Quick Sort in Javascript

quickSort.js

function quickSort(arr) {
  if (arr.length <= 1) return arr;

  const result = [];
  const pivot = arr[Math.floor(arr.length / 2)];
  const left = arr.filter(el => el < pivot);
  const right = arr.filter(el => el > pivot);

  return result.concat(quickSort(left), pivot, quickSort(right));
}

const unsorted = [7, 1, 5, 2, 9, 53, 22];

console.log(quickSort(unsorted));

Problem: Cannot sort duplicated values