Asynchronous fixtures are defined just like ordinary pytest fixtures, except they should be decorated with @pytest_asyncio.fixture.
All scopes are supported, but if you use a non-function scope you will need to redefine the event_loop fixture to have the same or broader scope. Async fixtures need the event loop, and so must have the same or narrower scope than the event_loop fixture.
auto mode automatically converts async fixtures declared with the standard @pytest.fixture decorator to asyncio-driven versions.