chore: complete test coverage

Author: dopry

tests/test_oauth2_validators.py

@@ -241,6 +241,22 @@ def test_load_application_overwrites_client_on_client_id_mismatch(self):
         self.assertEqual(self.request.client, self.application)
         another_application.delete()
 
+    @mock.patch.object(Application, "is_usable")
+    def test_load_application_returns_none_when_client_not_usable_cached(self, mock_is_usable):
+        mock_is_usable.return_value = False
+        self.request.client = self.application
+        application = self.validator._load_application("client_id", self.request)
+        self.assertIsNone(application)
+        self.assertIsNone(self.request.client)
+
+    @mock.patch.object(Application, "is_usable")
+    def test_load_application_returns_none_when_client_not_usable_db_lookup(self, mock_is_usable):
+        mock_is_usable.return_value = False
+        self.request.client = None
+        application = self.validator._load_application("client_id", self.request)
+        self.assertIsNone(application)
+        self.assertIsNone(self.request.client)
+
     def test_rotate_refresh_token__is_true(self):
         self.assertTrue(self.validator.rotate_refresh_token(mock.MagicMock()))