Ruby on rails RSpec class_Rails邮件间谍

我试图测试在保存模型时是否使用了特定的mailer类。在我的模型中，我有：

class Foo < ActiveRecord::Base
  def send_email
    if some_condition
      FooMailer.welcome.deliver_now
    else
      FooBarMailer.welcome.deliver_now
    end
  end
def

当我运行此测试时，失败的原因是：

(ClassDouble(FooMailer) (anonymous)).welcome(*(any args))
       expected: 1 time with any arguments
       received: 0 times with any arguments

---

问题似乎是您没有用spy替换mailer类的当前定义，因此spy没有收到任何消息。要替换它，请使用以下方法：

(ClassDouble(FooMailer) (anonymous)).welcome(*(any args))
       expected: 1 time with any arguments
       received: 0 times with any arguments

it 'uses the foo bar mailer' do
  foobar_mailer = class_spy(FooBarMailer)
  stub_const('FooBarMailer', foobar_mailer)
  subject.send_email
  # some_condition will evaluate to false here, so we'll use the FooBarMailer
  expect(foobar_mailer).to have_received :welcome
end