lib/retryable_queue_message.rb

@@ -1,3 +1,12 @@
+# This class should be used as a wrapper around GovukMessageQueueConsumer::Message
+# whenever we use an exchange that uses a dead letter exchange (dlx) as a retry
+# mechanism. Using a dlx in this way means sending counter intuitive responses to
+# RabbitMQ. Where an ack is the approach to mark a job as completed AND to mark a
+# job as failed, whereas discard actually signifies that we're going to retry the job.
+
+# You should only use this class if you're planning to retry via a dlx otherwise
+# it'll be very confusing!
+
 class RetryableQueueMessage
   delegate :payload, :headers, :status, :delivery_info, to: :queue_message
 
@@ -10,9 +19,6 @@ def done
   end
 
   def retry
-    # Some of our RabbitMQ exchanges are configured such that discarding a message
-    # pushes it to a queue to retry, so we have to a call an unintiuitvely named
-    # method totrigger a retry.
     queue_message.discard
   end