Why MagicMock can't be used in 'await' expression?

[heckad]

For example, I have the same code

import asynctest


class SomeAsyncClass:
    async def __aenter__(self):
        pass

    async def __aexit__(self, exc_type, exc_val, exc_tb):
        pass

    async def do_something(self):
        pass


async def method_using_SomeAsyncClass():
    async with SomeAsyncClass() as s:
        return await s.do_something()


@asynctest.patch('test.SomeAsyncClass')
async def test_some_test(some_async_class):
    res = await method_using_SomeAsyncClass()

And it fails with error: TypeError: object MagicMock can't be used in 'await' expression. Why and how to fix it?

[Martiusweb]

MagicMock is not awaitable, and the value returned by the call to __aenter__ is unspecified, thus returns a MagicMock. You need to tell to the mock of SomeAsyncClass what to return in a with statement. In your case, I guess you expect something like "self" thus: some_async_class.__aenter__.return_value = some_async_class() Should work.

…

On Thu, Aug 29, 2019, 16:22 Kazantcev Andrey ***@***.***> wrote: For example, I have the same code import asynctest class SomeAsyncClass: async def __aenter__(self): pass async def __aexit__(self, exc_type, exc_val, exc_tb): pass async def do_something(self): pass async def method_using_SomeAsyncClass(): async with SomeAsyncClass() as s: return await s.do_something() @asynctest.patch('test.SomeAsyncClass') async def test_some_test(some_async_class): res = await method_using_SomeAsyncClass() And it fails with error: TypeError: object MagicMock can't be used in 'await' expression. Why and how to fix it? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#140?email_source=notifications&email_token=AABPWGBP6OXNYPCFFS4LTTTQG7LQ5A5CNFSM4ISC5BO2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4HIG33MQ>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABPWGBXDOQ6BQBA47OKX4LQG7LQ5ANCNFSM4ISC5BOQ> .

[heckad]

It's not work some_async_class.__aenter__.return_value = some_async_class() The rison of this that some_async_class has been pathed. Also this

@asynctest.patch('test.SomeAsyncClass')
async def test_some_test(some_async_class):
    res = await some_async_class.do_something()

doesn't work. Why MagicMock not pathced methods in SomeAsyncClass?