from typing import Any, Dict, Optional import pytest from aws_lambda_powertools.shared.dynamodb_deserializer import TypeDeserializer class DeserialiserModel: def __init__(self, data: dict): self._data = data self._deserializer = TypeDeserializer() def _deserialize_dynamodb_dict(self) -> Optional[Dict[str, Any]]: if self._data is None: return None return {k: self._deserializer.deserialize(v) for k, v in self._data.items()} @property def data(self) -> Optional[Dict[str, Any]]: """The primary key attribute(s) for the DynamoDB item that was modified.""" return self._deserialize_dynamodb_dict() def test_deserializer(): model = DeserialiserModel( { "Id": {"S": "Id-123"}, "Name": {"S": "John Doe"}, "ZipCode": {"N": "12345"}, "Things": {"L": [{"N": "0"}, {"N": "1"}, {"N": "2"}, {"N": "3"}]}, "MoreThings": {"M": {"a": {"S": "foo"}, "b": {"S": "bar"}}}, }, ) assert model.data.get("Id") == "Id-123" assert model.data.get("Name") == "John Doe" assert model.data.get("ZipCode") == 12345 assert model.data.get("Things") == [0, 1, 2, 3] assert model.data.get("MoreThings") == {"a": "foo", "b": "bar"} def test_deserializer_error(): model = DeserialiserModel( { "Id": {"X": None}, }, ) with pytest.raises(TypeError): model.data.get("Id")