Testing Strategy

Test Pyramid

• Unit tests: service logic (fast, isolated)
• Integration tests: repo + in-memory DB
• API tests: FastAPI TestClient

Current examples: - tests/test_users_service.py - tests/test_users_repo.py - tests/test_users_api.py

Run Tests

pytest -q

Service Unit Test Example

with pytest.raises(ConflictError):
    service.create_user(UserCreate(email="john@example.com", full_name="John"))

DO

• Keep service tests independent from DB.
• Use in-memory SQLite for repo integration tests.
• Test endpoint status and response contracts.

DON'T

• Mock everything in repo tests.
• Assert implementation details instead of behavior.

Common Mistakes

• Writing only API tests and skipping business-rule unit tests.
• Sharing mutable test database state across test modules.

When to Break the Rule

End-to-end tests may use real DB containers for critical flows, but keep unit/integration suite as fast gate.