First pass over generics

[Tinche]

Support generic classes for has and fields.

[Tinche]

@hynek chants dump 3.6, dump 3.6

[hynek]

@Tinche chants coverage, coverage

[hynek]

Do you plan on finishing this up or can I close it?

[Tinche]

This can be merged, it can just be worked on further, but the further work gets a lot more complex. This first step has value on its own.

[hynek]

This cannot be merged because it's breaking CI.

[Tinche]

Ah, oops. Will work on it some more.

[Tinche]

Ok, there's something funky with coverage.

Locally, I'm getting this:

But this is obviously wrong, since if I put an Exception below the if, one test blows up. So the lines are being hit for sure.
Any ideas?

[hynek]

Does it maybe only get hit in a version that doesn't run under coverage?

[Tinche]

This was me running coverage locally, on Python 3.11. Going to try working on this some more.

[Tinche]

Ok, I got it.

Running coverage with this configuration is a little trickier than I thought. I had to run:

❯ rm .coverage*; coverage run -m pytest; and coverage combine;and coverage html;and open htmlcov/index.html

But then I get accurage coverage reports (modulo other Python versions, which are not important here).

Anyway, CI is green now.