Merge pull request #28 from thoov/arity

Add initializer initialize arguments deprecation

config/environment.js

@@ -14,7 +14,8 @@ module.exports = function(/* environment, appConfig */) {
       _ENABLE_RESOLVER_FUNCTION_SUPPORT: true,
       _ENABLE_DID_INIT_ATTRS_SUPPORT: true,
       _ENABLE_RENDER_SUPPORT: true,
-      _ENABLE_REVERSED_OBSERVER_SUPPORT: true
+      _ENABLE_REVERSED_OBSERVER_SUPPORT: true,
+      _ENABLE_INITIALIZER_ARGUMENTS_SUPPORT: true
     }
   };
 };

index.js

@@ -12,5 +12,6 @@ module.exports = {
     this.import('vendor/enumerable-contains.js');
     this.import('vendor/underscore-actions.js');
     this.import('vendor/reversed-observer.js');
+    this.import('vendor/initializer-arity.js');
   }
 };

tests/acceptance/arity-test.js

@@ -0,0 +1,10 @@
+import { test } from 'qunit';
+import moduleForAcceptance from '../../tests/helpers/module-for-acceptance';
+
+moduleForAcceptance('Acceptance | Initializer Initialize is deprecated for 2 arguments');
+
+test('that a deprecation is thrown when 2 arguments are present in the initializers initalize method', function(assert) {
+  assert.expectDeprecation('The `initialize` method for Application initializer \'arity\' should take only one argument - `App`, an instance of an `Application`');
+
+  visit('/');
+});

tests/dummy/app/initializers/arity.js

@@ -0,0 +1,9 @@
+//eslint-disable-next-line no-unused-vars
+export function initialize(container, application) {
+  // this is left blank
+}
+
+export default {
+  name: 'arity',
+  initialize: initialize
+}

vendor/initializer-arity.js

@@ -0,0 +1,36 @@
+(function() {
+  var _Ember;
+  if (typeof Ember !== 'undefined') {
+    _Ember = Ember;
+  } else {
+    _Ember = require('ember').default;
+  }
+
+  if (EmberENV && EmberENV._ENABLE_INITIALIZER_ARGUMENTS_SUPPORT !== true) {
+    return false;
+  }
+
+  _Ember.Engine.reopen({
+    /**
+      @private
+      @method runInitializers
+    */
+    runInitializers() {
+      this._runInitializer('initializers', (name, initializer) => {
+        _Ember.assert(`No application initializer named '${name}'`, !!initializer);
+        if (initializer.initialize.length === 2) {
+          _Ember.deprecate(`The \`initialize\` method for Application initializer '${name}' should take only one argument - \`App\`, an instance of an \`Application\`.`,
+          false, {
+            id: 'ember-application.app-initializer-initialize-arguments',
+            until: '3.0.0',
+            url: 'https://emberjs.com/deprecations/v2.x/#toc_initializer-arity'
+          });
+
+          initializer.initialize(this.__registry__, this);
+        } else {
+          initializer.initialize(this);
+        }
+      });
+    }
+  })
+})();