gecko/dom/workers/test/worker_driver.js

// Any copyright is dedicated to the Public Domain.
// http://creativecommons.org/publicdomain/zero/1.0/
//
// Utility script for writing worker tests.  In your main document do:
//
//  <script type="text/javascript" src="worker_driver.js"></script>
//  <script type="text/javascript">
//    workerTestExec('myWorkerTestCase.js')
//  </script>
//
// This will then spawn a worker, define some utility functions, and then
// execute the code in myWorkerTestCase.js.  You can then use these
// functions in your worker-side test:
//
//  ok() - like the SimpleTest assert
//  is() - like the SimpleTest assert
//  workerTestDone() - like SimpleTest.finish() indicating the test is complete
//
// There are also some functions for requesting information that requires
// SpecialPowers or other main-thread-only resources:
//
//  workerTestGetPrefs() - request an array of prefs value from the main thread
//  workerTestGetPermissions() - request an array permissions from the MT
//  workerTestGetVersion() - request the current version string from the MT
//  workerTestGetUserAgent() - request the user agent string from the MT
//
// For an example see test_worker_interfaces.html and test_worker_interfaces.js.

function workerTestExec(script) {
  SimpleTest.waitForExplicitFinish();
  var worker = new Worker('worker_wrapper.js');
  worker.onmessage = function(event) {
    if (event.data.type == 'finish') {
      SimpleTest.finish();

    } else if (event.data.type == 'status') {
      ok(event.data.status, event.data.msg);

    } else if (event.data.type == 'getPrefs') {
      var result = {};
      event.data.prefs.forEach(function(pref) {
        result[pref] = SpecialPowers.Services.prefs.getBoolPref(pref);
      });
      worker.postMessage({
        type: 'returnPrefs',
        prefs: event.data.prefs,
        result: result
      });

    } else if (event.data.type == 'getPermissions') {
      var result = {};
      event.data.permissions.forEach(function(permission) {
        result[permission] = SpecialPowers.hasPermission(permission, window.document);
      });
      worker.postMessage({
        type: 'returnPermissions',
        permissions: event.data.permissions,
        result: result
      });

    } else if (event.data.type == 'getVersion') {
      var result = SpecialPowers.Cc['@mozilla.org/xre/app-info;1'].getService(SpecialPowers.Ci.nsIXULAppInfo).version;
      worker.postMessage({
        type: 'returnVersion',
        result: result
      });

    } else if (event.data.type == 'getUserAgent') {
      worker.postMessage({
        type: 'returnUserAgent',
        result: navigator.userAgent
      });
    }
  }

  worker.onerror = function(event) {
    ok(false, 'Worker had an error: ' + event.data);
    SimpleTest.finish();
  };

  worker.postMessage({ script: script });
}