Rspec如何创建一个方法来“干燥”请求的一些参数？

Posted 2023-02-23

【中文标题】Rspec如何创建一个方法来“干燥”请求的一些参数？

【英文标题】：Rspec how to create an method to "DRY" only some params of a request?

【发布时间】：2018-08-23 00:22:08

【问题描述】：

我想测试我的项目的创建方法，但是这个创建方法在我的表单中有 3 个步骤，我想测试所有步骤。要测试每个步骤，我需要发送一个带有相应步骤参数的创建请求。

问题是：我在每一步都重复了很多参数，我想知道如何将常用参数放在一个方法中，然后调用它。

这是我的 rspec 文件

require 'rails_helper'

RSpec.describe Api::MenteeApplicationsController, type: :controller do
    describe "Api Mentee Application controller tests" do
        let(:edition)  create(:edition) 

        it 'should start create a Mentee Application, step 1' do
            edition
            post :create, application: 
                first_name: "Mentee", last_name: "Rspec", email: "[e-mail]",
                gender: "female", country: "IN", program_country: "IN",
                time_zone: "5 - Mumbai", communicating_in_english: "true",
                send_to_mentor_confirmed: "true",
                time_availability: 3,
                previous_programming_experience: "false" ,
                step: "1", steps: "3"

            expect(response).to have_http_status(200)
        end

        it 'should continue to create a Mentee Application, step 2' do
            post :create, application: 
                first_name: "Mentee", last_name: "Rspec", email: "[e-mail]",
                gender: "female", country: "IN", program_country: "IN",
                time_zone: "5 - Mumbai", communicating_in_english: "true",
                send_to_mentor_confirmed: "true",
                time_availability: 3,
                motivation: "Motivation",
                background: "Background",
                team_work_experience: "Team Work Experience",
                previous_programming_experience: "false" ,
                step: "2", steps: "3"

            expect(response).to have_http_status(200)
        end

        it 'should not create a Mentee Application in api format' do
            applications = MenteeApplication.count
            post :create, application: 
                first_name: "Mentee", last_name: "Rspec", email: "[e-mail]",
                gender: "female", country: "IN", program_country: "IN",
                time_zone: "5 - Mumbai", communicating_in_english: "true",
                send_to_mentor_confirmed: "true",
                motivation: "Motivation",
                background: "Background",
                team_work_experience: "Team Work Experience",
                previous_programming_experience: "false", experience: "",
                operating_system: "mac_os",
                project_proposal: "Project Proposal",
                roadmap: "Roadmap",
                time_availability: 3,
                engagements: ["master_student", "part_time", "volunteer", "one_project"] ,
            step: "3", steps: "3"

            expect(response).to have_http_status(:unprocessable_entity)
            expect(MenteeApplication.count).to be(0)
        end

        it 'should create a Mentee Application in api format (step 3)' do
            applications = MenteeApplication.count
            post :create, application: 
                first_name: "Mentee", last_name: "Rspec", email: "[e-mail]",
                gender: "female", country: "IN", program_country: "IN",
                time_zone: "5 - Mumbai", communicating_in_english: "true",
                send_to_mentor_confirmed: "true",
                motivation: "Motivation",
                background: "Background",
                programming_language: "ruby",
                team_work_experience: "Team Work Experience",
                previous_programming_experience: "false", experience: "",
                operating_system: "mac_os",
                project_proposal: "Project Proposal",
                roadmap: "Roadmap",
                time_availability: 3,
                engagements: ["master_student", "part_time", "volunteer", "one_project"] ,
            step: "3", steps: "3"

            expect(response).to have_http_status(200)
            expect(MenteeApplication.count).to be(applications+1)
            expect(flash[:notice]).to eq("Thank you for your application!")
        end

    end
end

如您所见，第 1 步中的参数在第 2 步和第 3 步中使用，所以我的想法是这样的：

def some_params
    params.require(:application).permit(first_name: "Mentee", last_name: "Rspec", email: "[e-mail]",
            gender: "female", country: "IN", program_country: "IN",
            time_zone: "5 - Mumbai", communicating_in_english: "true",
            send_to_mentor_confirmed: "true",
            time_availability: 3,
            previous_programming_experience: "false")
end

