[heisenzombie]

Yes, perhaps I wasn’t clear — I’m advocating for just the inlined version, not the nested function in the general case.

The nested function is, I think, fine when it’s so tiny it’s not worth unit testing (like, it-could-have-been-a-lambda small) or when bar is returned by foo (ie foo is higher order), in which case you can test the return value. Apart from that… restraint!