Fun article as always. As an added benefit to writing unit tests you might consider its documentation-esque qualities. Say you want to rewrite a module after a while. If sufficient time has passed and you’re a bit like me you’ve forgotten 90% of what you wrote because your brain has since made room for Westworld theories. If your previous you has done a good job defining unit tests that cover particularly hairy edge cases, making sure your new implementation passes these tests can help you remember why these requirements you defined in your tests were important in the first place. Not all tests might still be useful of course, but the general idea tracks.