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.

if (++read == n) {
            pos = clipPos(cm.doc, pos);
            makeChange(cm.doc, {from: pos, to: pos, text: splitLines(text.join("\n")), origin: "paste"}, "around");
          }
        };
        reader.readAsText(file);
      };
      for (var i = 0; i < n; ++i) loadFile(files[i], i);
    } else {
      
      if (cm.state.draggingText && !(posLess(pos, cm.doc.sel.from) || posLess(cm.doc.sel.to, pos))) {
        cm.state.draggingText(e);
        
        setTimeout(bind(focusInput, cm), 20);
        return;
      }
      try {
        var text = e.dataTransfer.getData("Text");
        if (text) {
          var curFrom = cm.doc.sel.from, curTo = cm.doc.sel.to;
          setSelection(cm.doc, pos, pos);
          if (cm.state.draggingText) replaceRange(cm.doc, "", curFrom, curTo, "paste");
          cm.replaceSelection(text, null, "paste");
          focusInput(cm);
        }
      }
      catch(e){}
    }
  }
  function onDragStart(cm, e) {