Remove function for forming dlq topic name (it's simple)

Remove accidental subscription to dlq topics in main class (tests passed earlier because the names had '-' instead of '.', meaning the topics were not touched in test)

src/hexkit/providers/akafka/provider/eventsub.py

@@ -222,13 +222,11 @@ async def construct(
         topics = translator.topics_of_interest
 
         if config.kafka_enable_dlq:
-            dlq_topics = [f"{topic}-{config.service_name}-dlq" for topic in topics]
-            topics.extend(dlq_topics)
+            topics.append(f"{config.service_name}-retry")
             if dlq_publisher is None:
                 error = ValueError("A publisher is required when the DLQ is enabled.")
                 logging.error(error)
                 raise error
-            topics.append(f"{config.service_name}-retry")
 
         consumer = kafka_consumer_cls(
             *topics,
@@ -290,10 +288,6 @@ def __init__(
         self._enable_dlq = config.kafka_enable_dlq
         self._retry_backoff = config.kafka_retry_backoff
 
-    def _get_dlq_topic(self, topic: str) -> str:
-        """Form the DLQ topic name for a given topic."""
-        return topic + self._dlq_suffix
-
     async def _publish_to_dlq(self, *, event: ExtractedEventInfo, exc: Exception):
         """Publish the event to the corresponding DLQ topic.
 
@@ -304,7 +298,7 @@ async def _publish_to_dlq(self, *, event: ExtractedEventInfo, exc: Exception):
         - `event`: The event to publish to the DLQ.
         - `exc`: The exception that caused the event to be published to the DLQ.
         """
-        dlq_topic = self._get_dlq_topic(event.topic)
+        dlq_topic = event.topic + self._dlq_suffix
         logging.debug("About to publish an event to DLQ topic '%s'", dlq_topic)
         await self._dlq_publisher.publish(  # type: ignore
             payload=event.payload,
@@ -433,7 +427,7 @@ def _extract_info(self, event: ConsumerEvent) -> ExtractedEventInfo:
 
     def _validate_extracted_info(self, event: ExtractedEventInfo):
         """Extract and validate the event, returning the correlation ID and the extracted info."""
-        dlq_topic = self._get_dlq_topic(event.topic)
+        dlq_topic = event.topic + self._dlq_suffix
         correlation_id = event.headers.get("correlation_id", "")
         errors = []
         if not event.type_:
@@ -482,7 +476,7 @@ async def _consume_event(self, event: ConsumerEvent) -> None:
                 await self._handle_consumption(event=event_info)
         except Exception:
             # Errors only bubble up here if the DLQ isn't used
-            dlq_topic = self._get_dlq_topic(event_info.topic)
+            dlq_topic = event_info.topic + self._dlq_suffix
             logging.critical(
                 "An error occurred while processing event of type '%s': %s. It was NOT"
                 " placed in the DLQ topic (%s)",
@@ -671,6 +665,10 @@ def __init__(
         self._publisher = dlq_publisher
         self._dlq_topic = dlq_topic
 
+        # In KafkaEventSubscriber, we get the service name from the config. However,
+        # the service name in effect here probably differs -- e.g., a DLQ-specific
+        # service might be running the KafkaDLQSubscriber. So we extract the service
+        # name from the DLQ topic name instead.
         service_name = service_name_from_dlq_topic(dlq_topic)
         self._retry_topic = service_name + "-retry"
         self._process_dlq_event = process_dlq_event