GH-94808: Cover PyOS_mystrnicmp and PyOS_mystricmp

[artemmukhin]

• Issue: Metabug: Improving C-level coverage #94808

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[artemmukhin]

I'm not sure who is best positioned to review this, but maybe @corona10 could take a look?

[corona10]

I'm not sure who is best positioned to review this, but maybe @corona10 could take a look?

Okay, I will take a look by this weekend :)

[artemmukhin]

@corona10 Thank you!

[corona10]

Would you like to separate the file into Modules/_testcapi/pyos.c
likewise https://github.com/python/cpython/blob/main/Modules/_testcapi/float.c ?

The test itself looks good.

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A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

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[artemmukhin]

I have made the requested changes; please review again.

@corona10 Thank you for the review! I've separated the tests.

Although I haven't managed to run the tests from Modules/_testcapi on my machine. Before separating, I ran my tests via ./python -m test -v test_capi, but now they are not executed as I see. I found the C API Tests paragraph in the devguide, but I didn't find how to run these tests. Could you please clarify?

[bedevere-bot]

Thanks for making the requested changes!

@corona10: please review the changes made to this pull request.

[artemmukhin]

I've found out that the tests were not executed because of the wrong naming.

Test_testcapi only executes the test method if its built-in name starts with test_ and doesn't end with _code:

cpython/Lib/test/test_capi/test_misc.py

Lines 1422 to 1425 in ced13c9

	class Test_testcapi(unittest.TestCase):
	locals().update((name, getattr(_testcapi, name))
	for name in dir(_testcapi)
	if name.startswith('test_') and not name.endswith('_code'))

It is mentioned in the C API Tests paragraph to some extent:

Functions named test_* are used as tests directly

But at first reading, I got confused because in _testcapi/float.c file, the test_ prefix is only used in the C function name:

cpython/Modules/_testcapi/float.c

Lines 84 to 88 in 534660f

	static PyMethodDef test_methods[] = {
	{"float_pack", test_float_pack, METH_VARARGS, NULL},
	{"float_unpack", test_float_unpack, METH_VARARGS, NULL},
	{NULL},
	};

However, in contrast to my tests, these test methods are actually executed through test_float.py:

cpython/Lib/test/test_float.py

Lines 1516 to 1519 in 534660f

	class PackTests(unittest.TestCase):
	def test_pack(self):
	self.assertEqual(_testcapi.float_pack(2, 1.5, BIG_ENDIAN),
	b'>\x00')

I hope this investigation might help other first-time contributors.

@corona10 If you think it would be helpful to clarify this point in the devguide, please let me know, and I'll be happy to open a corresponding PR.

[corona10]

I've found out that the tests were not executed because of the wrong naming.
Test_testcapi only executes the test method if its built-in name starts with test_ and doesn't end with _code:
But at first reading, I got confused because in testcapi/float.c file, the test prefix is only used in the C function name:
However, in contrast to my tests, these test methods are actually executed through test_float.py:

AFAIK, those things are intended.

[corona10]

LGTM

But I want to listen to the opinion of @erlend-aasland for this testing structure.

[artemmukhin]

@erlend-aasland could you please take a look?

[artemmukhin]

Thank you!

Cc @corona10