Issue 4795 - Use modern JavaScript syntax

lib/filterComposer.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
@@ skipping 17 matching lines @@
 let {port} = require("messaging");
 
 let readyPages = new ext.PageMap();
 
 /**
  * Checks whether the given page is ready to use the filter composer
  *
  * @param {Page} page
  * @return {boolean}
  */
-exports.isPageReady = function(page)
+exports.isPageReady = page =>
 {
   return readyPages.has(page);
 };
 
 function isValidString(s) {
   return s && s.indexOf("\0") == -1;
 }
 
 function escapeChar(chr)
 {
@@ skipping 10 matching lines @@
 }
 
 let escapeCSS =
 /**
  * Escapes a token (e.g. tag, id, class or attribute) to be used in CSS selectors.
  *
  * @param {string} s
  * @return {string}
  * @static
  */
-exports.escapeCSS = function(s)
+exports.escapeCSS = s =>
 {
   return s.replace(/^[\d\-]|[^\w\-\u0080-\uFFFF]/g, escapeChar);
 };
 
 let quoteCSS =
 /**
  * Quotes a string to be used as attribute value in CSS selectors.
  *
  * @param {string} value
  * @return {string}
  * @static
  */
-exports.quoteCSS = function(value)
+exports.quoteCSS = value =>
 {
   return '"' + value.replace(/["\\\{\}\x00-\x1F\x7F]/g, escapeChar) + '"';
 };
 
 function composeFilters(details)
 {
   let filters = [];
   let selectors = [];
 
   let page = details.page;
@@ skipping 141 matching lines @@
     baseURL: message.baseURL,
     page:    sender.page,
     frame:   sender.frame
   });
 });
 
 ext.pages.onLoading.addListener(page =>
 {
   page.sendMessage({type: "composer.content.finished"});
 });