testing-anti-patterns

Unit tests often pass while integration fails because they validate mock internals rather than real behavior. Avoid asserting mock behavior and ensure mocks preserve real dependency side effects to catch actual regressions.

To remove test-only methods from production code, migrate test-only cleanup logic and helpers into dedicated test utilities. This prevents polluting production classes and maintains clean separation between production and test logic.

Responsible mocking requires gate checks to understand dependency side effects, create complete mock structures, and mock at the correct level. This prevents over-mocking and incomplete mocks from breaking tests in JavaScript and TypeScript codebases.

Fix fragile tests by rewriting them to assert real behavior, unmocking the component, or moving test-only cleanup into test utilities. This ensures tests reflect real system behavior and remain reliable over time.

Yes, this approach applies when writing or modifying both unit and integration tests. It enforces TDD practices and responsible mocking across JavaScript and TypeScript codebases to prevent validating mock behavior and polluting production code.