Merge pull request #11861 from rwjblue/duplicate-keys

[BUGFIX release] Update HTMLBars to allow duplicate {{each}} keys.

package.json

@@ -32,7 +32,7 @@
     "finalhandler": "^0.4.0",
     "github": "^0.2.3",
     "glob": "~4.3.2",
-    "htmlbars": "0.13.33",
+    "htmlbars": "0.13.34",
     "qunit-extras": "^1.3.0",
     "qunitjs": "^1.16.0",
     "route-recognizer": "0.1.5",

packages/ember-htmlbars/lib/helpers/each.js

@@ -1,4 +1,3 @@
-import Error from 'ember-metal/error';
 import shouldDisplay from 'ember-views/streams/should_display';
 import decodeEachKey from 'ember-htmlbars/utils/decode-each-key';
 
@@ -74,14 +73,9 @@ export default function eachHelper(params, hash, blocks) {
   var keyPath = hash.key;
 
   if (shouldDisplay(list)) {
-    let seenKeys = {};
     forEach(list, (item, i) => {
       var key = decodeEachKey(item, keyPath, i);
-      if (seenKeys[key] === true) {
-        throw new Error(`Duplicate key found ('${key}') for '{{each}}' helper, please use a unique key or switch to '{{#each model key="@index"}}{{/each}}'.`);
-      } else {
-        seenKeys[key] = true;
-      }
+
       blocks.template.yieldItem(key, [item, i]);
     });
   } else if (blocks.inverse.yield) {

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

@@ -759,22 +759,19 @@ QUnit.test('can specify `@identity` to represent mixed object and primitive item
   equal(view.$().text(), 'foobarbaz');
 });
 
-QUnit.test('duplicate keys trigger a useful error (temporary until we can deal with this properly in HTMLBars)', function() {
+QUnit.test('duplicate keys work properly with primitive items', function() {
   runDestroy(view);
   view = EmberView.create({
     items: ['a', 'a', 'a'],
     template: compile('{{#each view.items as |item|}}{{item}}{{/each}}')
   });
 
-  throws(
-    function() {
-      runAppend(view);
-    },
-    `Duplicate key found ('a') for '{{each}}' helper, please use a unique key or switch to '{{#each model key="@index"}}{{/each}}'.`
-  );
+  runAppend(view);
+
+  equal(view.$().text(), 'aaa');
 });
 
-QUnit.test('pushing a new duplicate key will trigger a useful error (temporary until we can deal with this properly in HTMLBars)', function() {
+QUnit.test('pushing a new duplicate key will render properly with primitive items', function() {
   runDestroy(view);
   view = EmberView.create({
     items: A(['a', 'b', 'c']),
@@ -783,12 +780,49 @@ QUnit.test('pushing a new duplicate key will trigger a useful error (temporary u
 
   runAppend(view);
 
-  throws(
-    function() {
-      run(function() {
-        view.get('items').pushObject('a');
-      });
-    },
-    `Duplicate key found ('a') for '{{each}}' helper, please use a unique key or switch to '{{#each model key="@index"}}{{/each}}'.`
-  );
+  run(function() {
+    view.get('items').pushObject('a');
+  });
+
+  equal(view.$().text(), 'abca');
+});
+
+QUnit.test('duplicate keys work properly with objects', function() {
+  runDestroy(view);
+  let duplicateItem = { display: 'foo' };
+  view = EmberView.create({
+    items: [
+      duplicateItem,
+      duplicateItem,
+      { display: 'bar' },
+      { display: 'qux' }
+    ],
+    template: compile('{{#each view.items as |item|}}{{item.display}}{{/each}}')
+  });
+
+  runAppend(view);
+
+  equal(view.$().text(), 'foofoobarqux');
+});
+
+QUnit.test('pushing a new duplicate key will render properly with objects', function() {
+  runDestroy(view);
+
+  let duplicateItem = { display: 'foo' };
+  view = EmberView.create({
+    items: A([
+      duplicateItem,
+      { display: 'bar' },
+      { display: 'qux' }
+    ]),
+    template: compile('{{#each view.items as |item|}}{{item.display}}{{/each}}')
+  });
+
+  runAppend(view);
+
+  run(function() {
+    view.get('items').pushObject(duplicateItem);
+  });
+
+  equal(view.$().text(), 'foobarquxfoo');
 });