XDG implementation (which is also only used as a fallback when the three DE-specific implementations fail, even though all of them actually support XDG so having separate implementations is pointless)

Yes, the DE-specific implementations is pointless (as far as I know, I use a WM), but the XDG implementation is actually used first, and the function returns true if any impl returns true, like xdg() || gnome() || gnome_old() || kde().

rework the code so that there is a difference between "this DE wants light mode" and "couldn't figure out of this DE is in light or dark mode" - both of these are now represented by the "false" return value.

This isn't that bad? Yes, having an enum with three variants would be better and more readable, but the code just defaults to light mode if nothing wants dark mode, and prefers dark mode even if separate impls want both light and dark mode.

With multiple impls, you have to resolve conflicts somehow. You could, for example, match on current DE/WM name, only using the current DE's impl, defaulting to XDG, avoiding the problem entirely or just use first impl that doesn't return "default" or "error".

I don't like AI generated code, having reviewed some disgusting slop before. But it's better to criticize the code's actual faults, like the incorrect impls (which you listed) or failing the Linux CI.

[–] Markaos@discuss.tchncs.de 3 points 1 day ago

Yes, the DE-specific implementations is pointless (as far as I know, I use a WM), but the XDG implementation is actually used first, and the function returns true if any impl returns true, like xdg() || gnome() || gnome_old() || kde().

True, I must've read the code wrong when making the comment.

This isn't that bad?

Yes, which is why I take issue with a PR (or rather what should have been a PR) that introduces crap code with clearly visible low effort improvements - the submitter should've already done that so the project doesn't unnecessarily gain technical debt by accepting the change.

With multiple impls, you have to resolve conflicts somehow.

Yep, that's why I think it's important for the implementations to actually differentiate between light and fail state - that's the smallest change and allows you to keep the whole detection logic in the individual implementations. Combine that with XDG being the default/first one and you get something reasonable (in a world where the separate implementations are necessary). You do mention this, but I feel like the whole two paragraphs are just expanding on this idea.

But it's better to criticize the code's actual faults (...)

I made a mistake with the order in which the implementations are called, but I consider the rest of the comment to still stand and the criticisms to be valid.