Bugfix and regressiontest for Engine.routes (#932)

* RouteSet `def url_helpers` modelled after:

>>> Rails.application.routes.method(:url_helpers).source_location
```
["/usr/local/bundle/gems/actionpack-6.0.6.1/lib/action_dispatch/routing/route_set.rb", 478]
```

* Bugfix found by #931 (comment)

```
  E, [2025-08-26T00:00:44.351193 #2377] ERROR -- rbs: /home/runner/work/gem_rbs_collection/gem_rbs_collection/gems/railties/6.0/_test/.gem_rbs_collection/railties/6.0/railties.rbs:25:32...25:38: Could not find ::Mapper (RBS::NoTypeFoundError)

        def routes: () ?{ () [self: Mapper] -> void } -> ActionDispatch::Routing::RouteSet
                                    ^^^^^^
```

* 1 method call with untyped receiver detected from test.rb. Please assign the expected type to the receiver

* Cleanups

* Review response to #932 (review)

Author: yuzisee

gems/actionpack/6.0/actiondispatch.rbs

@@ -63,14 +63,23 @@ end
 
 module ActionDispatch
   module Routing
+    module PolymorphicRoutes
+      def polymorphic_url: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> String
+      def polymorphic_path: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> String
+    end
+
     class RouteSet
       def draw: () { () [self: Mapper] -> untyped } -> nil
+
+      def url_helpers: (?bool supports_path) -> RouteSet_AnonymousModule
+
+      class RouteSet_AnonymousModule
+        include ActiveSupport::Concern
+        include UrlFor
+        # https://github.com/rails/rails/blob/v6.0.6.1/actionpack/lib/action_dispatch/routing/route_set.rb#L478
+      end
     end
-  end
-end
 
-module ActionDispatch
-  module Routing
     class Mapper
       module HttpHelpers
         # Define a route that only recognizes HTTP GET.

gems/actionpack/6.0/actionpack-generated.rbs

@@ -9704,54 +9704,6 @@ module ActionDispatch
     #   form_for([blog, @post])         # => "/blog/posts/1"
     #
     module PolymorphicRoutes
-      # Constructs a call to a named RESTful route for the given record and returns the
-      # resulting URL string. For example:
-      #
-      #   # calls post_url(post)
-      #   polymorphic_url(post) # => "http://example.com/posts/1"
-      #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
-      #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
-      #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
-      #   polymorphic_url(Comment) # => "http://example.com/comments"
-      #
-      # ==== Options
-      #
-      # * <tt>:action</tt> - Specifies the action prefix for the named route:
-      #   <tt>:new</tt> or <tt>:edit</tt>. Default is no prefix.
-      # * <tt>:routing_type</tt> - Allowed values are <tt>:path</tt> or <tt>:url</tt>.
-      #   Default is <tt>:url</tt>.
-      #
-      # Also includes all the options from <tt>url_for</tt>. These include such
-      # things as <tt>:anchor</tt> or <tt>:trailing_slash</tt>. Example usage
-      # is given below:
-      #
-      #   polymorphic_url([blog, post], anchor: 'my_anchor')
-      #     # => "http://example.com/blogs/1/posts/1#my_anchor"
-      #   polymorphic_url([blog, post], anchor: 'my_anchor', script_name: "/my_app")
-      #     # => "http://example.com/my_app/blogs/1/posts/1#my_anchor"
-      #
-      # For all of these options, see the documentation for {url_for}[rdoc-ref:ActionDispatch::Routing::UrlFor].
-      #
-      # ==== Functionality
-      #
-      #   # an Article record
-      #   polymorphic_url(record)  # same as article_url(record)
-      #
-      #   # a Comment record
-      #   polymorphic_url(record)  # same as comment_url(record)
-      #
-      #   # it recognizes new records and maps to the collection
-      #   record = Comment.new
-      #   polymorphic_url(record)  # same as comments_url()
-      #
-      #   # the class of a record will also map to the collection
-      #   polymorphic_url(Comment) # same as comments_url()
-      #
-      def polymorphic_url: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> untyped
-
-      # Returns the path component of a URL for the given record.
-      def polymorphic_path: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> untyped
-
       private
 
       def polymorphic_url_for_action: (untyped action, untyped record_or_hash, untyped options) -> untyped
@@ -10078,8 +10030,6 @@ module ActionDispatch
 
       def define_mounted_helper: (untyped name, ?untyped? script_namer) -> (nil | untyped)
 
-      def url_helpers: (?bool supports_path) -> untyped
-
       def empty?: () -> untyped
 
       def add_route: (untyped mapping, untyped name) -> untyped

gems/actionpack/7.2/actiondispatch.rbs

@@ -63,14 +63,23 @@ end
 
 module ActionDispatch
   module Routing
+    module PolymorphicRoutes
+      def polymorphic_url: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> String
+      def polymorphic_path: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> String
+    end
+
     class RouteSet
       def draw: () { () [self: Mapper] -> untyped } -> nil
+
+      def url_helpers: (?bool supports_path) -> RouteSet_AnonymousModule
+
+      class RouteSet_AnonymousModule
+        include ActiveSupport::Concern
+        include UrlFor
+        # https://github.com/rails/rails/blob/v7.2.2.2/actionpack/lib/action_dispatch/routing/route_set.rb#L518
+      end
     end
-  end
-end
 
