Support setting the loop_factory in IsolatedAsyncioTestCase

[graingert]

Proposal:

I want to be able to create utility subclasses of IsolatedAsyncioTestCase that use either uvloop or a specific event loop using the asyncio.Runner(..., loop_factory=...) kwarg, Ideally it would look something like:

Another advantage of setting loop_factory would allow use of IsolatedAsyncioTestCase without using def tearDownModule(): asyncio.set_event_loop_policy(None) because asyncio.Runner does not call asyncio.get_event_loop_policy() when called with a loop_factory

class DefaultIsolatedAsyncioTestCase:
    """
    Use the most efficient event loop regardless of what has been configured with asyncio.set_event_loop_policy
    does not require `def tearDownModule(): asyncio.set_event_loop_policy(None)`
    """
    loop_factory = asyncio.EventLoop

or

class UvloopIsolatedAsyncioTestCase:
    """
    runs tests on uvloop
    """
    loop_factory = uvloop.new_event_loop

Has this already been discussed elsewhere?

I have already discussed this feature proposal on Discourse

Links to previous discussion of this feature:

https://discuss.python.org/t/support-setting-the-loop-factory-in-isolatedasynciotestcase/36027

Linked PRs

• gh-110774: allow setting the Runner(loop_factory=...) from IsolatedAsyncioTestCase #110776