Fixed #29258 -- Added type checking for login()'s backend argument.

1 files changed, 9 insertions, 0 deletions

diff --git a/tests/auth_tests/test_auth_backends.py b/tests/auth_tests/test_auth_backends.py
index 1a1950e989..25a910cdf1 100644
--- a/tests/auth_tests/test_auth_backends.py
+++ b/tests/auth_tests/test_auth_backends.py
@@ -695,6 +695,15 @@ class SelectingBackendTests(TestCase):
         with self.assertRaisesMessage(ValueError, expected_message):
             self.client._login(user)
 
+    def test_non_string_backend(self):
+        user = User.objects.create_user(self.username, 'email', self.password)
+        expected_message = (
+            'backend must be a dotted import path string (got '
+            '<class \'django.contrib.auth.backends.ModelBackend\'>).'
+        )
+        with self.assertRaisesMessage(TypeError, expected_message):
+            self.client._login(user, backend=ModelBackend)
+
     @override_settings(AUTHENTICATION_BACKENDS=[backend, other_backend])
     def test_backend_path_login_with_explicit_backends(self):
         user = User.objects.create_user(self.username, 'email', self.password)