Tests Pass but Contain Wrong Assertions That Miss Bugs

Your test suite passes with flying colors but bugs keep reaching production. The tests generated by Claude Code look comprehensive but contain assertions that are too weak, verify the wrong thing, or test implementation details rather than behavior. You have the illusion of safety without the actual protection.

This is more dangerous than having no tests at all because it creates false confidence. Developers merge code because 'all tests pass' without realizing the tests don't actually verify the critical behavior. The test suite becomes expensive to maintain but provides no value.

Common patterns include tests that only check response status codes without verifying response bodies, tests that mock so heavily they're testing the mocks, and tests that assert on object shape but not on computed values.