这有效

require 'test_helper'

class DealsControllerTest < ActionDispatch::IntegrationTest
  include Warden::Test::Helpers

  setup do
    @deal = deals(:one)
    @user = users(:one)
    # https://github.com/plataformatec/devise/wiki/How-To:-Test-with-Capybara
    @user.confirmed_at = Time.now
    @user.save
    login_as(@user, :scope => :user)
  end

  teardown do
    Warden.test_reset! 
  end