Promise.myAllsettled = function(list) {

    if (list.length === 0) return Promise.resolve([])

    const results = []

    let count = 0

​

    const settled = (index, status, res, resolve) => {

        results[index] = {

            status,

            ...res

        }

        count += 1

        if (count == list.length) {

            resolve(results)

        }

    }

    return new Promise((resolve) => {

        list.map((item, index) => {

            // 把数据都处理成Promise

            Promise.resolve(item).then(

                res => {

                    settled(index, 'fulfilled', {value: res}, resolve)

                },

                err => {

                    settled(index, 'rejected', {reason: err}, resolve)

                }

            )

        })

    })

}

​

const promise1 = Promise.resolve(3);

const promise2 = new Promise((resolve, reject) => setTimeout(reject, 100, 'foo'));

const promises = [promise1, promise2];

​

Promise.myAllsettled(promises).

  then((results) => results.forEach((result) => console.log(result, result.status)));