title: How to simulate a key event with modifier key pressed in an Ember.js integration test?
body: <p>I'm trying to test an event handler that reacts to the <code>shift</code> + <code>delete</code> key combo, but <a href="http://emberjs.com/api/classes/Ember.Test.html#method_keyEvent" rel="noreferrer">the Ember docs for the <code>Test.keyEvent</code> method</a> don't seem to mention any way to activate modifier keys.</p>
  
  <p>I tried issuing a <code>keydown</code> on <code>shift</code> (keyCode 16), then <code>keydown</code> on <code>delete</code> (keyCode 46):</p>
  
  <pre><code>keyEvent('.my input', 'keydown', 16);  // Shift
  keyEvent('.my input', 'keydown', 46);  // Delete
  keyEvent('.my input', 'keyup', 46);  // Delete
  keyEvent('.my input', 'keyup', 16);  // Shift
  </code></pre>
  
  <p>but the delete event's <code>shiftKey</code> property is still undefined</p>