gistfile1.txt

var Promise = require('bluebird');

function doSomethingAsync(data, callback) {
   return $blueBirdPromise
    .tap(function() {
      console.log('Op is successful');
    })
    .nodeify(callback);
};

allows to write:

doSomethingAsync(function(err, data) {

});

or doSomethingAsync.then(function(data) { }).catch(function(err) { });