Django LiveServerTestCase - Unable to force_login in multiple tests

Question

Versions

• Django version: 1.9
• Python: 3.5
• Django Rest Framework: 3.5.4

Error Observed:

Error
Traceback (most recent call last):
  File "/Users/ds/git/some_repo/integration/test_multiple_login.py", line 32, in test_two
    self.client.force_login(self.user)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/test/client.py", line 608, in force_login
    self._login(user)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/test/client.py", line 621, in _login
    login(request, user)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/contrib/auth/__init__.py", line 117, in login
    user_logged_in.send(sender=user.__class__, request=request, user=user)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/dispatch/dispatcher.py", line 192, in send
    response = receiver(signal=self, sender=sender, **named)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/contrib/auth/models.py", line 23, in update_last_login
    user.save(update_fields=['last_login'])
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/contrib/auth/base_user.py", line 74, in save
    super(AbstractBaseUser, self).save(*args, **kwargs)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/db/models/base.py", line 708, in save
    force_update=force_update, update_fields=update_fields)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/db/models/base.py", line 736, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File "/Users/ds/.pyenv/versions/3.5.7/envs/work_env/lib/python3.5/site-packages/django/db/models/base.py", line 805, in _save_table
    raise DatabaseError("Save with update_fields did not affect any rows.")
django.db.utils.DatabaseError: Save with update_fields did not affect any rows.

Sample Code to reproduce this:

from django.test import TestCase, LiveServerTestCase

from paths.factories import UserFactory


class ATestClass(LiveServerTestCase):

    @classmethod
    def setUpClass(cls):
        """
        Test Data common across all tests
        """

        super().setUpClass()

        cls.user = UserFactory(is_staff=False, is_superuser=False)

    def test_one(self):
        """
        Login and then do some actions
        """
        self.client.force_login(self.user)

        # do something
        self.assertTrue(True)

    def test_two(self):
        """
        Login and do some actions
        """

        self.client.force_login(self.user)

        # do something
        self.assertFalse(False)

What worked?

• If I replace LiveServerTestCase with TestCase it works as expected. However, since I need access to live_server_url I need to inherit from LiveServerTestCase for my use case

Why LiveServerTestCase?

• My Test class needs access to live_server_url.

What have I tried?

• I tried to move force_login statement to setUp method instead of doing the login within the test method - doesn't help
• I tried disconnecting the update_last_login signal user_logged_in.disconnect(update_last_login) - While the signal disconnected, and this allowed the test to progress (i.e. force_login statement in the second test went through without any runtime errors, but actual login failed and the API I was testing, returned 403 forbidden
• I tried setting last_login attribute on self.user object to None before the force_login statement - doesn't help.

But Django version is old

• I know, but for reasons outside of my control, I am not in a position to upgrade Django version. I am looking for some workable patch in my own tests that I can use to get my use case working.