`importlib_resources/tests/test_functional.py` test failures on big endian architectures

[mgorny]

When running the tests on big-endian architectures (sparc64, ppc64), we're getting the followin test failures:

$ tox -e py312 
.pkg-cpython312: recreate env because dependencies removed: setuptools>=56
.pkg-cpython312: remove tox env folder /home/mgorny/importlib_resources/.tox/.pkg-cpython312
.pkg-cpython312: install_requires> python -I -m pip install 'setuptools>=61.2' 'setuptools_scm[toml]>=3.4.1'
.pkg-cpython312: _optional_hooks> python /usr/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
.pkg-cpython312: get_requires_for_build_editable> python /usr/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
.pkg-cpython312: build_editable> python /usr/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta
py312: recreate env because dependencies removed: pytest-mypy; platform_python_implementation != "PyPy", pytest>=6
py312: remove tox env folder /home/mgorny/importlib_resources/.tox/py312
py312: install_package_deps> python -I -m pip install 'jaraco.test>=5.4' 'pytest!=8.1.*,>=6' 'pytest-checkdocs>=2.4' pytest-cov 'pytest-enabler>=2.2' pytest-mypy 'pytest-ruff>=0.2.1' 'zipp>=3.1.0; python_version < "3.10"' 'zipp>=3.17'
py312: install_package> python -I -m pip install --force-reinstall --no-deps /home/mgorny/importlib_resources/.tox/.tmp/package/10/importlib_resources-6.4.1.dev23+gbe5a270-0.editable-py3-none-any.whl
py312: commands[0]> pytest
========================================================= test session starts =========================================================
platform linux -- Python 3.12.3, pytest-8.2.2, pluggy-1.5.0
cachedir: .tox/py312/.pytest_cache
rootdir: /home/mgorny/importlib_resources
configfile: pytest.ini
plugins: enabler-3.1.1, mypy-0.10.3, checkdocs-2.13.0, cov-5.0.0, jaraco.test-5.4.0, ruff-0.4.0, typeguard-4.3.0
collected 313 items 

docs/conf.py .... [ 1%]
importlib_resources/__init__.py ... [ 2%]
importlib_resources/_adapters.py ... [ 3%]
importlib_resources/_common.py .... [ 4%]
importlib_resources/_functional.py ... [ 5%]
importlib_resources/_itertools.py .... [ 6%]
importlib_resources/abc.py ... [ 7%]
importlib_resources/compat/__init__.py ... [ 8%]
importlib_resources/compat/py38.py ... [ 9%]
importlib_resources/compat/py39.py ... [ 10%]
importlib_resources/future/__init__.py ... [ 11%]
importlib_resources/future/adapters.py ... [ 12%]
importlib_resources/readers.py ... [ 13%]
importlib_resources/simple.py ... [ 14%]
importlib_resources/tests/__init__.py ... [ 15%]
importlib_resources/tests/_path.py .... [ 16%]
importlib_resources/tests/compat/__init__.py ... [ 17%]
importlib_resources/tests/compat/py312.py ... [ 18%]
importlib_resources/tests/compat/py39.py ... [ 19%]
importlib_resources/tests/data01/__init__.py ... [ 20%]
importlib_resources/tests/data01/subdirectory/__init__.py ... [ 21%]
importlib_resources/tests/data02/__init__.py ... [ 22%]
importlib_resources/tests/data02/one/__init__.py ... [ 23%]
importlib_resources/tests/data02/two/__init__.py ... [ 24%]
importlib_resources/tests/test_compatibilty_files.py ................... [ 30%]
importlib_resources/tests/test_contents.py ...... [ 32%]
importlib_resources/tests/test_custom.py .... [ 33%]
importlib_resources/tests/test_files.py ......................... [ 41%]
importlib_resources/tests/test_functional.py .......F..F.....F..F. [ 48%]
importlib_resources/tests/test_open.py ........................................... [ 61%]
importlib_resources/tests/test_path.py ................ [ 67%]
importlib_resources/tests/test_read.py ....................................... [ 79%]
importlib_resources/tests/test_reader.py .................. [ 85%]
importlib_resources/tests/test_resource.py ....................s.................. [ 97%]
importlib_resources/tests/util.py ... [ 98%]
importlib_resources/tests/zip.py ... [ 99%]
. . [100%]

