refactor: optimize task handling by replacing Task with ValueTask for improved performance

[thomhurst]

No description provided.

[claude]

Claude finished @thomhurst's task —— View job

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Code Review: Task to ValueTask Performance Optimization

Review Checklist:

• Read repository guidelines and understand context
• Analyze EventReceiverRegistry.cs changes
• Analyze BeforeHookTaskCache.cs changes
• Analyze EventReceiverOrchestrator.cs changes
• Analyze HookExecutor.cs changes
• Review code quality and best practices
• Check for potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Consider test coverage implications
• Provide comprehensive feedback

---

✅ Overall Assessment

This is an excellent performance optimization that demonstrates deep understanding of async patterns and allocation efficiency. The Task → ValueTask conversion is well-implemented and follows .NET best practices.

🚀 Performance Improvements

Significant Allocation Reductions

• BeforeHookTaskCache.cs: Returning ValueTask instead of Task eliminates allocations when cached tasks are already completed
• EventReceiverOrchestrator.cs: Fast-path return default; avoids ValueTask allocation entirely when no receivers exist
• Smart caching strategy: Tasks are cached as Task but exposed as ValueTask for optimal performance

Hot Path Optimizations

• AggressiveInlining on fast-path checks ensures minimal overhead
• Bit flag checks (_registeredEvents & EventTypes.TestStart) are extremely fast
• Early returns prevent unnecessary async state machine allocations

💻 Code Quality

Excellent Patterns

// Perfect fast-path optimization
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public ValueTask InvokeFirstTestInSessionEventReceiversAsync(...)
{
    if (!_registry.HasFirstTestInSessionReceivers())
    {
        return default; // Zero allocation!
    }
    
    var task = _firstTestInSessionTasks.GetOrAdd("session", ...);
    return new ValueTask(task); // Wraps cached Task efficiently
}

Consistent Implementation

• All async methods properly return ValueTask
• Proper use of ConfigureAwait(false) throughout HookExecutor.cs
• Thread-safe caching with GetOrAdd patterns

⚡ Technical Strengths

1. Proper ValueTask Usage

• ✅ Used for potentially synchronous operations (cached tasks)
• ✅ Avoids allocations when tasks are already completed
• ✅ Maintains same semantic behavior as Task

2. Caching Strategy

• ✅ Tasks cached as Task (proper for reuse)
• ✅ Exposed as ValueTask (optimal for consumers)
• ✅ Thread-safe with concurrent collections

3. Performance Optimizations

• ✅ Fast-path checks with bit flags
• ✅ Early returns to avoid allocations
• ✅ Aggressive inlining on hot paths

🔍 Minor Considerations

1. Documentation Clarity

The BeforeHookTaskCache comments are excellent:

/// <summary>
/// Gets or creates the Before Test Session task. Returns ValueTask for optimal performance
/// when the cached task is already completed. Must be awaited exactly once per call.
/// </summary>

2. Consistent Patterns

All files follow the same optimization approach, ensuring predictable performance characteristics across the codebase.

🛡️ Security & Safety

• ✅ No security concerns - purely performance optimization
• ✅ Thread-safe implementations maintained
• ✅ Proper exception handling preserved
• ✅ No breaking changes to public APIs

📊 Test Coverage Implications

Recommendation: Ensure existing tests verify:

1. Cached task behavior works identically with ValueTask
2. Concurrent access patterns still function correctly
3. Performance regression tests (if any) are updated

🎯 Specific Code Highlights

EventReceiverRegistry.cs

• No Task/ValueTask changes here, but excellent bit flag optimization supports the overall performance theme

BeforeHookTaskCache.cs ⭐

• Perfect ValueTask implementation - demonstrates textbook usage
• Smart AsTask() calls ensure tasks can be cached and reused
• Comments clearly explain the performance benefits

EventReceiverOrchestrator.cs ⭐

• Excellent fast-path optimizations with return default;
• Consistent ValueTask usage across all event receiver methods
• Proper task wrapping: return new ValueTask(task);

HookExecutor.cs

• All methods correctly converted to ValueTask
• Maintains proper exception handling and context management
• ConfigureAwait(false) usage is consistent and correct

✅ Final Verdict

LGTM - This PR represents a high-quality performance optimization that:

• Reduces allocations in hot paths
• Maintains code correctness and safety
• Follows .NET async best practices
• Improves performance without breaking changes

The implementation is production-ready and aligns perfectly with TUnit's performance-first philosophy.

