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.

d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
    
    d.prevInput = "";
    
    
    d.alignWidgets = false;
    
    
    
    d.pollingFast = false;
    
    d.poll = new Delayed();
    d.cachedCharWidth = d.cachedTextHeight = null;
    d.measureLineCache = [];
    d.measureLineCachePos = 0;
    
    
    d.inaccurateSelection = false;
    
    
    d.maxLine = null;
    d.maxLineLength = 0;
    d.maxLineChanged = false;
    
    d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
    return d;
  }
  
  
  function loadMode(cm) {