1-example.js

var when = require('when');
var parallel = require('when/parallel');

parallel([getData, makeFolder])
	.spread(writeFile)
	.then(emailLink)
	.then(console.log);

function getData() {
	return when('the data');
}

function makeFolder() {
	return when('the folder');
}

function writeFile(data, folder) {
	return when(folder + '/' + data);
}

function emailLink(file) {
	return when('http://link.to/the/file');
}