interface SubmitEventInit extends EventInit {
  submitter?: HTMLElement | null;
}

globalThis.SubmitEvent = class SubmitEvent extends Event {
  get submitter() {
    return null;
  }

  constructor(type: string, eventInitDict?: SubmitEventInit) {
    super(type, eventInitDict);
  }
};

const submitterGetter = Object.getOwnPropertyDescriptors(SubmitEvent.prototype)
  .submitter.get;

import { expect, it } from '@jest/globals';
import '../';

// https://github.com/idea2app/event-submitter-polyfill/issues/8
it("doesn't polyfill submitter if SubmitEvent is already available", () => {
  const form = document.createElement('form');
  document.body.append(form);
  form.addEventListener('submit', e => e.preventDefault());
  form.dispatchEvent(new SubmitEvent('submit'));
  expect(
    Object.getOwnPropertyDescriptors(SubmitEvent.prototype).submitter.get
  ).toBe(submitterGetter);
});