Comparing Q.js and async.js

promises.js

var Q = require('q')
var async = require('async')

function dumbQ(value) {
	var deferred = Q.defer()
	setTimeout(function() {
		deferred.resolve(value)
	}, 200)
	return deferred.promise
}

function dumbA(value, callback) {
	setTimeout(function() {
		return callback(null, value)
	}, 200)
}

function callOneFunctionUsingQ() {
	dumbQ('a').then(function (a) {
		console.log('a', a.valueOf())
	})
}

function callOneFunctionUsingA() {
	dumbA('a', function(err, a) {
		console.log('a', a)
	})
}

function multipleFunctionsUsingQ() {
	var values = [dumbQ('a'), dumbQ('b')]
	Q.allResolved(values).then(function (results) {
		var c = results[0].valueOf() + results[1].valueOf()
		console.log('c', c)
	})
}

function multipleFunctionsUsingA() {
	var values = ['a', 'b']
	async.map(values, dumbA, function(err, results) {
		var c = results[0] + results[1]
		console.log('c', c)
	})
}

// callOneFunctionUsingQ()
// callOneFunctionUsingA()
// multipleFunctionsUsingQ()
// multipleFunctionsUsingA()