Quicksort in JavaScript

qsort.js

const arrayToSort = [1,9,2,8,3,7,4,6,5];

const sort = array => {
  if (array.length < 2) return array;
  const [pivot, ...restItems] = array;
  const less = [...restItems].filter(item => item < pivot);
  const greater = [...restItems].filter(item => item > pivot);
  console.log('test');
  return sort(less).concat(pivot).concat(sort(greater));
};

console.log(sort(arrayToSort));