但是没有用，我该怎么做？

【参考方案1】：

let 块允许您定义在测试用例中使用的变量 (its)。需要注意的一些关键点：

它们被延迟评估：在您调用变量之前，块中的代码不会运行（除非您使用 bang -- let! -- 这会强制评估） 它们可能会在内部contexts 中被覆盖

前往RSpec docs 了解更多信息。

---

您提供的代码可以像这样使用lets：

require 'rails_helper'

RSpec.describe Api::MenteeApplicationsController, type: :controller do
    describe "Api Mentee Application controller tests" do
        let(:edition)  create(:edition) 
        let(:first_step_params) do
          
            first_name: 'Mentee',
            last_name: 'Rspec',
            #...
            previous_programming_experience: false,
          
        end
        let(:second_step_params) do
          
            motivation: "Motivation",
            background: "Background",
            team_work_experience: "Team Work Experience",
          .merge(first_step_params)
        end
        let(:third_step_params) do
          
            operating_system: "mac_os",
            project_proposal: "Project Proposal",
            roadmap: "Roadmap",
            time_availability: 3,
            engagements: ["master_student", "part_time", "volunteer", "one_project"],
          .merge(third_step_params)
        end

        it 'should start create a Mentee Application, step 1' do
            edition                                                          

            post :create, application: first_step_params, step: "1", steps: "3"

            expect(response).to have_http_status(200)                        
        end                                                                  

        it 'should continue to create a Mentee Application, step 2' do       
            post :create, application: second_step_params, step: "2", steps: "3"

            expect(response).to have_http_status(200)                        
        end

        it 'should not create a Mentee Application in api format' do
            applications = MenteeApplication.count

            post :create, application: third_step_params, step: "3", steps: "3"

            expect(response).to have_http_status(:unprocessable_entity)
            expect(MenteeApplication.count).to be(0)
        end
    end
end

其他建议

1。不要实现控制器规范

控制器旨在成为用户界面和后台服务之间的薄软件层。他们的测试很难被承认为集成（端到端）或单元测试。

我建议您改为实施功能规范。 （capybara 非常适合使用 RSpec 进行 Rails 测试）

这个blog post 可能会提供更多关于此的见解。

2。不要在你的测试用例描述中使用 should

见betterspecs.org。

3。注意

中的最后一个逗号

let(:application_params) do                                                      
                                                                    
    first_name: 'Mentee',                                            
    last_name: 'Rspec',                                              
    #...                          
    previous_programming_experience: false,
                                                                    
end

它阻止incidental changes。

4。使用 .rspec 文件

内容如

--require rails_helper

因此您不需要在每个规范文件的顶部使用require 'rails_helper'。

5。使用contexts

这也是来自 betterspecs.org 的指导。你可以做类似的事情

RSpec.describe Api::MenteeApplicationsController, type: :controller do
    describe "Api Mentee Application controller tests" do
        let(:edition)  create(:edition) 
        let(:application_params) do
          
            #...
          
        end
        let(:step)  1 

        it 'should start create a Mentee Application' do
            edition

            post :create, application: application_params, step: step, steps: "3"

            expect(response).to have_http_status(200)
        end

        context 'in second step' do
          let(:step)  2 

          it 'should continue to create a Mentee Application' do
              post :create, application: application_params, step: step, steps: "3"

              expect(response).to have_http_status(200)
          end
        end
    end
end

contexts 也可以方便地处理额外的参数：

RSpec.describe Api::MenteeApplicationsController, type: :controller do
  describe "Api Mentee Application controller tests" do
    let(:edition)  create(:edition) 
    let(:application_params) do
      common_params.merge(additional_params)
    end
    let(:commom_params) do
      
        #...
      
    end
    let(:additional_params)   

    it 'creates an application' do
      post :create, application: application_params
    end

    context 'with API params' do
      let(:additional_params) do
        
          #...
        
      end

      it 'creates an application' do
        post :create, application: application_params
      end
    end
  end
end

