serialization fix for defaults (#757)

Fix serialization issue when there are defaults

langserve/serialization.py

@@ -116,8 +116,6 @@ def _decode_lc_objects(value: Any) -> Any:
         try:
             obj = WellKnownLCObject.model_validate(v)
             parsed = obj.root
-            if set(parsed.model_dump()) != set(value):
-                raise ValueError("Invalid object")
             return parsed
         except (ValidationError, ValueError, TypeError):
             return v

pyproject.toml

@@ -14,7 +14,7 @@ python = "^3.9"
 httpx = ">=0.23.0" # May be able to decrease this version
 fastapi = {version = ">=0.90.1,<1", optional = true}
 sse-starlette = {version = "^1.3.0", optional = true}
-langchain-core = "0.3.0dev4"
+langchain-core = "0.3.0dev5"
 orjson = ">=2"
 pyproject-toml = "^0.0.10"
 pydantic = "^2.7"

tests/unit_tests/test_serialization.py

@@ -6,6 +6,7 @@
 import pytest
 from langchain_core.documents.base import Document
 from langchain_core.messages import HumanMessage, HumanMessageChunk, SystemMessage
+from langchain_core.outputs import ChatGeneration
 from pydantic import BaseModel
 
 from langserve.serialization import (
@@ -48,8 +49,7 @@ def test_document_serialization() -> None:
             "numbers": [1, 2, 3],
             "boom": "Hello, world!",
         },
-        # Requires typing ChatGeneration with Anymessage
-        # [ChatGeneration(message=HumanMessage(content="Hello"))],
+        [ChatGeneration(message=HumanMessage(content="Hello"))],
     ],
 )
 def test_serialization(data: Any) -> None:

tests/unit_tests/test_server_client.py

@@ -2675,6 +2675,7 @@ async def test_astream_events_with_prompt_model_parser_chain(
                             {
                                 "additional_kwargs": {},
                                 "content": "hello",
+                                "example": False,
                                 "name": None,
                                 "response_metadata": {},
                                 "type": "human",
@@ -2867,6 +2868,7 @@ async def test_astream_events_with_prompt_model_parser_chain(
                         ],
                         "llm_output": None,
                         "run": None,
+                        "type": "LLMResult",
                     },
                 },
                 "event": "on_chat_model_end",