Fix attribute error for raw tuples in langchain (#261)

* Fix attribute error for raw tuples in langchain

* Add CHANGELOG

* Address feedback

* Cleanup test file

Author: rads-1996

instrumentation/opentelemetry-instrumentation-genai-langchain/.changelog/261.changed

@@ -0,0 +1 @@
+Support raw LangChain message inputs (`("role", content)` tuples, dicts, and strings) in input messages, so the prompt is recorded and duplicate `invoke_agent` spans are avoided.

instrumentation/opentelemetry-instrumentation-genai-langchain/src/opentelemetry/instrumentation/genai/langchain/utils.py

@@ -12,6 +12,7 @@
     AIMessage,
     BaseMessage,
     ToolMessage,
+    convert_to_messages,
 )
 
 from opentelemetry.semconv._incubating.attributes import (
@@ -152,11 +153,19 @@ def _message_parts(message: BaseMessage) -> list[MessagePart]:
 
 
 def to_input_messages(
-    messages: Iterable[BaseMessage],
+    messages: Iterable[Any],
 ) -> list[InputMessage]:
     """Convert LangChain messages into spec-conformant ``InputMessage`` s."""
+    try:
+        normalized_messages: Iterable[BaseMessage] = convert_to_messages(
+            list(messages)
+        )
+    except Exception:  # pylint: disable=broad-except
+        normalized_messages = [
+            m for m in messages if isinstance(m, BaseMessage)
+        ]
     result: list[InputMessage] = []
-    for message in messages:
+    for message in normalized_messages:
         parts = _message_parts(message)
         if not parts:
             continue

instrumentation/opentelemetry-instrumentation-genai-langchain/tests/test_callback_handler.py

@@ -11,6 +11,7 @@
 import uuid
 from unittest import mock
 
+import pytest
 from langchain_core.messages import AIMessage, HumanMessage
 from langchain_core.outputs import ChatGeneration, LLMResult
 
@@ -22,6 +23,7 @@
     make_last_output_message,
     make_output_message,
     serialize,
+    to_input_messages,
     to_output_messages,
 )
 from opentelemetry.util.genai.invocation import (
@@ -650,6 +652,64 @@ def test_messages_key_takes_priority_over_other_fields(self):
         assert len(result) == 1
         assert result[0].parts[0].content == "hello"
 
+    def test_messages_key_converts_raw_role_content_tuples(self):
+        result = make_input_message(
+            {"messages": [("human", "Hello"), HumanMessage(content="Hi")]}
+        )
+
+        assert len(result) == 2
+        assert result[0].role == "user"
+        assert result[0].parts[0].content == "Hello"
+        assert result[1].parts[0].content == "Hi"
+
+    def test_messages_key_converts_role_content_dicts(self):
+        result = make_input_message(
+            {"messages": [{"role": "user", "content": "Hello"}]}
+        )
+
+        assert len(result) == 1
+        assert result[0].role == "user"
+        assert result[0].parts[0].content == "Hello"
+
+    @pytest.mark.parametrize(
+        "bad_entry",
+        [
+            ("human",),  # too few items for (role, content)
+            ("human", "hi", "extra"),  # too many items
+            ("not_a_real_role", "hi"),  # unknown role string
+            {"content": "no role key"},  # dict missing role
+            {"role": "user"},  # dict missing content
+            None,  # not a message at all
+            42,  # not a message at all
+            object(),  # arbitrary object
+        ],
+    )
+    def test_messages_key_malformed_entry_does_not_raise(self, bad_entry):
+        result = make_input_message(
+            {"messages": [bad_entry, HumanMessage(content="Hi")]}
+        )
+
+        assert len(result) == 1
+        assert result[0].parts[0].content == "Hi"
+
+    def test_messages_key_all_malformed_returns_empty_without_raising(self):
+        result = make_input_message(
+            {"messages": [("human",), None, {"content": "x"}]}
+        )
+
+        assert result == []
+
+    def test_to_input_messages_never_raises_on_mixed_bad_input(self):
+        result = to_input_messages(
+            [object(), ("bad", "role", "shape"), HumanMessage(content="ok")]
+        )
+
+        assert len(result) == 1
+        assert result[0].parts[0].content == "ok"
+
+    def test_to_input_messages_empty_iterable_returns_empty(self):
+        assert to_input_messages([]) == []
+
     def test_fallback_serializes_non_message_state_fields(self):
         result = make_input_message({"user_query": "what is 2+2?"})