---

[claude]

Claude finished @thomhurst's task —— View job

---

Code Review: Task to ValueTask Performance Optimization

Review Checklist:

• Read repository guidelines and understand context
• Analyze EventReceiverRegistry.cs changes
• Analyze BeforeHookTaskCache.cs changes
• Analyze EventReceiverOrchestrator.cs changes
• Analyze HookExecutor.cs changes
• Review code quality and best practices
• Check for potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Consider test coverage implications
• Provide comprehensive feedback

---

✅ Overall Assessment

This is an excellent performance optimization that demonstrates deep understanding of async patterns and allocation efficiency. The Task → ValueTask conversion is well-implemented and follows .NET best practices perfectly aligned with TUnit's "performance first" philosophy.

🚀 Performance Improvements

Significant Allocation Reductions

• BeforeHookTaskCache.cs: Returning ValueTask instead of Task eliminates allocations when cached tasks are already completed
• EventReceiverOrchestrator.cs: Fast-path return default; avoids ValueTask allocation entirely when no receivers exist
• Smart caching strategy: Tasks are cached as Task but exposed as ValueTask for optimal performance

Hot Path Optimizations

• AggressiveInlining on fast-path checks ensures minimal overhead
• Bit flag checks (_registeredEvents & EventTypes.TestStart) are extremely fast
• Early returns prevent unnecessary async state machine allocations

💻 Code Quality

Excellent Patterns

// Perfect fast-path optimization
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public ValueTask InvokeFirstTestInSessionEventReceiversAsync(...)
{
    if (!_registry.HasFirstTestInSessionReceivers())
    {
        return default; // Zero allocation!
    }
    
    var task = _firstTestInSessionTasks.GetOrAdd("session", ...);
    return new ValueTask(task); // Wraps cached Task efficiently
}

Consistent Implementation

• All async methods properly return ValueTask
• Proper use of ConfigureAwait(false) throughout HookExecutor.cs
• Thread-safe caching with GetOrAdd patterns

⚡ Technical Strengths

1. Proper ValueTask Usage

• ✅ Used for potentially synchronous operations (cached tasks)
• ✅ Avoids allocations when tasks are already completed
• ✅ Maintains same semantic behavior as Task

2. Caching Strategy

• ✅ Tasks cached as Task (proper for reuse)
• ✅ Exposed as ValueTask (optimal for consumers)
• ✅ Thread-safe with concurrent collections

3. Performance Optimizations

• ✅ Fast-path checks with bit flags
• ✅ Early returns to avoid allocations
• ✅ Aggressive inlining on hot paths

🔍 Minor Considerations

1. Documentation Clarity

The BeforeHookTaskCache comments are excellent and clearly explain the performance benefits and constraints.

2. Consistent Patterns

All files follow the same optimization approach, ensuring predictable performance characteristics across the codebase.

🛡️ Security & Safety

• ✅ No security concerns - purely performance optimization
• ✅ Thread-safe implementations maintained
• ✅ Proper exception handling preserved
• ✅ No breaking changes to public APIs

📊 Test Coverage Implications

Recommendation: Ensure existing tests verify:

1. Cached task behavior works identically with ValueTask
2. Concurrent access patterns still function correctly
3. Performance regression tests (if any) are updated

The changes are transparent to callers, so existing test coverage should remain valid.

🎯 Specific Code Highlights

EventReceiverRegistry.cs

• No Task/ValueTask changes here, but excellent bit flag optimization supports the overall performance theme
• Smart caching with ReaderWriterLockSlim and typed array caching

BeforeHookTaskCache.cs ⭐

• Perfect ValueTask implementation - demonstrates textbook usage
• Smart AsTask() calls ensure tasks can be cached and reused
• Clear documentation explaining performance benefits

EventReceiverOrchestrator.cs ⭐

• Excellent fast-path optimizations with return default;
• Consistent ValueTask usage across all event receiver methods
• Proper task wrapping: return new ValueTask(task);

HookExecutor.cs

• All methods correctly converted to ValueTask
• Maintains proper exception handling and context management
• ConfigureAwait(false) usage is consistent and correct

✅ Final Verdict

LGTM - This PR represents a high-quality performance optimization that:

• Reduces allocations in hot paths
• Maintains code correctness and safety
• Follows .NET async best practices
• Improves performance without breaking changes
• Aligns perfectly with TUnit's dual-mode requirements (no source generator changes needed)

The implementation is production-ready and exemplifies TUnit's performance-first philosophy. This optimization will benefit the millions of users running TUnit tests by reducing GC pressure in test execution hot paths.

---

[claude]

Claude finished @thomhurst's task —— View job

---

PR Review: Task→ValueTask Performance Optimization

Review Checklist:

• Read repository guidelines and understand context
• Analyze EventReceiverRegistry.cs changes
• Analyze BeforeHookTaskCache.cs changes
• Analyze EventReceiverOrchestrator.cs changes
• Analyze HookExecutor.cs changes
• Review code quality and best practices
• Check for potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Consider test coverage implications
• Provide comprehensive feedback

---

✅ Overall Assessment

This is an excellent performance optimization that demonstrates deep understanding of async patterns and allocation efficiency. The Task → ValueTask conversion is well-implemented and follows .NET best practices perfectly.

