[linhongyu510]

Cancelling an ordinary asynchronous action currently records its step as completed, even though its state update never ran. Rebuilding the application with resume_at_next_action=True then skips that action and advances to its successor. For example, cancelling work while it waits for a response resumes at after with the old state.

Changes

• Preserve the original asyncio.CancelledError for _astep's post_run_step hooks before re-raising it. Persisters consequently record the step as failed and resume at the interrupted action.
• Cover astep and arun, with both function-based single-step actions and class-based multi-step actions. The tests cancel at an event-controlled await, rebuild from persisted state, retry, and verify the final result.

How I tested this

• On upstream 36e3ff3048c8cabd7aac6d5c373307934bf3c2df, all four new cases fail because the next action after recovery is after rather than work.
• With the fix, pytest tests/core/test_application.py tests/core/test_persistence.py tests/core/test_parallelism.py -q: 256 passed on Python 3.12.13.
• Black 23.11.0, isort 5.12.0, Flake8 6.1.0, ASF license-header checks, and git diff --check pass.
• Complete pre-commit run --files burr/core/application.py tests/core/test_application.py: passed, including the frontend lint-staged and ASF header hooks.

Notes

This concerns non-streaming step persistence. The streaming cleanup change in #1027 is already in the base. The top-level execute-hook reporting in #897 does not update _astep's step hooks or persistence status.

The existing cancellation still propagates to the caller. This does not shield persistence from repeated cancellation or change the handling of cancellation during a lifecycle hook.

This change was developed with an AI assistant. The reproduction and regression checks use no model or network service.

Checklist

• PR has an informative and human-readable title.
• Changes are limited to a single goal.
• Code passed the complete pre-commit check.
• The behavior change is tested.
• No new public functions or API are introduced.
• No placeholder code is added.
• The change corrects existing retry behavior without changing documented APIs.