Get root prototype on an object

getRootOf.js

function getRootOf(obj) {
  var proto = Object.getPrototypeOf(obj);
  while (!proto.hasOwnProperty('id')) {
    proto = Object.getPrototypeOf(proto);
  }
  return proto;
}

var Obj = {id: 1}

var obj1 = Object.create(Obj);

console.log(getRootOf(obj1));

var obj2 = Object.create(obj1);
console.log(Object.getPrototypeOf(obj2));
console.log(getRootOf(obj2));

getRootOf_v2.js

function getRootOf(obj) {
  var proto = Object.getPrototypeOf(obj);
  var emptyObjProto =  Object.getPrototypeOf({});
  while (Object.getPrototypeOf(proto) !== emptyObjProto) {
    proto = Object.getPrototypeOf(proto);
  }
  return proto;
}

var Obj = {id: 1}

var obj1 = Object.create(Obj);

console.log(getRootOf(obj1));

var obj2 = Object.create(obj1);
console.log(Object.getPrototypeOf(obj2));
console.log(getRootOf(obj2));