RailsTutorial第8章错误的参数数量（1对2）

我被困在第8章的结尾，在这里我得到以下错误消息：

test_authenticated？_should_return_false_for_a_user_with_nil_digest＃UserTest ArgumentError：参数数量错误（2为1）

app / models / user.rb：36：在“已验证？”中

test / models / user_test.rb：65：in'在'中阻止

本教程说，我应该通过它（绿色）。谢谢您的协助

user.rb文件是：

class User < ActiveRecord::Base
  attr_accessor :remember_token
  before_save { self.email = email.downcase }
  validates :name,  presence: true, length: { maximum: 50 }
  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
  validates :email, presence: true, length: { maximum: 255 },
                    format: { with: VALID_EMAIL_REGEX },
                    uniqueness: { case_sensitive: false }
  has_secure_password
  validates :password, presence: true, length: { minimum: 6 }

  # Returns the hash digest of the given string.
  def User.digest(string)
    cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
                                                  BCrypt::Engine.cost
    BCrypt::Password.create(string, cost: cost)
  end

  # Returns a random token.
  def User.new_token
    SecureRandom.urlsafe_base64
  end

  # Remembers a user in the database for use in persistent sessions.
  def remember
    self.remember_token = User.new_token
    update_attribute(:remember_digest, User.digest(remember_token))
  end

   # Forgets a user.
  def forget
    update_attribute(:remember_digest, nil)
  end

  # Returns true if the given token matches the digest.
  def authenticated?(remember_token)
    return false if remember_digest.nil?
    BCrypt::Password.new(remember_digest).is_password?(remember_token)
  end
end

user_test.rb是（64-66）：

test "authenticated? should return false for a user with nil digest" do
        assert_not @user.authenticated?(:remember, '')
end