gh-84753: Make inspect.iscoroutinefunction() work with AsyncMock

[sileht]

The inspect version was not working with unittest.mock.AsyncMock.

This change moves the asyncio fix for AsyncMock in inspect module and
make asyncio.iscoroutinefunction an alias of inspect.iscoroutinefunction.

• Issue: inspect.iscorutinefunction() returns False for unittest.mock.AsyncMock instances #84753

[ghost]

All commit authors signed the Contributor License Agreement.

[bedevere-bot]

Most changes to Python require a NEWS entry.

Please add it using the blurb_it web app or the blurb command-line tool.

[sileht]

@vstinner Can you take a look?

[graingert]

this shouldn't be needed AsyncMock already sets

cpython/Lib/unittest/mock.py

Lines 2175 to 2178 in 5fcfdd8

	code_mock = NonCallableMock(spec_set=CodeType)
	code_mock.co_flags = inspect.CO_COROUTINE
	self.__dict__['__code__'] = code_mock

[cjw296]

Why is this here instead of re-using asyncio.coroutines._is_coroutine?

[sileht]

I moved it from asyncio to inspect as the code using it is now located in inspect module.

[cjw296]

_is_coroutine feels like a property of asyncio, not inspect. I think it should stay where it is.

[sileht]

this shouldn't be needed AsyncMock already sets

cpython/Lib/unittest/mock.py

Lines 2175 to 2178 in 5fcfdd8

	code_mock = NonCallableMock(spec_set=CodeType)
	code_mock.co_flags = inspect.CO_COROUTINE
	self.__dict__['__code__'] = code_mock

The test cases I added passed was passing for asyncio version, but was not for the inspect version. So something doesn't work as expected.

[graingert]

looks like this issue is because mock.AsyncMock() doesn't pass inspect.isfunction:

from unittest import mock
import inspect

m = mock.AsyncMock()
with mock.patch("inspect.isfunction", new=lambda x: True):
    assert inspect.iscoroutinefunction(m)

Originally posted by @graingert in #84753 (comment)

[graingert]

Could CallableMixin mess about with __instancecheck__/__subclasscheck__/__class__ to pass isinstance(AsyncMock(), types.FunctionType)?

[sileht]

Could CallableMixin mess about with __instancecheck__/__subclasscheck__/__class__ to pass isinstance(AsyncMock(), types.FunctionType)?

I tried but this doesn't seem to work, I suspect this fall in isinstance C optimisation and __instancecheck__ and friends are never called.

[graingert]

I'm relying on inspect.iscoroutinefunction to reveal things that really really are Coroutine Functions, partials or methods and asyncio.iscoroutinefunction to reveal things that are Duck typed as a Coroutine Function

[sileht]

I'm relying on inspect.iscoroutinefunction to reveal things that really really are Coroutine Functions, partials or methods and asyncio.iscoroutinefunction to reveal things that are Duck typed as a Coroutine Function

According to the doc, the only difference is asyncio.iscoroutinefunction also works for deprecated generator based coroutine
This legacy coroutine will(have ?) be removed for 3.11, so now both functions should be the same.

[sileht]

But, I agree that my solution doesn't work. We should keep the _is_coroutine hack as-is until generated coroutine are removed and found another solution to make isfunction pass for AsyncMock().

[sileht]

I found another solution, I think it's cleaner.

[vstinner]

Can you try to preserve current coding style? Return early with False if a condition is false? Pseudo-code:

if not isfunction(f): return False
if not _signature_is_functionlike(f): return False
return bool(f.__code__.co_flags & flag)

[sileht]

done

[miss-islington]

Thanks @sileht for the PR, and @ambv for merging it 🌮🎉.. I'm working now to backport this PR to: 3.10, 3.11.
🐍🍒⛏🤖

[bedevere-bot]

GH-94460 is a backport of this pull request to the 3.11 branch.

[bedevere-bot]

GH-94461 is a backport of this pull request to the 3.10 branch.

[sileht]

Thanks all! That was fast 🚀

[tirkarthi]

This change seems to have caused a regression reported in #96127