bpo-45229: Make ElementTree tests discoverable

[serhiy-storchaka]

• Issue: Always use unittest for collecting tests in regrtests #89392

[vstinner]

Without the PR, main branch:

$ ./python -m test -v test_xml_etree_c
(...)
Warning -- test_xml_etree_c test runner returned None: <function test_main at 0x7f94a1758650>

Total duration: 2.3 sec
Total tests: run=0
Total test files: run=1/1

With the PR:

$ ./python -m test -v test_xml_etree_c
(...)
Total tests: run=208 skipped=6
Total test files: run=1/1

regrtest is able to count the number of tests, nice!

I counted manually the number of tests in the main branch (count the number of lines in short), and I also see 208 tests! I only see 5 skipped tests, but here 6 are announced. Aha, interesting!

[serhiy-storchaka]

I only see 5 skipped tests, but here 6 are announced.

It counts skipped NoAcceleratorTest. In the old code it was not added to the explicit list of test classes.

[miss-islington]

Thanks @serhiy-storchaka for the PR 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[miss-islington]

Sorry, @serhiy-storchaka, I could not cleanly backport this to 3.12 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 074ac1f72e392a576516639f650bac0519d1cb52 3.12

[miss-islington]

Sorry, @serhiy-storchaka, I could not cleanly backport this to 3.11 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 074ac1f72e392a576516639f650bac0519d1cb52 3.11

[bedevere-bot]

GH-108873 is a backport of this pull request to the 3.12 branch.

[bedevere-bot]

GH-108874 is a backport of this pull request to the 3.11 branch.

[vstinner]

It counts skipped NoAcceleratorTest. In the old code it was not added to the explicit list of test classes.

Minor but nice improvement to take :-)