Improve retry functionality in a few ways

[taldcroft]

Description

This addresses some shortcomings in the ska_helpers.retry module along with general improvements:

• Add MockFuncFailure class to help testing retries in other modules.
• Add retry_func for more convenient wrapping of functions.
• Update the default tries from -1 (infinite retries) to 3.
• Define __all__ in a more typical way and use this in the package __init__.py import.
• Clean up some cruft in the test module (I figured out how to use the pytest caplog).

Interface impacts

Retry defaults are changed, but no code in Ska was using the default since it was useless.

Testing

Unit tests

• Mac

(ska3) ➜  ska_helpers git:(add-mock-func-failure-class) git rev-parse --short HEAD
92558a6
(ska3) ➜  ska_helpers git:(add-mock-func-failure-class) pytest
========================================== test session starts ==========================================
platform darwin -- Python 3.12.8, pytest-8.3.4, pluggy-1.5.0
rootdir: /Users/aldcroft/git
configfile: pytest.ini
plugins: anyio-4.7.0, timeout-2.3.1
collected 75 items                                                                                      

ska_helpers/retry/tests/test_retry.py .................                                           [ 22%]
ska_helpers/tests/test_chandra_models.py ..................                                       [ 46%]
ska_helpers/tests/test_docs.py .                                                                  [ 48%]
ska_helpers/tests/test_git_helpers.py s                                                           [ 49%]
ska_helpers/tests/test_paths.py ......                                                            [ 57%]
ska_helpers/tests/test_run_info.py ..                                                             [ 60%]
ska_helpers/tests/test_utils.py ..............................                                    [100%]

===================================== 74 passed, 1 skipped in 5.49s =====================================

Independent check of unit tests by Jean

• Linux

ska3-jeanconn-kady> pytest
============================= test session starts ==============================
platform linux -- Python 3.12.8, pytest-8.3.4, pluggy-1.5.0
rootdir: /proj/sot/ska/jeanproj/git
configfile: pytest.ini
plugins: anyio-4.7.0, timeout-2.3.1
collected 75 items                                                                                                                    

ska_helpers/retry/tests/test_retry.py .................                                                                         [ 22%]
ska_helpers/tests/test_chandra_models.py ..................                                                                     [ 46%]
ska_helpers/tests/test_docs.py .                                                                                                [ 48%]
ska_helpers/tests/test_git_helpers.py .                                                                                         [ 49%]
ska_helpers/tests/test_paths.py ......                                                                                          [ 57%]
ska_helpers/tests/test_run_info.py ..                                                                                           [ 60%]
ska_helpers/tests/test_utils.py ..............................                                                                  [100%]

========================================================= 75 passed in 14.11s =========================================================
ska3-jeanconn-kady> git rev-parse HEAD
92558a6ceac02f506ead364327a75dc4204b321b

Functional tests

Some functional testing in related testing:

• Improve robustness of OCCweb utilities and kadi commands kadi#366
• Update ephem_stk code and testing for kadi.occweb built-in retry cheta#283

[jeanconn]

Looks good to me, though I am wondering if it would save trouble to just update retry and retry_call to also use RETRY_DEFAULTS .

[taldcroft]

Looks good to me, though I am wondering if it would save trouble to just update retry and retry_call to also use RETRY_DEFAULTS .

Not sure how much trouble it would save. Certainly this would change some existing behavior in ways that were not intended in the original, e.g. backoff=2 vs default backoff=1 in https://github.com/sot/arc/blob/5a7104495ca530a739c9c32e23a88e420db3dd8d/get_solar_flare_png.py#L27.

[jeanconn]

Yep, I'm only worried for maintainability that there's both the RETRY_DEFAULTS and the defaults that are baked-in to the other/older methods. So really RETRY_DEFAULTS doesn't seem to deserve being a module var. But there isn't that much code in here so I'm not passionate about any change.

[jeanconn]

LGTM. Thanks for the discussion about defaults.

[taldcroft]

Maybe it should be called RETRY_FUNC_DEFAULTS. The one utility of having it was being able to monkeypatch it for testing to make tests run faster.