Issue 4864 - Start using ESLint for adblockpluschrome

ext/common.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 {
+  /* eslint-disable no-var */
   var ext = {};
+  /* eslint-enable no-var */
 
   let EventTarget = ext._EventTarget = function()
   {
     this._listeners = [];
   };
   EventTarget.prototype = {
     addListener(listener)
     {
       if (this._listeners.indexOf(listener) == -1)
         this._listeners.push(listener);
     },
     removeListener(listener)
     {
       let idx = this._listeners.indexOf(listener);
       if (idx != -1)
         this._listeners.splice(idx, 1);
     },
-    _dispatch()
+    _dispatch(...args)
     {
       let results = [];
       let listeners = this._listeners.slice();
 
       for (let listener of listeners)
-        results.push(listener.apply(null, arguments));
+        results.push(listener(...args));
 
       return results;
     }
   };
+
+  // Workaround since HTMLCollection and NodeList didn't have iterator support
+  // before Chrome 51.
+  // https://bugs.chromium.org/p/chromium/issues/detail?id=401699
+  let arrayIterator = Array.prototype[Symbol.iterator];
+  if (!(Symbol.iterator in HTMLCollection.prototype))
+    HTMLCollection.prototype[Symbol.iterator] = arrayIterator;
+  if (!(Symbol.iterator in NodeList.prototype))
+    NodeList.prototype[Symbol.iterator] = arrayIterator;
+
+  /* Message passing */
+
+  ext.onMessage = new ext._EventTarget();
+
+
+  /* Background page */
+
+  ext.backgroundPage = {
+    sendMessage: chrome.runtime.sendMessage,
+    getWindow()
+    {
+      return chrome.extension.getBackgroundPage();
+    }
+  };
+
+
+  /* Utils */
+
+  ext.getURL = chrome.extension.getURL;
+  ext.i18n = chrome.i18n;
 }