如果我使用传播语法，如何完全返回内部嵌套对象的数组？

Question

I try to group the objects in an array, by their respective group number. I also added extra fields to tag objects if he/she is a leader or a member. That works, but my problem is, the 'advisers' objects inside my nested array were not returning. It is null when I uses spread syntax to return.

This is my array:

const data = [{
  "name": "John",
  "groupNo": 1
}, {
  "name": "Chelsea",
  "groupNo": 1
}, {
  "name": "Mark",
  "groupNo": 1
}, {
  "name": "Mary",
  "groupNo": 8
}, {
  advisers: [{
    "name": "Kenedy",
    "groupNo": 1
  }, {
    "name": "Chelsea",
    "groupNo": 1
  }, {
    "name": "Chris",
    "groupNo": 8
  }];
}];

This is my code for adding extra fields. It works but the advisers array is null .

const output = data.map(function(member) {
  if (this.has(member.groupNo)) {
    // Member
    return {
      ...member,
      "leaderNo": "",
      "memberNo": this.size
    }
  }
  // Leader
  this.add(member.groupNo)
  return {
    ...member,
    "leaderNo": this.size,
    "memberNo": ""
  }
}, new Set())

console.log(output);

I just want to retain all data in array including advisers array

Answer 1

Your array is not consistent so you can add a check for the advisers key in the map function and go from there. Something like:

const {advisers} = member; 
if(advisers){
   return {advisers};
}