============================================================== FAILURES ===============================================================
____________________________________________ FunctionalAPITest_StringAnchor.test_open_text ____________________________________________

self = <importlib_resources.tests.test_functional.FunctionalAPITest_StringAnchor testMethod=test_open_text>

 def test_open_text(self):
 with resources.open_text(self.anchor01, 'utf-8.file') as f:
 self.assertEqual(f.read(), 'Hello, UTF-8 world!\n')
 for path_parts in self._gen_resourcetxt_path_parts():
 with resources.open_text(
 self.anchor02,
 *path_parts,
 encoding='utf-8',
 ) as f:
 self.assertEqual(f.read(), 'a resource')
 # Use generic OSError, since e.g. attempting to read a directory can
 # fail with PermissionError rather than IsADirectoryError
 with self.assertRaises(OSError):
 resources.open_text(self.anchor01)
 with self.assertRaises(OSError):
 resources.open_text(self.anchor01, 'no-such-file')
 with resources.open_text(self.anchor01, 'utf-16.file') as f:
 with self.assertRaises(UnicodeDecodeError):
 f.read()
 with resources.open_text(
 self.anchor01,
 'binary.file',
 encoding='latin1',
 ) as f:
 self.assertEqual(f.read(), '\x00\x01\x02\x03')
 with resources.open_text(
 self.anchor01,
 'utf-16.file',
 errors='backslashreplace',
 ) as f:
> self.assertEqual(
 f.read(),
 'Hello, UTF-16 world!\n'.encode('utf-16').decode(
 errors='backslashreplace',
 ),
 )
E AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67 chars]00\n'
E - \xff\xfeHello, UTF-16 world!
E ? ^^^^
E + \xfe\xffHello, UTF-16 world!
E ? ++++ ^
E - 
E +

importlib_resources/tests/test_functional.py:131: AssertionError
____________________________________________ FunctionalAPITest_StringAnchor.test_read_text ____________________________________________

self = <importlib_resources.tests.test_functional.FunctionalAPITest_StringAnchor testMethod=test_read_text>

 def test_read_text(self):
 self.assertEqual(
 resources.read_text(self.anchor01, 'utf-8.file'),
 'Hello, UTF-8 world!\n',
 )
 self.assertEqual(
 resources.read_text(
 self.anchor02,
 'subdirectory',
 'subsubdir',
 'resource.txt',
 encoding='utf-8',
 ),
 'a resource',
 )
 for path_parts in self._gen_resourcetxt_path_parts():
 self.assertEqual(
 resources.read_text(
 self.anchor02,
 *path_parts,
 encoding='utf-8',
 ),
 'a resource',
 )
 # Use generic OSError, since e.g. attempting to read a directory can
 # fail with PermissionError rather than IsADirectoryError
 with self.assertRaises(OSError):
 resources.read_text(self.anchor01)
 with self.assertRaises(OSError):
 resources.read_text(self.anchor01, 'no-such-file')
 with self.assertRaises(UnicodeDecodeError):
 resources.read_text(self.anchor01, 'utf-16.file')
 self.assertEqual(
 resources.read_text(
 self.anchor01,
 'binary.file',
 encoding='latin1',
 ),
 '\x00\x01\x02\x03',
 )
> self.assertEqual(
 resources.read_text(
 self.anchor01,
 'utf-16.file',
 errors='backslashreplace',
 ),
 'Hello, UTF-16 world!\n'.encode('utf-16').decode(
 errors='backslashreplace',
 ),
 )
E AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67 chars]00\n'
E - \xff\xfeHello, UTF-16 world!
E ? ^^^^
E + \xfe\xffHello, UTF-16 world!
E ? ++++ ^
E - 
E +

importlib_resources/tests/test_functional.py:79: AssertionError
____________________________________________ FunctionalAPITest_ModuleAnchor.test_open_text ____________________________________________

self = <importlib_resources.tests.test_functional.FunctionalAPITest_ModuleAnchor testMethod=test_open_text>

