mock_controller.rb

# Don't know about better, but fewer lines:

def mock_controller
  ['test_request','test_response'].each {|fname| require "action_dispatch/testing/#{fname}" }
  controller = ApplicationController.new
  controller.perform_caching = true
  controller.cache_store = ActiveSupport::Cache::MemoryStore.new
  ['request','response'].each {|r| controller.send("#{r}=", ActionDispatch.const_get("Test#{r.capitalize}").new) }
  controller.initialize_template_class controller.response
  controller.assign_shortcuts controller.request, controller.response
  controller.default_url_options.merge!(DefaultUrlOptions) if defined?(DefaultUrlOptions)
  controller
end

Agreed. It would be really nice if ApplicationController.new simply did that; but I suppose there are probably good reasons it doesn't. If nothing else, not attaching the Request and Response keeps us from being enslaved to the Request/Reply pattern. I suppose you could rewrite Rails just a bit to use Command/Event and support a completely different kind of application... don't know why you would though.