Add type stubs from typeshed

[nenb]

(WIP, DO NOT MERGE - still waiting for internal review)

Ready for review.

Closes #49

[MarcoGorelli]

nice, just left a comment

[nenb]

@Tinche This is almost ready for a final review.

There is just one outstanding error that is arising from the type-checker that I am not certain about and would appreciate your guidance on.

In text.py, readable appears to be defined as both an async and a sync method. The sync method overwrites the async method, and so in practice it is a sync method. (This is my understanding anyway.)

mypy gets a little confused by redefining an async function by a sync function in this way. I can explicitly ignore it, but I first wanted to check with you whether this is deliberate behaviour?

[nenb]

Oops, I just saw #28! In which case, this PR is ready for review now.

[stankudrow]

Could you possibly separate these "typedefs" with a newline for readability?

[nenb]

Actually, it turns out that the typing style guide recommends to not use blank lines between methods except to group them: https://typing.python.org/en/latest/guides/writing_stubs.html#blank-lines.

I spent a small amount of time trying to override this in ruff but was not successful.

Do you mind very much keeping it the way it is?

[stankudrow]

Actually, it turns out that the typing style guide recommends to not use blank lines between methods except to group them: https://typing.python.org/en/latest/guides/writing_stubs.html#blank-lines.

I spent a small amount of time trying to override this in ruff but was not successful.

Do you mind very much keeping it the way it is?

I don't mind, thanks for the reference.

[stankudrow]

Also, but optional, you can move these pytest options into the pyproject.toml done like here in case you PR goes first.

[stankudrow]

And add the RUF set of rules - https://github.com/Tinche/aiofiles/pull/213/files#diff-50c86b7ed8ac2cf95bd48334961bf0530cdc77b5a56f852c5c61b89d735fd711R141 - just in case and if you like.