Am I one of your patients?

[black-snow]

I just stumbled over an issue with contextvars and async generators in my code. That led me to https://peps.python.org/pep-0568/ and further research brought me here.

I'm not 100% sure this is the actual problem, though - it's about 1 am now and after reading a lot my brain is a bit fried.

Let me describe my issue in code:

from unittest.mock import Mock
import contextvars

async def test_():
    m = Mock()
    cv = contextvars.ContextVar("cv", default={})

    async def dummy_async_method(i: int):
        # wrapped.set_mdc({f"coro{i}": f"coro{i}"})
        cv.set({f"coro{i}": f"coro{i}"})
        m.info(cv.get())
        yield f"c{i}.1"
        # cv({f"coro{i}": f"coro{i}"})  # by setting the var again the test passes
        m.info(cv.get())
        yield f"c{i}.2"

    gen1 = dummy_async_method(1)
    gen2 = dummy_async_method(2)

    # assert expected execution order
    assert await anext(gen1) == "c1.1"
    assert await anext(gen2) == "c2.1"
    assert await anext(gen1) == "c1.2"
    assert await anext(gen2) == "c2.2"

    # assert logger invocations with correct context
    assert m.info.call_args_list[0].args[0] == {"coro1": "coro1"}
    assert m.info.call_args_list[1].args[0] == {"coro2": "coro2"}
    assert m.info.call_args_list[2].args[0] == {"coro1": "coro1"}  # <-- fails here, is coro2: coro2
    assert m.info.call_args_list[3].args[0] == {"coro2": "coro2"}  # this, too, is coro2: coro2

I am like .93 confident I'm in the right place and I'll give extracontent a shot somewhere next week. But perhaps someone's faster.

Was there ever a follow-up to PEP 568? I can't find any plans on fixing this issue.

P. S.:
There's a print in PyContextLocal's constructor - is that intended? ;)
Also, the indentation in the first example here is off. I may file a PR once I caught some sleep.