feat: (core, standard-tests) support PDF inputs in ToolMessages (#33183)

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

@@ -1,11 +1,13 @@
 """Standard LangChain interface tests for Responses API"""
 
+import base64
 from pathlib import Path
 from typing import cast
 
+import httpx
 import pytest
 from langchain_core.language_models import BaseChatModel
-from langchain_core.messages import AIMessage
+from langchain_core.messages import AIMessage, HumanMessage, ToolMessage
 
 from langchain_openai import ChatOpenAI
 from tests.integration_tests.chat_models.test_base_standard import TestOpenAIStandard
@@ -52,6 +54,55 @@ class TestOpenAIResponses(TestOpenAIStandard):
         input_ = "What was the 3rd highest building in 2000?"
         return _invoke(llm, input_, stream)
 
+    @property
+    def supports_pdf_tool_message(self) -> bool:
+        # OpenAI requires a filename for PDF inputs
+        # For now, we test with filename in OpenAI-specific tests
+        return False
+
+    def test_openai_pdf_tool_messages(self, model: BaseChatModel) -> None:
+        """Test that the model can process PDF inputs in ToolMessages."""
+        url = "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf"
+        pdf_data = base64.b64encode(httpx.get(url).content).decode("utf-8")
+
+        tool_message = ToolMessage(
+            content=[
+                {
+                    "type": "file",
+                    "source_type": "base64",
+                    "data": pdf_data,
+                    "mime_type": "application/pdf",
+                    "filename": "my-pdf",  # specify filename
+                },
+            ],
+            tool_call_id="1",
+            name="random_pdf",
+        )
+
+        messages = [
+            HumanMessage(
+                "Get a random PDF using the tool and relay the title verbatim."
+            ),
+            AIMessage(
+                [],
+                tool_calls=[
+                    {
+                        "type": "tool_call",
+                        "id": "1",
+                        "name": "random_pdf",
+                        "args": {},
+                    }
+                ],
+            ),
+            tool_message,
+        ]
+
+        def random_pdf() -> str:
+            """Return a random PDF."""
+            return ""
+
+        _ = model.bind_tools([random_pdf]).invoke(messages)
+
 
 def _invoke(llm: ChatOpenAI, input_: str, stream: bool) -> AIMessage:
     if stream: