Estoy buscando una solución para un problema extraño. Tengo un controlador, que necesita autenticación (con la gema de diseño). Agregué el Devise TestHelpers pero no puedo hacerlo funcionar.

require 'test_helper'

class KeysControllerTest < ActionController::TestCase  
   include Devise::TestHelpers  
   fixtures :keys

   def setup
      @user = User.create!(
        :email => '[email protected]',
        :password => 'MyTestingPassword',
        :password_confirmation => 'MyTestingPassword'
      )
      sign_in @user
      @key = keys(:one)
   end

   test "should get index" do
      get :index    
      assert_response :success
      assert_not_nil assigns(:keys)
   end

   test "should get new" do
      get :new
      assert_response :success
   end

   test "should create key" do
      assert_difference('Key.count') do
         post :create, :key => @key.attributes
      end

      assert_redirected_to key_path(assigns(:key))
   end

   test "should destroy key" do
      assert_difference('Key.count', -1) do
         delete :destroy, :id => @key.to_param
      end

      assert_redirected_to keys_path
   end

fina

Y obtengo el siguiente resultado en mi ventana "prueba de rastrillo":

29) Failure:
test_should_create_key(KeysControllerTest) [/test/functional/keys_controller_test.rb:29]:
"Key.count" didn't change by 1.
<3> expected but was
<2>.

 30) Failure:
test_should_destroy_key(KeysControllerTest) [/test/functional/keys_controller_test.rb:37]:
"Key.count" didn't change by -1.
<1> expected but was
<2>.

 31) Failure:
test_should_get_index(KeysControllerTest) [/test/functional/keys_controller_test.rb:19]:
Expected response to be a <:success>, but was <302>

 32) Failure:
test_should_get_new(KeysControllerTest) [/test/functional/keys_controller_test.rb:25]:
Expected response to be a <:success>, but was <302>

¿Puede alguien decirme, por qué idear no se autentica? Estoy usando exactamente el mismo procedimiento para un AdminController y funciona perfectamente.