disbord/tests/CONSENT_MANAGER_RACE_CONDITION_TESTS.md

ConsentManager Race Condition Fix Tests

Overview

This test suite verifies the race condition fixes implemented in the ConsentManager to ensure thread safety and proper concurrency handling for the Discord Voice Chat Quote Bot.

Race Condition Fixes Tested

1. Cache Locking Mechanisms

• Fix: Added asyncio.Lock() (_cache_lock) for all cache operations
• Tests: Verify concurrent cache access is thread-safe and atomic
• Files: test_cache_updates_are_atomic, test_cache_reads_dont_interfere_with_writes

2. Background Task Management

• Fix: Proper lifecycle management of cleanup tasks with _cleanup_task
• Tests: Verify tasks are created, managed, and cleaned up correctly
• Files: test_cleanup_task_created_during_initialization, test_cleanup_method_cancels_background_tasks

3. Resource Cleanup

• Fix: Added cleanup() method for proper resource management
• Tests: Verify cleanup handles various edge cases gracefully
• Files: test_cleanup_handles_already_cancelled_tasks_gracefully, test_cleanup_handles_task_cancellation_exceptions

Test Categories

Race Condition Prevention Tests

1. Concurrent Consent Operations
   • test_concurrent_consent_granting_no_cache_corruption
   • test_concurrent_consent_revoking_works_properly
   • test_concurrent_cache_access_during_check_consent
   • test_concurrent_global_opt_out_operations

Background Task Management Tests

2. Task Lifecycle Management
   • test_cleanup_task_created_during_initialization
   • test_cleanup_method_cancels_background_tasks
   • test_cleanup_handles_already_cancelled_tasks_gracefully
   • test_cleanup_handles_task_cancellation_exceptions

Lock-Protected Operations Tests

3. Atomic Operations
   • test_cache_updates_are_atomic
   • test_cache_reads_dont_interfere_with_writes
   • test_performance_doesnt_degrade_significantly_with_locking

Edge Case Tests

4. Stress Testing
   • test_behavior_when_lock_held_for_extended_time
   • test_multiple_concurrent_operations_same_user
   • test_mixed_grant_revoke_check_operations_same_user
   • test_no_deadlocks_under_heavy_concurrent_load

Resource Management Tests

5. Cleanup and Consistency
   • test_cleanup_with_multiple_consent_managers
   • test_cache_consistency_after_concurrent_modifications

Key Test Features

Modern Python 3.12+ Patterns

• Full type annotations with proper generic typing
• Async fixtures for proper test isolation
• No use of Any type - specific type hints throughout
• Modern async/await patterns

Concurrency Testing Approach

# Example concurrent testing pattern
async def test_concurrent_operations():
    """Test concurrent operations using asyncio.gather."""
    results = await asyncio.gather(*[
        operation(user_id) for user_id in user_ids
    ], return_exceptions=True)
    
    # Verify all operations succeeded
    assert all(not isinstance(result, Exception) for result in results)

Performance Benchmarking

• Tests verify that locking doesn't significantly degrade performance
• Parametrized tests with different concurrency levels (5, 10, 20 operations)
• Timeout-based deadlock detection

Test Data Patterns

No Loops or Conditionals in Tests

Following the project's testing standards, all tests use:

• Inline function returns for clean code
• asyncio.gather for concurrent operations
• List comprehensions instead of loops
• Exception verification through return_exceptions=True

Mock Strategy

• Consistent mock database manager with predictable return values
• Proper async mock objects with AsyncMock
• Mock patching of external dependencies (ConsentTemplates, ConsentView)

Running the Tests

Individual Test File

pytest tests/test_consent_manager_fixes.py -v

With the Test Runner Script

./run_race_condition_tests.sh

Integration with Existing Tests

The tests complement the existing consent manager tests in:

• tests/unit/test_core/test_consent_manager.py

Test Coverage Areas

Thread Safety Verification

• ✅ Cache operations are atomic
• ✅ Concurrent reads don't interfere with writes
• ✅ Global opt-out operations are thread-safe
• ✅ No race conditions in consent granting/revoking

Background Task Management

• ✅ Tasks are properly created and managed
• ✅ Cleanup handles task cancellation gracefully
• ✅ Resource cleanup is thorough and exception-safe

Performance Impact

• ✅ Locking doesn't significantly impact performance
• ✅ System handles high concurrency loads
• ✅ No deadlocks under stress conditions

Edge Case Handling

• ✅ Extended lock holding scenarios
• ✅ Multiple operations on same user
• ✅ Mixed operation types
• ✅ Heavy concurrent load scenarios

Implementation Standards

Code Quality

• Modern Python 3.12+ syntax and typing
• Async-first patterns throughout
• Zero duplication - common patterns abstracted
• Full type safety with no Any types
• Comprehensive docstrings

Test Architecture

• Proper async fixture management
• Consistent mock object behavior
• Parametrized testing for scalability verification
• Exception safety verification
• Resource cleanup validation

This test suite ensures the ConsentManager race condition fixes are robust, performant, and maintain thread safety under all operational conditions.