Use custom visitor class for optimized url helpers

Rather than trying to use gsub to remove the optional route segments,
which will fail with nested optional segments, use a custom visitor
class that returns a empty string for group nodes.

Closes #9524

1 files changed, 6 insertions, 0 deletions

diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index 89f406a3d0..2bf7056ff7 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -3198,6 +3198,7 @@ class TestOptimizedNamedRoutes < ActionDispatch::IntegrationTest
     app.draw do
       ok = lambda { |env| [200, { 'Content-Type' => 'text/plain' }, []] }
       get '/foo' => ok, as: :foo
+      get '/post(/:action(/:id))' => ok, as: :posts
     end
   end
 
@@ -3215,6 +3216,11 @@ class TestOptimizedNamedRoutes < ActionDispatch::IntegrationTest
   test 'named route called on included module' do
     assert_equal '/foo', foo_path
   end
+
+  test 'nested optional segments are removed' do
+    assert_equal '/post', Routes.url_helpers.posts_path
+    assert_equal '/post', posts_path
+  end
 end
 
 class TestNamedRouteUrlHelpers < ActionDispatch::IntegrationTest