aselimc Test Pyramid
Structure
/ E2E \ <- Few, slow, test critical paths
/ Integration\ <- Medium, test component interactions
/ Unit \ <- Many, fast, test logic in isolation
Frameworks
| Language | Unit | Integration | E2E |
|---|---|---|---|
| Python | pytest | testcontainers, pytest | Playwright |
| JS/TS | vitest, jest | supertest | Playwright, Cypress |
| ROS2 | pytest | launch_testing | - |
Coverage
- Target 80%+ for critical business logic
- Don't chase 100% - diminishing returns
- Measure branch coverage, not just line coverage
Fixture Patterns
- Mock external services only (APIs, DBs, queues)
- Never mock internal logic (defeats the purpose)
- Use factories (factory_boy, fishery) over raw fixtures
- Testcontainers for real database integration tests
Key Libraries
pytest, jest, vitest, Playwright, testcontainers