perf: eliminate Func creation in ExecuteAsync

[TimothyMakkison]

Small change avoid Action creation by using a static lambda and manually boxing state.]

Before

After

[thomhurst]

Summary

Eliminates delegate allocation in DedicatedThreadExecutor.ExecuteAsync by using a static lambda with manually boxed state.

Critical Issues

None found ✅

Suggestions

None - this is a clean performance optimization that aligns with TUnit's "Performance First" principle.

Analysis

The change converts a capturing lambda (which allocates a closure object) to a static lambda with explicit state passing:

• All captured variables (this, action, tcs) are correctly passed through the tuple
• Thread-safety is maintained - the tuple is created before thread.Start(state)
• The optimization is meaningful since DedicatedThreadExecutor is used for STAThread tests and dedicated thread execution, making this a hot path
• AOT-compatible and uses modern C# patterns
• Bonus: Fixes indentation on line 412

The benchmark screenshots show measurable improvement in allocations, which directly supports TUnit's performance-first philosophy.

Verdict

✅ APPROVE - No critical issues