fix: filter unique classes to include only those with properties

[thomhurst]

Fixes #3084

[claude]

Claude finished @thomhurst's task —— View job

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Code Review Complete ✅

Reviewing PR #3086: "fix: filter unique classes to include only those with properties"

Todo List:

• Read repository guidelines (CLAUDE.md)
• Examine the modified file and understand the change
• Analyze the code change for potential issues
• Check test coverage considerations
• Provide comprehensive review feedback

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Review Feedback

Overall Assessment: ✅ Approved

This is a clean, targeted bug fix that improves performance by preventing unnecessary source generation. The change is minimal and well-placed.

Code Quality & Best Practices ✅

• Clean Implementation: The fix is implemented at the optimal location (line 150) in the pipeline after deduplication but before source generation
• Follows Repository Standards: Adheres to TUnit's performance-first philosophy mentioned in CLAUDE.md
• Modern C# Usage: Uses appropriate LINQ method chaining consistent with existing codebase patterns

Bug Prevention ✅

• Logic: The filter x.Properties.Length > 0 correctly identifies classes that have properties with data source attributes
• Prevents Empty Generation: Eliminates generation of property injection sources for classes without injectable properties
• Maintains Correctness: Classes with properties will still be processed normally

Performance Considerations ✅

• Positive Impact: Reduces unnecessary code generation for classes without data source properties
• Minimal Overhead: The Length > 0 check is O(1) and adds negligible performance cost
• Aligns with Framework Goals: Supports TUnit's "performance is paramount" principle

Security Concerns ✅

• No Security Issues: This is a filtering operation that doesn't introduce any security vulnerabilities
• Safe Operation: Only affects source generation, not runtime behavior

Test Coverage Considerations ⚠️

• Existing Tests: Found property injection tests in the test project (AbstractBaseClassPropertyInjectionTests.cs, etc.)
• Recommendation: Consider adding a specific test case to verify that classes without properties are excluded from source generation
• Snapshot Tests: According to CLAUDE.md, source generator changes should run dotnet test TUnit.Core.SourceGenerator.Tests to verify snapshots

Technical Details

File: PropertyInjectionSourceGenerator.cs:150
Change: Added .Where(x => x.Properties.Length > 0) filter
Impact: Prevents generation of empty PropertyInjectionSource_* classes

Minor Suggestions

1. Testing: Run dotnet test TUnit.Core.SourceGenerator.Tests to ensure snapshot tests pass
2. Edge Case Test: Consider adding a test that verifies classes without data source properties are properly excluded

This fix addresses the root cause efficiently and maintains the dual-mode architecture requirement mentioned in the repository guidelines.

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[aradalvand]

@thomhurst Could you please release this?