Testing

A four-layer testing strategy — Vitest unit tests, Storybook visual regression, MSW-backed integration tests, and Playwright smoke / full e2e.

The repo's automated test surface splits into four layers, ordered from fastest to slowest:

Layer	Tool	Where	What it catches
Unit	Vitest 4	Co-located `*.test.ts(x)` next to the code	Pure logic, hooks, reducers, route slug parsing
Integration	Vitest + Testing Library + MSW	`apps/web/src/...test.tsx`	Component-level behavior with mocked network
Visual regression	Playwright + Storybook	`apps/web/src/*/.visual.spec.ts` via `playwright.config.ts`	Pixel diff against committed snapshots
End-to-end (smoke)	Playwright	`apps/web/e2e/smoke/`	Unauthenticated + authenticated landing pages on real preview
End-to-end (full)	Playwright	`apps/web/e2e/full/`	Business flows (login, onboarding, chat) on real preview

Each layer is documented in its own page:

Playwright tiers — smoke / full / visual / preview / local configs
Storybook topology — five Storybook installs across the repo
MSW handlers and fixtures — how the mock layer is structured

Vitest unit tests

Unit tests live next to the code under test:

src/lib/foo.ts
src/lib/foo.test.ts

Vitest 4 (catalog) with happy-dom or jsdom as the default environment depending on the package. apps/web uses happy-dom; design-system/ui uses jsdom for features happy-dom doesn't implement (e.g. specific MediaQueryList behavior).

Run via:

pnpm test                            # all projects, via Moon
pnpm --filter @todayai-labs/web test        # one project
pnpm --filter @todayai-labs/web test --watch  # interactive

CI's Unit Tests check runs moon run :test and currently completes in ~30s across 200 test files / 2,095 tests.

Coverage thresholds

Currently not enforced. Tracked as a tier-2 improvement in TODO.md:

Add coverage.thresholds to apps/web/vitest.config.ts and design-system/*/vitest.config.ts so regressions show up in CI rather than only in local reports.

Coverage reports are still generated on demand (pnpm --filter @todayai-labs/web test --coverage), they just don't fail the build.

What this repo does not test

Type-level invariants beyond what TypeScript catches — no tsd / expect-type suites. We rely on tsgo --build for type safety and don't write tests asserting type shape.
Mutation testing — no Stryker. Test quality is judged by reviewers.
Cross-browser smoke — Playwright runs Chromium only. Firefox + WebKit for smoke are queued as a tier-2 improvement.

Each absence is deliberate and revisitable; check TODO.md for the current prioritization.

Vitest unit tests

Coverage thresholds

What this repo does not test

On this page