reactjs - missing ) after argument list when using react-router -

i'm using react-router v0.13.3 , react 0.13.3 build simple web app. big issue happened when tried integrate react-router.

so, here's error message: uncaught syntaxerror: missing ) after argument list

app.jsx

  var router = window.reactrouter;   var route = router.route;    app.view_search = 'search_view';   app.view_favorite = 'favorite_view';   app.view_result = 'result_view';    var routehandler = router.routehandler;   var app = react.createclass({     render () {       return (         <div>           <h1>app</h1>           <routehandler/>         </div>       )     }   });    // declare our routes , hierarchy   var routes = (     <route handler={app} path="/">       <route path="search" handler={app.searchview}/>       <route path="about" handler={app.aboutview}/>       <router.defaultroute handler={app.searchview}/>     </route>   );    router.run(routes, router.historylocation, (root) => {     react.render(<root/>, document.body);   }); 

the main javascript codes pasted above, error appeared when added last 3 lines. , web app using bower manage dependencies.

if use

  router.run(routes, router.historylocation, function(handler) {     react.render(<handler/>, document.body);   }); 

to replace last 3 lines. nothing shows on screen. know how solve it?

the parenthesis error because of arrow function use. ecmascript 6 feature , not supported browsers unfortunately.

since use gulp, easy add babel build steps. otherwise, use 'old' notation: function(root) {return ...}

as second issue point in comments, need source code of root try understand what's happening.