JSON repository appears to call item serialization twice on update vs. replace #50
Description
Building on the JSONDirectoryRepo framework, I implemented a model with a Pydantic field_serializer to convert a Decimal value to string. That worked well when calling the BaseRepo methods to add or replace files in the repository, but I turned up an unusual error when attempting to call update. I haven't tried to track it down more because I am using replace as a workaround.
From what I can tell, it appears that the update call attempts to serialize the model twice, causing a failure when the field_serializer is handed a string instead of the expected Decimal value. That points to a likely unnecessary call to item_to_dict somewhere along the way, probably in the JSONDirectoryRepo override of update.
I'm new to the codebase, and using @ManiMozaffar's fork to support Pydantic v2 - but the error appears to be in the mainline codebase. I'll attach the traceback output as a comment for reference.