Comment by sReinwald
From my experience: TDD helps here - write (or have AI write) tests first, review them as the spec, then let it implement.
But when I use Claude code, I also supervise it somewhat closely. I don't let it go wild, and if it starts to make changes to existing tests it better have a damn good reason or it gets the hose again.
The failure mode here is letting the AI manage both the implementation and the testing. May as well ask high schoolers to grade their own exams. Everyone got an A+, how surprising!
> TDD helps here - write (or have AI write) tests first, review them as the spec
I agree, although I think the problem usually comes in writing the spec in the first place. If you can write detailed enough specs the agent will usually give you exactly what you asked for. If you're spec is vague, it's hard to eyeball if the tests or even the implementation of the tests matches what you're looking for.