So how would you suggest to reword "Refactored invoice parser" for instance? I'm not asking the system to do anything here: in fact, it would be quite unfortunate if it would start doing anything different from what it does already. No, I'm just stating that this part of the system was a mess since its original creation back in Jurassic period and I just cleaned it up.
That's not how I've normally seen the advice to write imperative commit messages get interpreted. Quoting Documentation/CodingStyle from the Linux kernel (whose commit messages follow that pattern):
Describe your changes in imperative mood, e.g. "make xyzzy do frotz"
instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy
to do frotz", as if you are giving orders to the codebase to change
its behaviour.
Or, if you prefer not to anthropomorphize the codebase (because it hates that), you could also think of it as instructing someone to make the change (and then supplying a patch implementing that instruction).
And a quick search through the Linux kernel git log turns up 1416 messages of the form "subsystem: Refactor ...".
