AI-Generated Tests: The Hidden Cost

AI tools are increasingly used to generate tests, but without proper review they introduce hidden costs: redundant test cases, implementation-coupled tests, and duplicated setup code. The post walks through real-world anti-patterns — tests that verify call order instead of behavior, redundant string validation scenarios, and repeated object construction instead of reusing factories. The solution is intentional supervision: guide the AI when it makes mistakes, document desired patterns (e.g., in a CLAUDE.md file), and use frameworks that help plan and provide context. Passing tests and green CI don't guarantee a quality test suite — tests are documentation and must be maintained like production code.