GitFOSS

# From Rails
# https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/hash/deep_transform_values.rb
class Hash(K, V)
  # Returns a new hash with all values converted by the block operation.
  # This includes the values from the root hash and from all
  # nested hashes and arrays.
  #
  #  hash = { person: { name: 'Rob', age: '28' } }
  #
  #  hash.deep_transform_values{ |value| value.to_s.upcase }
  #  # => {person: {name: "ROB", age: "28"}}
  def deep_transform_values(&block : V -> _)
    _deep_transform_values_in_object self, &block
  end

  # Destructively converts all values by using the block operation.
  # This includes the values from the root hash and from all
  # nested hashes and arrays.
  def deep_transform_values!(&block : V -> V)
    _deep_transform_values_in_object! self, &block
  end

  private def _deep_transform_values_in_object(object, &block : V -> _)
    case object
    when Hash
      object.transform_values { |v| _deep_transform_values_in_object v, &block }
    when Array
      object.map { |e| _deep_transform_values_in_object e, &block }
    else
      return object
    end
  end

  private def _deep_transform_values_in_object!(object, &block : V -> V)
    case object
    when Hash
      object.transform_values! { |value| _deep_transform_values_in_object! value, &block }
    when Array
      object.map! { |e| _deep_transform_values_in_object! e, &block }
    else
      yield object
    end
  end
end