[FEATURE ember-application-initializer-context] Execute initializers in their respective context

Author: gf3

FEATURES.md

@@ -5,6 +5,13 @@ for a detailed explanation.
 
 ## Feature Flags
 
+* `ember-application-initializer-context`
+
+  Sets the context of the initializer function to its object instead of the
+  global object.
+
+  Added in [#10179](https://github.com/emberjs/ember.js/pull/10179).
+
 * `ember-testing-checkbox-helpers`
 
   Add `check` and `uncheck` test helpers.

features.json

@@ -14,7 +14,8 @@
     "new-computed-syntax": null,
     "ember-testing-checkbox-helpers": null,
     "ember-metal-stream": null,
-    "ember-htmlbars-each-with-index": true
+    "ember-htmlbars-each-with-index": true,
+    "ember-application-initializer-context": null
   },
   "debugStatements": [
     "Ember.warn",

packages/ember-application/lib/system/application.js

@@ -695,13 +695,19 @@ var Application = Namespace.extend(DeferredMixin, {
 
     for (var i = 0; i < initializers.length; i++) {
       initializer = initializersByName[initializers[i]];
-      graph.addEdges(initializer.name, initializer.initialize, initializer.before, initializer.after);
+      graph.addEdges(initializer.name, initializer, initializer.before, initializer.after);
     }
 
     graph.topsort(function (vertex) {
       var initializer = vertex.value;
       Ember.assert("No application initializer named '" + vertex.name + "'", !!initializer);
-      initializer(registry, namespace);
+
+      if (Ember.FEATURES.isEnabled("ember-application-initializer-context")) {
+        initializer.initialize(registry, namespace);
+      } else {
+        var ref = initializer.initialize;
+        ref(registry, namespace);
+      }
     });
   },
 

packages/ember-application/tests/system/initializers_test.js

@@ -239,3 +239,25 @@ test("initializers are per-app", function() {
     initialize: function(registry) {}
   });
 });
+
+if (Ember.FEATURES.isEnabled("ember-application-initializer-context")) {
+  test("initializers should be executed in their own context", function() {
+    expect(1);
+    var MyApplication = Application.extend();
+
+    MyApplication.initializer({
+      name: 'coolBabeInitializer',
+      myProperty: 'coolBabe',
+      initialize: function(registry, application) {
+        equal(this.myProperty, 'coolBabe', 'should have access to its own context');
+      }
+    });
+
+    run(function() {
+      app = MyApplication.create({
+        router: false,
+        rootElement: '#qunit-fixture'
+      });
+    });
+  });
+}