core[patch]: support Field deprecation (#25004)

![Screenshot 2024-08-02 at 4 23 17
PM](https://github.com/user-attachments/assets/c757e093-877e-4af6-9dcd-984195454158)

libs/core/langchain_core/_api/deprecation.py

@@ -133,6 +133,7 @@ def deprecated(
         _package: str = package,
     ) -> T:
         """Implementation of the decorator returned by `deprecated`."""
+        from pydantic.v1.fields import FieldInfo  # pydantic: ignore
 
         def emit_warning() -> None:
             """Emit the warning."""
@@ -207,6 +208,25 @@ def deprecated(
                 )
                 return cast(T, obj)
 
+        elif isinstance(obj, FieldInfo):
+            from langchain_core.pydantic_v1 import Field
+
+            wrapped = None
+            if not _obj_type:
+                _obj_type = "attribute"
+            if not _name:
+                raise ValueError()
+            old_doc = obj.description
+
+            def finalize(wrapper: Callable[..., Any], new_doc: str) -> T:
+                return Field(
+                    default=obj.default,
+                    default_factory=obj.default_factory,
+                    description=new_doc,
+                    alias=obj.alias,
+                    exclude=obj.exclude,
+                )
+
         elif isinstance(obj, property):
             if not _obj_type:
                 _obj_type = "attribute"

libs/core/langchain_core/language_models/chat_models.py

@@ -208,11 +208,18 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
 
     """  # noqa: E501
 
-    callback_manager: Optional[BaseCallbackManager] = Field(default=None, exclude=True)
-    """[DEPRECATED] Callback manager to add to the run trace."""
+    callback_manager: Optional[BaseCallbackManager] = deprecated(
+        name="callback_manager", since="0.1.7", removal="0.3.0", alternative="callbacks"
+    )(
+        Field(
+            default=None,
+            exclude=True,
+            description="Callback manager to add to the run trace.",
+        )
+    )
 
     rate_limiter: Optional[BaseRateLimiter] = Field(default=None, exclude=True)
-    """An optional rate limiter to use for limiting the number of requests."""
+    "An optional rate limiter to use for limiting the number of requests."
 
     disable_streaming: Union[bool, Literal["tool_calling"]] = False
     """Whether to disable streaming for this model.

libs/core/langchain_core/tools.py

@@ -330,8 +330,16 @@ class ChildTool(BaseTool):
 
     callbacks: Callbacks = Field(default=None, exclude=True)
     """Callbacks to be called during tool execution."""
-    callback_manager: Optional[BaseCallbackManager] = Field(default=None, exclude=True)
-    """Deprecated. Please use callbacks instead."""
+
+    callback_manager: Optional[BaseCallbackManager] = deprecated(
+        name="callback_manager", since="0.1.7", removal="0.3.0", alternative="callbacks"
+    )(
+        Field(
+            default=None,
+            exclude=True,
+            description="Callback manager to add to the run trace.",
+        )
+    )
     tags: Optional[List[str]] = None
     """Optional list of tags associated with the tool. Defaults to None.
     These tags will be associated with each call to this tool,