From c4012c274468677aec31dbfa226e5a51ef5c3fb7 Mon Sep 17 00:00:00 2001
From: hmnfalahi <hmnfalahi@gmail.com>
Date: Sat, 20 Apr 2024 12:55:27 +0330
Subject: [PATCH] Modified _get_python_function_required_args to ignore
 self/cls from required args of class functions

---
 .../langchain_core/utils/function_calling.py  |  8 +++--
 .../unit_tests/utils/test_function_calling.py | 34 ++++++++++++++++++-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/libs/core/langchain_core/utils/function_calling.py b/libs/core/langchain_core/utils/function_calling.py
index 860259a93e35f..5861becb5f321 100644
--- a/libs/core/langchain_core/utils/function_calling.py
+++ b/libs/core/langchain_core/utils/function_calling.py
@@ -17,6 +17,7 @@
     Union,
     cast,
 )
+from types import FunctionType, MethodType
 
 from typing_extensions import TypedDict
 
@@ -200,8 +201,11 @@ def _get_python_function_required_args(function: Callable) -> List[str]:
     required = spec.args[: -len(spec.defaults)] if spec.defaults else spec.args
     required += [k for k in spec.kwonlyargs if k not in (spec.kwonlydefaults or {})]
 
-    is_class = type(function) is type
-    if is_class and required[0] == "self":
+    is_function_type = isinstance(function, FunctionType)
+    is_method_type = isinstance(function, MethodType)
+    if is_function_type and required[0] == "self":
+        required = required[1:]
+    elif is_method_type and required[0] == "cls":
         required = required[1:]
     return required
 
diff --git a/libs/core/tests/unit_tests/utils/test_function_calling.py b/libs/core/tests/unit_tests/utils/test_function_calling.py
index 00328bcf29b44..b58ade6746df8 100644
--- a/libs/core/tests/unit_tests/utils/test_function_calling.py
+++ b/libs/core/tests/unit_tests/utils/test_function_calling.py
@@ -71,11 +71,42 @@ def json_schema() -> Dict:
     }
 
 
+@pytest.fixture()
+def dummy_instance_method() -> object:
+    class Dummy:
+        def dummy_function(self, arg1: int, arg2: Literal["bar", "baz"]) -> None:
+            """dummy function
+
+            Args:
+                arg1: foo
+                arg2: one of 'bar', 'baz'
+            """
+            pass
+    return Dummy
+
+
+@pytest.fixture()
+def dummy_class_method() -> object:
+    class Dummy:
+        @classmethod
+        def dummy_function(cls, arg1: int, arg2: Literal["bar", "baz"]) -> None:
+            """dummy function
+
+            Args:
+                arg1: foo
+                arg2: one of 'bar', 'baz'
+            """
+            pass
+    return Dummy
+
+
 def test_convert_to_openai_function(
     pydantic: Type[BaseModel],
     function: Callable,
     dummy_tool: BaseTool,
     json_schema: Dict,
+    dummy_instance_method: object,
+    dummy_class_method: object,
 ) -> None:
     expected = {
         "name": "dummy_function",
@@ -94,7 +125,8 @@ def test_convert_to_openai_function(
         },
     }
 
-    for fn in (pydantic, function, dummy_tool, json_schema, expected):
+    for fn in (pydantic, function, dummy_tool, json_schema, expected,
+               dummy_instance_method.dummy_function, dummy_class_method.dummy_function):
         actual = convert_to_openai_function(fn)  # type: ignore
         assert actual == expected