Yang Cen c8fd3e97d1 test(python): cover stable main udf registration identity (#4094) ...

## Other changes

### What changed?

- Add a subprocess regression harness for an ordinary `@udf` function
defined in `__main__`.
- Verify the full registration request, artifact digest, and Function
signature stay identical across independent Python processes and
renamed/moved script paths.
- Verify body, referenced-global, and annotation changes still produce
distinct artifact identities, with annotation changes also producing a
distinct Function signature.

### Why is the change needed?


[ENT-2441](https://linear.app/lancedb/issue/ENT-2441/make-sure-function-defined-in-main-gets-stable-signature)
tracks the stability guarantee. Investigation on the exact `840e1d73`
main base found that LanceDB already packages canonical source instead
of cloudpickle bytes, so the unchanged `__main__` function is stable and
no production-code fix is needed. This change closes the missing
regression-test coverage.


[GEN-950](https://linear.app/lancedb/issue/GEN-950/class-based-udfs-defined-in-main-get-a-new-auto-version-on-every-run)
remains a separate Geneva checkpoint-version issue for class-based
callables. LanceDB's Function API continues to accept synchronous Python
functions only.

## Validation

- `cd python && uv run --extra tests pytest
python/tests/test_first_class_function_slice2.py -q` (`40 passed`)
- `uv run --project python --extra dev ruff format .`
- `uv run --project python --extra dev ruff check .` (`All checks
passed!`)

2026-08-31 22:34:34 +08:00

..

lancedb

feat: add drop_function client APIs (#4097)

2026-08-31 22:17:11 +08:00

tests

test(python): cover stable main udf registration identity (#4094)

2026-08-31 22:34:34 +08:00

type_tests

fix(python): expose inline types to downstream checkers (#3817)

2026-08-07 17:31:42 +08:00