async.auto.js

async.auto({
    get_data: function(callback){
        callback(null, 'data', 'converted to array');
    },
    make_folder: function(callback){
        callback(null, 'folder');
    },
    write_file: ['get_data', 'make_folder', function(callback, results){
        callback(null, 'filename');
    }],
    email_link: ['write_file', function(callback, results){
        callback(null, {'file':results.write_file, 'email':'[email protected]'});
    }]
}, function(err, results) {
    console.log('err = ', err);
    console.log('results = ', results);
});

bluebird.js

var getData = getDataAsync();

var makeFolder = makeFolderAsync();

var writeFile = Promise.all([
    getData,
    makeFolder
]).spread(writeFileAsync);

var emailLink = writeFile.then(emailLinkAsync);

emailLink.then(function (results) {
    console.log('results =', results);
}).catch(function (err) {
    console.log('err =', err);
});