Fix: Update serialization logic to handle Message instances and improve error handling in tests

Author: grongierisc

CHANGELOG.md

@@ -19,7 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 - Fix dataclass message serialization
-  - Go back to best effort serialization type check is not forced
+  - Go back to best effort serialization : type check is not forced
+  - For checking use PydanticMessage
 
 ## [3.4.0] - 2025-03-24
 

src/iop/_serialization.py

@@ -10,7 +10,7 @@
 from . import _iris
 from pydantic import BaseModel, TypeAdapter, ValidationError
 
-from iop._message import _PydanticPickleMessage
+from iop._message import _PydanticPickleMessage, _Message
 from iop._utils import _Utils
 
 class SerializationError(Exception):
@@ -31,10 +31,10 @@ def _convert_to_json_safe(obj: Any) -> Any:
         """Convert objects to JSON-safe format."""
         if isinstance(obj, BaseModel):
             return obj.model_dump_json()
-        elif is_dataclass(obj):
+        elif is_dataclass(obj) and isinstance(obj, _Message):
             return TempPydanticModel.model_validate(dataclass_to_dict(obj)).model_dump_json()
         else:
-            raise SerializationError(f"Object {obj} must be a Pydantic model or dataclass")
+            raise SerializationError(f"Object {obj} must be a Pydantic model or dataclass Message")
 
     @staticmethod
     def serialize(message: Any, use_pickle: bool = False) -> Any:

src/tests/test_serialization.py

@@ -15,16 +15,23 @@
     deserialize_pickle_message,
 )
 
+from iop import Message
+
 class NonDataclass:
     def __init__(self, value):
         self.value = value
 
+@dataclass
+class Empty(Message):
+    pass
+
 @dataclass
 class Object:
     value: str
 
 @dataclass
-class FullMessge:
+class FullMessge(Message):
+    """Full message class with various fields."""
     text: str
     dikt: dict
     text_json: str
@@ -48,11 +55,28 @@ class MyObject:
     bar: float = 3.14
 
 @dataclass
-class Msg:
+class Msg(Message):
     text: str
     number: int
     my_obj: MyObject
 
+def test_empty_serialization():
+    # Create an empty message
+    msg = Empty()
+    msg.foo = 42
+    msg.bar = "hello"
+
+    # Test serialization
+    serial = serialize_message(msg)
+    assert type(serial).__module__.startswith('iris') and serial._IsA("IOP.Message")
+    assert serial.classname == f"{Empty.__module__}.{Empty.__name__}"
+    
+    # Test deserialization
+    result = deserialize_message(serial)
+    assert isinstance(result, Empty)
+    assert result.foo == msg.foo
+    assert result.bar == msg.bar
+
 def test_message_serialization():
     msg = Msg(text="hello", number=42, my_obj=None)
 
@@ -76,6 +100,15 @@ def test_message_serialization():
     assert result.number == msg.number
     assert result.my_obj == my_obj
 
+def test_raise_not_message():
+    # Create a message with an invalid object
+    msg = MyObject(value="test", foo=None)
+
+    # Test serialization
+    with pytest.raises(SerializationError):
+        serialize_message(msg)
+
+
 def test_unexpexted_obj_serialization():
     # Create an invalid message
     msg = Msg(text="hello", number=42, my_obj=None)