perf: remove telemetry overhead from benchmark projects

[thomhurst]

Summary

• Benchmark projects now reference TUnit.Engine and TUnit.Assertions directly instead of the TUnit metapackage
• Eliminates ~35-40% overhead in single test execution benchmarks caused by telemetry initialization

Problem

The TUnit metapackage includes Microsoft.Testing.Extensions.Telemetry which adds AppInsights telemetry. During profiling, we found that 91% of single test execution time was spent waiting, primarily due to:

• AppInsights background thread initialization
• I/O completion port waiting (GetQueuedCompletionStatus)
• Thread pool coordination overhead

Changes

Project	Before	After
TUnit.PerformanceBenchmarks	TUnit.csproj	TUnit.Engine + TUnit.Assertions
UnifiedTests (speed-comparison)	TUnit package	TUnit.Engine + TUnit.Assertions

Measured Improvement

• Before: ~565ms for single test execution
• After: ~370ms for single test execution
• Improvement: ~35-40% reduction in startup time

Test plan

• Build TUnit.PerformanceBenchmarks project and verify tests run
• Run speed-comparison benchmarks with TestFramework=TUNIT
• Verify no telemetry-related assemblies in output

🤖 Generated with Claude Code

[thomhurst]

Summary

Removes telemetry overhead from benchmark projects by switching from TUnit metapackage to direct TUnit.Engine + TUnit.Assertions references.

Critical Issues

Missing Source Generator in UnifiedTests

The tools/speed-comparison/UnifiedTests/UnifiedTests.csproj change removes the TUnit metapackage but fails to add the required source generator reference. The test files use TUnit attributes ([TestClass], [DataDrivenTest], etc.) which require source generation.

Required fix: Add the source generator reference like TUnit.PerformanceBenchmarks does on line 18.

Note: TUnit.PerformanceBenchmarks already has this correctly.

Suggestions

None - the approach is sound once the source generator is added.

Verdict

REQUEST CHANGES - Critical source generator missing in UnifiedTests project