Answer 1

//函数
Promise.retry = function (promise, num) {
    console.log(num);
    return promise().then(res => res, function () {
        return num == 1 ? promise() : Promise.retry(promise, --num)
    });
}
//箭头函数
Promise.retry = (promise, num) =>
    promise().then(res => res, () =>
        num == 1 ? promise() : Promise.retry(promise, --num)
    );


//test
Promise.retry(Promise.resolve.bind(Promise, "reslove"), 5);
Promise.retry(Promise.reject.bind(Promise, "reject"), 5);