Adding docstring

Author: leandrodamascena

aws_lambda_powertools/utilities/kafka_consumer/deserializer/no_op.py renamed to aws_lambda_powertools/utilities/kafka_consumer/deserializer/default.py

@@ -1,24 +1,24 @@
 from __future__ import annotations
 
+import base64
 from typing import Any
 
 from aws_lambda_powertools.utilities.kafka_consumer.deserializer.base import DeserializerBase
 
 
-class NoOpDeserializer(DeserializerBase):
+class DefaultDeserializer(DeserializerBase):
     """
-    A pass-through deserializer that performs no transformation on the input data.
+    A default deserializer that performs base64 decode + binary decode on the input data.
 
-    This deserializer simply returns the input data unchanged, which is useful when
-    no deserialization is needed or when handling raw data formats.
+    This deserializer simply returns the input data with base64 decode, which is useful when
+    no customized deserialization is needed or when handling raw data formats.
     """
 
     def deserialize(self, data: bytes | str) -> dict[str, Any]:
         """
-        Return the input data unchanged.
+        Return the input data base64 decoded.
 
-        This method implements the deserialize interface but performs no transformation,
-        simply returning the input data as-is.
+        This method implements the deserialize interface and performs base64 decode.
 
         Parameters
         ----------
@@ -28,9 +28,7 @@ def deserialize(self, data: bytes | str) -> dict[str, Any]:
         Returns
         -------
         dict[str, Any]
-            The input data unchanged. Note that despite the type annotation,
-            this method returns the exact same object that was passed in,
-            preserving its original type.
+            The input data base64 decoded.
 
         Example
         --------
@@ -46,4 +44,4 @@ def deserialize(self, data: bytes | str) -> dict[str, Any]:
         >>> result = deserializer.deserialize(bytes_data)
         >>> print(result == bytes_data)  # Output: True
         """
-        return data
+        return base64.b64decode(data).decode("utf-8")

aws_lambda_powertools/utilities/kafka_consumer/deserializer/deserializer.py

@@ -2,8 +2,8 @@
 
 from typing import TYPE_CHECKING, Any
 
+from aws_lambda_powertools.utilities.kafka_consumer.deserializer.default import DefaultDeserializer
 from aws_lambda_powertools.utilities.kafka_consumer.deserializer.json import JsonDeserializer
-from aws_lambda_powertools.utilities.kafka_consumer.deserializer.no_op import NoOpDeserializer
 
 if TYPE_CHECKING:
     from aws_lambda_powertools.utilities.kafka_consumer.deserializer.base import DeserializerBase
@@ -68,4 +68,5 @@ def get_deserializer(schema_type: str | object, schema_value: Any) -> Deserializ
     elif schema_type == "JSON":
         return JsonDeserializer()
 
-    return NoOpDeserializer()
+    # Default to default deserializer that is base64 decode + bytes decoded
+    return DefaultDeserializer()

aws_lambda_powertools/utilities/kafka_consumer/deserializer/json.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import base64
 import json
 
 from aws_lambda_powertools.utilities.kafka_consumer.deserializer.base import DeserializerBase
@@ -46,7 +47,7 @@ def deserialize(self, data: bytes | str) -> dict:
         """
         try:
             value = self._decode_input(data)
-            return json.loads(value.decode("utf-8"))
+            return json.loads(base64.b64decode(value).decode("utf-8"))
         except Exception as e:
             raise KafkaConsumerDeserializationError(
                 f"JSON deserialization error: {type(e).__name__}: {str(e)}",

aws_lambda_powertools/utilities/kafka_consumer/serialization/base.py

@@ -8,6 +8,46 @@
 
 
 class OutputSerializerBase(ABC):
+    """
+    Abstract base class for output serializers.
+
+    This class defines the interface for serializers that transform dictionary data
+    into specific output formats or class instances.
+
+    Methods
+    -------
+    serialize(data, output_class)
+        Abstract method that must be implemented by subclasses to serialize data.
+
+    Examples
+    --------
+    >>> class MyOutputSerializer(OutputSerializerBase):
+    ...     def serialize(self, data: dict[str, Any], output_class=None):
+    ...         if output_class:
+    ...             # Convert dictionary to class instance
+    ...             return output_class(**data)
+    ...         return data  # Return as is if no output class provided
+    """
     @abstractmethod
     def serialize(self, data: dict[str, Any], output_class: type[T] | None = None) -> T | dict[str, Any]:
+        """
+        Serialize dictionary data into a specific output format or class instance.
+
+        This abstract method must be implemented by subclasses to provide
+        specific serialization logic.
+
+        Parameters
+        ----------
+        data : dict[str, Any]
+            The dictionary data to serialize.
+        output_class : type[T] or None, optional
+            Optional class type to convert the dictionary into. If provided,
+            the method should return an instance of this class.
+
+        Returns
+        -------
+        T or dict[str, Any]
+            An instance of output_class if provided, otherwise a processed dictionary.
+            The generic type T represents the type of the output_class.
+        """
         pass

tests/functional/kafka_consumer/_avro/test_kafka_consumer_with_avro.py

@@ -87,7 +87,10 @@ def kafka_event_with_avro_data(avro_encoded_value, avro_encoded_key):
 
 
 def test_kafka_consumer_with_avro_and_dataclass(
-    kafka_event_with_avro_data, avro_value_schema, lambda_context, user_value_dataclass,
+    kafka_event_with_avro_data,
+    avro_value_schema,
+    lambda_context,
+    user_value_dataclass,
 ):
     """Test Kafka consumer with Avro deserialization and dataclass output serialization."""
 
@@ -120,7 +123,10 @@ def handler(event: ConsumerRecords, context):
 
 
 def test_kafka_consumer_with_avro_and_custom_object(
-    kafka_event_with_avro_data, avro_value_schema, lambda_context, user_value_dict,
+    kafka_event_with_avro_data,
+    avro_value_schema,
+    lambda_context,
+    user_value_dict,
 ):
     """Test Kafka consumer with Avro deserialization and custom object serialization."""
 
@@ -280,7 +286,12 @@ def lambda_handler(event: ConsumerRecords, context):
 
 
 def test_kafka_consumer_with_different_serializers_for_key_and_value(
-    kafka_event_with_avro_data, lambda_context, avro_value_schema, avro_key_schema, user_key_dataclass, user_value_dict,
+    kafka_event_with_avro_data,
+    lambda_context,
+    avro_value_schema,
+    avro_key_schema,
+    user_key_dataclass,
+    user_value_dict,
 ):
     """Test using different serializer types for key and value."""