> One way I like to consider this is to look back after a bug is found, and ask how many tests would have been needed to detect it. The minimal answer is of cou

> One way I like to consider this is to look back after a bug is found, and ask how many tests would have been needed to detect it. The minimal answer is of course one, but we can't reasonably believe that this exact test would be the next one added. No, you can't. That's why when the bug occurs, you can add that test and then that bug never happens again.