ruby-on-rails - Rails 教程 : RSpec test decoupling

Question

我正在尝试 Exercise 2 of Chapter 8.5在迈克尔·哈特尔的 Ruby on Rails Tutorial .练习如下:

按照第 8.3.3 节中的示例，浏览用户和身份验证请求规范(即当前位于 spec/requests 目录中的文件)并在 spec/support/utilities.rb 中定义实用程序函数以将测试与实现分离。额外的功劳:将支持代码组织到单独的文件和模块中，并通过将模块正确地包含在规范帮助文件中来使一切正常工作。

示例 8.3.3:实用程序.rb

include ApplicationHelper

def valid_signin(user)
  fill_in "Email",    with: user.email
  fill_in "Password", with: user.password
  click_button "Sign in"
end

RSpec::Matchers.define :have_error_message do |message|
  match do |page|
    page.should have_selector('div.alert.alert-error', text: message)
  end
end

定义 valid_signin(user)函数用于 authentication_pages_spec.rb 的以下 block 中并且工作正常。

describe "with valid information" do
    let(:user){FactoryGirl.create(:user)}
    before { valid_signin(user) }

    it { should have_selector('title', text: user.name) }
    it { should have_link('Profile', href: user_path(user)) }
    it { should have_link('Sign out', href: signout_path) }
    it { should_not have_link('Sign in', href: signin_path) }

    describe "followed by signout" do
        before { click_link "Sign out" }
        it { should have_link('Sign in') }
    end
end

因此，通过这个示例，我开始创建自己的名称 valid_signup(user) :

def valid_signup(user)
    fill_in "Name",         with: user.name
    fill_in "Email",        with: user.email
    fill_in "Password",     with: user.password
    fill_in "Confirmation",         with: user.password_confirmation
end

我在 user_pages_spec.rb 中使用这个 block 像这样:

describe "with valid information" do
  let(:user){FactoryGirl.create(:user)}
  before { valid_signup(user) }

  it "should create a user" do
    expect { click_button submit }.to change(User, :count).by(1)
  end

  describe "after saving the user" do
    before { click_button submit }
    let(:user) { User.find_by_email(user.email) }

    it { should have_selector('title', text: user.name) }
    it { should have_selector('div.alert.alert-success', text: 'Welcome') }
    it { should have_link('Sign out') }
  end
end

它不起作用。 Spork/Guard 报告以下错误:

Failures:

  1) UserPages signup with valid information should create a user
     Failure/Error: expect { click_button submit }.to change(User, :count).by(1)
       count should have been changed by 1, but was changed by 0
     # ./spec/requests/user_pages_spec.rb:46:in `block (4 levels) in '

  2) UserPages signup with valid information after saving the user 
     Failure/Error: before { valid_signup(user) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/support/utilities.rb:10:in `valid_signup'
     # ./spec/requests/user_pages_spec.rb:43:in `block (4 levels) in '

  3) UserPages signup with valid information after saving the user 
     Failure/Error: before { valid_signup(user) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/support/utilities.rb:10:in `valid_signup'
     # ./spec/requests/user_pages_spec.rb:43:in `block (4 levels) in '

  4) UserPages signup with valid information after saving the user 
     Failure/Error: before { valid_signup(user) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/support/utilities.rb:10:in `valid_signup'
     # ./spec/requests/user_pages_spec.rb:43:in `block (4 levels) in '

这些错误似乎暗示了我的 valid_signup(user) 中的 user.name utilities.rb中的函数没有定义，但我看不出有什么原因。我已经多次重启 Guard，并执行了 rake db:test:prepare确保测试数据库(使用 postgresql)是有序的。

这是我的 factories.rb为了完整性:

FactoryGirl.define do
    factory :user do
        name    "Example User"
        email   "user@example.com"
        password    "foobar"
        password_confirmation   "foobar"
    end
end

