How to add a unique ID to each entry in my JSON object?

Instead of using a number/id in the recursive function I build a string.

let myTree = [{
    text: 'Batteries',
    children: [{
        text: 'BatteryCharge'
      },
      {
        text: 'LiIonBattery'
      }
    ]
  },
  {
    text: 'Supplemental',
    children: [{
      text: 'LidarSensor',
      children: [{
          text: 'Side'
        },
        {
          text: 'Tower'
        }
      ]
    }]
  }
];


function addUniqueID(arr, idstr = '') {
  arr.forEach((obj, i) => {
    obj.id = `${idstr}${i}`;
    if (obj.children) {
      addUniqueID(obj.children, `${obj.id}-`);
    }
  });
}

addUniqueID(myTree);

console.log(myTree);