using koa and socket.io to serve static pages and chat messages

I am using koa and socket.io to serve both static html pages and process chat messages sent to the socket. The following code works as a server :-

var app = require('koa')();
var router = require('koa-router')();
var views = require('co-views');
var render = views('.', { map: { html: 'swig' }});
                                                              <--- [1]
router.get('/', function *(next) {
    console.log('index.html');
    this.body = yield render('index.html');
});

app.use(router.routes());

var server = require('http').createServer(app.callback());    <--- [2]
var io = require('socket.io')(server);                        <--- [3]

io.on('connection', function(socket) {
    socket.on('chat message', function(msg, callback) {
        console.log('got message - ' + msg);
        io.emit('chat message', msg);
        if (callback) {
            callback();
        }
    });
});

server.listen(8080);

my question is; if I move [2] and [3] up to [1] with the rest of the server set up the get router doesn't work.

Does anyone know why?

The following is the client code :-

var io = require('socket.io-client');
var socket = io('http://localhost:8080');

socket.on('connect', function() {
    console.log('socket connected');

    socket.emit('chat message', 'hello world !!!!!!', function() {
        console.log('emit');
        socket.close();
    });
});

socket.on('disconnect', function() {
    console.log('socket disconnect');
});