Unexpected token < error in react router component

Question

I'm trying to write router component for my react app. I'm create new react class and define some routes in componentDidMount method. This is full method

componentDidMount: function () {

    var me = this;

    router.get('/', function(req){
        me.setState({
            component: <MainPage />
        });
    });

    router.get('/realty', function(req){
        me.setState({
            component: <RealtyPage />
        });
    });

    router.get('/realty/:id', function(req){
        me.setState({
            component: <RealtyPage id={req.params.id} />
        });
    });

},

When I'm go to '/' or '/realty' all works. But, when I'm go to the 'realty/new' I've got error Uncaught SyntaxError: Unexpected token < in app.js:1. But Chrome debugger display that error in my index.html and I even can't debug this in browser. This error happens every time, when I go to the route with '/'. I.m trying to use other client-side routers, like page.js, rlite, grapnel, but all still the same. Maybe someone have any idea about this error?

UPD: This is fuul code of router component. Now it use page.js fo routing and I see the same error

var React = require('react');
var page = require('page');


var MainPage = require('../components/MainPage');
var RealtyPage = require('../components/RealtyPage');


var Router = React.createClass({

    getInitialState: function(){
        return {
            component: <RealtyPage />
        }
    },

    componentDidMount: function () {

        var me = this;

        page('/', function (ctx) {
            me.setState({
                component: <MainPage />
            });
        });

        page('/realty', function (ctx) {
            me.setState({
                component: <RealtyPage />
            });
        });

        page.start();

    },

    render: function(){
        return this.state.component
    }
});

module.exports = Router;

Answer 1

The "unexpected token" error can show up for a number of different reasons. I ran into a similar problem, and in my case the problem was that the script tag to load the generated bundle in the html was like so:

<script src="scripts/app.js"></script>

When navigating to a route with a parameter (same thing will happen to a nested route or a route with more than one segment), browser would try to load the script using the wrong url. In my case the route path was 'user/:id', and the browser made a request to 'http://127.0.0.1:3000/user/scripts/app.js' instead of 'http://127.0.0.1:3000/scripts/app.js'. The solution was easy, change the script tag to this:

<script src="/scripts/app.js"></script>