Fix NPE when UserIdentity is null

Author: carlzogh

aws-lambda-java-events-sdk-transformer/src/main/java/com/amazonaws/services/lambda/runtime/events/transformers/dynamodb/DynamodbRecordTransformer.java

@@ -16,7 +16,9 @@ public static Record toRecordV2(final DynamodbEvent.DynamodbStreamRecord record)
                 .eventSource(record.getEventSource())
                 .eventVersion(record.getEventVersion())
                 .userIdentity(
-                        DynamodbIdentityTransformer.toIdentityV2(record.getUserIdentity())
+                        record.getUserIdentity() != null
+                                ? DynamodbIdentityTransformer.toIdentityV2(record.getUserIdentity())
+                                : null
                 )
                 .build();
     }

aws-lambda-java-events-sdk-transformer/src/test/java/com/amazonaws/services/lambda/runtime/events/transformers/dynamodb/DynamodbRecordTransformerTest.java

@@ -50,4 +50,14 @@ public void testToRecordV2() {
         Assertions.assertEquals(record_v2, convertedRecord);
     }
 
+    @Test
+    public void testToRecordV2WhenUserIdentityIsNull() {
+        DynamodbEvent.DynamodbStreamRecord record = record_event.clone();
+        record.setUserIdentity(null);
+
+        Assertions.assertDoesNotThrow(() -> {
+            DynamodbRecordTransformer.toRecordV2(record);
+        });
+    }
+
 }