 def test_open_text(self):
 with resources.open_text(self.anchor01, 'utf-8.file') as f:
 self.assertEqual(f.read(), 'Hello, UTF-8 world!\n')
 for path_parts in self._gen_resourcetxt_path_parts():
 with resources.open_text(
 self.anchor02,
 *path_parts,
 encoding='utf-8',
 ) as f:
 self.assertEqual(f.read(), 'a resource')
 # Use generic OSError, since e.g. attempting to read a directory can
 # fail with PermissionError rather than IsADirectoryError
 with self.assertRaises(OSError):
 resources.open_text(self.anchor01)
 with self.assertRaises(OSError):
 resources.open_text(self.anchor01, 'no-such-file')
 with resources.open_text(self.anchor01, 'utf-16.file') as f:
 with self.assertRaises(UnicodeDecodeError):
 f.read()
 with resources.open_text(
 self.anchor01,
 'binary.file',
 encoding='latin1',
 ) as f:
 self.assertEqual(f.read(), '\x00\x01\x02\x03')
 with resources.open_text(
 self.anchor01,
 'utf-16.file',
 errors='backslashreplace',
 ) as f:
> self.assertEqual(
 f.read(),
 'Hello, UTF-16 world!\n'.encode('utf-16').decode(
 errors='backslashreplace',
 ),
 )
E AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67 chars]00\n'
E - \xff\xfeHello, UTF-16 world!
E ? ^^^^
E + \xfe\xffHello, UTF-16 world!
E ? ++++ ^
E - 
E +

importlib_resources/tests/test_functional.py:131: AssertionError
____________________________________________ FunctionalAPITest_ModuleAnchor.test_read_text ____________________________________________

self = <importlib_resources.tests.test_functional.FunctionalAPITest_ModuleAnchor testMethod=test_read_text>

 def test_read_text(self):
 self.assertEqual(
 resources.read_text(self.anchor01, 'utf-8.file'),
 'Hello, UTF-8 world!\n',
 )
 self.assertEqual(
 resources.read_text(
 self.anchor02,
 'subdirectory',
 'subsubdir',
 'resource.txt',
 encoding='utf-8',
 ),
 'a resource',
 )
 for path_parts in self._gen_resourcetxt_path_parts():
 self.assertEqual(
 resources.read_text(
 self.anchor02,
 *path_parts,
 encoding='utf-8',
 ),
 'a resource',
 )
 # Use generic OSError, since e.g. attempting to read a directory can
 # fail with PermissionError rather than IsADirectoryError
 with self.assertRaises(OSError):
 resources.read_text(self.anchor01)
 with self.assertRaises(OSError):
 resources.read_text(self.anchor01, 'no-such-file')
 with self.assertRaises(UnicodeDecodeError):
 resources.read_text(self.anchor01, 'utf-16.file')
 self.assertEqual(
 resources.read_text(
 self.anchor01,
 'binary.file',
 encoding='latin1',
 ),
 '\x00\x01\x02\x03',
 )
> self.assertEqual(
 resources.read_text(
 self.anchor01,
 'utf-16.file',
 errors='backslashreplace',
 ),
 'Hello, UTF-16 world!\n'.encode('utf-16').decode(
 errors='backslashreplace',
 ),
 )
E AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67 chars]00\n'
E - \xff\xfeHello, UTF-16 world!
E ? ^^^^
E + \xfe\xffHello, UTF-16 world!
E ? ++++ ^
E - 
E +

importlib_resources/tests/test_functional.py:79: AssertionError
========================================================== warnings summary ===========================================================
docs/conf.py::mypy
 /home/mgorny/importlib_resources/.tox/py312/lib/python3.12/site-packages/mypy/config_parser.py:271: EncodingWarning: 'encoding' argument not specified
 config_parser.read(config_file)

docs/conf.py::mypy
 /home/mgorny/importlib_resources/.tox/py312/lib/python3.12/site-packages/mypy/modulefinder.py:851: EncodingWarning: 'encoding' argument not specified
 with open(versions_path) as f:

docs/conf.py::mypy
docs/conf.py::mypy
docs/conf.py::mypy
docs/conf.py::mypy
 /home/mgorny/importlib_resources/.tox/py312/lib/python3.12/site-packages/mypy/metastore.py:95: EncodingWarning: 'encoding' argument not specified
 with open(os.path.join(self.cache_dir_prefix, name)) as f:

docs/conf.py: 13 warnings
 /home/mgorny/importlib_resources/.tox/py312/lib/python3.12/site-packages/mypy/metastore.py:108: EncodingWarning: 'encoding' argument not specified
 with open(tmp_filename, "w") as f:

