From c2c85663e2dd06c9ed9c9ec2d02202d6d668d7f0 Mon Sep 17 00:00:00 2001
From: Benjy Weinberger <benjyw@gmail.com>
Date: Wed, 9 Jan 2019 10:58:25 -0500
Subject: [PATCH] Fixed #30087 -- Tested error handling for empty 'default'
 database.

---
 tests/db_utils/tests.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tests/db_utils/tests.py b/tests/db_utils/tests.py
index 4e35e6bb8b..a6cfb43667 100644
--- a/tests/db_utils/tests.py
+++ b/tests/db_utils/tests.py
@@ -10,8 +10,18 @@ from django.test import SimpleTestCase, TestCase
 class ConnectionHandlerTests(SimpleTestCase):
 
     def test_connection_handler_no_databases(self):
-        """Empty DATABASES setting defaults to the dummy backend."""
-        DATABASES = {}
+        """
+        Empty DATABASES and empty 'default' settings default to the dummy
+        backend.
+        """
+        for DATABASES in (
+            {},  # Empty DATABASES setting.
+            {'default': {}},  # Empty 'default' database.
+        ):
+            with self.subTest(DATABASES=DATABASES):
+                self.assertImproperlyConfigured(DATABASES)
+
+    def assertImproperlyConfigured(self, DATABASES):
         conns = ConnectionHandler(DATABASES)
         self.assertEqual(conns[DEFAULT_DB_ALIAS].settings_dict['ENGINE'], 'django.db.backends.dummy')
         msg = (