FWIW I do both. I work for a top tier tech company and I write pretty commit messages, test my code, and all that jazz. But for the side-project I do at home? Y

FWIW I do both. I work for a top tier tech company and I write pretty commit messages, test my code, and all that jazz. But for the side-project I do at home? You bet I'm cutting corners. I also think the guts of a TS function don't matter much though. Write a test to confirm the behavior is correct, and then make the return type and argument types correct so that people can call it without hassle. If you need to use 'any' or 'as' inside the function, then go for it.