add properties for tumbling window to dynamodb stream

Author: kiitosu

aws_lambda_powertools/utilities/data_classes/dynamo_db_stream_event.py

@@ -140,12 +140,25 @@ def user_identity(self) -> dict:
         return self.get("userIdentity") or {}
 
 
+class KinesisStreamWindow(DictWrapper):
+    @property
+    def start(self) -> str:
+        """The time window started"""
+        return self["start"]
+
+    @property
+    def end(self) -> str:
+        """The time window will end"""
+        return self["end"]
+
+
 class DynamoDBStreamEvent(DictWrapper):
     """Dynamo DB Stream Event
 
     Documentation:
     -------------
     - https://docs.aws.amazon.com/lambda/latest/dg/with-ddb.html
+    - https://docs.aws.amazon.com/lambda/latest/dg/services-ddb-windows.html
 
     Example
     -------
@@ -167,3 +180,30 @@ def lambda_handler(event: DynamoDBStreamEvent, context: LambdaContext):
     def records(self) -> Iterator[DynamoDBRecord]:
         for record in self["Records"]:
             yield DynamoDBRecord(record)
+
+    @property
+    def window(self) -> KinesisStreamWindow | None:
+        window = self.get("window")
+        if window:
+            return KinesisStreamWindow(window)
+        return window
+
+    @property
+    def state(self) -> dict[str, Any]:
+        return self.get("state") or {}
+
+    @property
+    def shard_id(self) -> str | None:
+        return self.get("shardId")
+
+    @property
+    def event_source_arn(self) -> str | None:
+        return self.get("eventSourceARN")
+
+    @property
+    def is_final_invoke_for_window(self) -> bool | None:
+        return self.get("isFinalInvokeForWindow")
+
+    @property
+    def is_window_terminated_early(self) -> bool | None:
+        return self.get("isWindowTerminatedEarly")

tests/events/dynamoStreamTumblingWindowEvent.json

@@ -0,0 +1,101 @@
+{
+  "Records": [
+    {
+      "eventID": "1",
+      "eventName": "INSERT",
+      "eventVersion": "1.0",
+      "eventSource": "aws:dynamodb",
+      "awsRegion": "us-east-1",
+      "dynamodb": {
+        "Keys": {
+          "Id": {
+            "N": "101"
+          }
+        },
+        "NewImage": {
+          "Message": {
+            "S": "New item!"
+          },
+          "Id": {
+            "N": "101"
+          }
+        },
+        "SequenceNumber": "111",
+        "SizeBytes": 26,
+        "StreamViewType": "NEW_AND_OLD_IMAGES"
+      },
+      "eventSourceARN": "stream-ARN"
+    },
+    {
+      "eventID": "2",
+      "eventName": "MODIFY",
+      "eventVersion": "1.0",
+      "eventSource": "aws:dynamodb",
+      "awsRegion": "us-east-1",
+      "dynamodb": {
+        "Keys": {
+          "Id": {
+            "N": "101"
+          }
+        },
+        "NewImage": {
+          "Message": {
+            "S": "This item has changed"
+          },
+          "Id": {
+            "N": "101"
+          }
+        },
+        "OldImage": {
+          "Message": {
+            "S": "New item!"
+          },
+          "Id": {
+            "N": "101"
+          }
+        },
+        "SequenceNumber": "222",
+        "SizeBytes": 59,
+        "StreamViewType": "NEW_AND_OLD_IMAGES"
+      },
+      "eventSourceARN": "stream-ARN"
+    },
+    {
+      "eventID": "3",
+      "eventName": "REMOVE",
+      "eventVersion": "1.0",
+      "eventSource": "aws:dynamodb",
+      "awsRegion": "us-east-1",
+      "dynamodb": {
+        "Keys": {
+          "Id": {
+            "N": "101"
+          }
+        },
+        "OldImage": {
+          "Message": {
+            "S": "This item has changed"
+          },
+          "Id": {
+            "N": "101"
+          }
+        },
+        "SequenceNumber": "333",
+        "SizeBytes": 38,
+        "StreamViewType": "NEW_AND_OLD_IMAGES"
+      },
+      "eventSourceARN": "stream-ARN"
+    }
+  ],
+  "window": {
+    "start": "2020-07-30T17:00:00Z",
+    "end": "2020-07-30T17:05:00Z"
+  },
+  "state": {
+    "1": "state1"
+  },
+  "shardId": "shard123456789",
+  "eventSourceARN": "stream-ARN",
+  "isFinalInvokeForWindow": false,
+  "isWindowTerminatedEarly": false
+}

tests/unit/data_classes/required_dependencies/test_dynamo_db_stream_event.py

@@ -46,6 +46,40 @@ def test_dynamodb_stream_trigger_event():
     assert dynamodb.stream_view_type == StreamViewType.NEW_AND_OLD_IMAGES
 
 
+def test_dynamodb_stream_trigger_with_tumbling_window_event():
+    raw_event = load_event("dynamoStreamTumblingWindowEvent.json")
+    parsed_event = DynamoDBStreamEvent(raw_event)
+
+    records = list(parsed_event.records)
+
+    record = records[0]
+    record_raw = raw_event["Records"][0]
+    assert record.aws_region == record_raw["awsRegion"]
+    assert record.event_id == record_raw["eventID"]
+    assert record.event_name is DynamoDBRecordEventName.INSERT
+    assert record.event_source == record_raw["eventSource"]
+    assert record.event_source_arn == record_raw["eventSourceARN"]
+    assert record.event_version == record_raw["eventVersion"]
+    assert record.user_identity == {}
+    dynamodb = record.dynamodb
+    assert dynamodb is not None
+    keys = dynamodb.keys
+    assert keys is not None
+    assert keys["Id"] == DECIMAL_CONTEXT.create_decimal(101)
+    assert dynamodb.new_image.get("Message") == record_raw["dynamodb"]["NewImage"]["Message"]["S"]
+    assert dynamodb.old_image == {}
+    assert dynamodb.sequence_number == record_raw["dynamodb"]["SequenceNumber"]
+    assert dynamodb.size_bytes == record_raw["dynamodb"]["SizeBytes"]
+    assert dynamodb.stream_view_type == StreamViewType.NEW_AND_OLD_IMAGES
+
+    assert parsed_event.window.raw_event == raw_event["window"]
+    assert parsed_event.state == raw_event["state"]
+    assert parsed_event.shard_id == raw_event["shardId"]
+    assert parsed_event.event_source_arn == raw_event["eventSourceARN"]
+    assert parsed_event.is_final_invoke_for_window == raw_event["isFinalInvokeForWindow"]
+    assert parsed_event.is_window_terminated_early == raw_event["isWindowTerminatedEarly"]
+
+
 def test_dynamodb_stream_record_deserialization_large_int():
     data = {
         "Keys": {"key1": {"attr1": "value1"}},