-module ActionDispatch
-  module Routing
     class Mapper
       module HttpHelpers
         # Define a route that only recognizes HTTP GET.

gems/actionpack/7.2/actionpack-generated.rbs

@@ -9704,54 +9704,6 @@ module ActionDispatch
     #   form_for([blog, @post])         # => "/blog/posts/1"
     #
     module PolymorphicRoutes
-      # Constructs a call to a named RESTful route for the given record and returns the
-      # resulting URL string. For example:
-      #
-      #   # calls post_url(post)
-      #   polymorphic_url(post) # => "http://example.com/posts/1"
-      #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
-      #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
-      #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
-      #   polymorphic_url(Comment) # => "http://example.com/comments"
-      #
-      # ==== Options
-      #
-      # * <tt>:action</tt> - Specifies the action prefix for the named route:
-      #   <tt>:new</tt> or <tt>:edit</tt>. Default is no prefix.
-      # * <tt>:routing_type</tt> - Allowed values are <tt>:path</tt> or <tt>:url</tt>.
-      #   Default is <tt>:url</tt>.
-      #
-      # Also includes all the options from <tt>url_for</tt>. These include such
-      # things as <tt>:anchor</tt> or <tt>:trailing_slash</tt>. Example usage
-      # is given below:
-      #
-      #   polymorphic_url([blog, post], anchor: 'my_anchor')
-      #     # => "http://example.com/blogs/1/posts/1#my_anchor"
-      #   polymorphic_url([blog, post], anchor: 'my_anchor', script_name: "/my_app")
-      #     # => "http://example.com/my_app/blogs/1/posts/1#my_anchor"
-      #
-      # For all of these options, see the documentation for {url_for}[rdoc-ref:ActionDispatch::Routing::UrlFor].
-      #
-      # ==== Functionality
-      #
-      #   # an Article record
-      #   polymorphic_url(record)  # same as article_url(record)
-      #
-      #   # a Comment record
-      #   polymorphic_url(record)  # same as comment_url(record)
-      #
-      #   # it recognizes new records and maps to the collection
-      #   record = Comment.new
-      #   polymorphic_url(record)  # same as comments_url()
-      #
-      #   # the class of a record will also map to the collection
-      #   polymorphic_url(Comment) # same as comments_url()
-      #
-      def polymorphic_url: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> untyped
-
-      # Returns the path component of a URL for the given record.
-      def polymorphic_path: (untyped record_or_hash_or_array, ?::Hash[untyped, untyped] options) -> untyped
-
       private
 
       def polymorphic_url_for_action: (untyped action, untyped record_or_hash, untyped options) -> untyped
@@ -10078,8 +10030,6 @@ module ActionDispatch
 
       def define_mounted_helper: (untyped name, ?untyped? script_namer) -> (nil | untyped)
 
-      def url_helpers: (?bool supports_path) -> untyped
-
       def empty?: () -> untyped
 
       def add_route: (untyped mapping, untyped name) -> untyped

gems/railties/6.0/_test/test.rb

@@ -0,0 +1,10 @@
+Rails.application.routes.draw do
+  resources :test1_models
+end
+
+raise <<~HEREDOC unless Rails.application.routes.url_helpers.polymorphic_path(:new_test1_model) == '/test1_models/new'
+  But it should work, since:
+  >>> Rails.application.routes.method(:url_helpers).source_location
+  ["/usr/local/bundle/gems/actionpack-6.0.6.1/lib/action_dispatch/routing/route_set.rb", 478]
+HEREDOC
+

gems/railties/6.0/railties-generated.rbs

@@ -4774,8 +4774,6 @@ module Rails
 
   attr_accessor self.logger: untyped
 
-  def self.application: () -> untyped
-
   # The Configuration instance used to configure the Rails environment
   def self.configuration: () -> untyped
 

gems/railties/6.0/railties.rbs

@@ -22,7 +22,7 @@ module Rails
   class Engine
     # Defines the routes for this engine. If a block is given to
     # routes, it is appended to the engine.
-    def routes: () ?{ () [self: Mapper] -> void } -> ActionDispatch::Routing::RouteSet
+    def routes: () ?{ () [self: ActionDispatch::Routing::Mapper] -> void } -> ActionDispatch::Routing::RouteSet
   end
 end
 
@@ -36,6 +36,8 @@ module Rails
 end
 
 module Rails
+  def self.application: () -> Rails::Application
+
   class Railties
     extend Initializable::ClassMethods
   end