Rspec and spawn gem: How to test "should_receive" in spawned_out process

Question

I have a controller action which calls a spawn block

class MyController <  ApplicationController
  ....
  def send_product_mails
    if @user.has_rights?
        spawn_block(:nice => 19 ) do 
          @current_product.send_mail
        end
    end
  end
  ...
end

and I want to spec thet send_mail is called on @current_product, but it tells me it didn't receive it.. How should one do it?

My Spec looks like so:

it "works with spawn" do
  # Setup: create Product, Usersession (via UserSession.create(user))
  get :send_product_mails, :id => product.id
  MyController.any_instance.should_receive(:spawn_block).and_yield("sd")
end

I want to spec that something is passed to the spawn_block if the user has the rights, and nothing otherwise. Right now with different trys (calling .should_receive in the test on MyController, MyController.any_instance, @controller, with or without and_yield this always gives errors that the message spawn_block wasn't received. (Yes, I checked that the rights are acutally okay by adding a puts-debug-output within the if-statement.)

EDIT: Gave more context and code to the question, and what I've tried

Answer 1

You need to setup the expectation (the call to should_receive) before the code under test runs.