Rails integration causes an "Initialization autoloaded the constants ActionText::ContentHelper" warning

[kemenaran]

Summary

When adding the Mailjet gem to a Rails project through the Gemfile, it causes Rails to issue a warning in the console when starting the app:

DEPRECATION WARNING: Initialization autoloaded the constants ActionText::ContentHelper and ActionText::TagHelper.

Steps to reproduce

1. Add mailjet to the Gemfile

   # Gemfile
   gem 'mailjet'

2. Start the Rails app

   bin/rails server

Details

The issue occurs because Mailjet's Rail integration causes ActionMail to be loaded early.

This will in turn:

1. trigger Rails' action_text.helpers initializer early,
2. which will cause ActionController::Base to be loaded before ActionText,
3. which will cause ActionText constants to be automatically discovered,
4. which will cause the warning above.

Workaround

A workaround is to not require the mailjet gem automatically.

# Gemfile
gem 'mailjet', require: false

# config/initializers/mailjet
ActiveSupport.on_load(:action_mailer) do
  require 'mailjet'

  Mailjet.configure do |config|
    # …
  end
end

[kemenaran]

Thanks! 💚