testing-anti-patterns

Testing anti-patterns include verifying mock behavior instead of real component logic, adding test-only methods to production code, and over-mocking without understanding dependencies. Review your unit, integration, and end-to-end tests against these three core violations to catch brittle tests early.

Testing mock behavior creates false confidence—you're validating the mock's configuration, not your actual code. This iron law prevents brittle tests that pass despite production failures. Always test real component behavior and dependencies instead.

Smart mocking uses mocks with complete, realistic data structures after understanding your actual dependencies. Over-mocking adds unnecessary mocks with incomplete setups, making tests misleading and harder to maintain. Gate every mock decision against genuine dependency needs.

Test-only methods violate the separation of concerns and complicate production logic. Before adding any test-specific code or gate functions, confirm the dependency truly requires it. This iron law keeps production classes focused and maintainable.

Yes. The three iron laws—never test mock behavior, never add test-only production methods, never mock without understanding dependencies—apply consistently across unit, integration, and end-to-end tests in production-like environments for uniform test quality.

Brittle tests fail unpredictably during refactoring despite correct logic, and false confidence from mock-behavior testing masks real production bugs. Poor testing practices create maintainability nightmares and erode code reliability over time.