在我继续尝试解耦更多的测试套件之前，我非常想解决这个错误，更重要的是，了解它的原因。

编辑

我已经尝试过您的提示，并在 user_pages_spec.rb 中编辑了函数如下:

describe "with valid information" do
      before { valid_signup(user) }

      it "should create a user" do
        expect { click_button submit }.to change(User, :count).by(1)
      end

      describe "after saving the user" do
        before { click_button submit }
        let(:user) { User.find_by_email('user@example.com') }

        it { should have_selector('title', text: user.name) }
        it { should have_selector('div.alert.alert-success', text: 'Welcome') }
        it { should have_link('Sign out') }
      end
    end

由于我删除了 let(:user){FactoryGirl.create(:user)}从函数中我猜到函数中不再创建用户所以我需要定义 valid_signup(user)如 user valid_signup 的变量不再由 FactoryGirl 填充:

def valid_signup(user)
    fill_in "Name",     with: "Example User"
    fill_in "Email",    with: "user@example.com"
    fill_in "Password", with: "foobar"
    fill_in "Confirmation", with: "foobar"
end

这不起作用，并给了我以下错误:

Failures:


1) UserPages signup with valid information should create a user
 Failure/Error: before { valid_signup(user) }
 NameError:
 undefined local variable or method user' for #<RSpec::Core::ExampleGroup::Nested_5::Nested_3::Nested_2:0x007fdafc5088c0>
 # ./spec/requests/user_pages_spec.rb:42:inblock (4 levels) in '
2) UserPages signup with valid information after saving the user Failure/Error: it { should have_selector('title', text: user.name) } NoMethodError: undefined method name' for nil:NilClass
 # ./spec/requests/user_pages_spec.rb:52:inblock (5 levels) in '

我还尝试使用 valid_signup(user) 运行测试我以前使用它的方式(使用 user.name, user.email, user.password, user.password_confirmation ，它也不起作用，有错误:

Failures:

  1) UserPages signup with valid information should create a user
     Failure/Error: before { valid_signup(user) }
     NameError:
       undefined local variable or method `user' for #
     # ./spec/requests/user_pages_spec.rb:42:in `block (4 levels) in '

  2) UserPages signup with valid information after saving the user 
     Failure/Error: it { should have_selector('title', text: user.name) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/requests/user_pages_spec.rb:52:in `block (5 levels) in '

接下来我尝试在不传递变量的情况下运行它 user_pages_spec.rb : before { valid_signup() }并且在 utilities.rb 中的函数中没有变量:

def valid_signup()
    fill_in "Name",     with: "Example User"
    fill_in "Email",    with: "user@example.com"
    fill_in "Password", with: "foobar"
    fill_in "Confirmation", with: "foobar"
end

这返回:

Failures:

  1) UserPages signup with valid information should create a user
     Failure/Error: before { valid_signup(user) }
     NameError:
       undefined local variable or method `user' for #
     # ./spec/requests/user_pages_spec.rb:42:in `block (4 levels) in '

  2) UserPages signup with valid information after saving the user 
     Failure/Error: it { should have_selector('title', text: user.name) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/requests/user_pages_spec.rb:52:in `block (5 levels) in '

仍然没有更接近答案。我可能忽略了一些简单的事情。不知道是什么。不过，我得到了我第一次做错的事情:我只是认为 FactoryGirl 是一种创建变量的方法，但我不知道它实际上对我的测试数据库做了什么。

Answer 1

我将尝试解释您的原始测试中发生了什么(我发现它比编辑后的版本更容易修复):

describe "with valid information" do
  let(:user) {FactoryGirl.build(:user)} # FactoryGirl.create will save the instance, you should be using build instead
  before { valid_signup(user) }

  it "should create a user" do
    expect { click_button submit }.to change(User, :count).by(1)
  end

  describe "after saving the user" do
    before { click_button submit }
    # let(:user) { User.find_by_email(user.email) } # this is not needed any more 

    it { should have_selector('title', text: user.name) }
    it { should have_selector('div.alert.alert-success', text: 'Welcome') }
    it { should have_link('Sign out') }
  end
end

关于 FactoryGirl 使用的更多信息: https://github.com/thoughtbot/factory_girl/blob/master/GETTING_STARTED.md#using-factories