Add the member route helper

lib/rage/router/dsl.rb

@@ -267,6 +267,27 @@ def collection(&block)
       @path_prefixes = orig_path_prefixes
     end
 
+    # Add a member route.
+    #
+    # @example Add a `photos/:id/preview` path instead of `photos/:photo_id/preview`
+    #   resources :photos do
+    #     member do
+    #       get "preview"
+    #     end
+    #   end
+    def member(&block)
+      orig_path_prefixes = @path_prefixes
+
+      if (param_prefix = @path_prefixes.last)&.start_with?(":") && @controllers.any?
+        member_prefix = param_prefix.delete_prefix(":#{to_singular(@controllers.last)}_")
+        @path_prefixes = [*@path_prefixes[0...-1], ":#{member_prefix}"]
+      end
+
+      instance_eval &block
+
+      @path_prefixes = orig_path_prefixes
+    end
+
     # Automatically create REST routes for a resource.
     #
     # @example Create five REST routes, all mapping to the `Photos` controller:

spec/router/dsl_spec.rb

@@ -575,6 +575,31 @@ def call(env)
       end
     end
 
+    it "correctly creates nested routes on member" do
+      expect(router).to receive(:on).with("GET", "/photos/:id", "photos#show", instance_of(Hash))
+      expect(router).to receive(:on).with("POST", "/photos/:id/like", "photos#like", instance_of(Hash))
+
+      dsl.draw do
+        resources :photos, only: :show do
+          member do
+            post :like
+          end
+        end
+      end
+    end
+
+    it "correctly creates nested routes on member with a custom param" do
+      expect(router).to receive(:on).with("POST", "/photos/:photo_uuid/like", "photos#like", instance_of(Hash))
+
+      dsl.draw do
+        resources :photos, only: [], param: :photo_uuid do
+          member do
+            post :like
+          end
+        end
+      end
+    end
+
     it "correctly creates nested resources" do
       expect(router).to receive(:on).with("GET", "/albums", "albums#index", instance_of(Hash))
       expect(router).to receive(:on).with("POST", "/albums", "albums#create", instance_of(Hash))
@@ -606,6 +631,7 @@ def call(env)
       expect(router).to receive(:on).with("DELETE", "/albums/:album_slug/my_photos/:id", "photos#destroy", instance_of(Hash))
       expect(router).to receive(:on).with("POST", "/albums/:album_slug/my_photos/:photo_id/add_to_album", "photos#add_to_album", instance_of(Hash))
       expect(router).to receive(:on).with("POST", "/albums/:album_slug/my_photos/like_all", "photo_likes#create", instance_of(Hash))
+      expect(router).to receive(:on).with("GET", "/albums/:album_slug/my_photos/:id/keywords", "photos#keywords", instance_of(Hash))
 
       expect(router).to receive(:on).with("POST", "/albums/sort", "albums#sort", instance_of(Hash))
       expect(router).to receive(:on).with("PATCH", "/albums/:album_slug/tag", "albums#tag", instance_of(Hash))
@@ -618,6 +644,10 @@ def call(env)
             collection do
               post "like_all", to: "photo_likes#create"
             end
+
+            member do
+              get :keywords
+            end
           end
 
           collection do