Mock out sessions with Rack::Test

test.rb

require File.join(File.dirname(__FILE__), 'test_helper.rb')

class AppTest < Test::Unit::TestCase

  def test_get_root_path
    current_session.rack_session[:user_id] = "1337"
    get "/"
    assert last_response.ok?
  end
end

test_helper.rb

module Rack
  module Test
    class Session
      alias_method :old_env_for, :env_for
      def rack_session
        @rack_session ||= {}
      end
      def rack_session=(hash)
        @rack_session = hash
      end
      def env_for(path, env)
        old_env_for(path, env).merge({'rack.session' => rack_session})
      end
    end
  end
end

Thank you, I use Rack::Session::Redis in my application and adding this patch in my test_helper.rb save my time.