Diff's two hashes with eachother

hash_diff.rb

  def diff_hash(from, to)
    differences = {}

    to.each do |key, value|
      if value.is_a? Hash
        differences[key] = diff_hash_changed_items(from[key], value)

      elsif value.is_a?(Array)
        differences[key] = diff_array(value, from[key])

      elsif from && from.has_key?(key) && value.to_s != from[key].to_s
        differences[key] = [value, from[key]]

      elsif !from || !from.has_key?(key)
        differences[key] = [nil, value]

      end
    end

    differences
  end

  def diff_array(from, to)
    differences = []

    to.each_with_index do |sub_value, index|
      if from[index]
        differences[index] = diff_hash_changed_items(from[index], sub_value)
      else
        differences[index] = diff_hash_changed_items(nil, sub_value)
      end
    end

    differences
  end