Implementation of Insertion sort. Ascending / Descending

gistfile1.rb

def insertion_sort(array)
  for j in 1...array.length
     i = j - 1
     key = array[j]
     while i >= 0 && array[i] > key
        array[i+1] = array[i]
        i = i - 1
     end
     array[i+1] = key
  end
  array
end

def reverse_insertion_sort(array)
  for j in 1...array.length
    i = j - 1
    key = array[j]
    while i >= 0 && array[i] < key
      array[i+1] = array[i]
      i = i - 1
    end
    array[i+1] = key
  end
  array
end

require 'test/unit'

class InsertionTest < Test::Unit::TestCase
  def test_insertion_sort
    assert_equal([2,3,4,4,6,8], insertion_sort([4,3,2,8,6,4]))
  end

  def test_reverse_insertion_sort
    assert_equal([8,6,4,4,3,2], reverse_insertion_sort([4,3,2,8,6,4]))
  end
end