A pretty reasonable test would be that some function panics on invalid input, in this case by way of integer overflow. This test would pass in a debug build, bu

A pretty reasonable test would be that some function panics on invalid input, in this case by way of integer overflow. This test would pass in a debug build, but could cause unintended, possibly even insecure, behavior in a release build. Ideally you would run your tests in both debug and release modes, though. :)