请注意，post 方法调用在两种上下文中变得完全相同。这将允许重用它（在before 块甚至另一个let 块中）。

【讨论】：

这不提供新的应用程序参数。

谢谢@JohanWentholt。我已经更新了答案。你怎么看？

我不想成为讨厌的人，但是您已经添加了第 3 步参数，但仍然忽略了第 2 步。

@MatheusSantana 这适用于第 1 步，但我无法使其适用于第 2 步和第 3 步。第 2 步的代码：post :create, application: application_params motivation: "Motivation", background: "Background", team_work_experience: "Team Work Experience" , step: "2", steps: "3"

最后要记住的最后一件事是与前面的参数合并，它会覆盖您正在创建的哈希。这意味着如果您有两个冲突的键，则选择前一个参数的值。如果您不希望这种行为，您必须更改顺序并在以前的参数上调用 #merge，提供新添加的内容。

【参考方案2】：

我想我会很想像下面那样做。本质上：

创建一个名为 @full_application 的记忆变量并将其包装在一个方法中（我已在测试底部完成此操作）。

创建常量，规定每个测试所需的值的子集，例如 STEP_ONE_PARAMS、STEP_TWO_PARAMS 等。

在每个it 块中，使用.slice 和上面定义的常量从full_application 中“获取”您要使用的值。

类似这样的：

require 'rails_helper'

RSpec.describe Api::MenteeApplicationsController, type: :controller do

  STEP_ONE_PARAMS = %w(
    first_name
    last_name
    email
    gender
    country
    communicating_in_english
    send_to_mentor_confirmed
    time_availability
    previous_programming_experience
  ).freeze

  STEP_TWO_PARAMS = STEP_ONE_PARAMS.dup.concat(%w(
    motivation
    background
    team_work_experience
  )).freeze

  STEP_THREE_PARAMS = STEP_TWO_PARAMS.dup.concat(%w(
    operating_system
    project_proposal
    roadmap
    engagements
  )).freeze

    describe "Api Mentee Application controller tests" do
        let(:edition)  create(:edition) 

        it 'should start create a Mentee Application, step 1' do
            edition
            post :create, application: full_application.slice(*STEP_ONE_PARAMS),
                step: "1", steps: "3"

            expect(response).to have_http_status(200)
        end

        it 'should continue to create a Mentee Application, step 2' do
            post :create, application: full_application.slice(*STEP_TWO_PARAMS),
                step: "2", steps: "3"

            expect(response).to have_http_status(200)
        end

        it 'should not create a Mentee Application in api format' do
            applications = MenteeApplication.count
            post :create, application: full_application.slice(*STEP_THREE_PARAMS),
            step: "3", steps: "3"

            expect(response).to have_http_status(:unprocessable_entity)
            expect(MenteeApplication.count).to be(0)
        end

        it 'should create a Mentee Application in api format (step 3)' do
            applications = MenteeApplication.count
            post :create, application: full_application,
            step: "3", steps: "3"

            expect(response).to have_http_status(200)
            expect(MenteeApplication.count).to be(applications+1)
            expect(flash[:notice]).to eq("Thank you for your application!")
        end

    end
end


def full_application
  @full_application ||= 
    first_name:                       "Mentee", 
    last_name:                        "Rspec", 
    email:                            "[e-mail]",
    gender:                           "female", 
    country:                          "IN", 
    program_country:                  "IN",
    time_zone:                        "5 - Mumbai", 
    communicating_in_english:         "true",
    send_to_mentor_confirmed:         "true",
    motivation:                       "Motivation",
    background:                       "Background",
    programming_language:             "ruby",
    team_work_experience:             "Team Work Experience",
    previous_programming_experience:  "false", 
    experience:                       "",
    operating_system:                 "mac_os",
    project_proposal:                 "Project Proposal",
    roadmap:                          "Roadmap",
    time_availability:                3,
    engagements: [
      "master_student", 
      "part_time", 
      "volunteer", 
      "one_project"
    ] 
  
end

【讨论】：

为什么使用arr1.dup.concat(arr2) 而不是arr1 + arr2？或者你不知道数组上的+ 方法？

哦，哇！数组上有一个+ 方法？！？顺便说一句，concat 和 + 不一样。 Here's 一个关于这个话题的问答，虽然那里有很多。在这种特殊情况下，OP 可能会采取任何一种方式而不会产生重大后果。