gecko-dev/toolkit/content/tests/widgets/head.js

"use strict";

const InspectorUtils = SpecialPowers.InspectorUtils;

var tests = [];

function waitForCondition(condition, nextTest, errorMsg) {
  var tries = 0;
  var interval = setInterval(function() {
    if (tries >= 30) {
      ok(false, errorMsg);
      moveOn();
    }
    var conditionPassed;
    try {
      conditionPassed = condition();
    } catch (e) {
      ok(false, e + "\n" + e.stack);
      conditionPassed = false;
    }
    if (conditionPassed) {
      moveOn();
    }
    tries++;
  }, 100);
  var moveOn = function() { clearInterval(interval); nextTest(); };
}

function getElementWithinVideo(video, aValue) {
  const shadowRoot = SpecialPowers.wrap(video).openOrClosedShadowRoot;
  return shadowRoot.getElementById(aValue);
}

function executeTests() {
  return tests
    .map(fn => () => new Promise(fn))
    .reduce((promise, task) => promise.then(task), Promise.resolve());
}