“NoMethodError：未定義的方法`admin？' for nil：NilClass“ - 測試錯誤

Question

我目前正在通過Michael Hartl的Rails教程（第12章）學習Ruby on Rails。 我突然得到以下錯誤。

UsersControllerTest＃test_should_redirect_destroy_when_not_logged_in：NoMethodError：undefined method admin?' for nil:NilClass app/controllers/users_controller.rb:92:in admin?' for nil:NilClass app/controllers/users_controller.rb:92:in admin_user'test / controllers / users_controller_test.rb:48:in block (2 levels) in <class:UsersControllerTest>' test/controllers/users_controller_test.rb:47:in在'塊

這是我的測試代碼：

test "should redirect destroy when not logged in" do
assert_no_difference 'User.count' do
  delete :destroy, id: @user
end
assert_redirected_to login_url
end

我剩下的代碼：

class UsersController < ApplicationController
before_action :correct_user,   only: [:edit, :update]
before_action :admin_user,     only: :destroy
before_action :logged_in_user, only: [:index, :edit, :update, :destroy,
                                    :following, :followers]

def destroy
User.find(params[:id]).destroy
flash[:success] = "User deleted"
redirect_to users_url
end

def index
@users = User.paginate(page: params[:page])
end

def show
@user = User.find(params[:id])
@microposts = @user.microposts.paginate(page: params[:page])
end

def new
@user = User.new
end

def create
@user = User.new(user_params)
if @user.save
  @user.send_activation_email
  flash[:info] = "Please check your email to activate your account."
  redirect_to root_url
else
  render 'new'
end
end

def edit
@user = User.find(params[:id])
end

def update
@user = User.find(params[:id])
if @user.update_attributes(user_params)
  flash[:success] = "Profile updated"
  redirect_to @user
else
  render 'edit'
end
end

def following
@title = "Following"
@user  = User.find(params[:id])
@users = @user.following.paginate(page: params[:page])
render 'show_follow'
end

def followers
@title = "Followers"
@user  = User.find(params[:id])
@users = @user.followers.paginate(page: params[:page])
render 'show_follow'
end


private

def user_params
  params.require(:user).permit(:name, :email, :password,
                               :password_confirmation)
end

# Before filters

# Confirms a logged-in user.
def logged_in_user
  unless logged_in?
  store_location
    flash[:danger] = "Please log in."
    redirect_to login_url
  end
end

# Confirms the correct user.
def correct_user
  @user = User.find(params[:id])
  redirect_to(root_url) unless current_user?(@user)
end

# Confirms an admin user.
def admin_user
  redirect_to(root_url) unless current_user.admin?
end
end

有人可以看看，告訴我哪里出錯了？ 代碼基本上是從教程中復制的，所以我很茫然。

謝謝。

Answer 1

我在Hartl教程中遇到了同樣的錯誤。 問題是遺漏：在users_controller.rb中列出9.53中的銷毀操作。 一旦發現缺少一點，測試就恢復了綠色。

也就是說，如果有人能夠准確解釋為什么會出現這種情況，那將會很棒。

正確的代碼：

before_action :logged_in_user, only: [:index, :edit, :update, :destroy]

Answer 2

像這樣更改admin_user方法： -

def admin_user
    redirect_to(root_url) unless current_user.present? && current_user.admin?
end

這將首先檢查current_user是否存在，然后檢查第二個條件（current_user.admin？）。 如果current_user.present？ 將是假的，然后它不會檢查第二個條件。

Answer 3

您需要更新admin_user方法以檢查用戶是否已登錄。

# Confirms an admin user.
def admin_user
  redirect_to(root_url) if current_user.nil? || !current_user.admin?
end