Naive native array implementation in JavaScript

my_array.js

/**
 * as (typeof []) is "object"
 */
function MyArray() {
  const array = Object.create(MyArray.prototype);
  Object.defineProperty(array, 'length', {
    value: 0,
    enumerable: false,
    writable: true,
  });

  for (const key in arguments) {
    array.push(arguments[key]);
  }

  return array;
}

MyArray.prototype.push = function (item) {
  const index = this.length;
  this[index] = item;
  this.length += 1;
  return this.length;
}

MyArray.prototype.pop = function () {
  const index = this.length - 1;
  if (index >= 0) {
    const item = this[index];
    delete this[index];
    this.length -= 1;
    return item;
  }
}