Rspec: everyday-rspec实操。5：controller test（了解基础）

第 5 章 控制器测试 

5.1基础

rails generate rspec:controller home 

RSpec.describe HomeController, type: :controller do

  describe '#index' do

    it "responds successfully" do

      get :index

      expect(response).to be_success

      # response 对象包含应用返回给浏览器的所有数据，包括 HTTP 响应码。

      # be_success 检查响应的状态是成 功(200 响应)还是失败(例如 500 异常)。

      expect(response).to have_http_status "200" 

    end

  end

end

be_success匹配器 ,have_http_status()匹配器

5.2要验证身份的controller test

如果程序有Devise。测试的时候，需要身份验证，则使用Devise Test helpers

Devise includes some test helpers for controller and integration tests. In order to use them, you need to include the repective module in you test cases/specs. 

包含一个测试模块.

class PostsControllerTest < ActionController::TestCase
include Devise::Test::ControllerHelpers
end

class PostsTests < ActionDispatch::IntegrationTest
include Devise::Test::IntegrationHelpers
end

RSpec.configure do |config|
config.include Devise::Test::IntegrationHelpers, type: :feature

 config.include Devise::Test::ControllerHelpers, type: :controller

 config.include Devise::Test::ControllerHelpers, type: :view

end

然后就可以使用sign_in, sign_out方法了

redirect_to 匹配器 

以下测试都是get的测试。

ProjectsController

  #inde

    as an authenticated user

      responds successfully

      returns a 200 response

    as a guest

      returns a 302 response

      redirects to the sign_in page

  #show

    as an authorized user

      responds successfully

    as an unauthorized user

      redirects to the dashboard

5.3 测试用户输入。

HTTP GET外，还有POST, PATCH, DELETE与controller交互。

Method: FactoryBot::Syntax::Methods#attributes_for

#attributes_for(name, *traits_and_overrides, &block) ⇒ Hash

根据factories中的注册的name, 生成一个hash属性。

  describe '#create' do

    context "as an authenticated user" do

      before do

        @user = FactoryGirl.create(:user)

      end

      it "adds a project" do

        project_params = FactoryGirl.attributes_for(:project)

        sign_in @user

        expect {

          post :create, params: {project: project_params }

        }.to change(@user.projects, :count).by(1)

#expect(@user.projects.count).to eq(1)  #替代方法 

      end

    end

change()方法，by()方法，是哪里定义的？ 

在gem rspec-expectations 中定义的。

This class is part of a private API. 文档提示：私有类，尽量避免使用.

https://www.rubydoc.info/gems/rspec-expectations/RSpec/Matchers:change 

  describe '#update' do

    context 'as an authorized user' do

      before do

        @user = FactoryGirl.create(:user)

        @project = FactoryGirl.create(:project, owner: @user)

      end

      it "updates a project" do

        project_params = FactoryGirl.attributes_for(:project, name: "New Project Name")

        sign_in @user

        patch :update, params: {id: @project.id, project: project_params}

#已经更新数据库，但内存里@project实例变量没有更新，所以要reload. 

        @project.reload

        expect(@project.name).to eq "New Project Name"

      end

    end

  end

reload()方法 从数据库中根据接收者的primary-key id调取record并更新接收者的属性。

Reloading is commonly used in test suites to test something is actually written to the database, or when some action modifies the corresponding row in the database but not the object in memory:

经常用于测试，测试记录实际已写入数据库，或者测试当一些action在数据库中修改了相关记录但在内存中已存在这个对象变量是否更新。

5.4 测试用户输入导致的错误 

    context "with invalid attributes" do

      before do

        @user = FactoryGirl.create(:user)

      end

      it "does not add a project" do

        project_params = FactoryGirl.attributes_for(:project, :invalid)

        sign_in @user

        post :create, params: {project: project_params}

        expect(@user.projects.count).to eq(0)

        # expect {

        #   post :create, params: { project: project_params }

        # }.to_not change(@user.projects, :count)

      end

    end

这里用到trait，在projects.rb的中定义的一个trait

trait :invalid do

  name nil

end 

⚠️ trait 和 factory继承的区别，一个是增加特点，用的时候需要和预构件一起用；一个是完全继承父类属性并增加自己的特色，是一个新的预构件。

5.5

处理非 HTML 输出 ，如何编写对JSON格式的测试。

bin/rails g rspec:controller tasks 

spec/controllers/tasks_controller_spec.rb 测试控制器show动作

RSpec.describe TasksController, type: :controller do

  before do

    @user = FactoryGirl.create(:user)

    @project = FactoryGirl.create(:project, owner:@user)

    @task = @project.tasks.create!(name: "Test task")

  end

  describe '#show' do

    it "responds with JSON formatted output" do

      sign_in @user

      get :show, format: :json,

        params:{project_id: @project.id, id: @task.id}

      expect(response.content_type).to eq "application/json"

    end

  end

end

通过format: :json格式，控制器处理相应的请求，返回application/json类型的内容。

content_type方法属于 ActionDispatch::Response类的实例方法。

5.6小结

控制器测试，测试的是user登陆和未登陆状态下，已经不同用户权限下，对action 是否成功的测试。

在实际测试中，控制器测试已经不流行了。