gecko-dev/accessible/tests/browser/browser_shutdown_scope_lifecycle.js

/* 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/. */

"use strict";

add_task(async function() {
  // Create a11y service inside of the function scope. Its reference should be
  // released once the anonimous function is called.
  const [a11yInitObserver, a11yInit] = initAccService();
  await a11yInitObserver;
  const a11yInitThenShutdown = a11yInit.then(async () => {
    const [a11yShutdownObserver, a11yShutdown] = shutdownAccService();
    await a11yShutdownObserver;
    return a11yShutdown;
  });

  (function() {
    let accService = Cc["@mozilla.org/accessibilityService;1"].getService(
      Ci.nsIAccessibilityService
    );
    ok(accService, "Service initialized");
  })();

  // Force garbage collection that should trigger shutdown.
  forceGC();
  await a11yInitThenShutdown;
});