title: confirm() click simulation "yes or no" in vue jest
body: <p>I have to make a test for a vue instance using jest and the test includes a confirm pop up, question is how to simulate click on "Yes" in the pop up. I was trying to use:
  window.confirm = jest.fn(() => true);
  and:
  window.confirm = () => true;
  and inventing something like that:
  wrapper.confirm = () => true;
  But no luck, maybe someone had similar problem?</p>