hacks that help getting a rails 2 app run like a rails 3 app

rails_2_hacks.rb

# test
if Rails::VERSION::MAJOR == 2
  # make integration tests use rack response, so we can test our middlewares
  # and not only the pure controller response

  ActionController::Base.class_eval do
    # this is usually done just-in-time by #process but we need to do it earlier
    include ActionController::Integration::ControllerCapture

    # then we hide last_instantiation from #process
    def self.last_instantiation;end
  end

  ActionController::Integration::Session.class_eval do
    def process_with_rackify(*args)
      process_without_rackify(*args)
    ensure
      # needed e.g. inside of assert_redirect_to
      capture = ActionController::Integration::ControllerCapture::ClassMethods

      # not set by original #process
      @response.redirected_to = @response.headers["Location"] if @response
      if @controller = capture.send(:class_variable_get, :@@last_instantiation)
        @request = @controller.request
        @response.template = @controller.response.template if @response && @controller.response
        @controller.send(:set_test_assigns)
      end
    end
    alias_method_chain :process, :rackify
  end
end

# test
if Rails::VERSION::MAJOR == 2
  # set default accept to text/html as rails 3 does
  def initialize_default_values_with_accept(*args)
    @env["HTTP_ACCEPT"] ||= "text/html"
    initialize_default_values_without_accept(*args)
  end
  alias_method_chain :initialize_default_values, :accept unless method_defined?(:initialize_default_values_without_accept)

  # reset format before request as rails 3 does
  def recycle_with_format_reset!
    @format = nil
    recycle_without_format_reset!
  end
  alias_method_chain :recycle!, :format_reset unless method_defined?(:recycle_without_format_reset!)
end

#test
if Rails::VERSION::MAJOR == 2
  # make integration tests use rack response, so we can test our middlewares
  # and not only the pure controller response

  ActionController::Base.class_eval do
    # this is usually done just-in-time by #process but we need to do it earlier
    include ActionController::Integration::ControllerCapture

    # then we hide last_instantiation from #process
    def self.last_instantiation;end
  end

  ActionController::Integration::Session.class_eval do
    def process_with_rackify(*args)
      process_without_rackify(*args)
    ensure
      # needed e.g. inside of assert_redirect_to
      capture = ActionController::Integration::ControllerCapture::ClassMethods

      # not set by original #process
      @response.redirected_to = @response.headers["Location"] if @response
      if @controller = capture.send(:class_variable_get, :@@last_instantiation)
        @request = @controller.request
        @response.template = @controller.response.template if @response && @controller.response
        @controller.send(:set_test_assigns)
      end
    end
    alias_method_chain :process, :rackify
  end
end