Protocols in `wsgiref.types` should use `@abstractmethod`

[srittau]

Feature or enhancement

Proposal:

See this discussion in #127648 for reference.

Cc @JelleZijlstra

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

[AlexWaygood]

If it's accepted, I'm not sure this would be backportable -- it could be considered a breaking change. What if a class inherits from one of these protocols but doesn't override one of the methods you're proposing to make abstract?

[srittau]

That is indeed a breaking change, and probably one where there's not good deprecation path. But I also assume that the impact is rather small and would point to actual bugs. But checking the top 1000 or so packages for this would be a good idea.