如何在RSpec中編寫可重用的共享示例

Question

我每次運行這個時都會收到wrong number of arguments (1 for 0)。我究竟做錯了什麼？

describe Payment do 
    before { @payment = build_stubbed(:payment) } 
    subject { @payment } 

    shared_examples 'a foreign key' do |key| 
    it "can't be nil, blank, or not an int" do 
     [nil, "", " ", "a", 1.1].each do |value| 
     @payment.send key, value 
     @payment.should_not be_valid 
     end 
    end 
    end 

    describe "validation" do 
    describe "order_id" do 
     it_behaves_like 'a foreign key', :order_id 
    end 
    end 
end 

失敗消息：

1) Payment validation order_id behaves like a foreign key can't be nil, blank, or not an int 
    Failure/Error: @payment.send(key, value) 
    ArgumentError: 
     wrong number of arguments (1 for 0) 
    Shared Example Group: "a foreign key" called from ./spec/models/payment_spec.rb:27 
    # ./spec/models/payment_spec.rb:18:in `block (4 levels) in <top (required)>' 
    # ./spec/models/payment_spec.rb:17:in `each' 
    # ./spec/models/payment_spec.rb:17:in `block (3 levels) in <top (required)>' 

Answer 1

我並沒有提供正確的setter方法：@payment.send(key, value)

相反，我需要使用@payment.send("#{key}=", value)