False Context manager 'async_generator' doesn't implement __enter__ and __exit__

[davetapley]

Bug description

# repro.py

# inspired by:
# https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager

import time
from contextlib import asynccontextmanager


@asynccontextmanager
async def timeit():
    now = time.monotonic()
    try:
        yield
    finally:
        print(f'it took {time.monotonic() - now}s to run')


with timeit():
    print('hello world')

Configuration

Command used

pylint repro.py

Pylint output

repro.py:14:0: E1129: Context manager 'async_generator' doesn't implement __enter__ and __exit__. (not-context-manager)

Expected behavior

No error.

Pylint version

pylint 3.3.1
astroid 3.3.10
Python 3.12.2 (main, Feb 25 2024, 04:38:01) [Clang 17.0.6 ]

OS / Environment

No response

Additional dependencies

[cdce8p]

timeit is an async context manager so you'll need to use async with.

async def main():
    async with timeit():
        print('hello world')

Technically the error message is correct since @asynccontextmanger only implements __aenter__ and __exit__. Maybe a different error message would be more helpful here? Something like "timeit is an async context manager, you'll need to use async with".