fix(managed files): answer 400 for a chat file part with no file object instead of 500

enterprise/litellm_enterprise/proxy/hooks/managed_files.py

@@ -1742,10 +1742,11 @@ class _PROXY_LiteLLMManagedFiles(CustomLogger, BaseFileEndpoints):
                         continue
                     for c in content:
                         if c.get("type") == "file":
-                            file_object = cast(ChatCompletionFileObject, c)
-                            file_object_file_field = file_object["file"]
+                            file_object_file_field = cast(Dict[str, object], c).get("file")
+                            if not isinstance(file_object_file_field, dict):
+                                continue
                             file_id = file_object_file_field.get("file_id")
-                            if file_id:
+                            if isinstance(file_id, str) and file_id:
                                 file_ids.append(file_id)
         return file_ids
 

tests/unit/enterprise/proxy/hooks/test_managed_files.py

@@ -332,6 +332,26 @@ def test_get_file_ids_from_messages_skips_bedrock_content_blocks_without_type():
     assert file_ids == ["file-keep"]
 
 
+def test_get_file_ids_from_messages_leaves_malformed_file_parts_to_request_validation():
+    proxy_managed_files = PROXY_LiteLLMManagedFiles(
+        DualCache(), prisma_client=MagicMock()
+    )
+    messages = [
+        {
+            "role": "user",
+            "content": [
+                {"type": "file"},
+                {"type": "file", "file": "file-raw"},
+                {"type": "file", "file": None},
+                {"type": "file", "file": {"file_id": 7}},
+                {"type": "file", "file": {"file_id": "file-keep"}},
+            ],
+        }
+    ]
+    file_ids = proxy_managed_files.get_file_ids_from_messages(messages)
+    assert file_ids == ["file-keep"]
+
+
 @pytest.mark.asyncio
 async def test_async_pre_call_hook_batch_retrieve():
     from litellm.proxy._types import UserAPIKeyAuth