gecko-dev/dom/workers/test/relativeLoad_sub_worker.js

/**
 * Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/publicdomain/zero/1.0/
 */
const importSubURL = "relativeLoad_sub_import.js";

onmessage = function(event) {
  var xhr = new XMLHttpRequest();
  xhr.open("GET", "testXHR.txt", false);
  xhr.send(null);
  if (xhr.status != 404) {
    throw "Loaded an xhr from the wrong location!";
  }

  importScripts(importSubURL);
  var worker = new Worker("relativeLoad_sub_worker2.js");
  worker.onerror = function(event) {
    throw event.data;
  };
  worker.onmessage = function(event) {
    if (event.data != workerSubURL) {
      throw "Bad data!";
    }
    postMessage(workerSubURL);
  };
};