Improve engine routes installation

lib/generators/shopify_app/add_declarative_webhook/add_declarative_webhook_generator.rb

@@ -31,8 +31,7 @@ def add_webhook_controller
       end
 
       def add_webhook_route
-        route = "\t\t\tpost '#{file_name}', to: '#{file_name}#receive'\n"
-        inject_into_file("config/routes.rb", route, after: /namespace :webhooks do\n/)
+        route "post '#{file_name}', to: '#{file_name}#receive'", namespace: :webhooks
       end
 
       private

lib/generators/shopify_app/install/install_generator.rb

@@ -53,6 +53,10 @@ def mount_engine
         route("mount ShopifyApp::Engine, at: '/'")
       end
 
+      def setup_routes
+        route "# Add your webhook routes here\n", namespace: [:webhooks]
+      end
+
       def insert_hosts_into_development_config
         "Rails.application.configure do\n"
           .then { insert_tunnel_host_rules("ngrok", _1, NGROK_HOST + "\n") }

test/app_templates/config/routes.rb

@@ -8,12 +8,13 @@
         get :count
       end
     end
-    namespace :webhooks do
-      post "/app_uninstalled", to: "app_uninstalled#receive"
-      post "/customers_data_request", to: "customers_data_request#receive"
-      post "/customers_redact", to: "customers_redact#receive"
-      post "/shop_redact", to: "shop_redact#receive"
-    end
+  end
+
+  namespace :webhooks do
+    post "/app_uninstalled", to: "app_uninstalled#receive"
+    post "/customers_data_request", to: "customers_data_request#receive"
+    post "/customers_redact", to: "customers_redact#receive"
+    post "/shop_redact", to: "shop_redact#receive"
   end
 
   mount ShopifyApp::Engine, at: "/"

test/dummy/config/routes.rb

@@ -1,6 +1,9 @@
 # frozen_string_literal: true
 
 Rails.application.routes.draw do
-  mount ShopifyApp::Engine, at: "/"
-  root to: "dummy_home#index"
+  root :to => 'dummy_home#index'
+  namespace :webhooks do
+    # Add your webhook routes here
+  end
+  mount ShopifyApp::Engine, at: '/'
 end