How to supply a mock class method for python unit test?

Question

Let\'s say I have a class like this.

   class SomeProductionProcess(CustomCachedSingleTon):

       def loaddata():
           \"\"\"
           Uses an iterator         


        

Answer 1

To easily mock out a class method with a structured return_value, can use unittest.mock.Mock.

from unittest.mock import Mock

mockObject = SomeProductionProcess
mockObject.loaddata = Mock(return_value=True)

EDIT:

Since you want to mock out the method with a custom implementation, you could just create a custom mock method object and swap out the original method at testing runtime.

def custom_method(*args, **kwargs):
    # do custom implementation

SomeProductionProcess.loaddata = custom_method