How do i mock patch a nested method call

Question

So this is quite a 'complex' test case i want to tackle.

I have a Django Model, named Store and that store has many methods and fields. I want to test a specific method of the Store Model, beging get_orders(self)

That get_orders(self) method calls on an external API trough an instance of module.

So we have the MarketPlace module. That Marketplace module has several methods like, get_orders(), create_order(), etc.

The Store model has an attribute that is an instance of the Marketplace module and via that route the method is called. How do i test the Store.get_orders(self)?

#/app/stores/models.py

class Store(models.Model):
    store_name = models.CharField(max_length=100, blank=False)
    marketplace_api_key = models.CharField(max_length=100, blank=False)
    
    @property
    def marketplace_instance(self):
        markets = MarketPlace(api_key=self.marketplace_api_key )
        return market

    def get_orders(self):
        # this is the method i want to mock
        open_orders = self.marketplace_instance.get_open_orders()

#/app/controllers/MarketPlace/MarketPlace.py

class MarketPlace(models.Model):
    api_key = models.CharField(max_length=100, blank=False)
    
    def get_open_orders(self):
        url = f'https://marketplace.com/?apikey={self.api_key}'
        r = requests.get(url, headers=headers)
        
        if r.status_code == 200:
            return r.json()
        else:
            return None

#/app/stores/tests/test_models.py

class StoreTests(TestCase):

    @classmethod
    def setUpTestData(cls):
        cls.store = StoreFactory()
        cls.mock_open_order_patcher = patch('controllers.MarketPlace.Marketplace.MarketPlace.get_open_orders')
        cls.mock_open_order = cls.mock_open_order_patcher .start()

    @classmethod
    def tearDown(cls) -> None:
        cls.mock_open_order_patcher .stop()

   def test_get_orders_marketplace(self):
       orders_response = {}
      
       self.mock_open_order.return_value = MagicMock(ok=True)
       self.mock_open_order.return_value.json.return_value = orders_response
       assert self.store.get_orders()       

Answer 1

So it worked...

By doing the test like this:

@patch.object(Store, 'get_orders')
@patch.object(Marketplace, 'get_open_orders')
def test_get_orders_marketplace(self, mock_get_id, mock_get):
    ....