Reviewing Test Quality

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.