title: IE11 + Edge 12-13-14: random JavaScript parsing errors, caused by very long object?
body: <p>I'm getting reports of JavaScript errors in production (from TrackJS.com) from IE &amp; Edge browsers like:</p>
  
  <ul>
  <li>Expected identifier, string or number</li>
  <li>Unterminated string constant</li>
  <li>Expected ': ', '}' or ';'</li>
  <li>illegal character</li>
  </ul>
  
  <p>And when I check the error file / line, it's sometimes in "mathiasbynens/he" library (look on GitHub), like here: <a href="https://cloud.githubusercontent.com/assets/310134/24353407/b3d0ba6e-12ed-11e7-92f4-19e13bf4cfa4.png" rel="nofollow noreferrer">example 1</a></p>
  
  <p>And sometimes it's in other parts of the code (like in YUI library). I've got lots of these and they seem completely random (targeting what seems to be valid code): <a href="https://cloud.githubusercontent.com/assets/310134/24353434/cd9d8422-12ed-11e7-9061-20c2198f5ede.png" rel="nofollow noreferrer">example 2</a></p>
  
  <p>The only idea I have would be that IE croaks when loading the very long JSON defined in the .js.
  Have you ever had any issue of this kind?</p>