Config for default test `loop_scope`?

[BryceCicada]

pytest-asyncio v0.24 supports independent event-loop scopes and fixture caching scopes. This is great, thank you. However, I had some confusion while working with this. I thought I'd share in case there's an elegant solution I've not spotted.

The following works fine:

import asyncio
import pytest
import pytest_asyncio

loop: asyncio.AbstractEventLoop | None = None


@pytest_asyncio.fixture(loop_scope="session")
async def loop_fixture():
    global loop
    loop = asyncio.get_running_loop()


@pytest_asyncio.fixture(loop_scope="session", scope="function")
async def another_fixture():
    return "foo"


@pytest.mark.asyncio(loop_scope="session")
async def test_a(loop_fixture, another_fixture):
    global loop
    assert loop == asyncio.get_running_loop()
    assert another_fixture == "foo"

and with a minor change I've convinced myself that another_fixture really is function-scoped. All good.

However, if I have pyproject.toml containing:

[tool.pytest.ini_options]
asyncio_default_fixture_loop_scope = "session"

my initial (hopeful) expectation was that I would not need to write loop_scope="session" everywhere, but this is mistaken:

import asyncio
import pytest
import pytest_asyncio

loop: asyncio.AbstractEventLoop | None = None


@pytest_asyncio.fixture
async def loop_fixture():
    global loop
    loop = asyncio.get_running_loop()


@pytest_asyncio.fixture(scope="function")
async def another_fixture():
    return "foo"


@pytest.mark.asyncio
async def test_a(loop_fixture, another_fixture):
    global loop
    assert loop == asyncio.get_running_loop()
    assert another_fixture == "foo"

with error:

E   pytest_asyncio.plugin.MultipleEventLoopsRequestedError: Multiple asyncio event loops with different scopes have been requested

Of course, the solution is to omit loop_scope="session" only the fixtures, but keep it on the test function itself like:

@pytest.mark.asyncio(loop_scope="session")
async def test_a(loop_fixture, another_fixture):
    ...

but in a suite of many tests, it's boilerplate.

I've understood asyncio_default_fixture_loop_scope was intended to relieve such boilerplate on the fixtures, but is there something similar possible for the tests themselves? I know I could write a hook to add this marker to the tests, but my gut feeling says this magic would confuse later. On the other hand, I could imagine some config like asyncio_default_test_loop_scope... is there something neat I've missed?

[BryceCicada]

I see this is already under thought at #793.

[BryceCicada]

I've gone with:

• A hook to add local_scope="session" to tests, and additionally
• Added config asyncio_mode = "auto" so I can remove @pytest.mark.asyncio from tests to further reduce the boilerplate.

I'll keep an eye on #793. Closing this.