openai[patch]: accept function_call dict in bind_functions (#16483)

Confusing that you can't pass in a dict

libs/partners/openai/langchain_openai/chat_models/base.py

@@ -18,6 +18,7 @@ from typing import (
     Sequence,
     Tuple,
     Type,
+    TypedDict,
     Union,
     cast,
 )
@@ -182,6 +183,10 @@ def _convert_delta_to_message_chunk(
         return default_class(content=content)  # type: ignore
 
 
+class _FunctionCall(TypedDict):
+    name: str
+
+
 class ChatOpenAI(BaseChatModel):
     """`OpenAI` Chat large language models API.
 
@@ -632,7 +637,9 @@ class ChatOpenAI(BaseChatModel):
     def bind_functions(
         self,
         functions: Sequence[Union[Dict[str, Any], Type[BaseModel], Callable, BaseTool]],
-        function_call: Optional[str] = None,
+        function_call: Optional[
+            Union[_FunctionCall, str, Literal["auto", "none"]]
+        ] = None,
         **kwargs: Any,
     ) -> Runnable[LanguageModelInput, BaseMessage]:
         """Bind functions (and other objects) to this chat model.
@@ -658,18 +665,26 @@ class ChatOpenAI(BaseChatModel):
 
         formatted_functions = [convert_to_openai_function(fn) for fn in functions]
         if function_call is not None:
-            if len(formatted_functions) != 1:
+            function_call = (
+                {"name": function_call}
+                if isinstance(function_call, str)
+                and function_call not in ("auto", "none")
+                else function_call
+            )
+            if isinstance(function_call, dict) and len(formatted_functions) != 1:
                 raise ValueError(
                     "When specifying `function_call`, you must provide exactly one "
                     "function."
                 )
-            if formatted_functions[0]["name"] != function_call:
+            if (
+                isinstance(function_call, dict)
+                and formatted_functions[0]["name"] != function_call["name"]
+            ):
                 raise ValueError(
                     f"Function call {function_call} was specified, but the only "
                     f"provided function was {formatted_functions[0]['name']}."
                 )
-            function_call_ = {"name": function_call}
-            kwargs = {**kwargs, "function_call": function_call_}
+            kwargs = {**kwargs, "function_call": function_call}
         return super().bind(
             functions=formatted_functions,
             **kwargs,