sjakthol / asynctest-patch-issue-demo Goto Github PK

A project that demonstrates problem in asynctest.mock.patch decorator of the python asynctest library.

• Create a python3 virtualenv and run pip install -r requirements.txt
• Run python test_async.py to see the patching failure
• Run python test_sync.py to see the corresponding behavior of unittest package.

You have an async method in a library (here async_package.gen.generate()) your module calls (here my_package.module.method_async()). When testing your module (test in test_async.py), you want to mock out the call to the external library.

The results are following:

• when patch() is a decorator of the test case, the original method is called instead of the mocked one (patching failed)
• when patch() is used as a context manager, the mocked method is called (correct)

test_sync.py performs a similar test using sync methods and the standard unittest package and there patching works both as a decorator and as a context manager (when used on a sync method).