RSpec测试中sign_in方法未定义问题排查求助

问题场景 #

编写请求类型的控制器测试，验证GET请求返回200状态码，但按网上方案在spec_helper.rb引入Devise助手后，仍然报错：

NoMethodError:
       undefined method `sign_in' for #<RSpec::ExampleGroups::ApplicationFunnelController::Index::WhenAccessed "returns 200" (./spec/requests/application_funnel_controller_spec.rb:7)>

测试代码：

require 'spec_helper'

RSpec.describe ApplicationFunnelController, type: :request do
  describe "index" do
    context "when accessed" do
      it "returns 200" do
        user = FactoryBot.create(:user)
        group = FactoryBot.create(:group, name: 'Testers')
        user.groups << group
        sign_in user

        get become_a_member_path

        expect(response.status).to eq 200
      end
    end
  end
end

问题原因 #

你的测试类型是type: :request，但当前spec_helper.rb里只给controller、view、routing类型的测试引入了Devise控制器助手，请求测试需要使用Devise集成测试助手才能获得sign_in方法。

解决方案 #

修改spec_helper.rb中的RSpec配置块，添加针对request类型的Devise助手引入：

1. 对于Devise 4.1及以上版本，使用Devise::Test::IntegrationHelpers（推荐）：

RSpec.configure do |config|
  # 给控制器、视图、路由测试保留原有助手
  config.include Devise::Test::ControllerHelpers, type: [:controller, :view, :routing]
  # 给请求测试添加集成助手
  config.include Devise::Test::IntegrationHelpers, type: :request
  
  # 其他原有配置保持不变
  config.infer_spec_type_from_file_location!

  DEFAULT_CLEANER_STRATEGY = :transaction

  def with_truncation
    DatabaseCleaner.strategy = :truncation
    yield
  ensure
    DatabaseCleaner.strategy = DEFAULT_CLEANER_STRATEGY
  end

  config.include ActiveSupport::Testing::TimeHelpers

  config.before :suite do
    ActiveJob::Base.queue_adapter = :test
    DatabaseCleaner.strategy = DEFAULT_CLEANER_STRATEGY
    unless ENV["SEED"] == "false"
      DatabaseCleaner.clean_with(:truncation, except: %w(ar_internal_metadata schema_migrations))
    end
    Rails.application.load_tasks
  end

  config.before { ActionMailer::Base.deliveries.clear }
end

2. 如果是Devise旧版本（低于4.1），可替换为Devise::TestHelpers，但优先建议升级Devise并使用集成助手。

修改后重新运行测试，sign_in方法即可正常调用，测试能顺利验证请求状态码。

内容的提问来源于stack exchange，提问作者Misha Krul