在Rails中测试作用域链的最佳方法

Question

在我所有的ruby on rails应用程序中,我尝试不在控制器中使用数据库,因为它们应该独立于持久性类.我用了嘲笑.

以下是rspec和rspec-mock的示例:

class CouponsController < ApplicationController
  def index
    @coupons = Coupon.all
  end
end

require 'spec_helper'
describe CouponsController do
  let(:all_coupons) { mock } 
  it 'should return all coupons' do
    Coupon.should_receive(:all).and_return(all_coupons)
    get :index
    assigns(:coupons).should == all_coupons
    response.should be_success
  end
end

但是如果控制器包含更复杂的范围,例如:

class CouponsController < ApplicationController
  def index
    @coupons = Coupon.unredeemed.by_shop(shop).by_country(country)
  end
end

你知道测试simillar范围链的任何好方法吗？

我认为以下测试看起来不太好:

require 'spec_helper'
describe CouponsController do
  it 'should return all coupons' do
    Coupon.should_receive(:unredeemed).and_return(result = mock)
    result.should_receive(:by_shop).with(shop).and_return(result)
    result.should_receive(:by_country).with(country).and_return(result)
    get :index
    assigns(:coupons).should == result
    response.should be_success
  end
end

Answer 1

你可以使用stub_chain方法.

就像是:

Coupon.stub_chain(:unredeemed, :by_shop, :by_country).and_return(result)

只是一个例子.