Change our mypy configuration to disallow untyped defs by default, which ensures *new* files added to the code base are fully typed.
To avoid having to type-annotate everything now, add `# mypy: allow-untyped-defs` to files which are not fully type annotated yet.
As we fully type annotate those modules, we can then just remove that directive from the top.
Makes `AbstractContextManager` the shared base class between "raises" and other context managers.
The motivation is for type checkers to narrow `pytest.raises(...) if x else nullcontext()` to a `ContextManager` rather than `object`.
The previous typing had an object passed to the user, which they can't
do anything with without asserting, which is inconvenient. Change it to
Any instead.
Note that what comes *back* to pytest (the return value) should be an
`object`, because we want to handle arbitrary objects without assuming
anything about them.
pre-commit-ci[bot]
Bruno Oliveira
Adam J. Stewart
Ilya Konstantinov
Ran Benita