openai[patch]: detect old models in with_structured_output (#29392)

Co-authored-by: ccurme <chester.curme@gmail.com>

libs/partners/openai/tests/integration_tests/chat_models/test_base.py

@@ -27,6 +27,7 @@ from langchain_tests.integration_tests.chat_models import (
     magic_function as invalid_magic_function,
 )
 from pydantic import BaseModel, Field
+from typing_extensions import TypedDict
 
 from langchain_openai import ChatOpenAI
 from tests.unit_tests.fake.callbacks import FakeCallbackHandler
@@ -1220,3 +1221,14 @@ def test_o1_doesnt_stream() -> None:
 def test_o1_stream_default_works() -> None:
     result = list(ChatOpenAI(model="o1").stream("say 'hi'"))
     assert len(result) > 0
+
+
+def test_structured_output_old_model() -> None:
+    class Output(TypedDict):
+        """output."""
+
+        foo: str
+
+    llm = ChatOpenAI(model="gpt-4").with_structured_output(Output)
+    output = llm.invoke("bar")
+    assert "foo" in output

libs/partners/openai/tests/unit_tests/chat_models/test_azure.py

@@ -3,6 +3,9 @@
 import os
 from unittest import mock
 
+import pytest
+from typing_extensions import TypedDict
+
 from langchain_openai import AzureChatOpenAI
 
 
@@ -59,3 +62,22 @@ def test_initialize_azure_openai_with_openai_api_base_set() -> None:
         ls_params = llm._get_ls_params()
         assert ls_params["ls_provider"] == "azure"
         assert ls_params["ls_model_name"] == "35-turbo-dev"
+
+
+def test_structured_output_old_model() -> None:
+    class Output(TypedDict):
+        """output."""
+
+        foo: str
+
+    with pytest.warns(match="Cannot use method='json_schema'"):
+        llm = AzureChatOpenAI(  # type: ignore[call-arg]
+            model="gpt-35-turbo",
+            azure_deployment="35-turbo-dev",
+            openai_api_version="2023-05-15",
+            azure_endpoint="my-base-url",
+        ).with_structured_output(Output)
+
+    # assert tool calling was used instead of json_schema
+    assert "tools" in llm.steps[0].kwargs  # type: ignore
+    assert "response_format" not in llm.steps[0].kwargs  # type: ignore

libs/partners/openai/tests/unit_tests/chat_models/test_base.py

@@ -746,7 +746,7 @@ class Foo(BaseModel):
 def test_schema_from_with_structured_output(schema: Type) -> None:
     """Test schema from with_structured_output."""
 
-    llm = ChatOpenAI()
+    llm = ChatOpenAI(model="gpt-4o")
 
     structured_llm = llm.with_structured_output(
         schema, method="json_schema", strict=True
@@ -886,3 +886,16 @@ def test_init_o1() -> None:
     with pytest.warns(None) as record:  # type: ignore[call-overload]
         ChatOpenAI(model="o1", reasoning_effort="medium")
     assert len(record) == 0
+
+
+def test_structured_output_old_model() -> None:
+    class Output(TypedDict):
+        """output."""
+
+        foo: str
+
+    with pytest.warns(match="Cannot use method='json_schema'"):
+        llm = ChatOpenAI(model="gpt-4").with_structured_output(Output)
+    # assert tool calling was used instead of json_schema
+    assert "tools" in llm.steps[0].kwargs  # type: ignore
+    assert "response_format" not in llm.steps[0].kwargs  # type: ignore