gistfile1.js

var Promise = require('bluebird');

var pipeline = function (tasksThatReturnPromises, prevValue) {

    var first = tasksThatReturnPromises.shift();

    return Promise.resolve(first(prevValue)).then(function (v) {
        if (tasksThatReturnPromises.length === 0) {
            return v;
        } else {
            return pipeline(tasksThatReturnPromises, v);
        }
    });

};

var fs = Promise.promisifyAll(require('fs'));



pipeline([
    function () {
        return fs.readFileAsync('./pipe.js');
    },
    function (contents) {
        return contents.toString();
    },
    function (stringedContents) {
        return new Promise(function (resolve, reject) {
            setTimeout(function () {
                resolve('LOL' + stringedContents + 'LOL');
            }, 3000);
        });
    }
]).then(function (result) {
    console.log(result);
});