AbortablePromise

abortable-promise.js

class AbortablePromise{
    constructor(fn, parent) {
        this._reject;
        this._aborted = false;
        this._parent = parent;
        this._promise = Promise.race([
            new Promise((res, rej) => {
                this._reject = rej;
            }),
            new Promise(fn)
        ])
        .then((res) => res);
    }

    abort() {
        if (this._parent) {
            this._parent.abort();
        }
        this._reject({aborted: true});
    }

    toPromise() {
        return this._promise;
    }
    
    then(fn1, fn2) {
        return new AbortablePromise((res, rej) => {
            return this.toPromise().then(fn1, fn2).then(res, rej);
        }, this);
    }

    catch(fn) {
        return new AbortablePromise((resolve, reject) => {
            return this.toPromise().catch(res => {
                if (res && res.aborted) {
                    return Promise.reject(res);
                }
                return fn(res);
            }).then(resolve, reject);
        }, this);
    }
        
    finally(fn) {
        return new AbortablePromise((res, rej) => {
            return this.toPromise().finally(fn).then(res, rej);
        }, this);
    }
}
const delay = () => new Promise(res => setTimeout(()=> {res("delay")}, 5000));

// promise
const p = new AbortablePromise((res, rej) => res("aa"))
    .then(() => {console.log(1); return Promise.reject(123)})
    .catch((res) => {console.log(res);console.log("error")})
    .then(() => {console.log(2); return delay()})
    .then((res) => {console.log(res);console.log(3); return delay()})
    .then(() => {console.log(4); return delay()})
    .then(() => {console.log(5); return delay()})
    .then(() => {console.log(6); return delay()})
    .finally(()=> {console.log("end")});

console.log(p) // p.abort();
    
// async / await
const fn = async () => {
    p2 = new AbortablePromise((res, rej) => {return delay().then(res)});
    await p2;
    console.log(2)
}
fn();