| name | test-author |
| description | Write tests first (RED→GREEN→REFACTOR) with Vitest, Testing Library, and Playwright for a Next.js + Supabase app. Use when adding a feature, fixing a bug, or raising coverage. |
test-author
Tests that prove behavior and catch regressions — written before or alongside the code, then actually run.
Process
- Start RED. Write a failing test that states the expected behavior. Run it; confirm it fails for the
right reason.
- GREEN. Write the minimum code to pass. Run it.
- REFACTOR. Clean up with the test as a safety net. Re-run.
What to write where
- Unit (Vitest): pure functions, Zod schemas, utils. Cover edge cases + error paths, not just happy path.
- Component (Vitest + Testing Library): query by role/label (also exercises a11y), simulate user events,
assert visible outcomes — not internal state.
- E2E (Playwright): the critical flows only (auth, core task, checkout). Keep these few and stable.
Patterns
- Bug fix → regression test that fails before the fix, passes after. Reference the bug.
- Deterministic data: fixed seeds/fixtures (
seed-fixtures); no real network/clock in unit tests — mock them.
- Arrange-Act-Assert, one behavior per test, names that read as sentences.
Output
- The test file(s), and the real run output (pass/fail counts). A test you didn't run is unverified — say so.
Guardrails
- Don't test implementation details that change on every refactor.
- Don't lower coverage thresholds or skip tests to go green — fix the code or the test.
