title: Force ReactJS to throw real errors when propTypes validation fails?
body: <p>At present, if <code>propType</code> validation fails, ReactJS uses <code>console.warn</code> to emit a warning. I really, really want a real error in dev mode, so it can fail our continuous integration build, instead of just printing a message that might be lost in the shuffle.</p>
  
  <p>There's already been discussion of this, e.g. in <a href="https://github.com/facebook/react/issues/1587" rel="noreferrer">this feature request</a>, and this <a href="https://stackoverflow.com/questions/26908918/proptypes-isrequired-constraint-mis-leading-behaviour-in-react">related question</a> describes the current behavior as expected. That's fine, but <strong>I personally want it to throw an error.</strong></p>
  
  <p>Assuming that ReactJS doesn't provide better support for this any time soon, <strong>what's the best workaround?</strong> So far, the best I've come up with is to override <code>console.warn</code> for tests, e.g. </p>
  
  <pre><code>console.warn = function(msg) {
      throw new Error(msg);
  };
  </code></pre>
  
  <p>The downside of this is, it can be tricky to implement in tests, and it's not React-specific, so other <code>console.warn</code> calls also need to be handled.</p>