pytest_cases.parametrize() makes pytest.mark.anyio not working

[dybi]

import asyncio

import pytest
import pytest_cases


@pytest.fixture
async def bar_1():
    await asyncio.sleep(0.1)
    return 1


@pytest.fixture
async def bar_2():
    await asyncio.sleep(0.1)
    return 2


@pytest.mark.anyio
@pytest_cases.parametrize("bar", [bar_1, bar_2])
async def test_foo(bar):
    result = await bar()
    assert result > 0

the above code produces the following error:

    def async_warn_and_skip(nodeid: str) -> None:
        msg = "async def functions are not natively supported and have been skipped.\n"
        msg += (
            "You need to install a suitable plugin for your async framework, for example:\n"
        )
        msg += "  - anyio\n"
        msg += "  - pytest-asyncio\n"
        msg += "  - pytest-tornasync\n"
        msg += "  - pytest-trio\n"
        msg += "  - pytest-twisted"
>       warnings.warn(PytestUnhandledCoroutineWarning(msg.format(nodeid)))
E       pytest.PytestUnhandledCoroutineWarning: async def functions are not natively supported and have been skipped.
E       You need to install a suitable plugin for your async framework, for example:
E         - anyio
E         - pytest-asyncio
E         - pytest-tornasync
E         - pytest-trio
E         - pytest-twisted

../../.virtualenvs/sf/lib/python3.10/site-packages/_pytest/python.py:172: PytestUnhandledCoroutineWarning

It looks like using pytest_cases.parametrize() would "cancel" pytest.mark.anyio. The order of the decorators doesn't matter - the same error is produced.

Versions:

anyio                 3.6.1
pytest-cases      3.6.13

[smarie]

Thanks @dybi for this issue !
Indeed, the two plugins do not seem compatible. This is probably due to the fact that pytest_cases.parametrize generates a wrapper function around your test function :

python-pytest-cases/src/pytest_cases/fixture_parametrize_plus.py

Lines 1062 to 1085 in ab3b719

	if not isgeneratorfunction(test_func):
	# normal test or fixture function with return statement
	@wraps(test_func, new_sig=new_sig)
	def wrapped_test_func(*args, **kwargs): # noqa
	if kwargs.get(fixture_union_name, None) is NOT_USED:
	# TODO why this ? it is probably useless: this fixture
	# is private and will never end up in another union
	return NOT_USED
	else:
	replace_paramfixture_with_values(kwargs)
	return test_func(*args, **kwargs)
	else:
	# generator test or fixture function (with one or several yield statements)
	@wraps(test_func, new_sig=new_sig)
	def wrapped_test_func(*args, **kwargs): # noqa
	if kwargs.get(fixture_union_name, None) is NOT_USED:
	# TODO why this ? it is probably useless: this fixture
	# is private and will never end up in another union
	yield NOT_USED
	else:
	replace_paramfixture_with_values(kwargs)
	for res in test_func(*args, **kwargs):
	yield res

Today, this wrapper does not intelligently turn into an async wrapper when the wrapped function is an async. It therefore would need to be improved. By the way not sure that makefun supports this in wraps so maybe we would need to upgrade it too first.
If you wish to propose PRs do not hesitate !

[smarie]

Apparently I already implemented support for coroutines in makefun :)
so this should (maybe) be easier after all

https://smarie.github.io/python-makefun/#generators-and-coroutines