Fix excessive logging in create_pr.py that creates 43MB+ log files

[mohammedahmed18]

Problem

Line 38 of create_pr.py logged all keys from the function_to_tests dictionary using list(function_to_tests.keys()). For large codebases like budibase (1012 functions), this creates massive log files (43MB+) with a single DEBUG statement printing thousands of function names.

Evidence

• Trace ID: 3d2ad2f0-254a-4401-9c93-84f691acabf0 (43MB log, 534K lines)
• Location: Line 533922 shows list of 1000+ function keys in single log entry
• Impact: Affects 4/22 logs (18%) in recent optimization run
• Size: Each occurrence adds ~100KB to log file

Root Cause

Debug logging statement at line 38 was designed for small projects but became problematic when used with monorepos containing hundreds of packages:

# Before (buggy):
logger.debug(f"[PR-DEBUG] function_to_tests keys: {list(function_to_tests.keys())}")

Fix

Changed to log only the count:

# After (fixed):
logger.debug(f"[PR-DEBUG] function_to_tests has {len(function_to_tests)} keys")

This reduces log output from ~100KB to ~50 bytes per call.

Testing

• ✅ Added 2 regression tests in test_create_pr_logging_bug.py
• ✅ Tests verify count is logged, not full key list
• ✅ Tests verify log output stays under 10KB (vs 100KB+ before)
• ✅ All existing tests pass
• ✅ Linting passes (uv run prek)

Impact

• Severity: MEDIUM (doesn't break functionality, but bloats logs)
• Type: Systematic (reproducible on every optimization run with large codebases)
• Benefits: Significantly reduces log file sizes for monorepo projects

Related Issues

Part of comprehensive bug-fixing effort for Codeflash optimization stability.

[claude]

Claude finished @mohammedahmed18's task in 2m 18s —— View job

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PR Review Summary

• Triage PR size — SMALL (1 line of production code changed)
• Run lint/typecheck — prek passed; mypy has 4 errors in the new test file
• Resolve stale threads — none found
• Review code
• Duplicate detection
• Post summary

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Prek Checks

uv run prek run --from-ref origin/main — passed (no issues).

mypy reports 4 errors in the new test file (test_create_pr_logging_bug.py) — missing return type annotations and a missing type annotation for a dict variable. These are in test code and won't affect runtime behavior.

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Code Review

The fix itself is correct. Changing list(function_to_tests.keys()) → len(function_to_tests) resolves the 43MB log issue.

However, there are two broader concerns:

1. The [PR-DEBUG] statements are temporary debug code — they should all be removed

codeflash/result/create_pr.py contains 18+ [PR-DEBUG]-prefixed logger.debug() calls. The [PR-DEBUG] prefix is a hallmark of ad-hoc debugging code that was never cleaned up. Fixing only line 38 leaves the rest in production:

• Line 47 (loop): logger.debug(f"[PR-DEBUG] test_file: {tf.tests_in_file.test_file}, test_type={tf.tests_in_file.test_type}") — iterates over all test files for every function; still O(n) output
• Lines 69–77 (loop): Two debug lines per registry entry, called inside existing_tests_source_for which can be called per-function
• Lines 134–141: Per-invocation-id debug lines inside the main processing loop

The right fix is to remove all [PR-DEBUG] statements, not patch the worst one. They're noise in the debug log and contribute to bloat at scale.

Fix this →

2. Test file is overbuilt for a 1-line change

test_create_pr_logging_bug.py is 147 lines for a fix that just changes one log format string. The two tests are near-identical (large dict vs small dict) and both verify the same thing. The size assertion (< 10000 bytes) is also brittle — it ties test correctness to output byte counts that will vary with Python version and log handler configuration.

A simpler, more direct test would just assert the log message format directly using caplog.

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Duplicate Detection

No duplicates detected. The changed function existing_tests_source_for has no equivalent in other modules.

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Test Coverage

Tests pass. Coverage for the changed production line is confirmed by the added tests.

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