExecuted("ILInlining", 0x06000001, 0.5);
-			log.AstTransformExecuted("PatternStatementTransform", 1.5);
+			log.DecompileTypeStart(marker + "Type");
+			log.DecompileTypeStop(marker + "Type");
+			log.DecompileMemberStart(marker + "Type.M", 0x06000001, (int)DecompiledMemberKind.Method, 42);
+			log.DecompileMemberStop(marker + "Type.M", 0x06000001, (int)DecompiledMemberKind.Method);
+			log.TypeSystemInitStart(marker + "module");
+			log.TypeSystemInitStop(marker + "module", 3);
+			log.AssemblyResolveStart(marker + "Reference");
+			log.AssemblyResolveStop(marker + "Reference", marker + "Reference.dll", true);
+			log.ProjectDecompilationStart(marker + "module");
+			log.ProjectDecompilationStop(marker + "module", 10, 2);
+			log.ProjectFileStart(marker + "File.cs", 5);
+			log.ProjectFileStop(marker + "File.cs");
+			log.ILTransformExecuted(marker + "ILInlining", 0x06000001, 0.5);
+			log.AstTransformExecuted(marker + "PatternStatementTransform", 1.5);
 
 			// A mismatch between an [Event] method's signature and its WriteEvent call surfaces
 			// as an "EventSourceMessage" error event on the same provider.
@@ -153,7 +156,10 @@ namespace ICSharpCode.Decompiler.Tests.Instrumentation
 			};
 			foreach (string eventName in expected)
 			{
-				Assert.That(listener.EventsNamed(eventName), Has.Count.EqualTo(1), eventName);
+				var markedEvents = listener.EventsNamed(eventName)
+					.Where(p => p.Values.OfType<string>().Any(v => v.StartsWith(marker, StringComparison.Ordinal)))
+					.ToList();
+				Assert.That(markedEvents, Has.Count.EqualTo(1), eventName);
 			}
 		}
 

ICSharpCode.Decompiler/TypeSystem/DecompilerTypeSystem.cs

@@ -287,8 +287,9 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			}
 		}
 
-		/// <returns>The number of referenced assemblies (including transitively pulled-in
-		/// type-forwarder targets) that were successfully resolved.</returns>
+		/// <returns>The number of references in the final set passed to Init(): distinct
+		/// resolved assemblies (same-name lower-version duplicates dropped) plus resolved
+		/// non-assembly modules.</returns>
 		private async Task<int> InitializeCoreAsync(MetadataFile mainModule, IAssemblyResolver assemblyResolver)
 		{
 			// Load referenced assemblies and type-forwarder references.
@@ -415,7 +416,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 				Init(mainModuleWithOptions, referencedAssembliesWithOptions);
 			}
 			this.mainModule = (MetadataModule)base.MainModule;
-			return referencedAssemblies.Count;
+			return referencedAssembliesWithOptions.Count;
 
 			void AddToQueue(bool isAssembly, MetadataFile mainModule, object reference)
 			{

ILSpy.Tests/Instrumentation/ILSpyXEventSourceTests.cs

@@ -87,22 +87,28 @@ public class ILSpyXEventSourceTests
 	[Test]
 	public void FiringEveryEventProducesNoEventSourceErrors()
 	{
+		// The provider is process-wide and other tests load/search assemblies concurrently,
+		// so every string payload carries this marker and the count assertions filter on it.
+		// SnapshotLookupBuildStart/Stop have no string payload; their sentinel assemblyCount
+		// is distinctive enough (real snapshots in these tests stay far below it).
+		const string marker = "SchemaSmokeTest.";
+		const int lookupSentinel = 987654;
 		using var listener = new RecordingListener(EventLevel.Verbose, EventKeywords.All);
 		var log = ILSpyXEventSource.Log;
-		log.AssemblyLoadStart("test.dll");
-		log.AssemblyLoadStop("test.dll", "PEFileLoader", true);
-		log.AssemblyResolveStart("System.Runtime");
-		log.AssemblyResolveStop("System.Runtime", (int)AssemblyResolveOutcome.FoundInList);
-		log.SnapshotLookupBuildStart(10);
-		log.SnapshotLookupBuildStop(10);
-		log.DebugInfoLoadStart("test.dll");
-		log.DebugInfoLoadStop("test.dll", "PortableDebugInfoProvider");
-		log.SearchModuleStart("TestModule", "MemberSearchStrategy");
-		log.SearchModuleStop("TestModule", "MemberSearchStrategy");
-		log.AnalyzerScopeStart("MyNamespace.MyType");
-		log.AnalyzerScopeStop("MyNamespace.MyType", 3);
-		log.PackageOpened("app.zip", "zip", 12);
-		log.PackageEntryExtracted("lib/test.dll", 4096L, 0.5);
+		log.AssemblyLoadStart(marker + "test.dll");
+		log.AssemblyLoadStop(marker + "test.dll", "PEFileLoader", true);
+		log.AssemblyResolveStart(marker + "Reference");
+		log.AssemblyResolveStop(marker + "Reference", (int)AssemblyResolveOutcome.FoundInList);
+		log.SnapshotLookupBuildStart(lookupSentinel);
+		log.SnapshotLookupBuildStop(lookupSentinel);
+		log.DebugInfoLoadStart(marker + "test.dll");
+		log.DebugInfoLoadStop(marker + "test.dll", "PortableDebugInfoProvider");
+		log.SearchModuleStart(marker + "TestModule", "MemberSearchStrategy");
+		log.SearchModuleStop(marker + "TestModule", "MemberSearchStrategy");
+		log.AnalyzerScopeStart(marker + "MyType");
+		log.AnalyzerScopeStop(marker + "MyType", 3);
+		log.PackageOpened(marker + "app.zip", "zip", 12);
+		log.PackageEntryExtracted(marker + "lib/test.dll", 4096L, 0.5);
 
 		// A mismatch between an [Event] method's signature and its WriteEvent call surfaces
 		// as an "EventSourceMessage" error event on the same provider.
@@ -111,7 +117,6 @@ public class ILSpyXEventSourceTests
 		string[] expected = {
 			"AssemblyLoadStart", "AssemblyLoadStop",
 			"AssemblyResolveStart", "AssemblyResolveStop",
-			"SnapshotLookupBuildStart", "SnapshotLookupBuildStop",
 			"DebugInfoLoadStart", "DebugInfoLoadStop",
 			"SearchModuleStart", "SearchModuleStop",
 			"AnalyzerScopeStart", "AnalyzerScopeStop",
@@ -120,7 +125,18 @@ public class ILSpyXEventSourceTests
 		};
 		foreach (string eventName in expected)
 		{
-			Assert.That(listener.EventsNamed(eventName), Has.Count.EqualTo(1), eventName);
+			var markedEvents = listener.EventsNamed(eventName)
+				.Where(p => p.Values.OfType<string>().Any(v => v.StartsWith(marker, StringComparison.Ordinal)))
+				.ToList();
+			Assert.That(markedEvents, Has.Count.EqualTo(1), eventName);
+		}
+
+		foreach (string eventName in new[] { "SnapshotLookupBuildStart", "SnapshotLookupBuildStop" })
+		{
+			var markedEvents = listener.EventsNamed(eventName)
+				.Where(p => (int)p["assemblyCount"]! == lookupSentinel)
+				.ToList();
+			Assert.That(markedEvents, Has.Count.EqualTo(1), eventName);
 		}
 	}