[BUGFIX beta] Do not rely prototype extensions (objectAt)

Do not use prototype extension for `objectAt`.

Related to #9269 and based on the work of @stefanpenner in #10899.

If this is acceptable, will continue addressing one extension at a time for quicker merging.

(cherry picked from commit cd0d186)

packages/ember-extension-support/lib/data_adapter.js

@@ -6,6 +6,7 @@ import EmberObject from 'ember-runtime/system/object';
 import { A as emberA } from 'ember-runtime/system/native_array';
 import Application from 'ember-application/system/application';
 import { getOwner } from 'container/owner';
+import { objectAt } from 'ember-runtime/mixins/array';
 
 /**
 @module ember
@@ -206,7 +207,7 @@ export default EmberObject.extend({
 
     var contentDidChange = (array, idx, removedCount, addedCount) => {
       for (var i = idx; i < idx + addedCount; i++) {
-        var record = array.objectAt(i);
+        var record = objectAt(array, i);
         var wrapped = this.wrapRecord(record);
         releaseMethods.push(this.observeRecord(record, recordUpdated));
         recordsAdded([wrapped]);

packages/ember-htmlbars/tests/helpers/collection_test.js

@@ -19,6 +19,8 @@ import { OWNER } from 'container/owner';
 import { registerKeyword, resetKeyword } from 'ember-htmlbars/tests/utils';
 import viewKeyword from 'ember-htmlbars/keywords/view';
 
+import { objectAt } from 'ember-runtime/mixins/array';
+
 var trim = jQuery.trim;
 
 var view;
@@ -28,13 +30,13 @@ var TemplateTests, owner, lookup, originalViewKeyword;
 
 
 function nthChild(view, nth) {
-  return get(view, 'childViews').objectAt(nth || 0);
+  return objectAt(get(view, 'childViews'), nth || 0);
 }
 
 var firstChild = nthChild;
 
 function firstGrandchild(view) {
-  return get(get(view, 'childViews').objectAt(0), 'childViews').objectAt(0);
+  return objectAt(get(objectAt(get(view, 'childViews'), 0), 'childViews'), 0);
 }
 
 QUnit.module('collection helper [LEGACY]', {

packages/ember-htmlbars/tests/helpers/view_test.js

@@ -28,16 +28,18 @@ import viewKeyword from 'ember-htmlbars/keywords/view';
 import { OWNER } from 'container/owner';
 import buildOwner from 'container/tests/test-helpers/build-owner';
 
+import { objectAt } from 'ember-runtime/mixins/array';
+
 var view, originalLookup, owner, lookup, originalViewKeyword;
 
 var trim = jQuery.trim;
 
 function firstGrandchild(view) {
-  return get(get(view, 'childViews').objectAt(0), 'childViews').objectAt(0);
+  return objectAt(get(objectAt(get(view, 'childViews'), 0), 'childViews'), 0);
 }
 
 function nthChild(view, nth) {
-  return get(view, 'childViews').objectAt(nth || 0);
+  return objectAt(get(view, 'childViews'), nth || 0);
 }
 
 function viewClass(options) {

packages/ember-runtime/lib/mixins/array.js

@@ -47,6 +47,14 @@ function arrayObserversHelper(obj, target, opts, operation, notify) {
   return obj;
 }
 
+export function objectAt(content, idx) {
+  if (content.objectAt) {
+    return content.objectAt(idx);
+  }
+
+  return content[idx];
+}
+
 // ..........................................................
 // ARRAY
 //
@@ -148,16 +156,12 @@ export default Mixin.create(Enumerable, {
     @public
    */
   objectsAt(indexes) {
-    var self = this;
-
-    return indexes.map(function(idx) {
-      return self.objectAt(idx);
-    });
+    return indexes.map(idx => objectAt(this, idx));
   },
 
   // overrides Ember.Enumerable version
   nextObject(idx) {
-    return this.objectAt(idx);
+    return objectAt(this, idx);
   },
 
   /**
@@ -182,11 +186,11 @@ export default Mixin.create(Enumerable, {
   }),
 
   firstObject: computed(function() {
-    return this.objectAt(0);
+    return objectAt(this, 0);
   }),
 
   lastObject: computed(function() {
-    return this.objectAt(get(this, 'length') - 1);
+    return objectAt(this, get(this, 'length') - 1);
   }),
 
