zeitwerk-2.1.9, ruby-2.5.5, Rails 6.0 upgrade uninitialized constant ApplicationJob (NameError)

[fredv]

First of all, thank you so much for tackling autoloading.

When upgrading a large Rails 5.2 app, I'm encountering the following:

.rbenv/versions/2.5.5/lib/ruby/gems/2.5.0/gems/zeitwerk-2.1.9/lib/zeitwerk/loader.rb:351:in const_get': uninitialized constant ApplicationJob (NameError) Did you mean? ApplicationJob

After enabling the log, it happens when zeitwerk starts loading the jobs folder in the Rails app.
The folder contains a file "application_job.rb" with the following content:
class ApplicationJob < ActiveJob::Base queue_as :default end

As this is a quite common pattern, I wonder what the correct way of declaration and usage of such Base Wrapper classes is in order for the autoloading to pick up on it. I also wonder, why the class name is picked up by the typo suggestion below the error output but not Zeitwerk.

Is this a matter of load order, do extensions of Rails Base classes need to be placed in a different namespace or loaded before-hand?

[byroot]

No, it should definitely work, there must be something else that cause this exception.

Could you shared more details? e.g. the last few lines of the zeitwerk logs, and potentially try to repro in a new app.

[fredv]

@byroot thank you for your reply! In a newly created rails 6 app it works fine. I resolved the issue as it was caused by ApplicationJob being referenced in an initializer by moving the code to config.after_initialize.