majiayu000 Unit Testing Skill
When to Use
- Writing unit tests for frontend or backend
- Reviewing test coverage and isolation
- Refactoring test structure
Critical Patterns
Frontend
- Use RTL for user-centric tests
- Mock dependencies and hooks
- Test UI logic in isolation
Backend
- Use Jest for logic isolation
- Mock I/O and external services
- Test pure functions and modules
Decision Tree
- UI or logic? → Use RTL or Jest
- Need mocks? → Use jest.mock or manual mocks
- Async code? → Use async/await in tests
Edge Cases
- Flaky async tests
- Mocking native modules
- Coverage gaps