Burglary Series (21): Sign Your Name Again

It's the police again. They need more signatures. You should also sign each room list separately. However, the document they sent is incomplete as there is only one room present. As a good citizen that you are, you sign it nevertheless.

This challenge is a bit different as the function you are given already contains some code that you should not change or remove. Also, don't use a return statement, it is already included.

The function receives an object with one nested object as an argument. Your task is:

• on the root object: prevent any kind of changes.
• on the nested object: prevent new properties from being added BUT allow for existing properties to be changed.

Examples

const obj = {
  kitchen: {
    knives: 500,
    stereo: 200,
    signature: ""
  },
signature: "Rocky Balboa"
}

signAgain(obj) {
  // add your code here

  obj.signature = "Terminator"
  obj.extraProperty = "not possible"
  obj.kitchen.piano = 1000
  obj.kitchen.signature = "Rocky Balboa"
  return obj

} ➞ {
  kitchen: {
    knives: 500,
    stereo: 200,
    signature: "Rocky Balboa", //only this field was changed
  },
  signature: "Rocky Balboa"
}

Notes

• For simplicity sake, there's only one nested object.
• If you have suggestions on how to present or further test this challenge please leave a comment.
• This series is part of a collection that focuses on objects. If you are interested in following the breath-taking narrative skills of yours truly or just do some object focused challenges (the challenges are ordered in ascending difficulty order), you can more easily do that here.