insertion sort in ruby

insertsort.rb

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