   // optimized version from Enumerable
@@ -235,7 +239,7 @@ export default Mixin.create(Enumerable, {
     }
 
     while (beginIndex < endIndex) {
-      ret[ret.length] = this.objectAt(beginIndex++);
+      ret[ret.length] = objectAt(this, beginIndex++);
     }
 
     return ret;
@@ -277,7 +281,7 @@ export default Mixin.create(Enumerable, {
     }
 
     for (idx = startAt; idx < len; idx++) {
-      if (this.objectAt(idx) === object) {
+      if (objectAt(this, idx) === object) {
         return idx;
       }
     }
@@ -321,7 +325,7 @@ export default Mixin.create(Enumerable, {
     }
 
     for (idx = startAt; idx >= 0; idx--) {
-      if (this.objectAt(idx) === object) {
+      if (objectAt(this, idx) === object) {
         return idx;
       }
     }
@@ -434,7 +438,7 @@ export default Mixin.create(Enumerable, {
       lim = startIdx + removeAmt;
 
       for (var idx = startIdx; idx < lim; idx++) {
-        removing.push(this.objectAt(idx));
+        removing.push(objectAt(this, idx));
       }
     } else {
       removing = removeAmt;
@@ -482,7 +486,7 @@ export default Mixin.create(Enumerable, {
       lim = startIdx + addAmt;
 
       for (var idx = startIdx; idx < lim; idx++) {
-        adding.push(this.objectAt(idx));
+        adding.push(objectAt(this, idx));
       }
     } else {
       adding = addAmt;
@@ -500,12 +504,12 @@ export default Mixin.create(Enumerable, {
     var cachedFirst = cacheFor(this, 'firstObject');
     var cachedLast = cacheFor(this, 'lastObject');
 
-    if (this.objectAt(0) !== cachedFirst) {
+    if (objectAt(this, 0) !== cachedFirst) {
       propertyWillChange(this, 'firstObject');
       propertyDidChange(this, 'firstObject');
     }
 
-    if (this.objectAt(length - 1) !== cachedLast) {
+    if (objectAt(this, length - 1) !== cachedLast) {
       propertyWillChange(this, 'lastObject');
       propertyDidChange(this, 'lastObject');
     }

packages/ember-runtime/lib/mixins/mutable_array.js

@@ -21,7 +21,7 @@ var EMPTY = [];
 import { get } from 'ember-metal/property_get';
 import EmberError from 'ember-metal/error';
 import { Mixin } from 'ember-metal/mixin';
-import EmberArray from 'ember-runtime/mixins/array';
+import EmberArray, { objectAt } from 'ember-runtime/mixins/array';
 import MutableEnumerable from 'ember-runtime/mixins/mutable_enumerable';
 import Enumerable from 'ember-runtime/mixins/enumerable';
 
@@ -221,7 +221,7 @@ export default Mixin.create(EmberArray, MutableEnumerable, {
       return null;
     }
 
-    var ret = this.objectAt(len - 1);
+    var ret = objectAt(this, len - 1);
     this.removeAt(len - 1, 1);
     return ret;
   },
@@ -246,7 +246,7 @@ export default Mixin.create(EmberArray, MutableEnumerable, {
       return null;
     }
 
-    var ret = this.objectAt(0);
+    var ret = objectAt(this, 0);
     this.removeAt(0);
     return ret;
   },
@@ -362,7 +362,7 @@ export default Mixin.create(EmberArray, MutableEnumerable, {
   removeObject(obj) {
     var loc = get(this, 'length') || 0;
     while (--loc >= 0) {
-      var curObject = this.objectAt(loc);
+      var curObject = objectAt(this, loc);
 
       if (curObject === obj) {
         this.removeAt(loc);

packages/ember-runtime/lib/system/array_proxy.js

@@ -17,6 +17,7 @@ import EmberObject from 'ember-runtime/system/object';
 import MutableArray from 'ember-runtime/mixins/mutable_array';
 import Enumerable from 'ember-runtime/mixins/enumerable';
 import alias from 'ember-metal/alias';
+import { objectAt } from 'ember-runtime/mixins/array';
 
