class ActionDispatch::Routing::RouteSet

def generate_url_helpers(supports_path)
  routes = self
  Module.new do
    extend ActiveSupport::Concern
    include UrlFor
    # Define url_for in the singleton level so one can do:
    # Rails.application.routes.url_helpers.url_for(args)
    proxy_class = Class.new do
      include UrlFor
      include routes.named_routes.path_helpers_module
      include routes.named_routes.url_helpers_module
      attr_reader :_routes
      def initialize(routes)
        @_routes = routes
      end
      def optimize_routes_generation?
        @_routes.optimize_routes_generation?
      end
    end
    @_proxy = proxy_class.new(routes)
    class << self
      def url_for(options)
        @_proxy.url_for(options)
      end
      def full_url_for(options)
        @_proxy.full_url_for(options)
      end
      def route_for(name, *args)
        @_proxy.route_for(name, *args)
      end
      def optimize_routes_generation?
        @_proxy.optimize_routes_generation?
      end
      def polymorphic_url(record_or_hash_or_array, options = {})
        @_proxy.polymorphic_url(record_or_hash_or_array, options)
      end
      def polymorphic_path(record_or_hash_or_array, options = {})
        @_proxy.polymorphic_path(record_or_hash_or_array, options)
      end
      def _routes; @_proxy._routes; end
      def url_options; {}; end
    end
    url_helpers = routes.named_routes.url_helpers_module
    # Make named_routes available in the module singleton
    # as well, so one can do:
    # Rails.application.routes.url_helpers.posts_path
    extend url_helpers
    # Any class that includes this module will get all
    # named routes...
    include url_helpers
    if supports_path
      path_helpers = routes.named_routes.path_helpers_module
      include path_helpers
      extend path_helpers
    end
    # plus a singleton class method called _routes ...
    included do
      redefine_singleton_method(:_routes) { routes }
    end
    # And an instance method _routes. Note that
    # UrlFor (included in this module) add extra
    # conveniences for working with @_routes.
    define_method(:_routes) { @_routes || routes }
    define_method(:_generate_paths_by_default) do
      supports_path
    end
    private :_generate_paths_by_default
    # If the module is included more than once (for example, in a subclass
    # of an ancestor that includes the module), ensure that the `_routes`
    # singleton and instance methods return the desired route set by
    # including a new copy of the module (recursively if necessary). Note
    # that this method is called for each inclusion, whereas the above
    # `included` block is run only for the initial inclusion of each copy.
    def self.included(base)
      super
      if base.respond_to?(:_routes) && !base._routes.equal?(@_proxy._routes)
        @dup_for_reinclude ||= self.dup
        base.include @dup_for_reinclude
      end
    end
  end
end