JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgithub.com/petkaantonov/bluebird/master/js/browser/bluebird.js"></script>

JavaScript

Promise.delay(1000).then(function() {
    return Promise.delay(1000).then(function () {
        return Promise.delay(2000);
    }).then(function () {
        return Promise.delay(5000)
    });
}).then(function () {
    alert("This is only shown after 8 seconds and not one");
});