1.js

var Q = require('q');
var request = require('request');

var url = 'https://api.github.com/users/boo1ean';
var userAgent = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.94 Safari/537.36';

var getInfo = function() {
	var deferred = Q.defer();

	var opt = {
		url: url,
		headers: {
			'User-Agent': userAgent
		}
	};

	request(opt, function(err, res, body) {
		if (err || res.statusCode != 200) {
			deferred.reject('hahaha');
		} else {
			deferred.resolve(body);
		}
	});

	return deferred.promise;
};

var getError = function(x) {
	var deferred = Q.defer();

	setTimeout(function() {
		deferred.resolve(x + ' seconds!');
	}, 2000);

	return deferred.promise;
};

Q.all([
	getError(1),
	getError(2),
	getError(3),
	getError(4)
]).then(function(results) {
	console.log(results);
});

getInfo()
	.then(function(body) {
		console.log(body);
		return getError();
	}).then(function(number) {
		console.log(number);
		return 2;
	}).then(function(number) {
		console.log(number);
	}).catch(function(reason) {
		console.log('ERROR', reason);
	});