ActiveJob was introduced so that all Rails apps have the adequate queuing infrastructure in place. It is not dependent on the actual queue adapter that is selected, allowing for easy switching between queue infrastructures in the future.
It means that queue configurations become the responsibility of the queue adapter and not ActiveJob itself. Hence, ActiveJob allows for priority levels to be set if the queue adapter supports it.
While this works great in building queueing systems, it often hinders writing tests for ActiveJob. However, the Rails team is working towards unifying that!
When writing ActiveJob tests,
only minimal configurations were testable,
such as the
time to queue and
It was not possible to write tests for jobs
that make use of the
It would throw a
parameter priority not found error.