 /**
 @module ember
@@ -102,7 +103,7 @@ var ArrayProxy = EmberObject.extend(MutableArray, {
     @private
   */
   objectAtContent(idx) {
-    return get(this, 'arrangedContent').objectAt(idx);
+    return objectAt(get(this, 'arrangedContent'), idx);
   },
 
   /**
@@ -312,7 +313,7 @@ var ArrayProxy = EmberObject.extend(MutableArray, {
       // Get a list of indices in original content to remove
       for (i = start; i < start + len; i++) {
         // Use arrangedContent here so we avoid confusion with objects transformed by objectAtContent
-        indices.push(content.indexOf(arrangedContent.objectAt(i)));
+        indices.push(content.indexOf(objectAt(arrangedContent, i)));
       }
 
       // Replace in reverse order since indices will change

packages/ember-runtime/lib/system/each_proxy.js

@@ -11,6 +11,7 @@ import {
   propertyWillChange
 } from 'ember-metal/property_events';
 import EmptyObject from 'ember-metal/empty_object';
+import { objectAt } from 'ember-runtime/mixins/array';
 
 /**
   This is the object instance returned when you get the `@each` property on an
@@ -110,7 +111,7 @@ EachProxy.prototype = {
 
 function addObserverForContentKey(content, keyName, proxy, idx, loc) {
   while (--loc >= idx) {
-    let item = content.objectAt(loc);
+    let item = objectAt(content, loc);
     if (item) {
       assert('When using @each to observe the array ' + content + ', the array must return an object', typeof item === 'object');
       _addBeforeObserver(item, keyName, proxy, 'contentKeyWillChange');
@@ -121,7 +122,7 @@ function addObserverForContentKey(content, keyName, proxy, idx, loc) {
 
 function removeObserverForContentKey(content, keyName, proxy, idx, loc) {
   while (--loc >= idx) {
-    let item = content.objectAt(loc);
+    let item = objectAt(content, loc);
     if (item) {
       _removeBeforeObserver(item, keyName, proxy, 'contentKeyWillChange');
       removeObserver(item, keyName, proxy, 'contentKeyDidChange');

packages/ember-runtime/tests/mixins/array_test.js

@@ -6,7 +6,7 @@ import { computed } from 'ember-metal/computed';
 import { testBoth } from 'ember-metal/tests/props_helper';
 import { ArrayTests } from 'ember-runtime/tests/suites/array';
 import EmberObject from 'ember-runtime/system/object';
-import EmberArray from 'ember-runtime/mixins/array';
+import EmberArray, { objectAt } from 'ember-runtime/mixins/array';
 import { A as emberA } from 'ember-runtime/system/native_array';
 
 /*
@@ -385,7 +385,7 @@ QUnit.test('modifying the array should also indicate the isDone prop itself has
   addObserver(each, 'isDone', function() { count++; });
 
   count = 0;
-  var item = ary.objectAt(2);
+  var item = objectAt(ary, 2);
   set(item, 'isDone', !get(item, 'isDone'));
   equal(count, 1, '@each.isDone should have notified');
 });
@@ -399,14 +399,14 @@ testBoth('should be clear caches for computed properties that have dependent key
     },
 
     common: computed('resources.@each.common', function() {
-      return get(get(this, 'resources').objectAt(0), 'common');
+      return get(objectAt(get(this, 'resources'), 0), 'common');
     })
   }).create();
 
   get(obj, 'resources').pushObject(EmberObject.create({ common: 'HI!' }));
   equal('HI!', get(obj, 'common'));
 
-  set(get(obj, 'resources').objectAt(0), 'common', 'BYE!');
+  set(objectAt(get(obj, 'resources'), 0), 'common', 'BYE!');
   equal('BYE!', get(obj, 'common'));
 });
 
