Used assertRaisesMessage() in template_backends tests.

tests/template_backends/test_utils.py

@@ -3,20 +3,17 @@ from django.template import engines
 from django.test import SimpleTestCase, override_settings
 
 
-class TemplateStringsTests(SimpleTestCase):
+class TemplateUtilsTests(SimpleTestCase):
 
-    @override_settings(TEMPLATES=[{
-        'BACKEND': 'raise.import.error',
-    }])
+    @override_settings(TEMPLATES=[{'BACKEND': 'raise.import.error'}])
     def test_backend_import_error(self):
         """
-        Failing to import a backend keeps raising the original import error.
-
-        Regression test for #24265.
+        Failing to import a backend keeps raising the original import error
+        (#24265).
         """
-        with self.assertRaises(ImportError):
+        with self.assertRaisesRegex(ImportError, "No module named '?raise"):
             engines.all()
-        with self.assertRaises(ImportError):
+        with self.assertRaisesRegex(ImportError, "No module named '?raise"):
             engines.all()
 
     @override_settings(TEMPLATES=[{
@@ -27,13 +24,13 @@ class TemplateStringsTests(SimpleTestCase):
     }])
     def test_backend_improperly_configured(self):
         """
-        Failing to initialize a backend keeps raising the original exception.
-
-        Regression test for #24265.
+        Failing to initialize a backend keeps raising the original exception
+        (#24265).
         """
-        with self.assertRaises(ImproperlyConfigured):
+        msg = 'app_dirs must not be set when loaders is defined.'
+        with self.assertRaisesMessage(ImproperlyConfigured, msg):
             engines.all()
-        with self.assertRaises(ImproperlyConfigured):
+        with self.assertRaisesMessage(ImproperlyConfigured, msg):
             engines.all()
 
     @override_settings(TEMPLATES=[{
@@ -42,5 +39,9 @@ class TemplateStringsTests(SimpleTestCase):
         'BACKEND': 'django.template.backends.django.DjangoTemplates',
     }])
     def test_backend_names_must_be_unique(self):
-        with self.assertRaises(ImproperlyConfigured):
+        msg = (
+            "Template engine aliases aren't unique, duplicates: django. Set "
+            "a unique NAME for each engine in settings.TEMPLATES."
+        )
+        with self.assertRaisesMessage(ImproperlyConfigured, msg):
             engines.all()