perf: Hot reload no longer holds the Editor's main thread after a compile to capture sources or to list assemblies

Assets/Tests/Editor/CompileStatusBridgeCommandTests.cs

@@ -52,6 +52,7 @@ public void BuildResponse_WhenUnityIsIdleAndResultMatches_ReturnsReadyResult()
                 isCompiling: false,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);
@@ -77,6 +78,7 @@ public void BuildResponse_WhenUnityIsStillCompiling_ReturnsNotReadyWithStoredRes
                 isCompiling: true,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);
@@ -101,6 +103,7 @@ public void BuildResponse_WhenRequestIdDiffers_DoesNotReturnStaleResult()
                 isCompiling: false,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);
@@ -124,6 +127,7 @@ public void BuildResponse_WhenUnityIsIdleAndPendingRequestHasNoReloadSignal_Wait
                 isCompiling: false,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);
@@ -152,6 +156,7 @@ public void BuildResponse_WhenUnityIsIdleAndPendingRequestObservedReload_Returns
                 isCompiling: false,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);
@@ -182,6 +187,37 @@ public void BuildResponse_WhenUnityIsBusyAndPendingRequestHasNoResult_WaitsForRe
                 isCompiling: true,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
+                _compileSessionLifecycleService,
+                _compileResultSessionRepository,
+                _pendingCompileSessionRepository);
+
+            Assert.That(response.Ready, Is.False);
+            Assert.That(response.HasResult, Is.False);
+            Assert.That(response.Result, Is.Null);
+            Assert.That(
+                UnityCliLoopEditorSessionStateTestFactory.GetSinglePendingCompileRequest(
+                    _pendingCompileSessionRepository).HasRequest,
+                Is.True);
+        }
+
+        [Test]
+        public void BuildResponse_WhileTheSnapshotCaptureHolds_IsNotReadyAndDoesNotRecoverAPendingResult()
+        {
+            // Verifies an idle Unity still withholds the compile completion, and leaves the pending
+            // request for a later poll, while the hot reload source snapshot capture is running.
+            _compileSessionLifecycleService.MarkPendingCompileRequest(
+                "compile_test_request",
+                forceRecompile: false,
+                markedAtUtc: System.DateTime.UtcNow);
+            _pendingCompileSessionRepository.MarkPendingCompileRequestReloadObserved();
+
+            GetCompileStatusResponse response = CompileStatusBridgeCommand.BuildResponse(
+                "compile_test_request",
+                isCompiling: false,
+                isUpdating: false,
+                isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: true,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);
@@ -210,6 +246,7 @@ public void BuildResponse_WhenForceCompilePendingRequestHasNoResult_ReturnsExpla
                 isCompiling: false,
                 isUpdating: false,
                 isDomainReloadInProgress: false,
+                isSnapshotCaptureHolding: false,
                 _compileSessionLifecycleService,
                 _compileResultSessionRepository,
                 _pendingCompileSessionRepository);

Assets/Tests/Editor/HotReload/CecilPdbRewrite.cs

@@ -0,0 +1,67 @@
+using System;
+using System.IO;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+using NUnit.Framework;
+
+using io.github.hatayama.UnityCliLoop.FirstPartyTools;
+
+namespace io.github.hatayama.UnityCliLoop.Tests.Editor.HotReload
+{
+    /// <summary>
+    /// Writes a copy of a compiled assembly of this project the way an IL post-processor does, for
+    /// tests that need a PDB which lost the documents no sequence point refers to.
+    /// </summary>
+    internal static class CecilPdbRewrite
+    {
+        // Writes the rewritten copy into a new temporary directory and returns the dll's path; the
+        // caller deletes the directory. Fails the test unless the copy kept the compiler's source
+        // count and lost a document, which every case that uses it relies on.
+        internal static string RewriteIntoNewDirectoryLosingDocuments(string projectRoot, string assemblyName)
+        {
+            string directory = Path.Combine(Path.GetTempPath(), "uloop-cecil-pdb-rewrite-" + Guid.NewGuid().ToString("N"));
+            string dllPath = Path.Combine(directory, HotReloadConstants.ScriptAssembliesRelativeDirectory, assemblyName + ".dll");
+            Directory.CreateDirectory(Path.GetDirectoryName(dllPath));
+            Rewrite(projectRoot, assemblyName, directory, dllPath);
+            HotReloadPdbCompilationInfo rewritten = HotReloadPdbCompilationInfo.Read(Path.ChangeExtension(dllPath, ".pdb"));
+            Assert.That(rewritten.SourceFileCount, Is.Not.Null, "Precondition: the rewritten PDB must keep the compiler's source count.");
+            Assert.That(rewritten.DocumentCount, Is.LessThan(rewritten.SourceFileCount.Value), "Precondition: the rewrite must drop some document.");
+            return dllPath;
+        }
+
+        // The temporary directory RewriteIntoNewDirectoryLosingDocuments created for the dll.
+        internal static string RootOf(string dllPath)
+        {
+            return Path.GetDirectoryName(Path.GetDirectoryName(Path.GetDirectoryName(dllPath)));
+        }
+
+        // Reads the assembly with its symbols and writes both again, as an IL post-processor does.
+        // Cecil keeps only the documents a method refers to. workDirectory receives the copy that is
+        // read, so the compiled files are never opened for writing.
+        internal static void Rewrite(string projectRoot, string assemblyName, string workDirectory, string outputDllPath)
+        {
+            CompiledAssemblyLayout real = CompiledAssemblyLayout.Resolve(projectRoot);
+            string sourceDll = Path.Combine(workDirectory, "Source", assemblyName + ".dll");
+            Directory.CreateDirectory(Path.GetDirectoryName(sourceDll));
+            File.Copy(real.DllPath(assemblyName), sourceDll);
+            File.Copy(real.PdbPath(assemblyName), Path.ChangeExtension(sourceDll, ".pdb"));
+            using (DefaultAssemblyResolver resolver = new DefaultAssemblyResolver())
+            {
+                resolver.AddSearchDirectory(real.CompiledAssembliesDirectory);
+                resolver.AddSearchDirectory(Path.GetDirectoryName(typeof(object).Assembly.Location));
+                using (ModuleDefinition module = ModuleDefinition.ReadModule(
+                    sourceDll,
+                    new ReaderParameters { ReadSymbols = true, AssemblyResolver = resolver }))
+                {
+                    module.Write(outputDllPath, new WriterParameters
+                    {
+                        WriteSymbols = true,
+                        SymbolWriterProvider = new PortablePdbWriterProvider(),
+                    });
+                }
+            }
+        }
+    }
+}