Merge pull request rails#54777 from Shopify/load_lazy_routes_in_test

Load lazy route set before inserting test routes

Author: gmcgibbon

actionpack/CHANGELOG.md

@@ -1,3 +1,10 @@
+*   Load lazy route sets before inserting test routes
+
+    Without loading lazy route sets early, we miss `after_routes_loaded` callbacks, or risk
+    invoking them with the test routes instead of the real ones if another load is triggered by an engine.
+
+    *Gannon McGibbon*
+
 *   Raise `AbstractController::DoubleRenderError` if `head` is called after rendering.
 
     After this change, invoking `head` will lead to an error if response body is already set:

actionpack/lib/action_dispatch/testing/assertions/routing.rb

@@ -25,7 +25,7 @@ def with_routing(&block)
             old_integration_session = nil
 
             setup do
-              old_routes = app.routes
+              old_routes = initialize_lazy_routes(app.routes)
               old_routes_call_method = old_routes.method(:call)
               old_integration_session = integration_session
               create_routes(&block)
@@ -38,7 +38,7 @@ def with_routing(&block)
         end
 
         def with_routing(&block)
-          old_routes = app.routes
+          old_routes = initialize_lazy_routes(app.routes)
           old_routes_call_method = old_routes.method(:call)
           old_integration_session = integration_session
           create_routes(&block)
@@ -47,6 +47,14 @@ def with_routing(&block)
         end
 
         private
+          def initialize_lazy_routes(routes)
+            if defined?(Rails::Engine::LazyRouteSet) && routes.is_a?(Rails::Engine::LazyRouteSet)
+              routes.tap(&:routes)
+            else
+              routes
+            end
+          end
+
           def create_routes
             app = self.app
             routes = ActionDispatch::Routing::RouteSet.new

railties/test/application/integration_test_case_test.rb

@@ -72,5 +72,48 @@ def test_app_returns_action_dispatch_test_app_by_default
       output = rails("test")
       assert_match(/0 failures, 0 errors/, output)
     end
+
+    test "routes are loaded before inserting test routes" do
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+          get "/c", as: :c, to: "users#show"
+        end
+      RUBY
+
+      app_file "config/initializers/after_routes_loaded.rb", <<-RUBY
+        Rails.configuration.after_routes_loaded do
+          $after_routes_loaded = true
+        end
+      RUBY
+
+      app_file "app/controllers/users_controller.rb", <<-RUBY
+        class UsersController < ActionController::Base
+          def index
+            render json: { loaded: $after_routes_loaded }
+          end
+        end
+      RUBY
+
+      app_file "test/controllers/users_controller_test.rb", <<-RUBY
+        require "test_helper"
+
+        class UsersControllerTest < ActionDispatch::IntegrationTest
+          with_routing do |set|
+            set.draw do
+              resources(:users, only: :index)
+            end
+          end
+
+          test "lazy route loading" do
+            get("/users")
+
+            assert_equal({ "loaded" => true }, JSON.parse(response.body))
+          end
+        end
+      RUBY
+
+      output = rails("test")
+      assert_match(/0 failures, 0 errors/, output)
+    end
   end
 end