http://random-rails.blogspot.com/2010/07/ive-been-working-lot-these-days-on.html

hosts_controller_test.rb

require 'test_helper'

class HostsControllerTest < ActionController::TestCase
  context "Logged in as admin" do
    setup do
      @user = Factory.build(:admin_user) ## build, not create since it won't hit the database then
      HostsController.any_instance.stubs(:current_user).returns(@user)
    end
  
    context "on INDEX action" do
      setup do
        get :index
      end

      should respond_with(:success)
      should render_template(:index)
      should respond_with_content_type(:html)    
    end
      
  end
end