Merge pull request rails#44586 from Shopify/action-view-eager-loading

Eager load controllers `view_context_class`

Author: byroot

actionmailer/lib/action_mailer.rb

@@ -58,6 +58,10 @@ def self.eager_load!
 
     require "mail"
     Mail.eager_autoload!
+
+    Base.descendants.each do |mailer|
+      mailer.eager_load! unless mailer.abstract?
+    end
   end
 end
 

actionmailer/lib/action_mailer/railtie.rb

@@ -74,12 +74,6 @@ class Railtie < Rails::Railtie # :nodoc:
       end
     end
 
-    initializer "action_mailer.eager_load_actions" do
-      ActiveSupport.on_load(:after_initialize) do
-        ActionMailer::Base.descendants.each(&:action_methods) if config.eager_load
-      end
-    end
-
     config.after_initialize do |app|
       options = app.config.action_mailer
 

actionpack/lib/abstract_controller.rb

@@ -24,5 +24,10 @@ module AbstractController
   def self.eager_load!
     super
     AbstractController::Caching.eager_load!
+    AbstractController::Base.descendants.each do |controller|
+      unless controller.abstract?
+        controller.eager_load!
+      end
+    end
   end
 end

actionpack/lib/abstract_controller/base.rb

@@ -127,6 +127,11 @@ def method_added(name)
         super
         clear_action_methods!
       end
+
+      def eager_load! # :nodoc:
+        action_methods
+        nil
+      end
     end
 
     abstract!

actionpack/lib/action_controller/railtie.rb

@@ -14,6 +14,7 @@ class Railtie < Rails::Railtie # :nodoc:
     config.action_controller.log_query_tags_around_actions = true
     config.action_controller.wrap_parameters_by_default = false
 
+    config.eager_load_namespaces << AbstractController
     config.eager_load_namespaces << ActionController
 
     initializer "action_controller.assets_config", group: :all do |app|
@@ -99,12 +100,6 @@ class Railtie < Rails::Railtie # :nodoc:
       end
     end
 
-    initializer "action_controller.eager_load_actions" do
-      ActiveSupport.on_load(:after_initialize) do
-        ActionController::Metal.descendants.each(&:action_methods) if config.eager_load
-      end
-    end
-
     initializer "action_controller.query_log_tags" do |app|
       query_logs_tags_enabled = app.config.respond_to?(:active_record) &&
         app.config.active_record.query_log_tags_enabled &&

actionview/lib/action_view/rendering.rb

@@ -72,6 +72,12 @@ def build_view_context_class(klass, supports_path, routes, helpers)
         end
       end
 
+      def eager_load!
+        super
+        view_context_class
+        nil
+      end
+
       def view_context_class
         klass = ActionView::LookupContext::DetailsKey.view_context_class(ActionView::Base)
 

railties/test/application/configuration_test.rb

@@ -291,7 +291,7 @@ def change
       assert_instance_of Pathname, Rails.public_path
     end
 
-    test "does not eager load controller actions in development" do
+    test "does not eager load controllers state actions in development" do
       app_file "app/controllers/posts_controller.rb", <<-RUBY
         class PostsController < ActionController::Base
           def index;end
@@ -302,9 +302,10 @@ def show;end
       app "development"
 
       assert_nil PostsController.instance_variable_get(:@action_methods)
+      assert_nil PostsController.instance_variable_get(:@view_context_class)
     end
 
-    test "eager loads controller actions in production" do
+    test "eager loads controllers state in production" do
       app_file "app/controllers/posts_controller.rb", <<-RUBY
         class PostsController < ActionController::Base
           def index;end
@@ -320,6 +321,7 @@ def show;end
       app "production"
 
       assert_equal %w(index show).to_set, PostsController.instance_variable_get(:@action_methods)
+      assert_not_nil PostsController.instance_variable_get(:@view_context_class)
     end
 
     test "does not eager load mailer actions in development" do