Testing Strategy

Testing Strategy

Stack

Tool	Role
Vitest	Runner (vitest.config.ts)
jsdom	DOM environment
Testing Library	renderHook, render, screen, act
v8 coverage	npm run test:coverage → Codecov in CI

Tests live next to hooks: src/hooks/*.test.ts / .tsx. Playground code is not unit-tested; it is validated by playground:build in CI and on pre-push.

What to cover

• Happy path return values and option defaults
• SSR / no-window defaults where relevant
• Effect cleanup (listeners, intervals, observers)
• Async dialogs: render render() from the hook and assert UI + promise resolution
• Edge cases: empty lists, paused timers (null delay), invalid keys

Prefer behavior over implementation details. Do not assert internal refs or private module state.

Gates

• pre-commit / CI: verify:commit runs test:coverage (and lint, typecheck, build)
• Codecov: uploads coverage/lcov.info from CI
• There is no Playwright / E2E suite — browser APIs are exercised under jsdom where practical

Commands

npm test
npm run test:coverage
npm run test:watch