測試失敗 - 一個類方法來調用另一個（「預期：1個時間參數，獲得0次」）

Question

我的問題：

我試圖存根返回該實例的類方法類，但我得到了題爲測試下面的錯誤「創建具有CSV數據的實例」：

Failures: 

    1) QuestionData.load_questions creates an instance with CSV data 
    Failure/Error: expect(question_data_class).to receive(:new).with(data).and_return(question_data_instance) 

     (QuestionData (class)).new([{:time_limit=>10, :text=>"Who was the legendary Benedictine monk who invented champagne?", :correct_...the world?", :correct_answer=>"Lake Superior", :option_2=>"Lake Victoria", :option_3=>"Lake Huron"}]) 
      expected: 1 time with arguments: ([{:time_limit=>10, :text=>"Who was the legendary Benedictine monk who invented champagne?", :correct_...the world?", :correct_answer=>"Lake Superior", :option_2=>"Lake Victoria", :option_3=>"Lake Huron"}]) 
      received: 0 times 

上下文：

的代碼（如下圖所示）的作品 - QuestionData.load_questions加載CSV文件中的數據，並將數據作爲參數調用QuestionData.new。然而，我對.load_questions方法的測試給出了上述錯誤。當它被調用時，QuestionData類的兩倍不會收到.new的存根，其中data加倍。

我試過研究如何測試存根，返回另一個存根或實例，但似乎無法找到相關答案。

我非常感謝任何幫助或建議，非常感謝！

代碼：

require "csv" 

class QuestionData 

    attr_reader :questions 

    def initialize(questions) 
    @questions = questions 
    end 

    def self.load_questions(file = './app/lib/question_list.csv', questions = []) 
    self.parse_csv(file, questions) 
    self.new(questions) 
    end 

    def self.parse_csv(file, questions) 
    CSV.foreach(file) do |row| 
     time_limit, text, correct_answer, option_2, option_3 = row[0], 
     row[1], row[2], row[3], row[4] 
     questions << { time_limit: time_limit, text: text, 
     correct_answer: correct_answer, option_2: option_2, option_3: option_3 
     } 
    end 
    end 

end 

測試文件：

require './app/models/question_data' 

describe QuestionData do 

    subject(:question_data_instance) { described_class.new(data) } 
    let(:question_data_class) { described_class } 
    let(:CSV) { double(:CSV, foreach: nil) } 
    let(:questions) { [] } 
    let(:file) { double(:file) } 
    let(:data) do 
    [{ 
     time_limit: 10, 
     text: "Who was the legendary Benedictine monk who invented champagne?", 
     correct_answer: "Dom Perignon", 
     option_2: "Ansgar", 
     option_3: "Willibrord" 
     }, 
     { 
     time_limit: 12, 
     text: "Name the largest freshwater lake in the world?", 
     correct_answer: "Lake Superior", 
     option_2: "Lake Victoria", 
     option_3: "Lake Huron" 
     }] 
    end 

    describe '#questions' do 
    it "has an array of question data from CSV" do 
     expect(question_data_instance.questions).to eq(data) 
    end 
    end 

    describe '.parse_csv' do 
    it "parses CSV data into hash data" do 
     expect(CSV).to receive(:foreach).with(file) 
     question_data_class.parse_csv(file, questions) 
    end 
    end 

    describe '.load_questions' do 
    it "calls '.parse_csv' method" do 
     expect(question_data_class).to receive(:parse_csv).with(file, questions) 
     question_data_class.load_questions(file, questions) 
    end 

    it "creates an instance with CSV data" do 
     allow(question_data_class).to receive(:load_questions).with(file, questions).and_return(question_data_instance) 
     allow(question_data_class).to receive(:new).with(data).and_return(question_data_instance) 
     expect(question_data_class).to receive(:new).with(data).and_return(question_data_instance) 
     question_data_class.load_questions(file, questions) 
    end 
    end 

    describe '.new' do 
    it "creates a new instance with CSV data" do 
     expect(question_data_class).to receive(:new).with(data).and_return(question_data_instance) 
     question_data_class.new(data) 
    end 
    end 

end 

Answer 1

的事情是，你是磕碰的電話：

allow(question_data_class).to receive(:load_questions).with(file) 

如果仍希望通話執行您需要添加：

and_call_original 

因此原始方法將被執行，您的代碼將在原始塊上調用新方法。

但問題是，您不需要存儲您只需更改存根的類就可以了，因爲您正在調用double方法，並且會嘗試在類中執行它，所以您可能需要你的第二個測試更改爲：

describe '.load_questions' do 
    it "creates an instance containing CSV data" do 
    expect(described_class).to receive(:new).with(data).and_return(question_data_instance) 
    described_class.load_questions(file) 
    end 
end