Fix package.json config overriding closer pyproject.toml in monorepos

[KRRT7]

Summary

• In parse_config_file(), package.json was always checked first by walking up from CWD. In monorepos with both a root package.json and a nested pyproject.toml with [tool.codeflash], the JS config would win and set pytest_cmd to jest, causing Python function optimization to crash with FileNotFoundError: 'jest'.
• Now both config files are located first, and the one closer to CWD is preferred, so a pyproject.toml in the working directory takes precedence over a parent-directory package.json.

Fixes the CI failure in codeflash-ai/codeflash-internal#2335.

Test plan

• Existing test_config_js.py tests pass (81 passed)
• Existing test_config.py tests pass (22 passed)
• Existing test_tracer.py and test_formatter.py tests pass (52 passed)

[claude]

PR Review Summary

Prek Checks

✅ All prek checks pass (ruff check, ruff format).

Mypy Checks

✅ Fixed 5 pre-existing mypy errors in config_parser.py (committed and pushed):

• Fixed Item | Container assignment by using isinstance guard + dict() conversion
• Fixed incompatible loop variable reassignments by using distinct variable names per loop
• Fixed Any | None indexing by extracting formatter_cmds to a local variable

Code Review

No critical issues found. The PR correctly fixes the monorepo config resolution by:

• Comparing package.json and pyproject.toml proximity to CWD using path depth
• Using >= for ties (favoring package.json — preserves backward compat for same-directory cases)
• Both find_package_json() and find_closest_config_file() use the same upward-search-from-CWD algorithm, so the depth comparison is valid

Minor note: The new monorepo resolution logic (lines 92-120) has no test coverage. Consider adding tests for the case where both package.json and pyproject.toml exist at different depths.

Test Coverage

File	Stmts	Miss	Coverage
codeflash/code_utils/config_parser.py	136	50	63%

Overall project coverage: 79%

New lines not covered by tests:

• Lines 99-105: Depth comparison logic when both config files exist
• Lines 108-120: use_package_json branch with formatter validation

⚠️ The new config resolution logic (the core change of this PR) is not exercised by any tests. While the overall file coverage (63%) is below the 75% threshold, most uncovered lines are pre-existing. The PR-specific uncovered code is ~15 lines.

Codeflash Optimization PRs

No optimization PRs have all CI checks passing — none merged.

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Last updated: 2026-02-13T