title: React JSX file giving error "Cannot read property 'createElement' of undefined"
body: <p>I have a file test_stuff.js that I am running with <code>npm test</code></p>
  
  <p>It pretty much looks like this:</p>
  
  <pre><code>import { assert } from 'assert';
  import { MyProvider } from '../src/index';
  import { React } from 'react';
  
  const myProvider = (
    &lt;MyProvider&gt;
    &lt;/MyProvider&gt;
  );
  
  describe('Array', function() {
    describe('#indexOf()', function() {
      it('should return -1 when the value is not present', function() {
        assert.equal(-1, [1,2,3].indexOf(4));
      });
    });
  });
  </code></pre>
  
  <p>Unfortunately, I get the error</p>
  
  <pre><code>/Users/me/projects/myproj/test/test_stuff.js:11
  var myProvider = _react.React.createElement(_index.MyProvider, null);
                               ^
  
  TypeError: Cannot read property 'createElement' of undefined
      at Object.&lt;anonymous&gt; (/Users/me/projects/myproj/test/test_stuff.js:7:7)
  </code></pre>
  
  <p>What does that mean? I am importing React from 'react' successfully, so why would React be undefined? It is _react.React, whatever that means...</p>