Make the UrlResetMixin load the urlconf after resetting it, and fix the comment…

Make the UrlResetMixin load the urlconf after resetting it, and fix the comment client test that was leaving ENABLE_DISCUSSION_SERVICE at True

common/djangoapps/util/testing.py

 import sys
 
 from django.conf import settings
-from django.core.urlresolvers import clear_url_caches
+from django.core.urlresolvers import clear_url_caches, resolve
 
 
 class UrlResetMixin(object):
@@ -27,6 +27,9 @@ class UrlResetMixin(object):
             reload(sys.modules[urlconf])
         clear_url_caches()
 
+        # Resolve a URL so that the new urlconf gets loaded
+        resolve('/')
+
     def setUp(self):
         """Reset django default urlconf before tests and after tests"""
         super(UrlResetMixin, self).setUp()

lms/djangoapps/django_comment_client/base/tests.py

 import logging
 
-from django.conf import settings
 from django.test.utils import override_settings
 from django.test.client import Client
 from django.contrib.auth.models import User
@@ -21,16 +20,13 @@ log = logging.getLogger(__name__)
 @override_settings(MODULESTORE=TEST_DATA_MONGO_MODULESTORE)
 @patch('comment_client.utils.requests.request')
 class ViewsTestCase(UrlResetMixin, ModuleStoreTestCase):
+
+    @patch.dict("django.conf.settings.MITX_FEATURES", {"ENABLE_DISCUSSION_SERVICE": True})
     def setUp(self):
 
-        # This feature affects the contents of urls.py, so we change
-        # it before the call to super.setUp() which reloads urls.py (because
+        # Patching the ENABLE_DISCUSSION_SERVICE value affects the contents of urls.py,
+        # so we need to call super.setUp() which reloads urls.py (because
         # of the UrlResetMixin)
-
-        # This setting is cleaned up at the end of the test by @override_settings, which
-        # restores all of the old settings
-        settings.MITX_FEATURES['ENABLE_DISCUSSION_SERVICE'] = True
-
         super(ViewsTestCase, self).setUp()
 
         # create a course