Rails 7调用render_to_string触发turbo-rails NoMethodError错误求解决

Ruby version 3.2.2
Rails version 7.0.8

source 'https://rubygems.org'

ruby '3.2.2'

gem 'rails', '7.0.8'
gem 'puma', '~> 4.3.9'
gem 'sass-rails', '~>6.0.0'
gem 'jquery-rails'
gem 'sprockets', '3.7.2'

# gem 'bootstrap', '~> 5.1.3'

gem 'sprockets-rails'
gem 'turbo-rails'
gem 'stimulus-rails'
gem 'hotwire-rails'
gem 'importmap-rails'
gem 'jsbundling-rails'

gem 'jbuilder', '~> 2.5'
gem 'twilio-ruby', '5.72.1'
gem 'google-authenticator-rails'
gem 'friendly_id', '~> 5.2.0'
gem 'mysql2'

...

执行以下irb命令时触发错误：

irb(main):003:0> ActionController::Base.new.render_to_string( template: "shared/file_template/test2" )

错误信息：

/Users/xxx/Documents/projects/rails-project/vendor/cache/ruby/3.2.0/gems/turbo-rails-1.5.0/app/controllers/turbo/frames/frame_request.rb:36:in `turbo_frame_request_id': Could not render layout: undefined method `headers' for nil:NilClass (NoMethodError)

      request.headers["Turbo-Frame"]
             ^^^^^^^^
/Users/xxx/Documents/projects/rails-project/vendor/cache/ruby/3.2.0/gems/turbo-rails-1.5.0/app/controllers/turbo/frames/frame_request.rb:36:in `turbo_frame_request_id': undefined method `headers' for nil:NilClass (NoMethodError)

      request.headers["Turbo-Frame"]
             ^^^^^^^^

错误根源是直接实例化ActionController::Base时未初始化request对象，而Turbo Rails的帧处理逻辑依赖request.headers。可通过以下方式解决：

• 给控制器实例手动注入request对象：
  在调用render_to_string前，为控制器创建有效的request实例：

  controller = ActionController::Base.new
  # 初始化基础request对象
  controller.request = ActionDispatch::Request.new({})
  controller.render_to_string(template: "shared/file_template/test2")
  

  若需要贴近真实请求环境，可使用Rails的env配置：

  controller = ApplicationController.new
  controller.request = ActionDispatch::Request.new(Rails.application.env_config)
  controller.render_to_string(template: "shared/file_template/test2")
  

• 直接使用ActionView渲染模板：
  绕过控制器的Turbo钩子，直接用视图类渲染模板：

  view = ActionView::Base.new(ActionController::Base.view_paths, {})
  # 如需使用控制器辅助方法，可添加：view.include ApplicationController.helpers
  view.render(template: "shared/file_template/test2")
  

内容的提问来源于stack exchange，提问作者Jin Lim