---
description: TDD workflow, 80% coverage minimum, Vitest unit tests, and browser journey verification
alwaysApply: true
---

# Testing Requirements

## Minimum Test Coverage: 80%

Test types:

1. **Unit tests** — pure functions, transformers, validators, stores, utilities (`*.test.ts` / `*.test.tsx`, colocated or `__tests__/`)
2. **Component tests** — Testing Library in packages that already have it (`packages/ui`, `packages/core-events`)
3. **App journeys** — browser verification of `apps/web` flows (login, index / form / detail). There is no Playwright or NestJS E2E suite in this repo.

Runner: **Vitest**. Root command: `pnpm test`. Per-package: `pnpm --filter <pkg> test`. Also `pnpm typecheck` and `pnpm check:all`.

## Test-Driven Development

MANDATORY workflow:

1. Write test first (RED)
2. Run test — it should FAIL
3. Write minimal implementation (GREEN)
4. Run test — it should PASS
5. Refactor (IMPROVE)
6. Verify coverage (80%+)

## Troubleshooting Test Failures

1. Use **tdd-guide** agent
2. Check test isolation
3. Verify mocks are correct (`@repo/core-api` services, HTTP client — not a database)
4. Fix implementation, not tests (unless tests are wrong)

## Agent Support

- **tdd-guide** — Use PROACTIVELY for new features, enforces write-tests-first
- **e2e-runner** — Frontend journeys: Vitest + Testing Library, plus browser verification for `apps/web`
- Skill: `.agents/skills/tdd-workflow/`