4 files changed, 75 insertions, 3 deletions
diff --git a/railties/lib/rails/tasks/framework.rake b/railties/lib/rails/tasks/framework.rake
index 1a3711c446..2886986865 100644
--- a/railties/lib/rails/tasks/framework.rake
+++ b/railties/lib/rails/tasks/framework.rake
@@ -2,7 +2,7 @@
 
 namespace :app do
   desc "Update configs and some other initially generated files (or use just update:configs or update:bin)"
-  task update: [ "update:configs", "update:bin", "update:upgrade_guide_info" ]
+  task update: [ "update:configs", "update:bin", "update:active_storage", "update:upgrade_guide_info" ]
 
   desc "Applies the template supplied by LOCATION=(/path/to/template) or URL"
   task template: :environment do
@@ -51,6 +51,10 @@ namespace :app do
       Rails::AppUpdater.invoke_from_app_generator :update_bin_files
     end
 
+    task :active_storage do
+      Rails::AppUpdater.invoke_from_app_generator :update_active_storage
+    end
+
     task :upgrade_guide_info do
       Rails::AppUpdater.invoke_from_app_generator :display_upgrade_guide_info
     end
diff --git a/railties/lib/rails/tasks/statistics.rake b/railties/lib/rails/tasks/statistics.rake
index 8cacf4a49f..5abba7d3b4 100644
--- a/railties/lib/rails/tasks/statistics.rake
+++ b/railties/lib/rails/tasks/statistics.rake
@@ -9,6 +9,7 @@ STATS_DIRECTORIES = [
   %w(Jobs               app/jobs),
   %w(Models             app/models),
   %w(Mailers            app/mailers),
+  %w(Mailboxes          app/mailboxes),
   %w(Channels           app/channels),
   %w(JavaScripts        app/assets/javascripts),
   %w(JavaScript         app/javascript),
@@ -18,6 +19,8 @@ STATS_DIRECTORIES = [
   %w(Helper\ tests      test/helpers),
   %w(Model\ tests       test/models),
   %w(Mailer\ tests      test/mailers),
+  %w(Mailbox\ tests     test/mailboxes),
+  %w(Channel\ tests     test/channels),
   %w(Job\ tests         test/jobs),
   %w(Integration\ tests test/integration),
   %w(System\ tests      test/system),
diff --git a/railties/lib/rails/tasks/yarn.rake b/railties/lib/rails/tasks/yarn.rake
index 4fb8586b69..48a8d8e143 100644
--- a/railties/lib/rails/tasks/yarn.rake
+++ b/railties/lib/rails/tasks/yarn.rake
@@ -6,8 +6,7 @@ namespace :yarn do
     # Install only production deps when for not usual envs.
     valid_node_envs = %w[test development production]
     node_env = ENV.fetch("NODE_ENV") do
-      rails_env = ENV["RAILS_ENV"]
-      valid_node_envs.include?(rails_env) ? rails_env : "production"
+      valid_node_envs.include?(Rails.env) ? Rails.env : "production"
     end
     system({ "NODE_ENV" => node_env }, "#{Rails.root}/bin/yarn install --no-progress --frozen-lockfile")
   end
diff --git a/railties/lib/rails/tasks/zeitwerk.rake b/railties/lib/rails/tasks/zeitwerk.rake
new file mode 100644
index 0000000000..5421af6e8b
--- /dev/null
+++ b/railties/lib/rails/tasks/zeitwerk.rake
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+ensure_zeitwerk_mode = ->() do
+  unless Rails.autoloaders.zeitwerk_enabled?
+    abort "Please, enable :zeitwerk mode in config/application.rb and try again."
+  end
+end
+
+eager_load = ->() do
+  puts "Hold on, I am eager loading the application."
+  Zeitwerk::Loader.eager_load_all
+end
+
+report_not_checked = ->(not_checked) do
+  puts
+  puts <<~EOS
+    WARNING: The files in these directories cannot be checked because they
+    are not eager loaded:
+  EOS
+  puts
+
+  not_checked.each { |dir| puts "  #{dir}" }
+  puts
+
+  puts <<~EOS
+    You may verify them manually, or add them to config.eager_load_paths
+    in config/application.rb and run zeitwerk:check again.
+  EOS
+  puts
+end
+
+report = ->(not_checked) do
+  if not_checked.any?
+    report_not_checked[not_checked]
+    puts "Otherwise, all is good!"
+  else
+    puts "All is good!"
+  end
+end
+
+namespace :zeitwerk do
+  desc "Checks project structure for Zeitwerk compatibility"
+  task check: :environment do
+    ensure_zeitwerk_mode[]
+
+    begin
+      eager_load[]
+    rescue NameError => e
+      if e.message =~ /expected file .*? to define constant \S+/
+        abort $&.sub(/#{Regexp.escape(Rails.root.to_s)}./, "")
+      else
+        raise
+      end
+    end
+
+    eager_load_paths = Rails.configuration.eager_load_namespaces.map do |eln|
+      eln.config.eager_load_paths if eln.respond_to?(:config)
+    end.compact.flatten
+
+    not_checked = ActiveSupport::Dependencies.autoload_paths - eager_load_paths
+    not_checked.select! { |dir| Dir.exist?(dir) }
+    not_checked.reject! { |dir| Dir.empty?(dir) }
+
+    report[not_checked]
+  end
+end