Agreed - given a complete and correct test suite! But even so, "correct" code is not necessarily efficient or readable code. And note that writing the complete

Agreed - given a complete and correct test suite! But even so, "correct" code is not necessarily efficient or readable code. And note that writing the complete and correct test suite is likely to be a task of similar difficulty to designing and writing good code! I'm not saying don't test, but I am saying that non-trivial testing is difficult.