Issue 4795 - Use modern JavaScript syntax

lib/filterValidation.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 97 matching lines @@
  *
  */
 
 let parseFilter =
 /**
  * Parses and validates a filter given by the user.
  *
  * @param {string}  text
  * @return {ParsedFilter}
  */
-exports.parseFilter = function(text)
+exports.parseFilter = text =>
 {
   let filter = null;
   text = Filter.normalize(text);
 
   if (text)
   {
     if (text[0] == "[")
       return {error: new FilterParsingError("unexpected-filter-list-header")};
 
     filter = Filter.fromText(text);
@@ skipping 13 matching lines @@
  * @property {Filter[]} filters  The parsed result without invalid filters.
  * @property {FilterParsingError[]} errors  See {@link module:filterValidation~FilterParsingError FilterParsingError}
  */
 
 /**
  * Parses and validates a newline-separated list of filters given by the user.
  *
  * @param {string}  text
  * @return {ParsedFilters}
  */
-exports.parseFilters = function(text)
+exports.parseFilters = text =>
 {
   let lines = text.split("\n");
   let filters = [];
   let errors = [];
 
   for (let i = 0; i < lines.length; i++)
   {
     let {filter, error} = parseFilter(lines[i]);
 
     if (filter)
       filters.push(filter);
 
     if (error)
     {
       error.lineno = i + 1;
       errors.push(error);
     }
   }
 
   return {filters: filters, errors: errors};
 };