fix: Before(TestSession) ignores HookExecutor

[thomhurst]

Fixes #2749

[claude]

Claude finished @thomhurst's task —— View job

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PR Review: fix: Before(TestSession) ignores HookExecutor

Summary: This PR addresses issue #2749 by fixing TestSession and TestDiscovery hooks that were ignoring the HookExecutor attribute. The fix consolidates hook discovery from runtime reflection to compile-time source generation.

Key Changes Analysis

✅ Major Architectural Improvement:

• Removed: ReflectionHookDiscoveryService.cs (460 lines) - runtime reflection-based hook discovery
• Enhanced: HookMetadataGenerator.cs - now handles HookExecutor extraction at compile time
• Simplified: Hook collection logic in HookCollectionService.cs and HookOrchestrator.cs

Code Quality Review

✅ Excellent:

1. Performance Improvement: Moving from runtime reflection to compile-time generation eliminates reflection overhead during test execution
2. Source Generation Enhancement: The GetHookExecutorType() method (HookMetadataGenerator.cs:243-270) properly handles both generic HookExecutorAttribute<T> and non-generic HookExecutorAttribute(Type) variants
3. Comprehensive Test Coverage: HookExecutorTests.cs provides excellent coverage testing HookExecutor with all hook types (TestSession, TestDiscovery, Assembly, Class, Test)
4. Thread Safety: All hook execution properly uses the HookExecutor.Execute*() methods which handle thread apartment state correctly

✅ Good Design Patterns:

• Proper separation of concerns between generation and execution
• Consistent error handling with detailed logging
• Maintains backward compatibility

Potential Issues & Concerns

⚠️ Minor Performance Consideration:

• Line 786 in HookMetadataGenerator.cs: The HookExecutorHelper.GetHookExecutor() creates new instances with new {hookExecutor}(). Consider if hook executors should be singletons to avoid unnecessary allocations.

⚠️ Code Duplication:

• The hook generation code has some repetitive patterns that could potentially be consolidated, but this is acceptable for source generation where explicitness is often preferred over abstraction.

Security & Best Practices

✅ Security: No security concerns identified. The code properly validates input and uses strongly-typed generation.

✅ Best Practices:

• Proper null checking and error handling
• Uses GloballyQualified() extension for type names to avoid namespace conflicts
• Comprehensive exception handling in hook execution

Test Coverage Assessment

✅ Excellent Test Coverage:
The new HookExecutorTests.cs comprehensively tests:

• All hook scopes: TestSession, TestDiscovery, Assembly, Class, Test
• Both static and instance hooks
• Proper executor usage (STAThreadExecutor)
• Verification that hooks actually execute with correct thread apartment state

Performance Considerations

✅ Significant Performance Improvement:

• Eliminates runtime reflection lookup overhead
• Compile-time generation reduces startup time
• Hook metadata is pre-computed and cached

Final Assessment

This is a high-quality fix that addresses the core issue while improving the overall architecture. The migration from runtime reflection to compile-time source generation is a significant improvement that:

1. ✅ Fixes the bug: TestSession and TestDiscovery hooks now properly respect HookExecutor
2. ✅ Improves performance: Eliminates reflection overhead
3. ✅ Enhances maintainability: Centralized hook metadata generation
4. ✅ Maintains compatibility: No breaking changes to public API
5. ✅ Comprehensive testing: Excellent test coverage for the fix

Recommendation: ✅ APPROVE - This PR successfully fixes the issue with a well-architected solution that improves the codebase overall.

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