__spreadArray不符合预期

[rabit2022]

// iife file test1.jsfl
(function () {
    const set = new Set();
    set.add(0);
    set.add(1);

    // 1.应该使用的方法
    const arr = Array.from(set);
    console.log(arr);


    var __spreadArray = (this && this.__spreadArray) || function (to, from, pack) {

        if (pack || arguments.length === 2) for (var i = 0, l = from.length, ar; i < l; i++) {
            if (ar || !(i in from)) {
                if (!ar) ar = Array.prototype.slice.call(from, 0, i);
                ar[i] = from[i];
            }
        }
        return to.concat(ar || Array.prototype.slice.call(from));
    };
    const arr2 = __spreadArray([],set,true)
    console.log(arr2);

    // 源代码
    console.log([...set])
})();

[ 0, 1 ]
[]
[ 0, 1 ]

[...set] 被翻译为 __spreadArray，但是set.length是undefined,返回[],不符合预期

可以添加以下代码(babel helpers方法)

function _iterableToArray(r) {if ("undefined" != typeof Symbol && null != r[Symbol.iterator] || null != r["@@iterator"]) return Array.from(r); }