Remove `SortedMixin`

app/assets/javascripts/admin/controllers/admin-user-fields.js.es6

@@ -6,12 +6,8 @@ export default Ember.Controller.extend({
   fieldTypes: null,
   createDisabled: Em.computed.gte('model.length', MAX_FIELDS),
 
-  arrangedContent: function() {
-    return Ember.ArrayProxy.extend(Ember.SortableMixin).create({
-      sortProperties: ['position'],
-      content: this.get('model')
-    });
-  }.property('model'),
+  fieldSortOrder: ['position'],
+  sortedFields: Ember.computed.sort('model', 'fieldSortOrder'),
 
   actions: {
     createField() {
@@ -20,9 +16,9 @@ export default Ember.Controller.extend({
     },
 
     moveUp(f) {
-      const idx = this.get('arrangedContent').indexOf(f);
+      const idx = this.get('sortedFields').indexOf(f);
       if (idx) {
-        const prev = this.get('arrangedContent').objectAt(idx-1);
+        const prev = this.get('sortedFields').objectAt(idx-1);
         const prevPos = prev.get('position');
 
         prev.update({ position: f.get('position') });
@@ -31,9 +27,9 @@ export default Ember.Controller.extend({
     },
 
     moveDown(f) {
-      const idx = this.get('arrangedContent').indexOf(f);
+      const idx = this.get('sortedFields').indexOf(f);
       if (idx > -1) {
-        const next = this.get('arrangedContent').objectAt(idx+1);
+        const next = this.get('sortedFields').objectAt(idx+1);
         const nextPos = next.get('position');
 
         next.update({ position: f.get('position') });

app/assets/javascripts/admin/templates/user-fields.hbs

@@ -4,11 +4,11 @@
   <p class="desc">{{i18n 'admin.user_fields.help'}}</p>
 
   {{#if model}}
-    {{#each arrangedContent as |uf|}}
+    {{#each sortedFields as |uf|}}
       {{admin-user-field-item userField=uf
                               fieldTypes=fieldTypes
-                              firstField=arrangedContent.firstObject
-                              lastField=arrangedContent.lastObject
+                              firstField=sortedFields.firstObject
+                              lastField=sortedFields.lastObject
                               destroyAction="destroy"
                               moveUpAction="moveUp"
                               moveDownAction="moveDown"}}

app/assets/javascripts/discourse/controllers/reorder-categories.js.es6

@@ -5,8 +5,6 @@ import { popupAjaxError } from 'discourse/lib/ajax-error';
 import { on, default as computed } from "ember-addons/ember-computed-decorators";
 import Ember from 'ember';
 
-const SortableArrayProxy = Ember.ArrayProxy.extend(Ember.SortableMixin);
-
 export default Ember.Controller.extend(ModalFunctionality, Ember.Evented, {
 
   @on('init')
@@ -20,12 +18,8 @@ export default Ember.Controller.extend(ModalFunctionality, Ember.Evented, {
     return categories.map(c => bufProxy.create({ content: c }));
   },
 
-  categoriesOrdered: function() {
-    return SortableArrayProxy.create({
-      sortProperties: ['content.position'],
-      content: this.get('categoriesBuffered')
-    });
-  }.property('categoriesBuffered'),
+  categoriesSorting: ['position'],
+  categoriesOrdered: Ember.computed.sort('categoriesBuffered', 'categoriesSorting'),
 
   showFixIndices: function() {
     const cats = this.get('categoriesOrdered');