Hartl Rails 教程：第 8 章测试错误"Password should be present"

Question

我是Ruby/Rails的新手，一直在学习Hartl教程，我已经完成了第8章，但现在我的一个测试无法通过。失败的测试如下：

  test "password should be present (nonblank)" do
    @user.password = @user.password_confirmation = " " * 6
    assert_not @user.valid?
  end

当我运行它时，测试输出以下内容：

2) Failure:
UserTest#test_password_should_be_present_(nonblank) [/home/ubuntu/workspace/sample_app/test/models/user_test.rb:61]:
Expected true to be nil or false

这个测试通过了，直到我运行了

$ rails generate migration add_remember_digest_to_users remember_digest:string
$ bundle exec rake db:migrate

我完成了本章的剩余部分，除了我之前提到的那个之外，所有的测试失败都得到了解决。这个测试似乎期望false或nil，但由于某种原因，我的代码返回true。

这是我的user.rb

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-zd-.]+.[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, 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
  # 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
  # Forgets a user.
  def forget
    update_attribute(:remember_digest, nil)
  end
end

我的用户_控制器.rb

class UsersController < ApplicationController
  def show
    @user = User.find(params[:id])
  end
  def new
    @user = User.new
  end
  def create
    @user = User.new(user_params)
    if @user.save
      log_in @user
      flash[:success] = "Welcome to the Sample App!"
      redirect_to @user
    else
      render 'new'
    end
  end
  private
    def user_params
      params.require(:user).permit(:name, :email, :password, 
                                   :password_confirmation)
   end
end

我的会话_controller.rb

class SessionsController < ApplicationController
  def new
  end
  def create
    user = User.find_by(email: params[:session][:email].downcase)
    if user && user.authenticate(params[:session][:password])
      log_in user
      params[:session][:remember_me] == '1' ? remember(user) : forget(user)
      redirect_to user
    else
      flash.now[:danger] = 'Invalid email/password combination'
      render 'new'
    end
  end
  def destroy
    log_out if logged_in?
    redirect_to root_url
  end
end

最后是我的sessions_helper.rb

模块SessionsHelper

  # Logs in the given user.
  def log_in(user)
    session[:user_id] = user.id
  end
  # Remembers a user in a persistent session.
  def remember(user)
    user.remember
    cookies.permanent.signed[:user_id] = user.id
    cookies.permanent[:remember_token] = user.remember_token
  end
  # Returns the user corresponding to the remember token cookie.
  def current_user
    if (user_id = session[:user_id])
      @current_user ||= User.find_by(id: user_id)
    elsif (user_id = cookies.signed[:user_id])
      user = User.find_by(id: user_id)
      if user && user.authenticated?(cookies[:remember_token])
        log_in user
        @current_user = user
      end
    end
  end
  # Returns true if the user is logged in, false otherwise.
  def logged_in?
    !current_user.nil?
  end
  # Forgets a persistent session.
  def forget(user)
    user.forget
    cookies.delete(:user_id)
    cookies.delete(:remember_token)
  end
  # Logs out the current user.
  def log_out
    forget(current_user)
    session.delete(:user_id)
    @current_user = nil
  end
end

如果这是一个简单的错误，我很抱歉，但我是这些语言的新手，已经为此挠头一段时间了。

感谢

Answer 1

尝试将密码验证更改为validates :password, length: { minimum: 6 }, presence: true

请参阅本书第6.2.2节。清单6.9使用以下代码来验证名称的存在：

class User < ActiveRecord::Base
  validates :name, presence: true
end

Michael接着解释说，presence: true还要求name属性不是Rails认为"空白"的空间列表。