Promise: Deferred vs. new Promise

promiseDeferredVsNewPromise.js

function fooAndBarInParallel() {
    // boiler-plate.  meh
    var constructed = new Promise(function(resolve, reject) {
        emitter.once('foo', function(food) {
            resolve(food);
        });
    });

    // such clean.  so code
    var deferred = Promise.deferred();
    emitter.once('bar', function(barred) {
        deferred.resolve(barred);
    });

    return Promise.all([
        constructed,
        deferred.promise,
    ]);
}