rspec的should_receive不工作，但想到的是工作

Question

我上課像下面

#bank.rb 
class Bank 
    def transfer(customer1, customer2, amount_to_transfer) 
     if customer1.my_money >= amount_to_transfer 
     customer1.my_money -= amount_to_transfer 
     customer2.my_money += amount_to_transfer 
     else 
     return "Insufficient funds" 
     end 
    end 
end 

class Customer 
    attr_accessor :my_money 

    def initialize(amount) 
    self.my_money = amount 
    end 
end 

而且我的規格文件看起來如下：

#spec/bank_spec.rb 
require './spec/spec_helper' 
require './bank' 

describe Bank do 
    context "#transfer" do 
    it "should return insufficient balance if transferred amount is greater than balance" do 
    customer1 = Customer.new(500) 
    customer2 = Customer.new(0) 

    customer1.stub(:my_money).and_return(1000) 
    customer2.stub(:my_money).and_return(0) 

    expect(Bank.new.transfer(customer1, customer2, 2000)).to eq("Insufficient funds") 
    expect(customer1).to have_received(:my_money) # This works 
    customer1.should_receive(:my_money) #throws error 
    end 
    end 
end 

按

https://relishapp.com/rspec/rspec-mocks/v/2-14/docs/message-expectations兩個 expect和 should_receive是相同的，但 expect比 should_receive更具可讀性。但爲什麼它失敗了？提前致謝。

Answer 1

地方這條線：

customer1.should_receive(:my_money) 

前

expect(Bank.new.transfer(customer1, customer2, 2000)).to eq("Insufficient funds") 

expect to have_received和should_receive有diffent意義

expect to have_received通行證，如果對象已經收到了預期的方法調用，而 should_receive通過僅對象將將來接收預期的方法調用（在當前範圍內）牛逼測試用例）

如果你會寫的

expect(customer1).to receive(:my_money) 

代替

expect(customer1).to have_received(:my_money) 

它會失敗過。除非將它放在調用此方法的行之前。