JavaScript Insertion Sort Algorithm

const insertionSort = (array, compareFn = defaultCompare) => {
  const { length } = array;
  let temp;
  for (let i = 1; i < length; i++) {
    let j = i;
    temp = array[i];
    // console.log('to be inserted ' + temp);
    while (j > 0 && compareFn(array[j - 1], temp) === Compare.BIGGER_THAN) {
      // console.log('shift ' + array[j - 1]);
      array[j] = array[j - 1];
      j--;
    }
    // console.log('insert ' + temp);
    array[j] = temp;
  }
  return array;
};

const Compare = {
  LESS_THAN: -1,
  BIGGER_THAN: 1,
  EQUALS: 0
};

function defaultCompare(a, b) {
  if (a === b) {
    return Compare.EQUALS;
  }
  return a < b ? Compare.LESS_THAN : Compare.BIGGER_THAN;
}

let array = [2,1,5,4,3,8,7,6];
array = insertionSort(array);
console.log(array);

Output:

[1, 2, 3, 4, 5, 6, 7, 8]