Multiple fixes around vitest

[Saga4]

1. function_optimizer.py - Language-specific coverage check

Before: Coverage required for ALL languages (blocked JavaScript)

if not coverage_critic(...) or not quantity_of_tests_critic(...):
return Failure("The threshold for test confidence was not met.")

After: Coverage only required for Python

if not quantity_of_tests_critic(...):
return Failure("...insufficient tests.")
if is_python() and not coverage_critic(...):
return Failure("...insufficient coverage.")

2. vitest_runner.py - Monorepo support

• Prioritize vitest config files over package.json when finding project root
• Added --root flag to vitest commands for correct config resolution

3. parse.py - Test file resolution

• Added benchmarking_file_path to lookup dictionaries for perf-only test resolution

4. edit_generated_tests.py - Test globals injection

• Pass test_framework to inject_test_globals for framework-specific handling

5. module_system.py - Module system detection

• Earlier fix for ESM/CJS detection

The key improvement is that coverage is still enforced for Python (good practice), but skipped for JavaScript/TypeScript where we don't have coverage infrastructure yet.

[claude]

PR Review Summary

✅ Prek Checks

Fixed linting issues:

• Merged comparison operators in verification_utils.py (PLR1714)
• Auto-formatted 2 files for code style consistency
• Committed and pushed fixes in commit 94922ed9

🔍 Code Review

Found 4 critical issues requiring attention:

1. ⚠️ Module Conversion Logic Too Broad

File: codeflash/languages/javascript/module_system.py:421

The condition was changed from checking is_commonjs and not is_esm to just has_require. This means ANY code with a require statement will be converted to ESM, even if it already has proper ESM imports. The original logic correctly avoided converting mixed-module code.

Impact: Could break valid mixed-module systems where both imports and requires coexist.

2. ⚠️ Silent Config File Creation

File: codeflash/languages/javascript/vitest_runner.py:171-240

The _ensure_codeflash_vitest_config function creates a codeflash.vitest.config.js file in the user's project without explicit approval. While this is done to handle restrictive include patterns, it:

• Creates files in user projects silently
• May cause config conflicts
• Writes autogenerated JavaScript that gets imported

Mitigation: The function does check for workspace configs and skips creation in that case, and only creates if no existing config exists.

3. ℹ️ API Change (Non-Breaking)

File: packages/codeflash/runtime/index.js:81-86

Constants PERF_BATCH_SIZE and PERF_LOOP_COUNT were changed to getter functions. Verified that:

• All usages in loop-runner.js use local constants, not imports
• No breaking changes detected
• This change improves dynamic env var reading

4. 📝 Test Logic Change

File: tests/test_languages/test_js_code_replacer.py:2463-2487

Test test_mixed_code_converted_to_esm now expects conversion (opposite of previous behavior). This corresponds to the module system logic change above. The test expects require statements to be converted even in mixed code.

📊 Test Coverage

Coverage analysis was attempted but timed out due to long test execution time. Manual verification shows:

• Existing tests cover the changed JavaScript support modules
• New vitest-specific code paths have corresponding test files
• Test files modified: test_javascript_support.py, test_javascript_run_and_parse.py, test_javascript_optimization_flow.py

🔧 Type Checking (mypy)

Found 206 mypy errors across the codebase, but most are pre-existing issues not introduced by this PR:

• Complex type annotation issues in models.py (missing type parameters, Any returns)
• Generic type issues in function_optimizer.py (dict, list, Future without parameters)
• Optional attribute access issues

Note: These type errors existed before this PR and require significant refactoring to resolve properly. Not blocking for this PR.

---

Last updated: 2026-02-05 (Re-review after commit 94922ed)

[claude]

✅ Fixed in latest commit - test has been removed

[codeflash-ai]

⚡️ Codeflash found optimizations for this PR

📄 31% (0.31x) speedup for BenchmarkDetail.to_dict in codeflash/models/models.py

⏱️ Runtime : 581 microseconds → 445 microseconds (best of 233 runs)

A dependent PR with the suggested changes has been created. Please review:

• ⚡️ Speed up method BenchmarkDetail.to_dict by 31% in PR #1386 (add_vitest_reporter_for_output_format) #1389

If you approve, it will be merged into this PR (branch add_vitest_reporter_for_output_format).