title: Testing react-contenteditable with react testing library
body: <p>How to test this component: <a href="https://github.com/lovasoa/react-contenteditable" rel="noreferrer">https://github.com/lovasoa/react-contenteditable</a>? How to mimic user action in test environment? I've tried following:</p>
  
  <pre><code>// The given element does not have a value setter
  fireEvent.change(sourceContent, {
    target: { value: "New content text" }
  });
  
  // This doesn't emit onChange Changes text content but onChange is not fired.
  fireEvent.change(sourceContent, {
    target: { textContent: "New content text" }
  });
  
  // This doesn't emit onChange. Changes inner html but onChange is not fired.
  fireEvent.change(sourceContent, {
    target: { innerHTML: "New content text" }
  });
  </code></pre>
  
  <p>All of the above are failed tests. I thought that if I change innerHTML then function provided in <code>onChange</code> will be fired. This is sample project with this problem: <a href="https://codesandbox.io/s/ecstatic-bush-m42hw?fontsize=14&amp;hidenavigation=1&amp;theme=dark" rel="noreferrer">https://codesandbox.io/s/ecstatic-bush-m42hw?fontsize=14&amp;hidenavigation=1&amp;theme=dark</a></p>