In place quicksort in JavaScript

quicksort.js

function quickSort(arr) {
  return quickSortAuxillary(arr, 0, arr.length - 1);
}

function quickSortAuxillary(arr, left, right) {
  if (left < right) {
    const middle = partition(arr, left, right);
    quickSortAuxillary(arr, left, middle - 1);
    quickSortAuxillary(arr, middle + 1, right);
  }
}

function partition(arr, left, right) {
  const pivot = arr[right];
  let i = left;
  for (let j = left; j < right; j++) {
    if (arr[j] < pivot) {
      swap(arr, i++, j);
    }
  }
  if (arr[right] < arr[i]) {
    swap(arr, i, right);
  }
  return i;
}

function swap(arr, i, j) {
  const temp = arr[i];
  arr[i] = arr[j];
  arr[j] = temp;
}