Unit Testing

Patterns for isolated, maintainable unit tests. Orchestrates jest and react-testing-library -- delegate to them for runner APIs and component queries.

When to Use

• Writing unit tests for frontend or backend code
• Reviewing test coverage, isolation, and structure
• Refactoring an existing test suite

Don't use for:

• Jest syntax and mock APIs -- delegate to jest skill
• React component queries -- delegate to react-testing-library skill
• Integration or E2E test strategy (different scope)

Critical Patterns