cancellablePromise.js

function cancellable() {
    let isRunning = true;
    const p = new Promise((resolve, reject) => {

        setTimeout(() => {
            if (!isRunning) return reject();
            resolve();
        }, 1000)
    });

    p.stoppp = () => (isRunning = false);
    return p;
}

var a = cancellable();
a.stoppp();
a.then(() => console.log('a resolved')).catch(e => console.log('a caught', e))



var b = cancellable();
b.then(() => console.log('b resolved')).catch(e => console.log('b caught', e))