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

---------- coverage: platform linux, python 3.12.3-final-0 -----------
Name Stmts Miss Cover Missing
-----------------------------------------------------------------------------------------
docs/conf.py 12 0 100%
importlib_resources/__init__.py 4 0 100%
importlib_resources/_adapters.py 90 2 98% 58, 157
importlib_resources/_common.py 101 5 95% 68-72
importlib_resources/_functional.py 32 0 100%
importlib_resources/abc.py 66 8 88% 27, 40, 48, 53, 162, 165, 168, 171
importlib_resources/compat/__init__.py 0 0 100%
importlib_resources/compat/py38.py 6 1 83% 11
importlib_resources/compat/py39.py 5 1 80% 10
importlib_resources/future/__init__.py 0 0 100%
importlib_resources/future/adapters.py 42 3 93% 37, 83-84
importlib_resources/readers.py 106 9 92% 29, 42-45, 52-53, 188-194
importlib_resources/tests/__init__.py 0 0 100%
importlib_resources/tests/compat/__init__.py 0 0 100%
importlib_resources/tests/compat/py39.py 3 0 100%
importlib_resources/tests/compat/py312.py 9 4 56% 11-15
importlib_resources/tests/data01/__init__.py 0 0 100%
importlib_resources/tests/data01/subdirectory/__init__.py 0 0 100%
importlib_resources/tests/data02/__init__.py 0 0 100%
importlib_resources/tests/data02/one/__init__.py 0 0 100%
importlib_resources/tests/data02/two/__init__.py 0 0 100%
importlib_resources/tests/test_compatibilty_files.py 67 0 100%
importlib_resources/tests/test_contents.py 19 0 100%
importlib_resources/tests/test_custom.py 29 0 100%
importlib_resources/tests/test_files.py 67 1 99% 117
importlib_resources/tests/test_functional.py 109 2 98% 7-9
importlib_resources/tests/test_open.py 58 1 98% 89
importlib_resources/tests/test_path.py 37 1 97% 65
importlib_resources/tests/test_read.py 51 1 98% 97
importlib_resources/tests/test_reader.py 94 1 99% 145
importlib_resources/tests/test_resource.py 128 1 99% 241
importlib_resources/tests/util.py 91 5 95% 32-35, 51
importlib_resources/tests/zip.py 20 0 100%
-----------------------------------------------------------------------------------------
TOTAL 1246 46 96%

================================================================ mypy =================================================================
Success: no issues found in 36 source files
======================================================= short test summary info =======================================================
FAILED importlib_resources/tests/test_functional.py::FunctionalAPITest_StringAnchor::test_open_text - AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67...
FAILED importlib_resources/tests/test_functional.py::FunctionalAPITest_StringAnchor::test_read_text - AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67...
FAILED importlib_resources/tests/test_functional.py::FunctionalAPITest_ModuleAnchor::test_open_text - AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67...
FAILED importlib_resources/tests/test_functional.py::FunctionalAPITest_ModuleAnchor::test_read_text - AssertionError: '\\xff\\xfeH\x00e\x00l\x00l\x00o\x00,\x00 \x00[67 chars]\x00' != '\\xfe\\xff\x00H\x00e\x00l\x00l\x00o\x00,\x00 [67...
================================== 4 failed, 308 passed, 1 skipped, 19 warnings in 64.12s (0:01:04) ===================================
py312: exit 1 (67.31 seconds) /home/mgorny/importlib_resources> pytest pid=1199072
 py312: FAIL code 1 (135.61=setup[68.30]+cmd[67.31] seconds)
 evaluation failed :( (136.06 seconds)

Reproduced with be5a270. I'll submit a PR shortly.

[jaraco]

Thanks for the report. It looks like this issue was also reported downstream at python/cpython#117569. Since there's already a fix there, I'm going to apply that one here to keep things in sync.