asyncio_mode deprecation warning is emitted for test suites that don't use aiohttp at all about pytest-aiohttp

[seifertm]

This is probably best addressed in pytest-asyncio.

Related issue:
pytest-dev/pytest-asyncio#293

[Dreamsorcerer]

I think this is really a design issue with pytest. All pytest plugins are implicitly loaded, so you are using it, simply by having it installed.

Furthermore, the default behaviour as mentioned in that warning is to enable support for any async tests, it has nothing to do with whether aiohttp is used or not.

[mgorny]

I agree. It's been reported a long time ago but unfortunately there's very little we can do at this point. I mean, I'm pretty sure you can imagine the fallout if plugins suddenly started needing to be enabled explicitly.

Hmm, I wonder if patching pytest-asyncio to default to auto would break stuff…

[Dreamsorcerer]

Surely it would, as the previous behaviour was always to require a decorator, so it would change the behaviour for everyone who has not configured the setting.

I believe the option was added to both projects in order to make them compatible, at this point I assume both projects do the same thing with very little differences.

I don't think there's anything to fix here though. The approach used by projects like pytest and flake8 which load plugins implicitly is to recommend using virtualenv etc. in order to only install plugins for each project you are working on, rather than installing them globally. So, I can only recommend the same, even if I dislike the approach myself.

[mgorny]

Unfortunately, using a virtualenv doesn't guarantee that the project will actually work in the production environment. The only way to do that is to run tests in exactly the same environment as the actual package will run.

[Dreamsorcerer]

Pretty sure they'd just recommend using a virtualenv in production too. Docker containers are also pretty popular these days too.

I believe the option was added to both projects in order to make them compatible, at this point I assume both projects do the same thing with very little differences.

Actually, just looked again, and it actually migrated to using pytest-asyncio. So, this project just changes the default unconfigured state to auto for backwards compatibility, and adds some fixtures.

[Dreamsorcerer]

I think another option would be to uninstall pytest-aiohttp, and use aiohttp.pytest_plugin explicitly. This seems to be what core aiohttp itself does: https://github.com/aio-libs/aiohttp/blob/master/tests/conftest.py#L31