@@ -428,7 +428,7 @@ testBoth('observers that contain @each in the path should fire only once the fir
   // Observer fires second time when new object is added
   get(obj, 'resources').pushObject(EmberObject.create({ common: 'HI!' }));
   // Observer fires third time when property on an object is changed
-  set(get(obj, 'resources').objectAt(0), 'common', 'BYE!');
+  set(objectAt(get(obj, 'resources'), 0), 'common', 'BYE!');
 
   equal(count, 2, 'observers should only be called once');
 });

packages/ember-runtime/tests/suites/array/objectAt.js

@@ -1,4 +1,5 @@
 import {SuiteModuleBuilder} from 'ember-runtime/tests/suites/suite';
+import { objectAt } from 'ember-runtime/mixins/array';
 
 var suite = SuiteModuleBuilder.create();
 
@@ -11,18 +12,18 @@ suite.test('should return object at specified index', function() {
   var idx;
 
   for (idx = 0;idx < len;idx++) {
-    equal(obj.objectAt(idx), expected[idx], `obj.objectAt(${idx}) should match`);
+    equal(objectAt(obj, idx), expected[idx], `obj.objectAt(${idx}) should match`);
   }
 });
 
 suite.test('should return undefined when requesting objects beyond index', function() {
   var obj;
 
   obj = this.newObject(this.newFixture(3));
-  equal(obj.objectAt(5), undefined, 'should return undefined for obj.objectAt(5) when len = 3');
+  equal(objectAt(obj, 5), undefined, 'should return undefined for obj.objectAt(5) when len = 3');
 
   obj = this.newObject([]);
-  equal(obj.objectAt(0), undefined, 'should return undefined for obj.objectAt(0) when len = 0');
+  equal(objectAt(obj, 0), undefined, 'should return undefined for obj.objectAt(0) when len = 0');
 });
 
 export default suite;

packages/ember-runtime/tests/system/array_proxy/arranged_content_test.js

@@ -2,6 +2,7 @@ import run from 'ember-metal/run_loop';
 import { computed } from 'ember-metal/computed';
 import ArrayProxy from 'ember-runtime/system/array_proxy';
 import { A as emberA } from 'ember-runtime/system/native_array';
+import { objectAt } from 'ember-runtime/mixins/array';
 
 var array;
 
@@ -69,7 +70,7 @@ QUnit.test('nextObject - returns object at index in arrangedContent', function()
 });
 
 QUnit.test('objectAt - returns object at index in arrangedContent', function() {
-  equal(array.objectAt(1), 4, 'returns object at index');
+  equal(objectAt(array, 1), 4, 'returns object at index');
 });
 
 // Not sure if we need a specific test for it, since it's internal
@@ -217,7 +218,7 @@ QUnit.module('ArrayProxy - arrangedContent with transforms', {
         }).property('content.[]'),
 
         objectAtContent(idx) {
-          var obj = this.get('arrangedContent').objectAt(idx);
+          var obj = objectAt(this.get('arrangedContent'), idx);
           return obj && obj.toString();
         }
       }).create({
@@ -246,7 +247,7 @@ QUnit.test('nextObject - returns object at index in arrangedContent', function()
 });
 
 QUnit.test('objectAt - returns object at index in arrangedContent', function() {
-  equal(array.objectAt(1), '4', 'returns object at index');
+  equal(objectAt(array, 1), '4', 'returns object at index');
 });
 
 // Not sure if we need a specific test for it, since it's internal

packages/ember-views/lib/views/collection_view.js

@@ -7,7 +7,7 @@ import Ember from 'ember-metal/core';
 import { assert, deprecate } from 'ember-metal/debug';
 import ContainerView from 'ember-views/views/container_view';
 import View from 'ember-views/views/view';
-import EmberArray from 'ember-runtime/mixins/array';
+import EmberArray, { objectAt } from 'ember-runtime/mixins/array';
 import { get } from 'ember-metal/property_get';
 import { set } from 'ember-metal/property_set';
 import { computed } from 'ember-metal/computed';
@@ -315,7 +315,7 @@ var CollectionView = ContainerView.extend(EmptyViewSupport, {
       itemViewClass = readViewFactory(itemViewClass, getOwner(this));
 
       for (idx = start; idx < start + added; idx++) {
-        item = content.objectAt(idx);
+        item = objectAt(content, idx);
         itemViewProps._context = this.keyword ? this.get('context') : item;
         itemViewProps.content = item;
         itemViewProps.contentIndex = idx;