Merge Sort Algorithm using javascript

mergeSort.js

function sort(arrL, arrR) {
  const newArray = []
  while (arrL.length && arrR.length) {
    arrR[0] < arrL[0]
      ? newArray.push(arrR.shift())
      : newArray.push(arrL.shift())
  }
  return newArray.concat(arrL, arrR)
}

function mergeSort(arr) {
  if (arr.length <= 1) return arr
  const divider = Math.ceil(arr.length / 2)
  const arrLeft = arr.slice(0, divider)
  const arrRight = arr.slice(divider)
  return sort(mergeSort(arrLeft), mergeSort(arrRight))
}

const arr = [7, 5, 1, 4, 9, 10, 2, 6, 8, 5, 5, 1000000, 33, 96, 98]

console.log(mergeSort(arr)) // [1, 2, 4, 5, 5, 5, 6, 7, 8, 9, 10, 33, 96, 98, 1000000]