unittest.TestCase setUpClass override and inheritance

Question

As can be seen in the following example, I've defined a BaseClass for all tests, each test case class inherits the base class.

Both classes needs to perform a one time initialization, when test_vehicles.py is executed, I need to make sure that setUpClass of the base class is invoked as well, not sure how to achieve that where @classmethod is in play.

# base.py
import unittest

class BaseClass(unittest.TestCase):
   @classmethod
   def setUpClass(cls):
       # initialize stuff 
       cls.app = app

---

# test_vehicles.py
class VehiclesTestCase(BaseClass):

    @classmethod
    def setUpClass(cls):
        # initialize stuff 
        cls.vehicle_id = '123'

    def test_get_vehicle(self):
       resp = self.app.get(self.vehicle_id)
       self.assertEqual(resp, True)



if __name__ == '__main__':
    unittest.main()

Answer 1

Similar question Using super with a class method . More information yoou can get also from https://docs.python.org/3/library/functions.html#super .

Solution: use super function and bound to the class

# test_vehicles.py
class VehiclesTestCase(BaseClass):

    @classmethod
    def setUpClass(cls):
        super(VehiclesTestCase, cls).setUpClass()
        cls.vehicle_id = '123'


if __name__ == '__main__':
    unittest.main()

Answer 2

You can use the super method in the inherited classes' setUpClass to access the setUpClass of BaseClass :

super().setUpClass()

If you don't want to call super in each child class, just create an abstract method in BaseClass and call it in setUpClass of BaseClass . VehiclesTestCase now has to implement this abstract method:

class BaseClass(unittest.TestCase):
   @classmethod
   def setUpClass(cls):
       # initialize stuff 
       cls.app = app

   @classmethod
   def _setUpChild(cls):
       raise NotImplementedError


class VehiclesTestCase(BaseClass):

    @classmethod
    def _setUpChild(cls):
        # initialize stuff 
        cls.vehicle_id = '123'

    def test_get_vehicle(self):
       resp = self.app.get(self.vehicle_id)
       self.assertEqual(resp, True)

I would also recommend that BaseClass is not a TestCase if it cannot run by itself. It would always show up in your test report although it has no tests. You can instead use multi-inheritance:

class BaseClass:
   # Stuff

class VehiclesTestCase(BaseClass, unittest.TestCase):
   # Stuff

The order of inheritance is important. Method lookup is done from left to right. This means that BaseClass.setUpClass overrides the setUpClass of TestCase .