fix: serialization improvements for nested unions. Related to #763 (#770

)

dataclasses_avroschema/schema_generator.py

@@ -46,6 +46,29 @@ def get_metadata(cls: "Type[CT]") -> SchemaMetadata:
             cls._metadata = SchemaMetadata.create(meta)
         return cls._metadata
 
+    @classmethod
+    def get_fullname(cls) -> str:
+        """
+        Fullname is composed of two parts: a name and a namespace
+        separated by a dot. A namespace is a dot-separated sequence of such names.
+        The empty string may also be used as a namespace to indicate the null namespace.
+        Equality of names (including field names and enum symbols)
+        as well as fullnames is case-sensitive.
+        """
+        # we need to make sure that the schema has been generated
+        cls.generate_schema()
+        metadata = cls.get_metadata()
+
+        if metadata.namespace:
+            # if the current record has a namespace we use it
+            return f"{metadata.namespace}.{cls.__name__}"
+        elif cls._parent is not None:
+            # if the record has a parent then we try to use the parent namespace
+            parent_metadata = cls._parent.get_metadata()
+            if parent_metadata.namespace:
+                return f"{parent_metadata.namespace}.{cls.__name__}"
+        return cls.__name__
+
     @classmethod
     def generate_schema(cls: "Type[CT]", schema_type: str = "avro") -> Optional[OrderedDict]:
         if cls._parser is None or cls.__mro__[1] != AvroModel:

dataclasses_avroschema/serialization.py

@@ -68,10 +68,10 @@ def deserialize(
 
     input_stream.flush()
 
-    return sanitize_unions(data=payload, model=model)  # type: ignore
+    return sanitize_payload(data=payload, model=model)  # type: ignore
 
 
-def sanitize_unions(*, data: JsonDict, model: "CT") -> JsonDict:
+def sanitize_payload(*, data: JsonDict, model: "CT") -> JsonDict:
     """
     This function tries to convert cast all the cases that have
     `unions` with a Tuple format (AvroType, payload), for example
@@ -81,20 +81,31 @@ def sanitize_unions(*, data: JsonDict, model: "CT") -> JsonDict:
     cleaned_data = {}
     for field_name, field_value in data.items():
         if isinstance(field_value, dict):
-            field_value = sanitize_unions(data=field_value, model=model)
+            field_value = sanitize_payload(data=field_value, model=model)
         elif isinstance(field_value, tuple) and len(field_value) == 2:
-            # the first value is the model/record name and the second
-            # is its payload
-            model_name, model_dict_value = field_value
-            avro_model = model.get_user_defined_type(name=model_name)
-            if avro_model is not None:
-                field_value = avro_model.parse_obj(model_dict_value)
+            field_value = sanitize_union(union=field_value, model=model)
 
         cleaned_data[field_name] = field_value
 
     return cleaned_data
 
 
+def sanitize_union(*, union: typing.Tuple, model: "CT") -> typing.Optional["CT"]:
+    # the first value is the model/record name and the second is its payload
+    model_name, model_value = union
+    if isinstance(model_value, dict):
+        # it can be a dict again so we need to sanitize
+        model_value = sanitize_payload(data=model_value, model=model)
+
+    model_name = model_name.split(".")[-1]
+
+    avro_model = model.get_user_defined_type(name=model_name)
+    if avro_model is not None:
+        return avro_model.parse_obj(model_value)
+
+    return model_value
+
+
 def datetime_to_str(value: datetime.datetime) -> str:
     return value.strftime(DATETIME_STR_FORMAT)
 

dataclasses_avroschema/utils.py

@@ -124,7 +124,7 @@ def standardize_custom_type(
             asdict = value.asdict()
 
         if is_union(model.__annotations__[field_name]) and include_type:
-            asdict["-type"] = value.__class__.__name__
+            asdict["-type"] = value.get_fullname()
         return asdict
 
     return value

pyproject.toml

@@ -67,6 +67,9 @@ cli = [
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
+[tool.mypy]
+check_untyped_defs  = true
+
 [[tool.mypy.overrides]]
 module = "stringcase.*"
 ignore_missing_imports = true