background.js

/*
 * Copyright (C) 2015-2017 Tomas Popela <tpopela@redhat.com>
 *
 * Licensed under the GNU General Public License Version 2
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

(() => {
  document.addEventListener('DOMContentLoaded', () => {
    // inspired with https://developer.chrome.com/extensions/webRequest
    chrome.webRequest.onBeforeSendHeaders.addListener(
      details => {
        const headers = details.requestHeaders;
        const headersLength = headers.length;

        for (let i = 0; i < headersLength; i++) {
          if (headers[i].name === 'User-Agent') {
            const value = headers[i].value;
            if (!value.includes('; tauOS;'))
              headers[i].value = value.replace('; Linux', '; tauOS; Linux');
            break;
          }
        }

        return { requestHeaders: headers };
      },
      {urls: ['<all_urls>']},
      ['blocking', 'requestHeaders']
    );
  });
})();