Refs #26666 -- Added ALLOWED_HOSTS validation when running tests.

Also used ALLOWED_HOSTS to check for external hosts in assertRedirects().

1 files changed, 7 insertions, 1 deletions

diff --git a/tests/test_client/tests.py b/tests/test_client/tests.py
index 1c43a2957e..3db42cb1c2 100644
--- a/tests/test_client/tests.py
+++ b/tests/test_client/tests.py
@@ -601,7 +601,13 @@ class ClientTest(TestCase):
         a relevant ValueError rather than a non-descript AssertionError.
         """
         response = self.client.get('/django_project_redirect/')
-        with self.assertRaisesMessage(ValueError, 'unable to fetch'):
+        msg = (
+            "The test client is unable to fetch remote URLs (got "
+            "https://www.djangoproject.com/). If the host is served by Django, "
+            "add 'www.djangoproject.com' to ALLOWED_HOSTS. "
+            "Otherwise, use assertRedirects(..., fetch_redirect_response=False)."
+        )
+        with self.assertRaisesMessage(ValueError, msg):
             self.assertRedirects(response, 'https://www.djangoproject.com/')
 
     def test_session_modifying_view(self):