Right now we use codemirror's JavaScript mode on the website but there's a JSX mode now so we should start using that instead.

lineObj = visualLine(cm.doc, lineObj);
    var h = 0, chunk = lineObj.parent;
    for (var i = 0; i < chunk.lines.length; ++i) {
      var line = chunk.lines[i];
      if (line == lineObj) break;
      else h += line.height;
    }
    for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
      for (var i = 0; i < p.children.length; ++i) {
        var cur = p.children[i];
        if (cur == chunk) break;
        else h += cur.height;
      }
    }
    return h;
  }
  function getOrder(line) {