k8w-super-promise/index.mjs

Promise with cancel and always

import 'core-js/es/promise/finally';

/**
 * @author k8w
 * email: me@k8w.io
 */
class SuperPromise {
    constructor(executor) {
        this[Symbol.toStringTag] = 'SuperPromise';
        /** have been rs or rj */
        this.isCompleted = false;
        this.isAborted = false;
        this._promise = new Promise((rs, rj) => {
            //重新定义resolve
            let newRs = (value) => {
                if (this.isAborted) {
                    return;
                }
                this.isCompleted = true;
                rs(value);
            };
            //重新定义reject
            let newRj = (err) => {
                if (this.isAborted) {
                    return;
                }
                this.isCompleted = true;
                rj(err);
            };
            executor(newRs, newRj);
        });
    }
    /**
     * 立即取消该Promise
     * 如果取消成功或之前已经取消，则返回true
     * 如果取消失败（已经resolve或reject），则返回false
     */
    abort() {
        var _a;
        if (this.isCompleted) {
            return false;
        }
        if (this.isAborted) {
            return true;
        }
        //abort handler
        this.isAborted = true;
        (_a = this.onAbort) === null || _a === void 0 ? void 0 : _a.call(this);
        return true;
    }
    then(onfulfilled, onrejected) {
        this._promise = this._promise.then(onfulfilled, onrejected);
        return this;
    }
    catch(onrejected) {
        this._promise = this._promise.catch(onrejected);
        return this;
    }
    finally(onfinally) {
        this._promise = this._promise.finally(onfinally);
        return this;
    }
}

export { SuperPromise };