gistfile1.py

# views.py
from myproject.myfunctions import upload_profile_picture


def profile_picture(request):
    # setup (checking for post, checking if the
    # user is authenticated, etc.)
    user = request.user
    pic_file = request.FILES['profile_picture']
    result_url = upload_profile_picture(pic_file)
    user.profile.picture_url = result_url
    user.profile.save()


# Tests...
import mock
from myproject import views
from django.test.client import RequestFactory


class TestProfileView(TestCase):
    @mock.patch("myproject.views.upload_profile_picture")
    def test_function_is_called(self, mock_obj):
        mock_obj.return_value = "test_url"

        factory = RequestFactory()
        request = factory.post('/customer/details')
        request.FILES = {'profile_picture': 'mocked_file'}

        views.profile_picture(request)

        mock_obj.assert_called_with('mocked_file')