Fix bug with eager_load in development environment

Modifies the routes simulator to allow for empty RouteSets, which are
created when secondary Engines are loaded.

2 files changed, 10 insertions, 1 deletions

diff --git a/actionpack/lib/action_dispatch/journey/routes.rb b/actionpack/lib/action_dispatch/journey/routes.rb
index 639c063495..3ba8361d77 100644
--- a/actionpack/lib/action_dispatch/journey/routes.rb
+++ b/actionpack/lib/action_dispatch/journey/routes.rb
@@ -51,7 +51,7 @@ module ActionDispatch
       def ast
         @ast ||= begin
           asts = anchored_routes.map(&:ast)
-          Nodes::Or.new(asts) unless asts.empty?
+          Nodes::Or.new(asts)
         end
       end
 
diff --git a/actionpack/test/journey/router_test.rb b/actionpack/test/journey/router_test.rb
index 183f421bcf..1f4e14aef6 100644
--- a/actionpack/test/journey/router_test.rb
+++ b/actionpack/test/journey/router_test.rb
@@ -493,6 +493,15 @@ module ActionDispatch
         assert_not called
       end
 
+      def test_eager_load_with_routes
+        get "/foo-bar", to: "foo#bar"
+        assert_nil router.eager_load!
+      end
+
+      def test_eager_load_without_routes
+        assert_nil router.eager_load!
+      end
+
       private
 
         def get(*args)