Django ORM - mock values().filter() chain

Question

I am trying to mock a chained call on the Djangos model.Manager() class. For now I want to mock the values() and filter() method.

Answer 1

Try this:

import mock
from mocktest.mockme.models import MyModel

class SimpleTest(TestCase):
    def test_chained_query(self):
        my_model_value_mock = mock.patch(MyModel.objects, 'value')
        my_model_value_mock.return_value.filter.return_value.count.return_value = 10000
        self.assertTrue(my_model_value_mock.return_value.filter.return_value.count.called)

Answer 2

@Gin's answer got me most of the way there, but in my case I'm patching MyModel.objects, and the query I'm mocking looks like this:

MyModel.objects.filter(arg1=user, arg2=something_else).order_by('-something').first()

so this worked for me:

@patch('MyModel.objects')
def test_a_function(mock, a_fixture):
    mock.filter.return_value.order_by.return_value.first.return_value = a_fixture
    result = the_func_im_testing(arg1, arg2)
    assert result == 'value'

Also, the order of the patched attributes matters, and must match the order you're calling them within the tested function.