Motivation / Background

Rails registers its internal development welcome route from routes_reloader.run_after_load_paths.

That hook currently calls app.routes.append on each route reload. RouteSet#append stores append blocks persistently, while route reloads clear and finalize the realized routes. As a result, repeated reload_routes! calls in development add another internal GET / welcome route each time.

Detail

Register the internal welcome route append block only once per application boot, while preserving the existing append behavior and route ordering. This keeps app-appended root routes taking precedence over the internal welcome route.

Additional information

No existing issue found for this specific duplicate welcome-route behavior.

Tests

• ruby -c railties/lib/rails/application/finisher.rb
• ruby -c railties/test/application/routing_test.rb
• bundle exec rubocop railties/lib/rails/application/finisher.rb railties/test/application/routing_test.rb
• cd railties && bin/test test/application/routing_test.rb -i '/not duplicated|appended root/'
• cd railties && bin/test test/application/routing_test.rb