【手写promise.all】

Promise.myall = function (list) {
    const results = [];
    let count = 0;
    return new Promise((resolve, reject) => {
        list.map((promise, index) => {
            promise.then((r) => {
                results[index] = r;
                count += 1;
                if (count === list.length) {
                    resolve(results)
                }
            }, (reason) => {
                reject(reason)
            })
        })
    })
}