IMO, if I ever have 100% code coverage, I did something wrong. The best I can usually achieve is 95-98%, because of my defensive coding to warn about the "impossible" use cases.
Escape a `while True` loop? Log it, along with the current state of the program, and blow up (so we can be restarted). Memory allocation error? Log it. The big "unexpected exception" clause around my main function? Log it.
Escape a `while True` loop? Log it, along with the current state of the program, and blow up (so we can be restarted). Memory allocation error? Log it. The big "unexpected exception" clause around my main function? Log it.
If I do hit those in testing, my code is wrong.