In langchain_core >=1.0 plain Generation no longer stores a .message
attribute - that only exists on ChatGeneration. Tests were constructing
Generation(message=AIMessage(...)) which silently dropped the message,
making hasattr(generation, "message") return False and skipping the
token-counting path (all usage assertions failed with 0).
- Replace Generation(message=...) with ChatGeneration(message=AIMessage(...))
in test_stats_handler_on_llm_end_with_usage and thread_safety test
- Use UsageMetadata(input_tokens=N, output_tokens=N, total_tokens=N)
instead of bare dict (total_tokens is required in langchain_core 1.2+)
- Pass usage_metadata via AIMessage constructor instead of post-init
attribute assignment (avoids pydantic validation bypass)
- Keep Generation(text=...) in test_stats_handler_on_llm_end_no_usage
(correctly tests the "no usage" branch — plain Generation has no .message)
Co-authored-by: aguzererler <6199053+aguzererler@users.noreply.github.com>
Agent-Logs-Url: https://github.com/aguzererler/TradingAgents/sessions/ce079791-08ef-4f2e-9f31-a1ae6a26b4cb
0e3edcdf5a