Undefined method 'enqueue' for Active job

[jgunnink]

Hello,

Firstly, thank you for this gem. I'm hoping to get some good use out of it.

I am attempting to use this gem in my app as a drop-in replacement for redis/sidekiq which is running background mail tasks.

Following the readme, I've setup the gem, and deployed the app. The application functions normally until a request to use the gem is fired. Specifically, I'm using devise to handle delivery of mail with the deliver_later

Code:

  # Override Devise notification to use background messaging queue.
  def send_devise_notification(notification, *args)
    devise_mailer.send(notification, self, *args).deliver_later
  end

Running this line of code yields in the following:

NoMethodError (undefined method `enqueue' for ActiveJob::GoogleCloudPubsub::Adapter:Class):

Looking through the gem source, I can see that the method does indeed exist, however at runtime it appears it's not available. Are there any additional setup configs which are perhaps assumed or is there something I've missed which could cause this?

I'm running Ruby 2.5.3 and Rails 4.2.1

Thank you for any help. 😄