[Claude Test Run]: Implement arena allocation for each test

[bradcypert]

Implements per-test arena allocation for better memory isolation and automatic cleanup.

Changes:

• Modified runTest() function to use ArenaAllocator
• Each test gets isolated memory that auto-cleans up
• Removed manual memory management calls
• Added explanatory comments

Fixes #9

Generated with Claude Code

[claude]

Claude finished @bradcypert's task —— View job

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Code Review Complete ✅

Todo List:

• Read and analyze the changed code in src/main.zig
• Evaluate code quality and adherence to best practices
• Check for potential bugs or issues
• Assess performance considerations
• Review security implications
• Evaluate test coverage aspects
• Provide comprehensive review feedback

Review Feedback

This is a well-implemented improvement that introduces per-test arena allocation for better memory isolation. Here's my detailed analysis:

✅ Code Quality & Best Practices

• Excellent use of RAII pattern: The arena allocator with defer arena.deinit() ensures automatic cleanup regardless of how the function exits
• Clear, descriptive comments: The explanatory comments on lines 102, 120, and 126 help future maintainers understand the memory management strategy
• Consistent with Zig idioms: Using ArenaAllocator for batch allocation/deallocation is a standard Zig pattern
• Proper parameter naming: base_allocator clearly distinguishes it from the arena allocator

✅ No Bugs or Issues Detected

• The implementation correctly initializes the arena from the base allocator
• The defer arena.deinit() is properly placed to ensure cleanup on all exit paths
• All existing error handling paths are preserved and will still properly clean up via the arena

⚡ Performance Considerations

Pros:

• Faster allocation: Arena allocation is significantly faster than individual allocations since it just bumps a pointer
• Better cache locality: Related allocations are physically close in memory
• Eliminates fragmentation: No need to track individual deallocations

Potential concerns:

• Memory usage: Arena holds all memory until test completion, which could increase peak usage for long-running tests
• Assessment: This trade-off is appropriate for test isolation and the improved performance likely outweighs the temporary memory increase

🔒 Security Assessment

• Memory safety: Arena allocation actually improves memory safety by eliminating potential memory leaks from missed free() calls
• Resource cleanup: The defer ensures cleanup even if tests panic or error out
• No security concerns identified

🧪 Test Coverage Implications

• Better test isolation: Each test now has completely isolated memory, preventing cross-test contamination
• More reliable tests: Memory issues in one test won't affect others
• Easier debugging: Memory-related issues will be isolated to specific tests

💡 Minor Suggestions

1. Consider adding a brief comment in the function documentation about the arena allocation strategy
2. The existing debug allocator in main() will still catch leaks in the arena itself, which is good

Overall Assessment

This is a high-quality improvement that follows Zig best practices and significantly improves the memory management strategy. The change is minimal, focused, and provides clear benefits for test reliability and performance. Approved ✅

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