class Hashdiff::LinearCompareArray

def index_of_match_after_additions
  return unless expected_additions > 0
  (1..expected_additions).each do |i|
    next_difference = item_difference(
      old_array[old_index],
      new_array[new_index + i],
      old_index
    )
    return new_index + i if next_difference.empty?
  end
  nil
end