bubbleSort.js

const array = [2, 5, 4, 3, 1];

function bubbleSort(array) {
  let swapped;
  do {
    swapped = false;
    for(let i = 0; i < array.length; i++) {
      if(array[i] && array[i + 1] && array[i] > array[i + 1]) {
        [array[i], array[i + 1]] = [array[i + 1], array[i]];
        swapped = true;
      }
    }
  } while(swapped);
  return array;
}

console.log(bubbleSort(array.slice())); // => [ 1, 2, 3, 4, 5 ]