From 30f2d1af03b1f1e981e8e15151079795914f8f2c Mon Sep 17 00:00:00 2001
From: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Date: Tue, 8 Dec 2020 07:05:49 +0100
Subject: [PATCH] Refs #32233 -- Added tests for nonexistent cache and
 databases aliases.

---
 tests/cache/tests.py    |  5 +++++
 tests/db_utils/tests.py | 28 +++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/tests/cache/tests.py b/tests/cache/tests.py
index 367d2d7119c..dd4d441ad13 100644
--- a/tests/cache/tests.py
+++ b/tests/cache/tests.py
@@ -2499,3 +2499,8 @@ class CacheHandlerTest(SimpleTestCase):
             t.join()
 
         self.assertIsNot(c[0], c[1])
+
+    def test_nonexistent_alias(self):
+        msg = "Could not find config for 'nonexistent' in settings.CACHES"
+        with self.assertRaisesMessage(InvalidCacheBackendError, msg):
+            caches['nonexistent']
diff --git a/tests/db_utils/tests.py b/tests/db_utils/tests.py
index 3ce8e82cd30..ca40d4d1e62 100644
--- a/tests/db_utils/tests.py
+++ b/tests/db_utils/tests.py
@@ -3,7 +3,9 @@ import unittest
 
 from django.core.exceptions import ImproperlyConfigured
 from django.db import DEFAULT_DB_ALIAS, ProgrammingError, connection
-from django.db.utils import ConnectionHandler, load_backend
+from django.db.utils import (
+    ConnectionDoesNotExist, ConnectionHandler, load_backend,
+)
 from django.test import SimpleTestCase, TestCase
 
 
@@ -38,6 +40,30 @@ class ConnectionHandlerTests(SimpleTestCase):
         with self.assertRaisesMessage(ImproperlyConfigured, msg):
             conns['other'].ensure_connection()
 
+    def test_nonexistent_alias(self):
+        msg = "The connection nonexistent doesn't exist"
+        conns = ConnectionHandler({
+            DEFAULT_DB_ALIAS: {'ENGINE': 'django.db.backends.dummy'},
+        })
+        with self.assertRaisesMessage(ConnectionDoesNotExist, msg):
+            conns['nonexistent']
+
+    def test_ensure_defaults_nonexistent_alias(self):
+        msg = "The connection nonexistent doesn't exist"
+        conns = ConnectionHandler({
+            DEFAULT_DB_ALIAS: {'ENGINE': 'django.db.backends.dummy'},
+        })
+        with self.assertRaisesMessage(ConnectionDoesNotExist, msg):
+            conns.ensure_defaults('nonexistent')
+
+    def test_prepare_test_settings_nonexistent_alias(self):
+        msg = "The connection nonexistent doesn't exist"
+        conns = ConnectionHandler({
+            DEFAULT_DB_ALIAS: {'ENGINE': 'django.db.backends.dummy'},
+        })
+        with self.assertRaisesMessage(ConnectionDoesNotExist, msg):
+            conns.prepare_test_settings('nonexistent')
+
 
 class DatabaseErrorWrapperTests(TestCase):