javascript - TypeError : cannot read property 'method' of undefined in nodejs Application -

i developing simple chat application using node.js , socket.io. when connecting socket.io face error of "cannot read property 'method' of undefined".

here app.js file code:-

var express = require('express'),      app = express(),      path = require('path')      cookieparser = require('cookie-parser')      session = require('express-session')      config = require('./config/config.js'),      connectmongo = require('connect-mongo')(session),      mongoose = require('mongoose').connect(config.dburl),      passport = require('passport'),      facebookstrategy = require('passport-facebook').strategy,      rooms = [] ;         app.set('views', path.join(__dirname , 'views'));      app.engine('html', require('hogan-express'));          app.set('view engine', 'html');       app.use(express.static(path.join(__dirname,'public')));       app.use(cookieparser());       var env = process.env.node_env || 'development';       if(env === 'development'){       // dev specific settings       app.use(session({secret:config.sessionsecret, saveuninitialized : true, resave : true}));             } else {        //production specific settings        app.use(session({           secret : config.sessionsecret,           saveuninitialized : true,           resave : true,            store : new connectmongo({              // url : config.dburl, (for avoiding 2 seperate connection)               mongooseconnection:mongoose.connections[0],               stringify : true           })        }));     }        app.use(passport.initialize());    app.use(passport.session());        require('./auth/passportauth.js')(passport , facebookstrategy , config , mongoose);        require('./routes/routes.js')(express,app ,passport , config);           /* app.listen (3000 , function(){      console.log("chatup working on port 3000");       console.log('mode:'+ env);   }); */      app.set('port', process.env.port || 3000);            var server = require('http').createserver(app);   var io = require('socket.io').listen(server);      require('./socket/socket.js')(io,rooms);      server.listen(app.get('port' , function(){       console.log('chat on port : '+ app.get('port'));   }))

and here chatrooms.html srcipt :-

$(function() {    var host = '{{config.host}}';    var socket = io.connect(host + '/roomlist'); //   http://localhost:3000/roomlist      socket.on('connect', function() {      console.log('connection established .. !');    })  })

json file contain "host":"http://localhost:3000"

but when run code there error :typeerror : cannot read property 'method' of undefined

console error :-

c:\users\ankur singh\desktop\node\chat app\node_modules\express\lib\router\index.js:138 debug('dispatching %s %s', req.method, req.url); ^

typeerror: cannot read property 'method' of undefined
    at function.handle (c:\users\ankur singh\desktop\node\chat app\node_modules\express\lib\router\index.js:138:33)
    at eventemitter.handle (c:\users\ankur singh\desktop\node\chat app\node_modules\express\lib\application.js:173:10)
    at server.app (c:\users\ankur singh\desktop\node\chat app\node_modules\express\lib\express.js:38:9)
    at server.g (events.js:260:16)
    at emitnone (events.js:67:13)
    at server.emit (events.js:166:7)
    at emitlisteningnt (net.js:1263:10)
    at nexttickcallbackwith1arg (node.js:444:9)
    at process._tickcallback (node.js:366:17)
    at module.runmain [as _ontimeout] (module.js:432:11)
    at timer.listontimeout (timers.js:92:15)

how rid of error. ??

picture of : /router/index.js file :-

error picture

after 9 hours of continuous struggling. have found solution of question.

the error code :-

app.set('port', process.env.port || 3000 );    server.listen(app.get('port' , function(){       console.log('chat on port : '+ app.get('port'));   }));    

and correct code :-

var port = process.env.port || 3000;        server.listen(port, function () {      console.log('updated : server listening @ port %d', port);    }); 

the reference link is:- correct code reference