AI Writes Tests Fast, But Often Tests the Wrong Thing, Developers Warned

AI tools can generate dozens of unit tests within seconds, giving developers a false sense of security through high coverage scores and passing results. The core problem is that AI reads a function's current implementation and writes tests to match it, rather than verifying the intended behavior or contract. This means bugs that break expected behavior can slip through undetected, since the tests were never designed to catch them in the first place. AI does offer genuine productivity gains in narrower tasks — such as generating boilerplate, parameterized inputs, and additional boundary cases once a developer has already defined the test contract. The key distinction is whether the developer or the AI is deciding what 'correct' means, as handing that judgment to AI is where test quality breaks down.