Failing tests with pylint 2.0.0 on Fedora rawhide

[lupinix]

While working on the upgrade of pylint to 2.0.0 in Fedora Rawhide, I recognized the following test failures:

=================================== FAILURES ===================================
_________________ test_functional[useless_object_inheritance] __________________
test_file = <test_functional.FunctionalTestFile object at 0x7fea7225df60>
    @pytest.mark.parametrize("test_file", TESTS, ids=TESTS_NAMES)
    def test_functional(test_file):
        LintTest = LintModuleOutputUpdate(test_file) if UPDATE else LintModuleTest(test_file)
        LintTest.setUp()
>       LintTest._runTest()
pylint/test/test_functional.py:378: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <test_functional.LintModuleTest object at 0x7fea698dcf98>
    def _runTest(self):
        self._linter.check([self._test_file.module])
    
        expected_messages, expected_text = self._get_expected()
        received_messages, received_text = self._get_received()
    
        if expected_messages != received_messages:
            msg = ['Wrong results for file "%s":' % (self._test_file.base)]
            missing, unexpected = multiset_difference(expected_messages,
                                                      received_messages)
            if missing:
                msg.append('\nExpected in testdata:')
                msg.extend(' %3d: %s' % msg for msg in sorted(missing))
            if unexpected:
                msg.append('\nUnexpected in testdata:')
                msg.extend(' %3d: %s' % msg for msg in sorted(unexpected))
>           pytest.fail('\n'.join(msg))
E           Failed: Wrong results for file "useless_object_inheritance":
E           
E           Unexpected in testdata:
E              6: unused-import
pylint/test/test_functional.py:322: Failed
________________________ test_good_comprehension_checks ________________________
    def test_good_comprehension_checks():
        [data for data in range(100)]
        [data for data in range(100) if data]
>       [data for data in range(100) if len(data)]
/builddir/build/BUILD/pylint-2.0.0/pylint/test/functional/using_constant_test.py:135: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
.0 = <range_iterator object at 0x7fea50604240>
>   [data for data in range(100) if len(data)]
E   TypeError: object of type 'int' has no len()
/builddir/build/BUILD/pylint-2.0.0/pylint/test/functional/using_constant_test.py:135: TypeError
============== 2 failed, 833 passed, 38 skipped in 256.88 seconds ==============

Python: 3.7.0
astroid: 2.0
pylint: 2.0.0
pytest: 3.6.3

Any idea on this?

Greetings,
Christian

[brycepg]

Could you post the command you used to execute the tests?

I can only reproduce one of these test failures (plus more) when executing the test directory directly from pylint installed in site-packages: pytest ~/envs/pylint2.0/lib/python3.6/site-packages/pylint/test

[PCManticore]

I think Bryce is right. I cannot reproduce the unused-import error though, but the TypeError reproduces just fine, and it is the result of pytest loading that file instead of being picked by the pylint test scaffold.

[lupinix]

The command is

python3 -m pytest -v

executed in source directory, not in site-packages.

[felixonmars]

I got only 1 failure on Arch's clean chroot with identical versions of the above dependencies:

=================================== FAILURES ===================================
_________________ test_functional[useless_object_inheritance] __________________

test_file = <test_functional.FunctionalTestFile object at 0x7f568c2c6be0>

    @pytest.mark.parametrize("test_file", TESTS, ids=TESTS_NAMES)
    def test_functional(test_file):
        LintTest = LintModuleOutputUpdate(test_file) if UPDATE else LintModuleTest(test_file)
        LintTest.setUp()
>       LintTest._runTest()

pylint/test/test_functional.py:378:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <test_functional.LintModuleTest object at 0x7f5688337da0>

    def _runTest(self):
        self._linter.check([self._test_file.module])

        expected_messages, expected_text = self._get_expected()
        received_messages, received_text = self._get_received()

        if expected_messages != received_messages:
            msg = ['Wrong results for file "%s":' % (self._test_file.base)]
            missing, unexpected = multiset_difference(expected_messages,
                                                      received_messages)
            if missing:
                msg.append('\nExpected in testdata:')
                msg.extend(' %3d: %s' % msg for msg in sorted(missing))
            if unexpected:
                msg.append('\nUnexpected in testdata:')
                msg.extend(' %3d: %s' % msg for msg in sorted(unexpected))
>           pytest.fail('\n'.join(msg))
E           Failed: Wrong results for file "useless_object_inheritance":
E
E           Unexpected in testdata:
E              6: unused-import

pylint/test/test_functional.py:322: Failed
====== 1 failed, 957 passed, 70 skipped, 201 deselected in 34.95 seconds =======

[felixonmars]

Note that I don't get the error with Python 3.6 and others unchanged. This should be related to Python 3.7 only.

[PCManticore]

Hi @lupinix This should now be fixed in pylint's master with d13c8c6. Long story short, it was caused by abc having a Python implementation with a different name, messing up a couple of our checks. We'll do another 2.1 release this week with a couple of fixes that addresses some 2.0 faults.

[lupinix]

I confirm it is fixed in 2.1.0, thanks!