Review: Test Quality

For Vitest configuration validation (pool options, coverage setup, deprecated patterns), see vitest-4/skills/reviewing-vitest-config/SKILL.md .

Checklist

Test Coverage

• Components have tests for user interactions

• Forms test both success and error paths

• Server Actions tested in isolation

• Custom hooks tested with renderHook

• Edge cases covered (empty states, errors, loading)

React 19 APIs

• Forms using useActionState have tests

• useOptimistic updates tested for immediate feedback

• useFormStatus tested within form component context

• Server Actions tested with mocked auth/database

• use() hook tested with Promises and Context

Testing Patterns

• Using @testing-library/react and @testing-library/user-event

• Queries prefer accessibility (getByRole , getByLabelText )

• waitFor used for async assertions

• Mocking external dependencies (API, database)

• Tests are isolated and don't depend on each other

Anti-Patterns

• ❌ Testing implementation details (internal state, methods)

• ❌ Querying by class names or data-testid when role available

• ❌ Not waiting for async updates (waitFor )

• ❌ Testing components without user interactions

• ❌ Missing error case tests

Server Action Testing

• Server Actions tested as functions (not through UI)

• Input validation tested

• Authentication/authorization tested

• Database operations mocked

• Error handling tested

For typed test fixtures and mocks, use the TYPES-generics skill from the typescript plugin.

For comprehensive testing patterns, see: research/react-19-comprehensive.md .