Yes, and exceptions. Tests must tickle all the exception paths. An exception that contains a dumb typo crashes the system instead of propagating up to get han

Yes, and exceptions. Tests must tickle all the exception paths. An exception that contains a dumb typo crashes the system instead of propagating up to get handled. Just touching the exception path roots those out. raise ValueError(' '.join('meaningful message with:', parameter) Is a stupid mistake that I still make all too often inside an exception handler.