title: How to mock/replace getter function of object with Jest?
body: <p>In Sinon I can do the following:</p>
  
  <pre><code>var myObj = {
      prop: 'foo'
  };
  
  sinon.stub(myObj, 'prop').get(function getterFn() {
      return 'bar';
  });
  
  myObj.prop; // 'bar'
  </code></pre>
  
  <p>But how can I do the same with Jest?
  I can't just overwrite the function with something like <code>jest.fn()</code>, because it won't replace the getter </p>
  
  <blockquote>
    <p>"can't set the value of get"</p>
  </blockquote>