sort-insertion/index.js

A simple and fast implementation of insertion sort

'use strict';

/**
 * Sort an array via insertion sort
 *
 * @param  {Array} arr - The array to be sorted.
 * @param  {Function} comparator - Determines how to compare values in the array.
 * @return {Array} - The sorted array.
 */
function insertionSort(arr, comparator) {
  comparator =
    comparator == null
      ? function(a, b) {
          return a > b;
        }
      : comparator;
  arr = arr.slice(0);
  for (var i = 1; i < arr.length; i++) {
    var j = i;
    while (j > 0 && comparator(arr[j - 1], arr[j])) {
      var temp = arr[j];
      arr[j] = arr[j - 1];
      arr[j - 1] = temp;
      j = j - 1;
    }
  }

  return arr;
}

module.exports = insertionSort;