asyncio_mode=auto does not mark static methods

[kriek]

Hi there,

I've migrated from 0.17.2 to 0.18.1 and activated auto asyncio_mode. It seems the mode is not able to apply asyncio marker to static methods.

The following minimized example:

class TestClass:
    @staticmethod
    async def test_static_method():
        await asyncio.sleep(0)

Fails as follows:

$ pytest test_static_method.py
============================================================================ test session starts =============================================================================
platform win32 -- Python 3.8.5, pytest-6.1.2, py-1.9.0, pluggy-0.13.1
rootdir: D:\git\pytest-asyncio, configfile: pytest.ini
plugins: asyncio-0.18.1
asyncio: mode=auto
collected 1 item

test_static_method.py s                                                                                                                                                 [100%]

============================================================================== warnings summary ==============================================================================
test_static_method.py::TestClass::test_static_method
  c:\users\kasyc\appdata\local\programs\python\python38\lib\site-packages\_pytest\python.py:173: PytestUnhandledCoroutineWarning: async def functions are not natively supporte
d and have been skipped.
  You need to install a suitable plugin for your async framework, for example:
    - anyio
    - pytest-asyncio
    - pytest-tornasync
    - pytest-trio
    - pytest-twisted
    warnings.warn(PytestUnhandledCoroutineWarning(msg.format(nodeid)))

-- Docs: https://docs.pytest.org/en/stable/warnings.html
======================================================================= 1 skipped, 1 warning in 0.09s ========================================================================

test_auto_mode.py could easily be extended to cover that extra use case but I am not sure how to adapt pytest_pycollect_makeitem to fix the problem.

As a side note, with 0.17.2, we were doing our own auto mode with the following code and it was working for functions, methods and static methods:

def pytest_collection_modifyitems(items):
    for item in items:
        if isinstance(item, pytest.Function) and inspect.iscoroutinefunction(
            item.function
        ):
            item.add_marker("asyncio")

[seifertm]

Thanks for letting us know! In fact, this has already been reported in #265. We decided to close that issue, because we thought the majority of users can opt to not use static test methods.

Is there any benefit of decorating tests with @staticmethod?

[kriek]

We have expensive pytest fixtures and we are using test classes to make use of "class" fixture scope. With it, we can control precisely when the teardown code is executed inside a test module.
We don't have attributes defined for our classes and using staticmethod is a way to mute the no-self-use pylint warning. We could alternatively have disabled it.

I wouldn't mind if the problem is not fixed, we added an explicit asyncio mark to affected staticmethod tests.

From what I investigated when reporting the issue, while obj is of type <class 'staticmethod'> (as you pointed out in #265), once the item is resolved via item = pytest.Function.from_parent(collector, name=name), inspect.iscoroutinefunction(item.function) == True.

Edit: fixed code sample, inspect.iscoroutinefunction() is to be called on item.function.

[asvetlov]

@kriek would you propose a patch?

[kriek]

I will give it a try.

[kriek]

PR 295 created. I found the staticmethod unwrapping code by inspecting pytest sources.