perf(checkpoint): eliminate json.dumps fallback by using orjson default handler #112
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The parent class JsonPlusSerializer doesn't have dumps() or loads() methods, only dumps_typed() and loads_typed(). This fix corrects the fallback logic to properly use the parent's typed serialization methods. Fixes AttributeError: 'super' object has no attribute 'dumps'
The bug was in line 28 where super().dumps(obj) was called, but the parent class JsonPlusSerializer doesn't have a dumps() method. The correct fix is to use orjson.dumps() with default=self._default, which properly delegates LangChain object serialization to the parent's _default method.
…dler fix Tests validate that the fix properly handles: - HumanMessage, AIMessage, SystemMessage, ToolMessage serialization - Lists of messages (common LangGraph pattern) - Nested structures with embedded messages - dumps_typed() method (used by checkpointer) - Backwards compatibility with non-LangChain objects - LangChain serialized format revival All tests pass, confirming the fix works correctly.
Renamed test_fix_standalone.py to test_jsonplus_redis_serializer.py to better describe what is being tested (the JsonPlusRedisSerializer class).
bsbodden
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bsbodden
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Description
Fixes #111 - Similar to #109
This PR fixes a bug in
JsonPlusRedisSerializer.dumps()that caused aTypeErrorwhen serializing LangChain message objects (e.g.,HumanMessage,AIMessage,SystemMessage).Changes
dumps()method:Replaced the call to non-existent
super().dumps()withorjson.dumps()usingdefault=self._default, which properly handles LangChain object serialization.loads()method:Enhanced error handling to gracefully fall back to
msgpackand other formats when JSON parsing fails.Introduced
tests/test_jsonplus_serializer_default_handler.pyto validate:dumps()/loads()anddumps_typed()/loads_typed()Root Cause
The previous implementation attempted to call
super().dumps()whenorjson.dumps(obj)raised aTypeError.However, the parent class
JsonPlusSerializerdoes not define adumps()method, so LangChain objects always failed to serialize.Solution
Use the existing
_defaulthandler from the parentJsonPlusSerializerclass withorjson:This leverages the parent class’s LangChain serialization logic while maintaining orjson’s performance benefits.
Testing
pytestAll tests pass, confirming that LangChain message objects now serialize and deserialize correctly.