Write broken commits for better review

I spend a lot of time reviewing code, and I think it’d be easier if I saw more tastefully broken commits. Commits construct a story about a change: “first this happened, then that, that another thing” is a good narrative; “first everything happened, the end”… not so much. Sometimes, telling that story is impossible without having a commit that breaks tests or doesn’t compile! The principle that usually drives me to commit broken code is making mechanical changes obviously mechanical and mechanically obvious: reformatting, renaming a function or file, re-indenting, … are not “real” changes like adding new code or optimising a loop, and intermixing mechanical & real changes all at once makes verifying either of them hard. If mechanical changes are separate, it’s easy to be sure of huge changes: “yes, this commit is solely running a code formatter on 3k files”. I can literally check out the parent commit, and run the same formatting command, and get the same result. Mechanically obvious!…