Quicksort implementation using JavaScript

quicksort.js

function quickSort(arr = []) {
  if (arr.length <= 1) {
    return arr;
  }
  let left = [], right = [], same = [];
  let mid = arr[Math.floor((arr.length - 1) / 2)];
  for (let value of arr) {
    if (value === mid) {
      same.push(value);
    } else if (value < mid) {
      left.push(value);
    } else {
      right.push(value);
    }
  }
  return [...quickSort(left), ...same, ...quickSort(right)];
}