sniffio fails to detect asyncio when run via twisted internet asyncio reactor

[BrynGibson]

I have been experimenting with using httpx as an async http client and have built an api client around this. I have been attempting to run test cases using twisted trial unittests. However running this fails as get an error with sniffio failing to detect that it is within an asyncio event loop.

Here is an example of showing what causes the error.

from twisted.trial import unittest
from foo import APIClientAsync


import asyncio
from twisted.internet import asyncioreactor
asyncioreactor.install(asyncio.get_event_loop())

class TestAPIClient(unittest.TestCase):

    def setUp(self):
        self.client = APIClientAsync()


    async def test_client(self):

        result = await self.client.request()

This will give the following error:

sniffio/_impl.py", line 93, in current_async_library raise AsyncLibraryNotFoundError( sniffio._impl.AsyncLibraryNotFoundError: unknown async library, or not in async context

Is this a known error, or is there any known workaround for this? Or should I switch to a different testing framework to enable asyncio detection?

[A5rocks]

sniffio is ultimately an attempt at standardizing figuring out the current async library. As part of this, things like trio and trio-asyncio have to tell it what is the current async library -- twisted's asyncio support seems like it would require this too? (so this is a feature twisted would have to implement)

I'm not too sure about how twisted does asyncio support under the hood so I won't immediately close this too.

[A5rocks]

Looking at sniffio's code, I'm surprised it doesn't work -- does asyncio.current_task() not work via twisted's asyncio support?