Clear named routes when routes.rb is reloaded

Fix an issue where Journey was failing to clear the named routes hash when the
routes were reloaded and since it doesn't overwrite existing routes then if a
route changed but wasn't renamed it kept the old definition. This was being
masked by the optimised url helpers so it only became apparent when passing an
options hash to the url helper.

actionpack/CHANGELOG.md

@@ -1,3 +1,11 @@
+*   Fix an issue where Journey was failing to clear the named routes hash when the
+    routes were reloaded and since it doesn't overwrite existing routes then if a
+    route changed but wasn't renamed it kept the old definition. This was being
+    masked by the optimised url helpers so it only became apparent when passing an
+    options hash to the url helper.
+
+    *Andrew White*
+
 *   Skip routes pointing to a redirect or mounted application when generating urls
     using an options hash as they aren't relevant and generate incorrect urls.
 

actionpack/lib/action_dispatch/journey/routes.rb

@@ -30,6 +30,7 @@ module ActionDispatch
 
       def clear
         routes.clear
+        named_routes.clear
       end
 
       def partitioned_routes

railties/test/application/routing_test.rb

@@ -372,6 +372,51 @@ module ApplicationTests
       end
     end
 
+    test 'named routes are cleared when reloading' do
+      app('development')
+
+      controller :foo, <<-RUBY
+        class FooController < ApplicationController
+          def index
+            render text: "foo"
+          end
+        end
+      RUBY
+
+      controller :bar, <<-RUBY
+        class BarController < ApplicationController
+          def index
+            render text: "bar"
+          end
+        end
+      RUBY
+
+      app_file 'config/routes.rb', <<-RUBY
+        Rails.application.routes.draw do
+          get ':locale/foo', to: 'foo#index', as: 'foo'
+        end
+      RUBY
+
+      get '/en/foo'
+      assert_equal 'foo', last_response.body
+      assert_equal '/en/foo', Rails.application.routes.url_helpers.foo_path(:locale => 'en')
+
+      app_file 'config/routes.rb', <<-RUBY
+        Rails.application.routes.draw do
+          get ':locale/bar', to: 'bar#index', as: 'foo'
+        end
+      RUBY
+
+      Rails.application.reload_routes!
+
+      get '/en/foo'
+      assert_equal 404, last_response.status
+
+      get '/en/bar'
+      assert_equal 'bar', last_response.body
+      assert_equal '/en/bar', Rails.application.routes.url_helpers.foo_path(:locale => 'en')
+    end
+
     test 'resource routing with irregular inflection' do
       app_file 'config/initializers/inflection.rb', <<-RUBY
         ActiveSupport::Inflector.inflections do |inflect|