Question

我试图在rspec 3.0中掌握新的allow语法（用于存根），并且非常感谢有人看着我的代码并告诉我它是对（或错）。< / p>

download.rb

class Download
  def download_file
    # code to download a file 
  end

  def valid_json
    # code to verify downloaded file is file type json
  end
end

download_spec.rb

require 'spec_helper'
require 'json_spec'  

describe Download do 
  let(:download)  {Download.new}

  describe "#download_file" do
    it 'downloads a file from remote file location ' do
      allow(download).to receive(:exist).and_return(true)
      download.download_file
      expect(download).to have_received(:exist).and_return(true)    
    end 
  end   

  describe "#valid_json" do
    it 'confirms downloaded file is JSON' do
      # download.to_json.should have_json_path("id")
      # download.to_json.should have_json_type(Integer).at_path("id")
      expect(download.to_json).to have_json_path("id")
      expect(download.to_json).to have_json_type(Integer).at_path("id")
    end 
  end
end

非常感谢提前！

Answer 1

我相信你在RSpec 3.0中使用了正确的存根语法，但我怀疑你在这种情况下使用它的动机。我强烈建议您查看Sandi Metz关于Ruby测试的演示文稿，这有助于澄清实际使用存根的适当情况。这是Sandi的Magic Tricks of Testing幻灯片。

根据您的测试名称，您真正应该测试的是文件对象是否是作为此方法的结果而创建的。这是您应该关注的唯一事项 - 将#download_file消息发送到download对象的直接公共副作用。除此之外的任何事情意味着您测试实现而不是接口。

describe Download do 
  let(:download) { Download.new }

  describe "#file" do
    context "before file has been downloaded" do
      it "returns nil" do
        expect(download.file).to be_nil
      end
    end
  end

  describe "#download_file" do
    it 'downloads a file from remote file location ' do
      # incoming command message to object under test
      download.download_file
      # assert direct public side effect
      expect(download.file).to be_a File
    end 
  end   
end

编辑：我忘记提及的一件事是，您可能需要在此处澄清您的问题或您的测试概念，以确定这些是用于单元测试还是集成测试。这可能会改变答案。

rspec 3.0存根语法 - 不确定是否正确

1 个答案: