Warn pydantic users who are not using contrib.pydantic

Author: dandavison

temporalio/converter.py

@@ -10,6 +10,7 @@
 import sys
 import traceback
 import uuid
+import warnings
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from datetime import datetime
@@ -1523,15 +1524,19 @@ def value_to_type(
     # the start of this function. We retain the following for backwards
     # compatibility with pydantic users who are not using contrib.pydantic, but
     # this is deprecated.
-    parse_obj_attr = inspect.getattr_static(hint, "parse_obj", None)
-    if isinstance(parse_obj_attr, classmethod) or isinstance(
-        parse_obj_attr, staticmethod
-    ):
-        if not isinstance(value, dict):
-            raise TypeError(
-                f"Cannot convert to {hint}, value is {type(value)} not dict"
+    for pydantic_attr in ["model_validate", "parse_obj"]:
+        pydantic_method = inspect.getattr_static(hint, pydantic_attr, None)
+        if isinstance(pydantic_method, classmethod) or isinstance(
+            pydantic_method, staticmethod
+        ):
+            if not isinstance(value, dict):
+                raise TypeError(
+                    f"Cannot convert to {hint}, value is {type(value)} not dict"
+                )
+            warnings.warn(
+                "It looks like you're using pydantic. Please use temporalio.contrib.pydantic.converter.pydantic_data_converter."
             )
-        return getattr(hint, "parse_obj")(value)
+            return getattr(hint, pydantic_attr)(value)
 
     # IntEnum
     if inspect.isclass(hint) and issubclass(hint, IntEnum):