HasMany improvements

packages/ember-model/lib/has_many.js

@@ -34,7 +34,10 @@ Ember.hasMany = function(type, options) {
       if (!existingArray) {
         existingArray = this.getHasMany(options.key || propertyKey, type, meta, this.container);
       }
-      return existingArray.setObjects(newContentArray);
+      if (!Ember.isEqual(newContentArray, existingArray)) {
+        return existingArray.setObjects(newContentArray);
+      }
+      return existingArray;
     }
   }).meta(meta);
 };

packages/ember-model/lib/has_many_array.js

@@ -123,10 +123,19 @@ Ember.ManyArray = Ember.RecordArray.extend({
   },
 
   load: function(content) {
-    Ember.setProperties(this, {
-      content: content,
-      originalContent: content.slice()
-    });
+    var currentContent = get(this, 'content');
+    var mustUpdateCollection = content.length !== currentContent.length;
+    for (var i = 0, l = content.length; i < l && !mustUpdateCollection; i++) {
+      var existingItem = currentContent[i];
+      var newItem = content[i];
+      mustUpdateCollection = newItem !== existingItem;
+    }
+    if (mustUpdateCollection) {
+      Ember.setProperties(this, {
+        content: content,
+        originalContent: content.slice()
+        });
+    }
     set(this, '_modifiedRecords', []);
   },
 

packages/ember-model/tests/has_many/embedded_objects_load_test.js

@@ -115,3 +115,57 @@ test("loading embedded data into a parent with deleted children deletes the chil
   equal(post.get('comments.length'), 1);
   equal(post.get('comments.firstObject.body'), 'new');
 });
+
+test("loading collections with same element twice does not trigger observers", function() {
+  expect(4);
+  var json = {
+    id: 1,
+    title: 'foo',
+    comments: [{
+      id: 1,
+      text: 'helo'
+    }]
+  };
+
+  var Comment = Ember.Model.extend({
+    id: attr(),
+    text: attr()
+  });
+  Comment.adapter = Ember.RESTAdapter.create();
+  Comment.url = '/comments';
+
+  var Article = Ember.Model.extend({
+    title: attr(),
+    comments: Ember.hasMany(Comment, { key: 'comments', embedded: true }),
+
+    commentsChangeCounter: 0,
+    commentsChanged: function() {
+      this.incrementProperty('commentsChangeCounter');
+    }.observes('comments.[]')
+  });
+  Article.adapter = Ember.RESTAdapter.create();
+  Article.url = '/articles';
+  Article.adapter._ajax = function() {
+    return new Ember.RSVP.Promise(function(resolve) {
+      resolve(json);
+    });
+  };
+
+  var article = Article.create();
+  Ember.run(article, article.load, json.id, json);
+  // Force collection to be taken into account (_registerHasManyArray)
+  var comments = article.get('comments');
+  equal(article.get('commentsChangeCounter'), 0, "Inital load didn't triggered observers");
+  var json2 = {
+    id: 1,
+    title: 'foo',
+    comments: [{
+      id: 1,
+      text: 'helo here' // <- updated
+    }]
+  };
+  Ember.run(article, article.load, json.id, json2);
+  equal(article.get('commentsChangeCounter'), 0, "Load with the same collection didn't triggered observers");
+  equal(comments.get('isDirty'), false, "comments should not be dirty");
+  deepEqual(Ember.run(comments, comments.mapBy, 'text'), ['helo here']);
+});

packages/ember-model/tests/has_many/manipulation_test.js

@@ -283,4 +283,50 @@ test("setting a hasMany array with setObjects", function() {
 
   equal(article.get('comments.length'), 3, "should be 3 comments after revert");
   equal(article.get('comments.isDirty'), false, "should not be dirty after revert");
-});
+});
+
+test("setting a has many array with the same array should not trigger its observers", function() {
+  expect(7);
+  var json = {
+    id: 1,
+    title: 'foo',
+    comments: [1, 2, 3]
+  };
+
+  var Comment = Ember.Model.extend({
+    text: attr()
+  });
+
+  var Article = Ember.Model.extend({
+    title: attr(),
+
+    comments: Ember.hasMany(Comment, { key: 'comments' }),
+
+    commentsChangeCounter: 0,
+    commentsChanged: function() {
+      this.incrementProperty('commentsChangeCounter');
+    }.observes('comments.[]')
+  });
+
+  Comment.adapter = Ember.FixtureAdapter.create();
+  Comment.FIXTURES = [
+    {id: 1, text: 'uno'},
+    {id: 2, text: 'dos'},
+    {id: 3, text: 'tres'}
+  ];
+
+  var article = Article.create();
+  Ember.run(article, article.load, json.id, json);
+
+  equal(article.get('comments.length'), 3, "should be 3 comments");
+
+  article.set('comments', article.get('comments'));
+  equal(article.get('comments.length'), 3, "should still be 3 comments");
+  equal(article.get('comments.isDirty'), false, "comments should not be dirty");
+  equal(article.get('commentsChangeCounter'), 0, "comment observers should not fire");
+
+  article.set('comments', [Comment.find(3)]);
+  equal(article.get('comments.length'), 1, "should be 1 comment after set");
+  equal(article.get('comments.isDirty'), true, "comments should be dirty after set");
+  equal(article.get('commentsChangeCounter'), 1, "comment observers should have fired 1 time");
+});