Missing type annotations in generic class description

[francois-rozet]

Describe the bug

With autodoc_typehints = 'description', the parameter type annotations of the constructor (__init__) of generic classes are missing from the description.

How to Reproduce

With autodoc_typehints = 'description' in conf.py,

from typing import *

#: whatever
T = TypeVar('T')

class Dummy(Generic[T]):
    r"""
    Arguments:
        arg: missing type annotation
    """

    def __init__(self, arg: str):
        pass

results in

in which the type annotation is missing for the arg parameter.

Expected behavior

The type annotations should not be missing.

Your project

N/A

Screenshots

No response

OS

Ubuntu 20.04

Python version

3.8.10

Sphinx version

5.0.2

Sphinx extensions

sphinx.ext.autodoc

Extra tools

No response

Additional context

This issue is probably related to #8219 and #8142.

[robsdedude]

I came across a similar issue with autodoc_typehints = 'description'. I'm working on a PR that will fix this and my issue.

Basically, the resolution doesn't work for constructors when autodoc_typehints = 'description'. So something like

from __future__ import annotations

import typing as t

class Dummy():
    r"""
    Arguments:
        arg: missing type annotation
    """

    def __init__(self, arg: t.Optional[str]):
        pass

will also end up with a wrong type hint. In this case, it will be t.Optional[str] instead of Optional[str] which it'd be for other methods.

[francois-rozet]

Hello @robsdedude, thanks for your PR, I hope it gets merged!

P.S. if you do a lot of rebase, avoid using issue identifiers in the commit message as it creates a lot of notifications 😅

[robsdedude]

Yeah, I just realized 🙈 I'm sorry.

[robsdedude]

So sorry for the pings. I'll change the commit message now for good.