The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 // get title directly

 self.postMessage(["equal", document.title, "Page Worker test",

             "Correct page title accessed directly"]);

 // get <p> directly

 let p = document.getElementById("paragraph");

 self.postMessage(["ok", !!p, "<p> can be accessed directly"]);

 self.postMessage(["equal", p.firstChild.nodeValue,

             "Lorem ipsum dolor sit amet.",

             "Correct text node expected"]);

 // Modify page

 let div = document.createElement("div");

 div.setAttribute("id", "block");

 div.appendChild(document.createTextNode("Test text created"));

 document.body.appendChild(div);

 // Check back the modification

 div = document.getElementById("block");

 self.postMessage(["ok", !!div, "<div> can be accessed directly"]);

 self.postMessage(["equal", div.firstChild.nodeValue,

             "Test text created", "Correct text node expected"]);

 self.postMessage(["done"]);