3 files changed, 22 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/path/pattern.rb b/actionpack/lib/action_dispatch/journey/path/pattern.rb
index 0902b9233e..cf0108ec32 100644
--- a/actionpack/lib/action_dispatch/journey/path/pattern.rb
+++ b/actionpack/lib/action_dispatch/journey/path/pattern.rb
@@ -31,6 +31,13 @@ module ActionDispatch
           Visitors::FormatBuilder.new.accept(spec)
         end
 
+        def eager_load!
+          required_names
+          offsets
+          to_regexp
+          nil
+        end
+
         def ast
           @spec.find_all(&:symbol?).each do |node|
             re = @requirements[node.to_sym]
diff --git a/actionpack/lib/action_dispatch/journey/route.rb b/actionpack/lib/action_dispatch/journey/route.rb
index f2ac4818d8..927fd369c4 100644
--- a/actionpack/lib/action_dispatch/journey/route.rb
+++ b/actionpack/lib/action_dispatch/journey/route.rb
@@ -73,6 +73,14 @@ module ActionDispatch
         @internal          = internal
       end
 
+      def eager_load!
+        path.eager_load!
+        ast
+        parts
+        required_defaults
+        nil
+      end
+
       def ast
         @decorated_ast ||= begin
           decorated_ast = path.ast
diff --git a/actionpack/lib/action_dispatch/journey/router.rb b/actionpack/lib/action_dispatch/journey/router.rb
index 084ae9325e..d55e1399e4 100644
--- a/actionpack/lib/action_dispatch/journey/router.rb
+++ b/actionpack/lib/action_dispatch/journey/router.rb
@@ -22,6 +22,13 @@ module ActionDispatch
         @routes = routes
       end
 
+      def eager_load!
+        # Eagerly trigger the simulator's initialization so
+        # it doesn't happen during a request cycle.
+        simulator
+        nil
+      end
+
       def serve(req)
         find_routes(req).each do |match, parameters, route|
           set_params  = req.path_parameters