Script – 22-22 Mar 9

var subsets = function (nums) {
  let res = nums.reduce(
    (subsets, value) =>
      subsets.concat(
        subsets
          .map((set) => [value, ...set])
          .sort(function (a, b) {
            return a - b;
          })
      ),
    [[]]
  );

  for (let i = 1; i < res.length + 1; i++) {
    res[i] = res[i].sort(function (a, b) {
      return a - b;
    });
  }

  return res;
};
console.log(subsets([1, 2, 3]));