Record Collection - 'Help'

Help
I don’t know what’s wrong with my code. Please check it, if you may.
I’m not able to pass this requirement:
After updateRecords(5439, "tracks", "Take a Chance on Me") , tracks should have "Take a Chance on Me" as the last element.

Your code so far


// Setup
var collection = {
    "2548": {
      "album": "Slippery When Wet",
      "artist": "Bon Jovi",
      "tracks": [ 
        "Let It Rock", 
        "You Give Love a Bad Name" 
      ]
    },
    "2468": {
      "album": "1999",
      "artist": "Prince",
      "tracks": [ 
        "1999", 
        "Little Red Corvette" 
      ]
    },
    "1245": {
      "artist": "Robert Palmer",
      "tracks": [ ]
    },
    "5439": {
      "album": "ABBA Gold"
    }
};
// Keep a copy of the collection for tests
var collectionCopy = JSON.parse(JSON.stringify(collection));
function updateRecords(id, prop, value) {
  if (prop == "tracks" && value !== "") {
    collection[id].tracks.push(value);
  }
  if (prop == "tracks" && !collection[id].hasOwnProperty("tracks")) {
    collection[id].tracks = [];
    collection[id].tracks.push(value);
  }
  if (prop !== "tracks" && value !== "") {
    collection[id][prop] = value;
  }
  if (value === "") {
    delete collection[id][prop];
  }

  return collection;
}
updateRecords(5439, "artist", "ABBA");

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36.

  if (prop == "tracks" && value !== "") {
    collection[id].tracks.push(value);
  }

When this code runs, it is possible that collection[id].tracks may not exist. In that case you are attempting to push to undefined.