rails为nilClass验证nomethoderror nil

Question

所以，我在RSpec中作为NoMethodError回来的'authenticate'方法遇到了问题。以下是我的代码。我正在大量借用Michael Hartl的Rails Tutorial，因为我只是在学习Rails和RSpec。

我已经在Hartl的教程中向我的用户模型添加了'has_secure_password'，并且我已成功创建了一个带有password_digest的用户，因此该方法正常运行。这些测试一目了然。不知怎的，我想知道我是否安装了RSpec错误。我已经按照教程进入了一个发球台，没有出现这样的错误。关于为什么会发生这种情况的任何想法？

我的User_spec.rb：

require 'spec_helper'

describe User do

  before do 
     @user = User.new(name: "Example User", email: "user@example.com") 
    end

  subject { @user }

  it { should respond_to(:name) }
  it { should respond_to(:email) }
  it { should respond_to(:password_digest) }
  it { should respond_to(:password) }
  it { should respond_to(:password_confirmation) }
  it { should respond_to(:authenticate) }

  it { should be_valid }

  describe  "when name is not present" do
    before { @user.name = ' ' } 
    it { should_not be_valid}
  end

  describe "name is too long" do
    before { @user.name = "a" * 51 }
    it { should_not be_valid }
  end

  describe "when email format is valid" do
    it "should be valid" do
        addresses = %w[user@foo.COM A_US-ER@f.b.org frst.lst@foo.jp a+b@baz.cn]
        addresses.each do |valid_address|
            @user.email = valid_address
            @user.should be_valid
    end
  end
end

  describe "when email format is invalid" do
    it "should be invalid" do
        addresses = %w[user@foo,com user_at_foo.org example.user@foo.
                     foo@bar_baz.com foo@bar+baz.com]
        addresses.each do |invalid_address|
            @user.email = invalid_address
            @user.should_not be_valid
        end
    end
  end

  describe "when email is taken" do
    before do
        user_with_same_email = @user.dup
        user_with_same_email.email = @user.email.upcase
        user_with_same_email.save
    end

    it { should_not be_valid }
  end

  describe "when password is not present" do
    before { @user.password = @user.password_confirmation = " " }
    it { should_not be_valid }
  end

  describe "when password doesn't match confirm" do
    before { @user.password_confirmation = "mismatch" }
    it { should_not be_valid } 
  end

  describe "when password confirm is nil" do
    before { @user.password_confirmation = nil }
    it { should be_invalid }
  end

  describe "with a password that's too short" do
    before { @user.password = @user.password_confirmation = "a" * 5 }
    it { should_not be_valid }
  end

  describe "return value of authenticate method" do
  before { @user.save }
  let(:found_user) { User.find_by_email(@user.email) }

  describe "with valid password" do
    it { should == found_user.authenticate(@user.password) }
  end

  describe "with invalid password" do
    let(:user_for_invalid_password) { found_user.authenticate("invalid") }

    it { should_not == user_for_invalid_password }
    specify { user_for_invalid_password.should be_false }
  end
 end
end

和我的Gemfile：

source 'https://rubygems.org'

 gem 'rails', '3.2.13'
# To use ActiveModel has_secure_password
 gem 'bcrypt-ruby',  '3.0.1'
 gem 'bootstrap-sass', '2.1'
# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'

group :development, :test do
  gem 'sqlite3', '1.3.5'
  gem 'rspec-rails', '2.11.0'
  gem 'guard-rspec', '1.2.1'
  gem 'guard-spork', '1.2.0'
  gem 'childprocess', '0.3.6'
  gem 'spork', '0.9.2'
end

group :development do
  gem 'annotate', '2.5.0'
end

# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails',   '3.2.5'
  gem 'coffee-rails', '3.2.2'
  gem 'uglifier', '1.2.3'
end
  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
  # gem 'therubyracer', :platforms => :ruby

 gem 'jquery-rails', '2.0.2'

group :test do
  gem 'capybara', '1.1.2'
  gem 'rb-inotify', '0.9'
  gem 'libnotify', '0.5.9'
end

group :production do
  gem 'pg', '0.12.2'
end


# To use Jbuilder templates for JSON
# gem 'jbuilder'

# Use unicorn as the app server
# gem 'unicorn'

# Deploy with Capistrano
# gem 'capistrano'

# To use debugger
# gem 'debugger'

我的用户模型：

class User < ActiveRecord::Base
 attr_accessible :email, :name, :password, :password_confirmation
 has_secure_password
 before_save { |user| user.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, 
                uniqueness: { case_sensitive: false }, 
                format: { with: VALID_EMAIL_REGEX }
 validates :password, presence: true, length: { minimum: 6 }
 validates :password_confirmation, presence: true

end

以下是我从RSpec看到的错误

1) User 
     Failure/Error: it { should be_valid }
       expected valid? to return true, got false
     # ./spec/models/user_spec.rb:29:in `block (2 levels) in <top (required)>'

  2) User return value of authenticate method with invalid password 
     Failure/Error: let(:user_for_invalid_password) { found_user.authenticate("invalid") }
     NoMethodError:
       undefined method `authenticate' for nil:NilClass
     # ./spec/models/user_spec.rb:101:in `block (4 levels) in <top (required)>'
     # ./spec/models/user_spec.rb:104:in `block (4 levels) in <top (required)>'

  3) User return value of authenticate method with invalid password 
     Failure/Error: let(:user_for_invalid_password) { found_user.authenticate("invalid") }
     NoMethodError:
       undefined method `authenticate' for nil:NilClass
     # ./spec/models/user_spec.rb:101:in `block (4 levels) in <top (required)>'
     # ./spec/models/user_spec.rb:103:in `block (4 levels) in <top (required)>'

  4) User return value of authenticate method with valid password 
     Failure/Error: it { should == found_user.authenticate(@user.password) }
     NoMethodError:
       undefined method `authenticate' for nil:NilClass
     # ./spec/models/user_spec.rb:97:in `block (4 levels) in <top (required)>'

  5) User when email format is valid should be valid
     Failure/Error: @user.should be_valid
       expected valid? to return true, got false
     # ./spec/models/user_spec.rb:46:in `block (4 levels) in <top (required)>'
     # ./spec/models/user_spec.rb:44:in `each'
     # ./spec/models/user_spec.rb:44:in `block (3 levels) in <top (required)>

更新

编辑实例用户解决了以下问题：

before do 
     @user = User.new(name: "Example User", email: "user@example.com", 
        password: "foobar", password_confirmation: "foobar") 
    end

Answer 1

在您的用户模型中，您正在验证是否存在密码，因此在您的规范中，您应该将密码传递给新的用户对象。那它应该是有效的。

我猜这也是你遇到身份验证方法问题的原因。