wip: don't mutate lines excluded from coverage

[nedbat]

Written by Claude. I haven't reviewed it.

[nedbat]

This now does what I needed it to do. I had code like this:

match something:
    ...

    case _NEVER:
        raise RuntimeError("Not implemented!")

and I have a coverage setting to exclude case _NEVER: clauses. mutmut was mutating those cases by deleting them, and the tests wouldn't fail, because those cases never ran, as expected.

With this pull request, those cases are not mutated, because the coverage analysis is used to understand that they are excluded.

[nedbat]

This is here to prevent #541 from stopping the run.

[nedbat]

Oops, removed this.

[boxed]

I looked through this a bit and it looks like a good improvement. The tests fail though, I guess that's because of the workaround for #541 ?

[boxed]

Great. This is merge-ready now then? Seems like an improvement over the code on main at least.

[nedbat]

I don't know of a reason not to merge it. I really haven't read the code I'm sorry to say. I understand if you'd want to hold off.