See if refusal attribute exists in ChatCompletionMessage before refer…

…encing it (#962)

Co-authored-by: Ivan Leo <ivanleomk@gmail.com>

instructor/function_calls.py

@@ -309,12 +309,15 @@ def parse_tools(
         strict: Optional[bool] = None,
     ) -> BaseModel:
         message = completion.choices[0].message
+        # this field seems to be missing when using instructor with some other tools (e.g. litellm)
+        # trying to fix this by adding a check
+        if hasattr(message, "refusal"):
+            assert (
+                message.refusal is None
+            ), f"Unable to generate a response due to {message.refusal}"
         assert (
             len(message.tool_calls or []) == 1
         ), "Instructor does not support multiple tool calls, use List[Model] instead."
-        assert (
-            message.refusal is None
-        ), f"Unable to generate a response due to {message.refusal}"
         tool_call = message.tool_calls[0]  # type: ignore
         assert (
             tool_call.function.name == cls.openai_schema["name"]  # type: ignore[index]

tests/test_function_calls.py

@@ -2,7 +2,9 @@
 
 import pytest
 from anthropic.types import Message, Usage
-from openai.types.chat.chat_completion import ChatCompletion
+from openai.types.chat.chat_completion import ChatCompletion, Choice
+from openai.types.chat.chat_completion_message import ChatCompletionMessage
+from openai.types.chat.chat_completion_message_tool_call import ChatCompletionMessageToolCall,  Function
 from pydantic import BaseModel, ValidationError
 
 import instructor
@@ -206,4 +208,106 @@ class Model(BaseModel):
 def test_mode_functions_deprecation_warning() -> None:
     from openai import OpenAI
     with pytest.warns(DeprecationWarning, match="The FUNCTIONS mode is deprecated and will be removed in future versions"):
-        _ = instructor.from_openai(OpenAI(), mode=instructor.Mode.FUNCTIONS)
+        _ = instructor.from_openai(OpenAI(), mode=instructor.Mode.FUNCTIONS)
+
+def test_refusal_attribute(test_model: type[OpenAISchema]):
+    completion = ChatCompletion(
+        id="test_id",
+        created=1234567890,
+        model="gpt-3.5-turbo",
+        object="chat.completion",
+        choices=[
+            Choice(
+                index=0,
+                message=ChatCompletionMessage(
+                    content="test_content",
+                    refusal="test_refusal",
+                    role="assistant",
+                    tool_calls=[],
+                ),
+                finish_reason="stop",
+                logprobs=None,
+            )
+        ],
+    )
+
+    try:
+
+        test_model.from_response(completion, mode=instructor.Mode.TOOLS)
+    except Exception as e:
+        assert "Unable to generate a response due to test_refusal" in str(e)
+
+
+def test_no_refusal_attribute(test_model: type[OpenAISchema]):
+    completion = ChatCompletion(
+        id="test_id",
+        created=1234567890,
+        model="gpt-3.5-turbo",
+        object="chat.completion",
+        choices=[
+            Choice(
+                index=0,
+                message=ChatCompletionMessage(
+                    content="test_content",
+                    refusal=None,
+                    role="assistant",
+                    tool_calls=[
+                        ChatCompletionMessageToolCall(
+                            id="test_id",
+                            function=Function(
+                                name="TestModel",
+                                arguments='{"data": "test_data", "name": "TestModel"}',
+                            ),
+                            type="function",
+                        )
+                    ],
+                ),
+                finish_reason="stop",
+                logprobs=None,
+            )
+        ],
+    )
+
+    resp = test_model.from_response(completion, mode=instructor.Mode.TOOLS)
+    assert resp.data == "test_data"
+    assert resp.name == "TestModel"
+
+
+def test_missing_refusal_attribute(test_model: type[OpenAISchema]):
+    message_without_refusal_attribute = ChatCompletionMessage(
+        content="test_content",
+        refusal="test_refusal",
+        role="assistant",
+        tool_calls=[
+            ChatCompletionMessageToolCall(
+                id="test_id",
+                function=Function(
+                    name="TestModel",
+                    arguments='{"data": "test_data", "name": "TestModel"}',
+                ),
+                type="function",
+            )
+        ],
+    )
+
+    del message_without_refusal_attribute.refusal
+    assert not hasattr(message_without_refusal_attribute, "refusal")
+
+    completion = ChatCompletion(
+        id="test_id",
+        created=1234567890,
+        model="gpt-3.5-turbo",
+        object="chat.completion",
+        choices=[
+            Choice(
+                index=0,
+                message=message_without_refusal_attribute,
+                finish_reason="stop",
+                logprobs=None,
+            )
+        ],
+    )
+
+    resp = test_model.from_response(completion, mode=instructor.Mode.TOOLS)
+    assert resp.data == "test_data"
+    assert resp.name == "TestModel"