use proper object notation and rename isNewRepo to isNewRepoEnabled

app/assets/javascripts/dispatcher.js

@@ -408,7 +408,7 @@ import UserFeatureHelper from './helpers/user_feature_helper';
         case 'projects:tree:show':
           shortcut_handler = new ShortcutsNavigation();
 
-          if (UserFeatureHelper.isNewRepo()) break;
+          if (UserFeatureHelper.isNewRepoEnabled()) break;
 
           new TreeView();
           new BlobViewer();
@@ -428,7 +428,7 @@ import UserFeatureHelper from './helpers/user_feature_helper';
           shortcut_handler = true;
           break;
         case 'projects:blob:show':
-          if (UserFeatureHelper.isNewRepo()) break;
+          if (UserFeatureHelper.isNewRepoEnabled()) break;
           new BlobViewer();
           initBlob();
           break;

app/assets/javascripts/helpers/user_feature_helper.js

 import Cookies from 'js-cookie';
 
-function isNewRepo() {
+export default {
+  isNewRepoEnabled() {
     return Cookies.get('new_repo') === 'true';
-}
-
-const UserFeatureHelper = {
-  isNewRepo,
+  },
 };
-
-export default UserFeatureHelper;