Function createAmpElement

testing/describes.js:953–972

* Creates a custom element without registration. * @param {!Window} win * @param {string=} opt_name * @param {typeof ./base-element.BaseElement} opt_implementationClass * @return {!AmpElement}

(win, opt_name, opt_implementationClass)

 * @return {!AmpElement}
 */
function createAmpElement(win, opt_name, opt_implementationClass) {
  // Create prototype and constructor.
  const name = opt_name || 'amp-element';
  const proto = createAmpElementForTesting(win).prototype;
  const ctor = function () {
    const el = win.document.createElement(name);
    el.__proto__ = proto;
    return el;
  };
  ctor.prototype = proto;
  proto.constructor = ctor;

  // Create the element instance.
  const element = new ctor();
  element.implementationClassForTesting =
    opt_implementationClass || BaseElement;
  element.createdCallback();
  element.classList.add('i-amphtml-element');
  return element;
}