Add RouteSet#append

Allows specifying blocks to the routeset that will get 	appended after the RouteSet is drawn.

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -217,27 +217,35 @@ module ActionDispatch
         self.valid_conditions.delete(:id)
         self.valid_conditions.push(:controller, :action)
 
+        @append = []
         @disable_clear_and_finalize = false
         clear!
       end
 
       def draw(&block)
         clear! unless @disable_clear_and_finalize
+        eval_block(block)
+        finalize! unless @disable_clear_and_finalize
 
+        nil
+      end
+
+      def append(&block)
+        @append << block
+      end
+
+      def eval_block(block)
         mapper = Mapper.new(self)
         if default_scope
           mapper.with_default_scope(default_scope, &block)
         else
           mapper.instance_exec(&block)
         end
-
-        finalize! unless @disable_clear_and_finalize
-
-        nil
       end
 
       def finalize!
         return if @finalized
+        @append.each { |blk| eval_block(blk) }
         @finalized = true
         @set.freeze
       end

actionpack/test/dispatch/routing_test.rb

@@ -2152,6 +2152,39 @@ private
   end
 end
 
+class TestAppendingRoutes < ActionController::IntegrationTest
+  def simple_app(resp)
+    lambda { |e| [ 200, { 'Content-Type' => 'text/plain' }, [resp] ] }
+  end
+
+  setup do
+    s = self
+    @app = ActionDispatch::Routing::RouteSet.new
+    @app.append do
+      match '/hello'   => s.simple_app('fail')
+      match '/goodbye' => s.simple_app('goodbye')
+    end
+
+    @app.draw do
+      match '/hello' => s.simple_app('hello')
+    end
+  end
+
+  def test_goodbye_should_be_available
+    get '/goodbye'
+    assert_equal 'goodbye', @response.body
+  end
+
+  def test_hello_should_not_be_overwritten
+    get '/hello'
+    assert_equal 'hello', @response.body
+  end
+
+  def test_missing_routes_are_still_missing
+    get '/random'
+    assert_equal 404, @response.status
+  end
+end
 
 class TestDefaultScope < ActionController::IntegrationTest
   module ::Blog

railties/test/application/routing_test.rb

@@ -177,6 +177,34 @@ module ApplicationTests
       assert_equal 'admin::foo', last_response.body
     end
 
+    test "reloads appended route blocks" do
+      app_file 'config/routes.rb', <<-RUBY
+        AppTemplate::Application.routes.draw do
+          match ':controller#:action'
+        end
+      RUBY
+
+      add_to_config <<-R
+        routes.append do
+          match '/win' => lambda { |e| [200, {'Content-Type'=>'text/plain'}, 'WIN'] }
+        end
+      R
+
+      app 'development'
+
+      get '/win'
+      assert_equal 'WIN', last_response.body
+
+      app_file 'config/routes.rb', <<-R
+        AppTemplate::Application.routes.draw do
+          match 'lol' => 'hello#index'
+        end
+      R
+
+      get '/win'
+      assert_equal 'WIN', last_response.body
+    end
+
     {"development" => "baz", "production" => "bar"}.each do |mode, expected|
       test "reloads routes when configuration is changed in #{mode}" do
         controller :foo, <<-RUBY