Spy on function

[Rachel-Rabinowitz]

I have something like this:

def C():
     # some logic
     return something

def B():
     # some logic
     return C()

def A():
     b = B()
     # some logic

I want to test A and mock the return value of C
Is there any way to do that?

[nicoddemus]

Hi @Rachel-Rabinowitz,

Yes, you have to mock C in the module which contains B. Supposing they are all in the same module, app.module, you would go like this using pytest-mock:

def test_a(mocker):
    mocker.patch("app.module.C", return_value=42)
    ...

[Rachel-Rabinowitz]

That is what I tried first but it didn't work,
the reason was that I used it via module,
I had an init.py with import *
probably the run was with full relative path

Thanks for the answere