From 0a053d2c8146e4a4739f92d48f1e2bdec75202e5 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 9 Sep 2026 14:21:40 -0700
Subject: [PATCH] test(guardrails): cover streamed tool-call name rewrites on
 chat and Messages

Skipping the name write-back in either handler left every test green; a
guardrail that renames a tool call now has a regression test on both the
chat chunk path and the Anthropic SSE path
---
 .../test_anthropic_guardrail_handler.py       | 23 +++++++++++++++++++
 .../test_openai_guardrail_handler.py          | 23 +++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/tests/test_litellm/llms/anthropic/chat/guardrail_translation/test_anthropic_guardrail_handler.py b/tests/test_litellm/llms/anthropic/chat/guardrail_translation/test_anthropic_guardrail_handler.py
index 64c243343d5..e091355b69d 100644
--- a/tests/test_litellm/llms/anthropic/chat/guardrail_translation/test_anthropic_guardrail_handler.py
+++ b/tests/test_litellm/llms/anthropic/chat/guardrail_translation/test_anthropic_guardrail_handler.py
@@ -367,6 +367,29 @@ class TestAnthropicMessagesHandlerStreamingOutputProcessing:
         assert '"stop_reason": "tool_use"' in raw
         assert "persim" not in raw
 
+    @pytest.mark.asyncio
+    async def test_deliver_ended_stream_rewrites_writes_tool_use_name_back_into_sse_chunks(self):
+        class RenameTool(CustomGuardrail):
+            async def apply_guardrail(self, inputs, request_data, input_type, logging_obj=None):
+                for tool_call in inputs.get("tool_calls", []):
+                    tool_call.function.name = "lookup_fruit_reviewed"
+                return inputs
+
+        handler = AnthropicMessagesHandler()
+        chunks = self._ended_tool_use_sse_chunks()
+
+        await handler.process_output_streaming_response(
+            responses_so_far=chunks,
+            guardrail_to_apply=RenameTool(guardrail_name="test"),
+            litellm_logging_obj=MagicMock(),
+            deliver_ended_stream_rewrites=True,
+        )
+
+        raw = b"".join(chunks).decode()
+        assert '"name": "lookup_fruit_reviewed"' in raw and '"id": "toolu_1"' in raw
+        assert '"name": "lookup_fruit"' not in raw
+        assert json.loads("".join(self._partial_jsons(chunks))) == {"fruit": "persimmon"}
+
     @pytest.mark.asyncio
     async def test_ended_stream_tool_use_rewrite_leaves_chunks_untouched_by_default(self):
         handler = AnthropicMessagesHandler()
diff --git a/tests/test_litellm/llms/openai/chat/guardrail_translation/test_openai_guardrail_handler.py b/tests/test_litellm/llms/openai/chat/guardrail_translation/test_openai_guardrail_handler.py
index c7011a6f00e..5a29a96829f 100644
--- a/tests/test_litellm/llms/openai/chat/guardrail_translation/test_openai_guardrail_handler.py
+++ b/tests/test_litellm/llms/openai/chat/guardrail_translation/test_openai_guardrail_handler.py
@@ -1171,6 +1171,29 @@ class TestOpenAIChatCompletionsHandlerStreamingOutput:
         assert chunks[3].choices[0].delta.tool_calls is None
         assert chunks[3].choices[0].finish_reason == "tool_calls"
 
+    @pytest.mark.asyncio
+    async def test_deliver_ended_stream_rewrites_writes_tool_call_name_back_into_chunks(self):
+        class RenameTool(CustomGuardrail):
+            async def apply_guardrail(self, inputs, request_data, input_type, logging_obj=None):
+                for tool_call in inputs.get("tool_calls", []):
+                    tool_call["function"]["name"] = "lookup_fruit_reviewed"
+                return inputs
+
+        handler = OpenAIChatCompletionsHandler()
+        chunks = self._ended_tool_call_stream_chunks()
+
+        await handler.process_output_streaming_response(
+            responses_so_far=chunks,
+            guardrail_to_apply=RenameTool(guardrail_name="test"),
+            litellm_logging_obj=None,
+            deliver_ended_stream_rewrites=True,
+        )
+
+        fragments = [chunk.choices[0].delta.tool_calls[0] for chunk in chunks[:3]]
+        assert [fragment.function.name for fragment in fragments] == ["lookup_fruit_reviewed", None, None]
+        assert json.loads("".join(fragment.function.arguments for fragment in fragments)) == {"fruit": "persimmon"}
+        assert fragments[0].id == "call_1"
+
     @pytest.mark.asyncio
     async def test_ended_stream_tool_call_rewrite_leaves_chunks_untouched_by_default(self):
         handler = OpenAIChatCompletionsHandler()