Fix tests stubs

[isra17]

The current typing yield the following error:

error: "Coroutine[Any, Any, AsyncIterator[Any]]" has no attribute "__aiter__" (not async iterable)  [attr-defined]

Related to python/mypy#10301

I also took time to add a typing test for every function in itertools that validate the iterator type. I added a dependency to mypy-type-assets to easily assert the type.

[maxfischer2781]

Good catch. I'll try and review this ASAP.

[maxfischer2781]

As a first glance, can you switch from the MyPy assertion plugin to using typing.assert_type (import it from typing_extensions)? The type checks should also work for PyRight, so a general means is preferable.

[isra17]

As a first glance, can you switch from the MyPy assertion plugin to using typing.assert_type (import it from typing_extensions)? The type checks should also work for PyRight, so a general means is preferable.

I wasn't aware of this new function, done!

[maxfischer2781]

Looks good. The only thing left to do is cleanup of unused dependencies.

[isra17]

Looks good. The only thing left to do is cleanup of unused dependencies.

Sorry, forgot to clean up, done

[maxfischer2781]

This is good to go. Thanks for spotting this issue and for your contribution! 👍