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Question: how to set fixture and async function same loop? #983
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solved, thx!
How did you solve it?
EDIT: For me it was adding this to
pyproject.toml[tool.pytest.ini_options] asyncio_default_fixture_loop_scope = "session"
And following the docs and adding this to
conftest.py: https://pytest-asyncio.readthedocs.io/en/latest/how-to-guides/run_session_tests_in_same_loop.htmlThat way all the tests run on the same loop as the fixtures (I have session-scoped db fixture that runs migrations, and a function scoped db fixture that wraps everything in a transaction; so I needed everything to run on the same loop).
change
@pytest_asyncio.fixture(scope="session") async def setup_env(): import asyncio loop1 = asyncio.get_running_loop() print(f"setup_env {loop1} - {id(loop1)}") yield
to
@pytest_asyncio.fixture(loop_scope="session") async def setup_env(): import asyncio loop1 = asyncio.get_running_loop() print(f"setup_env {loop1} - {id(loop1)}") yield
this makes
loop1==lop2@scastlara, have you encountered any issues with this approach? I have a similar case:
- A session-scoped fixture for AsyncEngine from SQLAlchemy
- A function-scoped fixture for AsyncSession
- Setting
asyncio_default_fixture_loop_scope = "session"
I'm curious if the approach you mentioned is the best way to handle this, or if there might be a better alternative.
@scastlara, have you encountered any issues with this approach? I have a similar case:
- A session-scoped fixture for AsyncEngine from SQLAlchemy
- A function-scoped fixture for AsyncSession
- Setting
asyncio_default_fixture_loop_scope = "session"
I'm curious if the approach you mentioned is the best way to handle this, or if there might be a better alternative.
Hey @nekeal ! No problems at all.
- In
pyproject.toml
asyncio_default_fixture_loop_scope = "session"
- In
conftest.py
def pytest_collection_modifyitems(items: Any) -> None: """ Make all tests run on the same event loop. This is necessary because our db session is created on the event loop, and we need to ensure all tests run on the same event loop as the db! See: https://pytest-asyncio.readthedocs.io/en/latest/how-to-guides/run_session_tests_in_same_loop.html """ pytest_asyncio_tests = (item for item in items if is_async_test(item)) session_scope_marker = pytest.mark.asyncio(loop_scope="session") for async_test in pytest_asyncio_tests: async_test.add_marker(session_scope_marker, append=False) @pytest.fixture(scope="session", autouse=True) async def prepare_testsuite_db() -> AsyncIterator[None]: """Set up test database and engine.""" engine = create_async_engine(get_database_url()) async with engine.begin() as conn: await conn.run_sync(Base.metadata.drop_all) await conn.run_sync(Base.metadata.create_all) await conn.commit() yield # Then the func scope db fixtures providing a transaction for each test
The testsuite is just as fast as before, no errors at all. Only thing lacking is being able to configure the loop scope of tests in pyproject.toml instead of having to do tricks with pytest hooks. But I think there was an open issue about this and the lib maintainer is fully aware. For now this is sufficient for me.
Reacted by Szymon CaderThank you, @scastlara! I agree that the hook is not an ideal solution, but just to be thorough, I ran a small benchmark. For a test suite consisting of 1,100 synchronous and 820 asynchronous tests, it takes less than a millisecond. So that's a good enough solution 🎉
Reacted by Sergio Castillo and Michael Seifert- locked and limited conversation to collaborators
on Dec 6, 2024
here is my code
test_something.pyand conftest.py
my question is how to make
loop1==loop2