JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/bluebird/3.1.5/bluebird.min.js"></script>

JavaScript

"use strict";
Promise.config({cancellation: true});

function delay(ms) {
	return new Promise(function(resolve, reject, onCancel){
  	let interval = setTimeout(ms, resolve);
    onCancel(() => {
    	clearInterval(interval);
      document.body.innerHTML += "Cancelled<br />";
    });
  });
}
document.body.innerHTML += "Starting: <br />";

var p = delay(1000);
p2 = p.then(() => document.body.innerHTML += ("P2"));
p3 = p.then(() => document.body.innerHTML += ("P3"));
p2.cancel();