[self-tests] test_add_option_kwargs fails on ppc64le

[stanislavlevin]

test_add_option_kwargs (loguru 0.7.0) fails on ppc64le machine with:

=================================== FAILURES =================================== 
_____________________________ test_file_buffering ______________________________ 
                                                                                 
tmp_path = PosixPath('/usr/src/tmp/pytest-of-builder/pytest-0/test_file_buffering0')
                                                                                 
>   ???                                                                          
E   AssertionError: assert '' != ''                                              
E    +  where '' = <bound method Path.read_text of PosixPath('/usr/src/tmp/pytest-of-builder/pytest-0/test_file_buffering0/test.log')>()                              
E    +    where <bound method Path.read_text of PosixPath('/usr/src/tmp/pytest-of-builder/pytest-0/test_file_buffering0/test.log')> = PosixPath('/usr/src/tmp/pytest-of-builder/pytest-0/test_file_buffering0/test.log').read_text
                                                                                 
file       = PosixPath('/usr/src/tmp/pytest-of-builder/pytest-0/test_file_buffering0/test.log')
tmp_path   = PosixPath('/usr/src/tmp/pytest-of-builder/pytest-0/test_file_buffering0')
                                                                                 
tests/test_add_option_kwargs.py:30: AssertionError

According to https://docs.python.org/3/library/functions.html#open:

When no buffering argument is given, the default buffering policy works as follows:

• Binary files are buffered in fixed-size chunks; the size of the buffer is chosen using a heuristic trying to determine the underlying device’s “block size” and falling back on io.DEFAULT_BUFFER_SIZE. On many systems, the buffer will typically be 4096 or 8192 bytes long.

On that machine:

(Pdb) file.stat().st_blksize
65536
(Pdb) io.DEFAULT_BUFFER_SIZE
8192

[Delgan]

Thanks for the report!

I can't remember why I wrote the test using buffering=-1.

loguru/tests/test_add_option_kwargs.py

Lines 24 to 30 in d379fed

	def test_file_buffering(tmp_path):
	file = tmp_path / "test.log"
	logger.add(file, format="{message}", buffering=-1)
	logger.debug("x" * (io.DEFAULT_BUFFER_SIZE // 2))
	assert file.read_text() == ""
	logger.debug("x" * (io.DEFAULT_BUFFER_SIZE * 2))
	assert file.read_text() != ""

I'll update the test so that it's deterministic and not OS-dependent.

[Delgan]

Now I remember why I implemented the test in this way. A fixed-size buffer can only be used with files opened in binary mode, but Loguru doesn't support binary mode.

The test can't be made fully deterministic, therefore I added a check to skip the test on platforms where an unexpected buffer size is encountered.

Thanks again for the report. It has been fixed on master branch.