Support `/group/xyz` paths as well as `/groups/xyz`

app/assets/javascripts/discourse/lib/url.js

@@ -129,7 +129,6 @@ Discourse.URL = Em.Object.createWithMixins({
       path = path.replace(rootURL, '');
     }
 
-
     // Rewrite /my/* urls
     if (path.indexOf('/my/') === 0) {
       var currentUser = Discourse.User.current();
@@ -141,6 +140,11 @@ Discourse.URL = Em.Object.createWithMixins({
       }
     }
 
+    // Rewrite /groups paths
+    if (path.indexOf('/group/') === 0) {
+      path = path.replace('group/', 'groups/');
+    }
+
     if (this.navigatedToPost(oldPath, path)) { return; }
     // Schedule a DOM cleanup event
     Em.run.scheduleOnce('afterRender', Discourse.Route, 'cleanDOM');

app/assets/javascripts/discourse/routes/build-topic-route.js.es6

@@ -41,9 +41,11 @@ export default function(filter, extras) {
 
     setupController: function(controller, model, trans) {
 
-      controller.setProperties(Em.getProperties(trans, _.keys(queryParams).map(function(v){
-        return 'queryParams.' + v;
-      })));
+      if (trans) {
+        controller.setProperties(Em.getProperties(trans, _.keys(queryParams).map(function(v){
+          return 'queryParams.' + v;
+        })));
+      }
 
 
       var periods = this.controllerFor('discovery').get('periods'),

config/routes.rb

@@ -269,6 +269,10 @@ Discourse::Application.routes.draw do
     get 'counts'
   end
 
+  # In case people try the wrong URL
+  get '/group/:id', to: redirect('/groups/%{id}')
+  get '/group/:id/members', to: redirect('/groups/%{id}/members')
+
   resources :posts do
     put "bookmark"
     put "wiki"