启动Node.js Express应用程序

Question

I created an application with

$ express -c stylus express_example

I can start my server with

$ npm start

but

$ node app.js

&

$ nodemon app.js

don't seem to work. I don't get any error messages though, terminal just goes to the next line. eg

$ node app.js
$

This is my bin/www file

#!/usr/bin/env node
var debug = require('debug')('my-application');
var app = require('../app');

app.set('port', process.env.PORT || 3000);

var server = app.listen(app.get('port'), function() {
    debug('Express server listening on port ' + server.address().port);
});

and my app.js file

var express = require('express');
var path = require('path');
var favicon = require('static-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();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(favicon());
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded());
app.use(cookieParser());
app.use(require('stylus').middleware(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);

/// catch 404 and forwarding to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

/// 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
        });
    });
}

// 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: {}
    });
});

module.exports = app;

Answer 1

Figured it out. Since my server is started in the bin/www file as opposed to the app.js file, from the terminal I went into my bin directory and then called

$ node wwww

or

$ nodemon www

Answer 2

Your npm start probably calls your bin/www file. Which contains the listen invocation to start your app.

Many people set up their app this way. eg. app.js to define and configure their app, and something like bin/www to actual get the server running. This way they can include the app.js into other parts, say tests, without actually starting the server when you require it.

Answer 3

You have in your package.json file a property where you can point out the entry point of your application. For example:

"scripts": {
  "start": "node ./bin/www"
}