Testing Preferences

# Testing

- Write tests with [vitest/jest/pytest]
- Use descriptive test names: "should [expected behavior] when [condition]"
- Prefer integration tests over unit tests for API routes
- Mock external services, never mock internal modules
- Run tests before committing: `npm test`
- Minimum coverage: 80% for new code

# Test Structure

- Place tests next to source files as `*.test.ts`
- Use `describe` blocks to group related tests
- Use `beforeEach` for shared setup, avoid `beforeAll`