RESTFUL Authentification plugin Functional tests - howto?

Rails
1

I am trying to write a functional test of my UserController index
action

require File.dirname(FILE) + ‘/…/test_helper’
require ‘users_controller’

class UsersControllerTest < Test::Unit::TestCase
def setup
@controller = UsersController.new
@request = ActionController::TestRequest.new
@response = ActionController::TestResponse.new
end

def test_should_get_index
login_as (:superadmin)
get :index
assert_response :success
assert_not_nil assigns(:users)
assert_equal 15, assigns(:users).total_entries

login_as (:quentin)
get :index
assert_response :success
assert_not_nil assigns(:users)
assert_equal 6, assigns(:users).total_entries

end
end

I am using the Restful Authentification plugin, without any problem
running my index action

class UsersController < ApplicationController
before_filter :login_required
def index
@roles = …
@users = User.display_users(current_user, @roles, params[:page])
…
end
…
end

on the first login_as (:superadmin), it’s OK, current_user is 1, but
when doing the login_as (:quentin), the current_user is NOT modified,
still being 1

I wrote in the login_as in :
module AuthenticatedTestHelper

Sets the current user in the session from the user fixtures.

def login_as(user)
@request.session[:user_id] = user ? users(user).id : nil
end
…
end

the @request.session[:user_id] is correctlt modified (user_id 1, then
user_id 2) but current_user in my index action is not… where
could be the problem located ??

thanks a lot to any info !

erwin