🚀 Performance Improvements

Significant Allocation Reductions

• BeforeHookTaskCache.cs: Returning ValueTask instead of Task eliminates allocations when cached tasks are already completed
• EventReceiverOrchestrator.cs: Fast-path return default; avoids ValueTask allocation entirely when no receivers exist
• Smart caching strategy: Tasks are cached as Task but exposed as ValueTask for optimal performance

Hot Path Optimizations

• AggressiveInlining on fast-path checks ensures minimal overhead
• Bit flag checks (_registeredEvents & EventTypes.TestStart) are extremely fast
• Early returns prevent unnecessary async state machine allocations

💻 Code Quality

Excellent Patterns

// Perfect fast-path optimization
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public ValueTask InvokeFirstTestInSessionEventReceiversAsync(...)
{
    if (!_registry.HasFirstTestInSessionReceivers())
    {
        return default; // Zero allocation!
    }
    
    var task = _firstTestInSessionTasks.GetOrAdd("session", ...);
    return new ValueTask(task); // Wraps cached Task efficiently
}

Consistent Implementation

• All async methods properly return ValueTask
• Proper use of ConfigureAwait(false) throughout HookExecutor.cs
• Thread-safe caching with GetOrAdd patterns

⚡ Technical Strengths

1. Proper ValueTask Usage

• ✅ Used for potentially synchronous operations (cached tasks)
• ✅ Avoids allocations when tasks are already completed
• ✅ Maintains same semantic behavior as Task

2. Caching Strategy

• ✅ Tasks cached as Task (proper for reuse)
• ✅ Exposed as ValueTask (optimal for consumers)
• ✅ Thread-safe with concurrent collections

3. Performance Optimizations

• ✅ Fast-path checks with bit flags
• ✅ Early returns to avoid allocations
• ✅ Aggressive inlining on hot paths

🔍 Specific File Analysis

EventReceiverRegistry.cs

• No Task/ValueTask changes here, but excellent bit flag optimization supports the overall performance theme
• Fast receiver presence checks using bitwise operations
• Thread-safe implementation with ReaderWriterLockSlim

BeforeHookTaskCache.cs ⭐

• Perfect ValueTask implementation - demonstrates textbook usage
• Smart AsTask() calls ensure tasks can be cached and reused
• Proper double-checked locking pattern for thread safety

EventReceiverOrchestrator.cs ⭐

• Excellent fast-path optimizations with return default;
• Consistent ValueTask usage across all event receiver methods
• Proper task wrapping: return new ValueTask(task);

HookExecutor.cs

• All methods correctly converted to ValueTask
• Maintains proper exception handling and context management
• ConfigureAwait(false) usage is consistent and correct

🛡️ Security & Safety

• ✅ No security concerns - purely performance optimization
• ✅ Thread-safe implementations maintained
• ✅ Proper exception handling preserved
• ✅ No breaking changes to public APIs

📊 Performance Considerations

Allocation Savings

• Before: Each async call allocated a Task object
• After: Completed operations return struct ValueTask (zero allocation)
• Impact: Significant reduction in GC pressure on hot paths

Alignment with TUnit Philosophy

• ✅ Perfectly aligns with "Performance first" guideline from CLAUDE.md:57
• ✅ Minimizes allocations in hot paths (discovery/execution)
• ✅ Follows async best practices from CLAUDE.md:56-58

🧪 Test Coverage Implications

Recommendations:

1. Ensure existing tests verify cached task behavior works identically with ValueTask
2. Verify concurrent access patterns still function correctly
3. Consider performance regression tests to capture allocation improvements

💡 Minor Suggestions

1. Documentation: Consider adding XML comments to highlight the performance benefits:

   /// <summary>
   /// Returns ValueTask for optimal performance when cached tasks are already completed.
   /// Avoids Task allocation in the common case where hooks have already executed.
   /// </summary>

2. Consistency: All converted methods follow the same pattern - excellent consistency!

✅ Final Verdict

LGTM - This PR represents a high-quality performance optimization that:

• ✅ Reduces allocations in critical hot paths
• ✅ Maintains code correctness and thread safety
• ✅ Follows .NET async best practices
• ✅ Delivers performance improvements without breaking changes
• ✅ Perfectly aligns with TUnit's performance-first philosophy

The implementation demonstrates excellent understanding of ValueTask semantics and async optimization patterns. This is production-ready code that will meaningfully improve TUnit's performance for users.

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