title: Reactjs : TypeError: Cannot read property 'propTypes' of undefined
body: <p>Please i am asked to write a unitTest for the following reactjs page. </p>
  
  <pre><code>export default class Collapsible extends React.Component {
      static propTypes = {
          title: React.PropTypes.string,
          children: React.PropTypes.any,
      };
  
      render() {
          const { title } = this.props;
          return (
              &lt;details&gt;
                  &lt;summary&gt;{title}&lt;/summary&gt;
                  {this.props.children}
              &lt;/details&gt;
          );
      }
  }
  </code></pre>
  
  <p>Following the tut <a href="https://blog.algolia.com/how-we-unit-test-react-components-using-expect-jsx/" rel="noreferrer">Here</a> I wrote my test below like</p>
  
  <pre><code>describe('Collapsible', ()=&gt;{
      it('works', ()=&gt;{
          let renderer = createRenderer();
          renderer.render(&lt;Collapsible title="MyTitle"&gt;&lt;span&gt;HEllo&lt;/span&gt;&lt;/Collapsible&gt;);
          let actualElement = renderer.getRenderOutput();
          let expectedElement = (&lt;details&gt;&lt;summary&gt;title&lt;/summary&gt;Details&lt;/details&gt;);
          expect(actualElement).toEqual(expectedElement);                     
      });
  });
  </code></pre>
  
  <p>However, my test is throwing the error in the title above, i am suspecting my props on the Collapsible (i.e title and children) are not assigning from the test . Please how do i address this? Any help or guidance would highly be appreciated.</p>