Rails 2.3.x - How to silence a helper method (which is called from a view) in a functional test (without RSpec)?

Question

Please do not tell me to “look for more” or other things, because all solutions for such a question do not work.

Simple: I have functional tests. I want to make easy access and see if the correct content is displayed.

  test "displays headline if user should see it" do
     get: index  
     assert_match / headline /, response.body
   end

   test "doesn't display headline if user shouldn't see it" do
     get: index
     assert_no_match / headline /, response.body
   end

and simple view

  <% if show_headline? (arg)%>
     headline
   <% end%>

and assistant:

  module TheHelper
     def show_headline? (arg)
       arg?  hard_code_logic: even_harder_logic
     end
   end

so what I need to do in the test is something like:

  test "displays headline if user should see it" do
     Something.stubs (: show_headline?). Returns (true)

     get: index  
     assert_match / headline /, response.body
   end

   test "doesn't display headline if user shouldn't see it" do
     Something.stubs (: show_headline?). Returns (false)

     get: index
     assert_no_match / headline /, response.body
   end

The question is, what is something? I want to disable it because I have helpers checked in module / helpers.

After the get helper gets remixes in the controller class. Please do not give me links to other answers, I read them (but, of course, I could read the wrong ones), and they do not work for me. I am using Rails 2.3.10 with Mocha 0.9.8.

Things that don't work:

  TheController.any_instance.stubs (: show_headline?)
 ActionView :: Base.any_instance ...
 @ controller.stubs ...

UPDATE:

The only layout that worked:

  <% self.stubs (: show_headline?). returns (true)>%
   <% if show_headline? (arg)%>
     headline
   <% end%>

but of course I won’t use it ... maybe this is the key