Add HTTP::Request#route_uri_pattern that returns URI pattern of matched route.

actionpack/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Add HTTP::Request#route_uri_pattern that returns URI pattern of matched route.
+
+    *Joel Hawksley*, *Kate Higa*
+
 *   Add `ActionDispatch::AssumeSSL` middleware that can be turned on via `config.assume_ssl`.
     It makes the application believe that all requests are arring over SSL. This is useful
     when proxying through a load balancer that terminates SSL, the forwarded request will appear

actionpack/lib/action_dispatch/http/request.rb

@@ -145,6 +145,18 @@ def request_method
       @request_method ||= check_method(super)
     end
 
+    # Returns the URI pattern of the matched route for the request,
+    # using the same format as `bin/rails routes`:
+    #
+    #   request.route_uri_pattern # => "/:controller(/:action(/:id))(.:format)"
+    def route_uri_pattern
+      get_header("action_dispatch.route_uri_pattern")
+    end
+
+    def route_uri_pattern=(pattern) # :nodoc:
+      set_header("action_dispatch.route_uri_pattern", pattern)
+    end
+
     def routes # :nodoc:
       get_header("action_dispatch.routes")
     end

actionpack/lib/action_dispatch/journey/router.rb

@@ -46,6 +46,7 @@ def serve(req)
           }
 
           req.path_parameters = tmp_params
+          req.route_uri_pattern = route.path.spec.to_s
 
           _, headers, _ = response = route.app.serve(req)
 

actionpack/test/controller/routing_test.rb

@@ -351,6 +351,17 @@ def test_default_setup
     assert_equal "/stuff", controller.url_for(controller: "/stuff", only_path: true)
   end
 
+  def test_route_uri_pattern
+    rs.draw { ActionDispatch.deprecator.silence { get "/:controller(/:action(/:id))" } }
+
+    get URI("http://test.host/admin/user/list/10")
+
+    assert_equal(
+      "/:controller(/:action(/:id))(.:format)",
+      controller.request.route_uri_pattern
+    )
+  end
+
   def test_route_with_colon_first
     rs.draw do
       ActionDispatch.deprecator.silence do