test-coverage

name	test-coverage
description	Analyze coverage, prioritize untested risk hotspots, generate missing tests, and verify threshold improvements.

Test Coverage

Use this skill to close meaningful coverage gaps, not just raise percentages.

Workflow

1. Run coverage:
   • pnpm test --coverage or npx vitest run --coverage
2. Parse summary and rank low-coverage files by risk:
   • Business-critical logic
   • Error handling paths
   • Security-sensitive branches
3. Generate targeted tests:
   • Unit for pure functions
   • Integration for service/API boundaries
   • E2E for critical user journeys
4. 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, and coverage.thresholds.

References

• Vitest coverage guide: https://vitest.dev/guide/coverage.html
• Vitest coverage config: https://vitest.dev/config/#coverage