Why isn't the counter not resetting in my loop?

Question

I have an array of shipments and I am running a loop on the array to find shipments which have more than one package so I can clone them within in a new array. I need to process shipping labels which produce one label per object in the array.

I have added a new key/value pair to show the individual package number from a counter but all my "BAG INDEX" are coming to the same number

// Function to sort the concatenated array
    function compare( a, b ) {
  if ( a["SNAP ID"] < b["SNAP ID"] ){
    return -1;
  }
  if ( a["SNAP ID"] > b["SNAP ID"] ){
    return 1;
  }
  return 0;
}

// Demo shipments array
var shipments = [{
    "SNAP ID": "1234567890",
    "FULL NAME": "Person 1",
    "PACKAGE QTY": 5
    },
    {
        "SNAP ID": "0987654321",
        "FULL NAME": "Person 2",
        "PACKAGE QTY": 2
    },
    {
        "SNAP ID": "5432167890",
        "FULL NAME": "Person 3",
        "PACKAGE QTY": 3
    }
];

// Empty array which will contain cloned shipment objects
var data = [];

// Running loop on the shipments array
for (var i = 0; i < shipments.length; i++) {

        var Pkg = shipments[i]["PACKAGE QTY"]
        var shipment = shipments[i]
        shipment["BAG INDEX"] = 1

    // Running loop on the shipments containing more the 1 packages
    if (Pkg > 1) {

        for (var k = 0; k < (Pkg - 1); k++) {

            data.push(shipment);
            shipment["BAG INDEX"] += 1; 

            };
        };
    };

    var complete = shipments.concat(data);
    var sorted = complete.sort(compare);
    console.log(sorted);

This is what I am getting back

0: {SNAP ID: "0987654321", FULL NAME: "Person 2", PACKAGE QTY: 2, BAG INDEX: 2}
1: {SNAP ID: "0987654321", FULL NAME: "Person 2", PACKAGE QTY: 2, BAG INDEX: 2}
2: {SNAP ID: "1234567890", FULL NAME: "Person 1", PACKAGE QTY: 5, BAG INDEX: 5}
3: {SNAP ID: "1234567890", FULL NAME: "Person 1", PACKAGE QTY: 5, BAG INDEX: 5}
4: {SNAP ID: "1234567890", FULL NAME: "Person 1", PACKAGE QTY: 5, BAG INDEX: 5}
5: {SNAP ID: "1234567890", FULL NAME: "Person 1", PACKAGE QTY: 5, BAG INDEX: 5}
6: {SNAP ID: "1234567890", FULL NAME: "Person 1", PACKAGE QTY: 5, BAG INDEX: 5}
7: {SNAP ID: "5432167890", FULL NAME: "Person 3", PACKAGE QTY: 3, BAG INDEX: 3}
8: {SNAP ID: "5432167890", FULL NAME: "Person 3", PACKAGE QTY: 3, BAG INDEX: 3}
9: {SNAP ID: "5432167890", FULL NAME: "Person 3", PACKAGE QTY: 3, BAG INDEX: 3}
length: 10

Answer 1

You have to create a copy of your object. Otherwise you will increase the BAG INDEX for the objects you already added to your data array as well.

Simply use:

data.push(Object.assign({}, shipment));

Answer 2

You need to create a new object in here:

if (Pkg > 1) {
        for (var k = 0; k < (Pkg - 1); k++) {
            data.push(shipment);
            shipment["BAG INDEX"] += 1; 
          };
  };

Otherwise you're just operating on the same shipment object.