class Grape::Validations::Validators::ValuesValidator

def check_values?(val, attr_name)
  values = @values.is_a?(Proc) && @values.arity.zero? ? @values.call : @values
  return true if values.nil?
  param_array = val.nil? ? [nil] : Array.wrap(val)
  return param_array.all? { |param| values.include?(param) } unless values.is_a?(Proc)
  begin
    param_array.all? { |param| values.call(param) }
  rescue StandardError => e
    warn "Error '#{e}' raised while validating attribute '#{attr_name}'"
    false
  end
end

def initialize(attrs, options, required, scope, opts)
  @values = options.is_a?(Hash) ? options[:value] : options
  super
end

def required_for_root_scope?
  return false unless @required
  scope = @scope
  scope = scope.parent while scope.lateral?
  scope.root?
end

def validate_param!(attr_name, params)
  return unless params.is_a?(Hash)
  val = params[attr_name]
  return if val.nil? && !required_for_root_scope?
  val = val.scrub if val.respond_to?(:scrub)
  # don't forget that +false.blank?+ is true
  return if val != false && val.blank? && @allow_blank
  return if check_values?(val, attr_name)
  raise Grape::Exceptions::Validation.new(
    params: [@scope.full_name(attr_name)],
    message: message(:values)
  )
end