zeitwerk.md

description
rails 6 autoloading behavior

Zeitwerk

https://guides.rubyonrails.org/v6.0.3/autoloading_and_reloading_constants.html discusses this

context: Seeing (suddenly) errors loading Notifications::WelcomeNotificationWorker when trying to instantiate a new user in tests in docker.

[2] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> create(:user)
NameError: uninitialized constant Notifications::WelcomeNotificationWorker
from /opt/apps/forem/app/models/notification.rb:79:in `send_welcome_notification'

Before I get much further - my suspicion is that the issue may be tied to two directories with classes in the Notifications module (app/services/notifications/ and app/workers/notifications/) and only the first getting searched.

This is only happening for me in docker (the same behavior does not happen in a local dev env).

I can confirm the Notifications module is loading correctly

[8] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> show-method Notifications
                                                                               
From: /opt/apps/forem/app/services/notifications.rb:1
Module name: Notifications
Number of lines: 78

module Notifications
  def self.user_data(user)

However - I tried the dumbest thing that could possibly work, and copied the worker from workers/notifications/ to services/notifications/ and still could not autoload the class. Additionally, none of the code in either subdirectory belonging to this namespace was loaded:

[7] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> constant = "Notifications::WelcomeNotificationWorker".constantize
NameError: uninitialized constant Notifications::WelcomeNotificationWorker                                             
from /opt/apps/forem/vendor/bundle/ruby/2.7.0/gems/activesupport-6.1.3.1/lib/active_support/inflector/methods.rb:288:in `const_get'

[16] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> Notifications.constants
=> []                                                 

Code is working when loaded (name is not wrong):

[2] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> Notifications.constants
=> []                                                                        
[3] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> load(Rails.root + "app/workers/notifications/welcome_notification_worker.rb")                                                     
=> true                                                                                                                            
[4] pry(#<RSpec::ExampleGroups::User::ProfileImage>)> Notifications.constants
=> [:WelcomeNotificationWorker]