app.set('port', port) 'TypeError: undefined n'est pas une fonction". Débutant, besoin d'idées

Je suis un amateur d'apprendre à construire avec node.js. J'ai suivi un tutoriel pour créer mon premier node.js app. Il a fonctionné parfaitement jusqu'à ce que j'ai entré 'npm démarrer". Le journal est:

C:\node\nodeteest3\bin\www:16
TypeError: undefined is not a function
    at Object.<anonymous> M+<C;\node\nodetest3\bin\www:16:5
    at Module_compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.module.runMain (module.js:501:10)
    at startup(node.js:129:16)
    at node.js:814:3

Puis elle sortie d'environ 20 lignes commençant par "npm ERR! "+ filepaths, que je ne pense pas que, du fait que l'erreur semble être dans le fichier bin. Le code est

#!/usr/bin/env node
/**
* Module dependencies.
*/

var app = require('../app');
var debug = require('debug')('nodetest3:server');
var http = require('http');

/**
* Get port from environment and store in Express.
 */

var port = normalizePort(process.env.PORT || '3000');

C'est là l'erreur des points:

[app.set('port', port);]

-------^erreur de pointeur 's'-donc clairement à propos des------------

app.set('port', port);
/**
* Create HTTP server.
*/
var server = http.createServer(app);
/**
* Listen on provided port, on all network interfaces.
*/
server.listen(port);
server.on('error', onError);
server.on('listening', onListening);
/**
* Normalize a port into a number, string, or false.
*/
function normalizePort(val) {
var port = parseInt(val, 10);
if (isNaN(port)) {
//named pipe
return val;
}
if (port >= 0) {
//port number
return port;
}
return false;
}
/**
* Event listener for HTTP server "error" event.
*/
function onError(error) {
if (error.syscall !== 'listen') {
throw error;
}
var bind = typeof port === 'string'
? 'Pipe ' + port
: 'Port ' + port;
//handle specific listen errors with friendly messages
switch (error.code) {
case 'EACCES':
console.error(bind + ' requires elevated privileges');
process.exit(1);
break;
case 'EADDRINUSE':
console.error(bind + ' is already in use');
process.exit(1);
break;
default:
throw error;
}
}
/**
* Event listener for HTTP server "listening" event.
*/
function onListening() {
var addr = server.address();
var bind = typeof addr === 'string'
? 'pipe ' + addr
: 'port ' + addr.port;
debug('Listening on ' + bind);
}
Like I said in the beginning, I'm a complete beginner with command-line/github, but I'm already in love with it. I try to practice it every night after I finish my homework, and am getting really frustrated about getting stuck because I haven't been able to move forward for four days now. Also, I'm running this on node.js and the OS is Windows 8. Anything helps!  Let me know if you want me to post any of the other code; I omitted so as to not add more than necessary.
"../app (app.js file) JUST ADDED"***************************
../app file:
[ App.js   ]
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser'); 
var routes = require('./routes/index');
var users = require('./routes/users');
var app = express();
/// catch 404 and forwarding to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
var app = express();
//error handlers
//development error handler
//will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
var app = express();
//view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
//uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json({estended: true}));
app.use(bodyParser.urlencoded({extended: true}));
app.use(cookieParser({extended:true}));
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);
// production error handler
//no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});

OriginalL'auteur alexcarll | 2015-05-12