業(yè)務(wù)場景

微信小程序中多張圖片選擇后一起上傳時需判斷多張圖片的異步上傳結(jié)果，成功了幾張，失敗了幾張
最新ES2020已有Promise.allSettled，可在代碼中先查看是否已有

代碼

    Promise.allSettled = Promise.allSettled || function(promises) {
        return new Promise(function(resolve, reject) {
            if (!Array.isArray(promises)) {
                return reject(
                    new TypeError("arguments must be an array")
                );
            }
            var resolvedCounter = 0;
            var promiseNum = promises.length;
            var resolvedValues = new Array(promiseNum);
            for (var i = 0; i < promiseNum; i++) {
                (function(i) {
                    Promise.resolve(promises[i]).then(
                        function(value) {
                            resolvedCounter++;
                            resolvedValues[i] = value;
                            if (resolvedCounter == promiseNum) {
                                return resolve(resolvedValues);
                            }
                        },
                        function(reason) {
                            resolvedCounter++;
                            resolvedValues[i] = reason;
                            if (resolvedCounter == promiseNum) {
                                return reject(reason);
                            }
                        }
                    );
                })(i);
            }
        });
    };