[issues/6508](-) key in KafkaRecordModel is made optional, added a new Kafka record without key into json files and added tests

Author: Weugene

aws_lambda_powertools/utilities/data_classes/kafka_event.py

@@ -37,14 +37,25 @@ def timestamp_type(self) -> str:
         return self["timestampType"]
 
     @property
-    def key(self) -> str:
-        """The raw (base64 encoded) Kafka record key."""
-        return self["key"]
+    def key(self) -> str | None:
+        """
+        The raw (base64 encoded) Kafka record key.
+
+        This key is optional; if not provided,
+        a round-robin algorithm will be used to determine
+        the partition for the message.
+        """
+
+        return self.get("key")
 
     @property
-    def decoded_key(self) -> bytes:
-        """Decode the base64 encoded key as bytes."""
-        return base64.b64decode(self.key)
+    def decoded_key(self) -> bytes | None:
+        """
+        Decode the base64 encoded key as bytes.
+
+        If the key is not provided, this will return None.
+        """
+        return None if self.key is None else base64.b64decode(self.key)
 
     @property
     def value(self) -> str:

tests/unit/data_classes/required_dependencies/test_kafka_event.py

@@ -21,7 +21,7 @@ def test_kafka_msk_event():
     assert parsed_event.decoded_bootstrap_servers == bootstrap_servers_list
 
     records = list(parsed_event.records)
-    assert len(records) == 1
+    assert len(records) == 2
     record = records[0]
     raw_record = raw_event["records"]["mytopic-0"][0]
     assert record.topic == raw_record["topic"]
@@ -37,6 +37,9 @@ def test_kafka_msk_event():
 
     assert parsed_event.record == records[0]
 
+    record = records[1]
+    assert record.key is None
+
 
 def test_kafka_self_managed_event():
     raw_event = load_event("kafkaEventSelfManaged.json")
@@ -52,7 +55,7 @@ def test_kafka_self_managed_event():
     assert parsed_event.decoded_bootstrap_servers == bootstrap_servers_list
 
     records = list(parsed_event.records)
-    assert len(records) == 1
+    assert len(records) == 2
     record = records[0]
     raw_record = raw_event["records"]["mytopic-0"][0]
     assert record.topic == raw_record["topic"]
@@ -68,14 +71,18 @@ def test_kafka_self_managed_event():
 
     assert parsed_event.record == records[0]
 
+    record = records[1]
+    assert record.key is None
+
 
 def test_kafka_record_property_with_stopiteration_error():
     # GIVEN a kafka event with one record
     raw_event = load_event("kafkaEventMsk.json")
     parsed_event = KafkaEvent(raw_event)
 
-    # WHEN calling record property twice
+    # WHEN calling record property thrice
     # THEN raise StopIteration
     with pytest.raises(StopIteration):
         assert parsed_event.record.topic is not None
-        assert parsed_event.record.partition is not None
+        assert parsed_event.record.topic is not None
+        assert parsed_event.record.topic is not None