如何使用rspec模拟模块内的类方法

Question

我试图测试一个调用外部API的create方法,但我在模拟外部API请求时遇到问题.继承了我的设置以及到目前为止我尝试过的内容:

class Update
  def self.create(properties)
    update = Update.new(properties)

    begin
      my_file = StoreClient::File.get(properties["id"])
      update.filename = my_file.filename
    rescue
      update.filename = ""
    end    

    update.save  
  end
end


context "Store request fails" do
  it "sets a blank filename" do
    store_double = double("StoreClient::File")
    store_double.should_receive(:get).with(an_instance_of(Hash)).and_throw(:sad)
    update = Update.create({ "id" => "222" })
    update.filename.should eq ""        
  end
end

此刻我得到了这个失败

 Failure/Error: store_double.should_receive(:get).with(an_instance_of(Hash)).and_throw(:sad)
   (Double "StoreClient::File").get(#<RSpec::Mocks::ArgumentMatchers::InstanceOf:0x000001037a9208 @klass=Hash>)
       expected: 1 time
       received: 0 times

为什么我的双重不工作,如何最好模拟调用StoreClient::File.get,以便我可以在成功或失败时测试创建方法？

Answer 1

问题是double("StoreClient::File")创建了一个名为 "StoreClient :: File" 的double ,它实际上并没有将自己替换为真实StoreClient::File对象.

在你的情况下,我认为你实际上不需要双倍.您可以直接get在StoreClient::File对象上存根方法,如下所示:

context "Store request fails" do
  it "sets a blank filename" do
    StoreClient::File.should_receive(:get).with(an_instance_of(Hash)).and_throw(:sad)
    update = Update.create({ "id" => "222" })
    update.filename.should eq ""        
  end
end