my-jobs.rb

ActiveJob::Base.queue_adapter = :delayed
$stdout.sync = true
$stdout.flush

class MyBaseJob < ActiveJob::Base
  # Stop delayed retrying at all
  def max_attempts
    0
  end

  def job_flailed
    puts "[#{self.class}] #job_flailed called"
    # TODO: Implement attached item logic here to clean up
  end

  # Public: Delayed::Base callback for error from #perform
  #
  # Called when Exception is raised, or ActiveJob hasn't handled error already. The ActiveJob instance
  # can be accessed through `job.payload_object`.
  #
  # @param job [Delayed::Job] the job that failed
  # @param exception [Exception] the exception that was raised
  def error(job, exception)
    puts "[#{self.class}] #error called"
    job_flailed
  end

  # Override: ActiveJob::Execution#rescue_with_handler
  #
  # Called when StandardError or subclasses are raised during job's #perform method. Called on every attempt
  # that raises an error.
  #
  # This MUST return the result of calling super to maintain existing behaviour.
  def rescue_with_handler(...)
    puts "[#{self.class}] #rescue_with_handler called"
    result = super(...)

    # If the job is being retried, it has `scheduled_at` set to truthy value
    unless scheduled_at
      job_flailed
    end

    result
  end
end

class MySensibleJob < MyBaseJob
  CustomError = Class.new(StandardError)

  retry_on CustomError, wait: 0, attempts: 2 do
    puts "[MySensibleJob] CustomError retry_on block called"
  end

  def perform
    puts
    puts "[MySensibleJob] #perform"
    raise CustomError
  end
end

class MyNaughtyJob < MyBaseJob
  discard_on StandardError

  def perform
    puts
    puts "[MyNaughtyJob] #perform"
    raise StandardError
  end
end

class MyBatshitJob < MyBaseJob
  def perform
    puts
    puts "[MyBatshitJob] #perform"
    raise Exception
  end
end

MySensibleJob.perform_later

MyNaughtyJob.perform_later

MyBatshitJob.perform_later

Delayed::Worker.new.work_off

sleep 5

output.txt

$ bin/rails runner tmp/my-jobs.rb

[MySensibleJob] #perform
[MySensibleJob] #rescue_with_handler called

[MyNaughtyJob] #perform
[MyNaughtyJob] #rescue_with_handler called
[MyNaughtyJob] #job_flailed called

[MyBatshitJob] #perform
[MyBatshitJob] #error called
[MyBatshitJob] #job_flailed called

[MySensibleJob] #perform
[MySensibleJob] #rescue_with_handler called
[MySensibleJob] CustomError retry_on block called
[MySensibleJob] #job_flailed called