Coverage Check

Context

Run in parallel:

• git diff --name-only - get unstaged files
• git diff -U0 --no-color - get changed line numbers

Commands

Sequential:

1. npm run test:ci - vitest with coverage
2. npm run coverage:report - generate lcov/text reports

Workflow

1. Get unstaged files and line ranges (parallel):
   • git diff --name-only
   • git diff -U0 --no-color
2. Run coverage:
   • npm run test:ci
   • npm run coverage:report
3. Save diff to a temp file, then run:

   git diff -U0 --no-color > /tmp/changes.diff
   python3 scripts/parse-lcov.py --lcov coverage/lcov.info --diff /tmp/changes.diff
   

   See lcov-format.md for lcov format details.
4. Report uncovered lines from stdout: file.ts:42
5. Summary from stderr: X/Y changed lines covered

Rules

• Only analyze unstaged changes (git diff)
• Use sequential commands: test:ci then coverage:report
• Use scripts/parse-lcov.py to parse lcov data and map to changed lines
• Report uncovered lines: file.ts:42
• Ignore files without coverage data (non-code files)

Error Handling

• If npm run test:ci fails → report test failures and stop; coverage cannot be generated with failing tests
• If coverage/lcov.info not found after test run → verify coverage.reporter includes lcov in the test runner config
• If git diff returns no changes → report no unstaged changes to check