How to mock.patch a class imported in another module

Question

I have a python class with such a module:

xy.py

from a.b import ClassA  class ClassB:   def method_1():     a = ClassA()     a.method2() 

then I have ClassA defined as:

b.py

from c import ClassC  class ClassA:   def method2():       c = ClassC()       c.method3() 

Now in this code, when writing test for xy.py I want to mock.patch ClassC, is there a way to achieve that in python?

obviously I tried:

mock.patch('a.b.ClassA.ClassC') 

and

mock.patch('a.b.c.ClassC') 

None of these worked.

Answer 1

You need to patch where ClassC is located so that's ClassC in b:

mock.patch('b.ClassC') 

Or, in other words, ClassC is imported into module b and so that's the scope in which ClassC needs to be patched.