Testing

Installed tools

• Vitest (runner, jsdom environment) + @testing-library/react, @testing-library/jest-dom, @testing-library/user-event.
• Config: vitest.config.ts (jsdom, src/test/setup.ts, #/* and @/* aliases).

Test pyramid

Level	Examples	Where
Unit (pure functions)	core/permissions (hasPermission), core/api/api-error (normalization), core/query/query-keys	*.test.ts next to the file
Component integration	login form (mocked API client)	src/routes/login.test.tsx
E2E / smoke	real login against the dev backend	manual (npm run dev + devtools)

The foundation targets the first two levels; features add their own tests following the same model.

Writing a test

npm test                # vitest run (once)
npm test -- --watch     # watch mode while developing

src/core/permissions/permissions.test.ts

import { describe, expect, it } from 'vitest'
import { hasPermission } from './permissions'

it('grants a present permission', () => {
  expect(hasPermission(['FINANCES.VOIR'], 'FINANCES.VOIR')).toBe(true)
})

UI tests (login)

• The API client is mocked (authApi.login, authApi.me); the session is a real createAuthSession({ tokenStorage: createMemoryTokenStore() }) or a fake session.
• We test: field-error mapping (details[].property → error under the input), French message display, the isSubmitting state.

Don’ts

• ❌ Test implementation details (CSS class snapshots, internals).
• ❌ Real network tests in the Vitest suite (slow, env-dependent).
• ❌ Ignore a failing test — fix it or remove it with justification.