I think you're hitting exactly the problem I was when I tried to quick fix this 😅

😇

I tried to fix this last night and you figured out that second hurdle (which is where I gave up). Nice!

This seems fine to me, but I have no idea what's good/bad for this part of the code.

FWIW this is a related case that I think is also this same bug:

function foo(
    a: number, b: number,
    c: number,
) {
    return a + c;
}

Removing b also behaves the same way. Should we be always preserving the newlines? Or are there cases where this turns out to matter?

I don't mind a targeted fix, of course. Would be great to have this in 4.9.

Thanks for the added tests. I think one could also do the same thing as parameters for type parameters as well. I've modified the PR to eliminate the new parameter (make it always true) and everything passes, which does seem to match my intuition.