class Grape::Validations::Validators::SameAsValidator

def build_message
  if options_key?(:message)
    @option[:message]
  else
    format I18n.t(:same_as, scope: 'grape.errors.messages'), parameter: @option
  end
end

def validate_param!(attr_name, params)
  confirmation = options_key?(:value) ? @option[:value] : @option
  return if params[attr_name] == params[confirmation]
  raise Grape::Exceptions::Validation.new(
    params: [@scope.full_name(attr_name)],
    message: build_message
  )
end