title: How to assert data type with Jest
body: <p>I'm using Jest to test my Node application.</p>
  <p>Is it possible for me to expect/assert a value to be a Date Object?</p>
  <p><code>expect(typeof result).toEqual(typeof Date())</code></p>
  <p>Was my attempt, but naturally returns [Object]. And so this would pass too {}.</p>
  <p>Thanks!</p>