Question

I am setting up a test that should expect calls on two “subscriber” instances:

  it "sends out sms to all the subscribers" do
    @user.subscribers.create!
    @user.subscribers.create!

    Subscriber.any_instance.should_receive(:send_message).with(@message).times(2)
    post :create, {:broadcast => valid_attributes}   
  end

The actual code is:

  def create
    @broadcast = Broadcast.new(params[:broadcast])
    current_user.subscribers.each do |subscriber|
      subscriber.send_message(@broadcast.message)
    end

    ...

The error:

  Failure/Error: post :create, {:broadcast => valid_attributes}
     ArgumentError:
       wrong number of arguments (1 for 0)
     # ./app/controllers/broadcasts_controller.rb:41:in `block in create'
     # ./app/controllers/broadcasts_controller.rb:40:in `create'
     # ./spec/controllers/broadcasts_controller_spec.rb:73:in `block (4 levels) in <top (required)>'

For some reason, if I add the line: Subscriber.any_instance.should_receive(:send_message).with(@message).times(2), it fails with that error message. If I remove that line, the test runs smoothly (no wrong number of argument problem). What am I doing wrong?

Answer 1

The error you’re getting is because the ‘times’ method is expected to be chained onto one of the other “receive count” expectations. You can use any one of the following:

should_receive(:send_message).with(@message).exactly(2).times
should_receive(:send_message).with(@message).at_most(2).times

You can also use one of the other alternatives that does not require the ‘times’ method:

should_receive(:send_message).with(@message).twice
should_receive(:send_message).with(@message).at_most(:twice)

More on that can be found in the rspec-mocks documentation

You may need to set the expectation BEFORE creating the subscribers:

it "sends out sms to all the subscribers" do
  Subscriber.any_instance.should_receive(:send_message).with(@message).twice

  @user.subscribers.create!
  @user.subscribers.create!

  post :create, {:broadcast => valid_attributes}   
end