Python - object MagicMock can't be used in 'await' expression

Question

When I was trying to mock an async function in unittest with MagicMock, I got this exception:

TypeError: object MagicMock can\'t be used in \'await\' expr

Answer 1

In python 3.8+ you can make use of the AsyncMock

async def test_that_mock_can_be_awaited():
   mock = AsyncMock()
   mock.x.return_value = 123
   result = await mock.x()
   assert result == 123

The class AsyncMock object will behave so the object is recognized as an async function, and the result of a call is an awaitable.

>>> mock = AsyncMock()
>>> asyncio.iscoroutinefunction(mock)
True
>>> inspect.isawaitable(mock())
True