@mbernal/nodejs-create-react-app/servers/express/server.js

#!/usr/bin/env node

/**
 * Module dependencies.
 */
const chalk = require('chalk');
const app = require('./app');
const http = require('http');
const log = console.log;
const dev = (str)=>{

    if(process.env.NODE_ENV!== "development") return;

    return console.log(str);
}

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

var port = normalizePort(process.env.PORT || '5000');
app.set('port', port);

/**
 * Create HTTP server.
 */

var server = http.createServer(app);

/**
 * Socket IO setup if it is attached via middleware
 */
var io = app.get('io');
if(io) io.attach(server);

/**
 * Listen on provided port, on all network interfaces.
 */


server.on('error', onError);
server.on('listening', onListening);
server.listen(port);

/**
 * 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;
    log(`Server ready at ${chalk.green.underline(`http://localhost:${addr.port}`)} \n`);
    dev(`To launch a development server, use ${chalk.blue('npm run start')}.\n`)
    dev("To pass requests from development server.");
    dev(`Set 'proxy' in package.json to ${chalk.blue(`http://localhost:${addr.port}`)} \n`)
}