Fix: #29 Enhance serialization functions to handle nested dataclasses and unexpected fields in messages

Author: grongierisc

CHANGELOG.md

@@ -17,6 +17,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Remove dependency on community driver
   - Use `iris` module instead
 
+### Fixed
+- Fix dataclass message serialization
+  - Go back to best effort serialization type check is not forced
+
 ## [3.4.0] - 2025-03-24
 
 ### Added

src/iop/_serialization.py

@@ -4,7 +4,7 @@
 import inspect
 import pickle
 import json
-from dataclasses import asdict, is_dataclass
+from dataclasses import is_dataclass
 from typing import Any, Dict, Type
 
 from . import _iris
@@ -149,12 +149,20 @@ def process_field(value: Any, field_type: Type) -> Any:
 def dataclass_to_dict(instance: Any) -> Dict:
     """Converts a class instance to a dictionary.
     Handles non attended fields."""
-    dikt = asdict(instance)
-    # assign any extra fields
-    for k, v in vars(instance).items():
-        if k not in dikt:
-            dikt[k] = v
-    return dikt
+    result = {}
+    for field in instance.__dict__:
+        value = getattr(instance, field)
+        if is_dataclass(value):
+            result[field] = dataclass_to_dict(value)
+        elif isinstance(value, list):
+            result[field] = [dataclass_to_dict(i) if is_dataclass(i) else i for i in value]
+        elif isinstance(value, dict):
+            result[field] = {k: dataclass_to_dict(v) if is_dataclass(v) else v for k, v in value.items()}
+        elif hasattr(value, '__dict__'):
+            result[field] = dataclass_to_dict(value)
+        else:
+            result[field] = value
+    return result
 
 # Maintain backwards compatibility
 serialize_pickle_message = lambda msg: MessageSerializer.serialize(msg, use_pickle=True)

src/tests/test_serialization.py

@@ -15,6 +15,10 @@
     deserialize_pickle_message,
 )
 
+class NonDataclass:
+    def __init__(self, value):
+        self.value = value
+
 @dataclass
 class Object:
     value: str
@@ -33,6 +37,9 @@ class FullMessge:
     uid: uuid.UUID
     data: bytes
     items: list  # Changed from df to a simple list
+    list_obj: list[Object] = None
+    dict_obj: dict[str, Object] = None
+    optional_obj: Optional[Object] = None
 
 @dataclass
 class MyObject:
@@ -47,8 +54,6 @@ class Msg:
     my_obj: MyObject
 
 def test_message_serialization():
-
-
     msg = Msg(text="hello", number=42, my_obj=None)
 
     my_obj = MyObject(value="test", foo=None)
@@ -71,6 +76,46 @@ def test_message_serialization():
     assert result.number == msg.number
     assert result.my_obj == my_obj
 
+def test_unexpexted_obj_serialization():
+    # Create an invalid message
+    msg = Msg(text="hello", number=42, my_obj=None)
+    msg.my_obj = NonDataclass(value="test")
+
+    # Test serialization
+    serial = serialize_message(msg)
+    assert type(serial).__module__.startswith('iris') and serial._IsA("IOP.Message")
+    assert serial.classname == f"{Msg.__module__}.{Msg.__name__}"
+
+    # Test deserialization
+    result = deserialize_message(serial)
+    assert isinstance(result, Msg)
+    assert result.text == msg.text
+    assert result.number == msg.number
+    assert result.my_obj.value == msg.my_obj.value
+
+
+def test_unexpected_fields():
+    # Create a message with unexpected fields
+    msg = Msg(text="hello", number=42, my_obj=None)
+    msg.unexpected_field = "unexpected"
+
+    my_obj = MyObject(value="test", foo=None)
+    my_obj.unexpected_field = "unexpected"
+    msg.my_obj = my_obj
+
+    # Test serialization
+    serial = serialize_message(msg)
+    assert type(serial).__module__.startswith('iris') and serial._IsA("IOP.Message")
+    assert serial.classname == f"{Msg.__module__}.{Msg.__name__}"
+
+    # Test deserialization
+    result = deserialize_message(serial)
+    assert isinstance(result, Msg)
+    assert result.text == msg.text
+    assert result.number == msg.number
+    assert result.unexpected_field == msg.unexpected_field
+    assert result.my_obj == my_obj
+
 
 def test_json_serialization():
     # Create test data
@@ -127,7 +172,10 @@ def test_pickle_serialization():
         dec=decimal.Decimal("3.14"),
         uid=uuid.uuid4(),
         data=b'hello world',
-        items=[{'col1': 1, 'col2': 'a'}, {'col1': 2, 'col2': 'b'}]
+        items=[{'col1': 1, 'col2': 'a'}, {'col1': 2, 'col2': 'b'}],
+        list_obj=[Object(value="item1"), Object(value="item2")],
+        dict_obj={'key1': Object(value="item1"), 'key2': Object(value="item2")},
+        optional_obj=Object(value="optional")
     )
 
     # Test serialization
@@ -150,6 +198,9 @@ def test_pickle_serialization():
     assert result.uid == msg.uid
     assert result.data == msg.data
     assert result.items == msg.items
+    assert result.list_obj == msg.list_obj
+    assert result.dict_obj == msg.dict_obj
+    assert result.optional_obj == msg.optional_obj
 
 def test_invalid_message_deserialization():
     # Create an invalid message without classname