Processing list using promises

processListUsingPromises.js

const Promise = require('bluebird');

const list = [1, 2, 3, 4];

function multiplyBy2(x) {
    return Promise.resolve(x * 2);
}

Promise.all(list.map(multiplyBy2))
    .then(console.log);

// Result will be 2, 4, 6, 8