materialofair Test Coverage
Use this skill to close meaningful coverage gaps, not just raise percentages.
Workflow
- Run coverage:
pnpm test --coverageornpx vitest run --coverage
- Parse summary and rank low-coverage files by risk:
- Business-critical logic
- Error handling paths
- Security-sensitive branches
- Generate targeted tests:
- Unit for pure functions
- Integration for service/API boundaries
- E2E for critical user journeys
- Re-run coverage and report before/after delta.
Coverage Rules
- Use thresholds per project policy; default target can start at 80%.
- Cover meaningful branches and failure modes, not only statements.
- Exclude generated/build/vendor files explicitly.
- Enable all-file analysis when feasible to avoid hidden zero-coverage files.
Vitest Guidance
- Default provider is V8; use Istanbul if project requires instrumentation parity.
- Configure
coverage.include,coverage.exclude, andcoverage.thresholds.
References
- Vitest coverage guide: https://vitest.dev/guide/coverage.html
- Vitest coverage config: https://vitest.dev/config/#coverage