diff options
Diffstat (limited to 'Lib/test')
| -rw-r--r-- | Lib/test/test_importlib/test_util.py | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py index d615375..ac18e5c 100644 --- a/Lib/test/test_importlib/test_util.py +++ b/Lib/test/test_importlib/test_util.py @@ -4,6 +4,7 @@ init = util.import_importlib('importlib') machinery = util.import_importlib('importlib.machinery') importlib_util = util.import_importlib('importlib.util') +import importlib.util import os import pathlib import string @@ -757,5 +758,48 @@ class PEP3147Tests: ) = util.test_both(PEP3147Tests, util=importlib_util) +class MagicNumberTests(unittest.TestCase): + """ + Test release compatibility issues relating to importlib + """ + @unittest.skipUnless( + sys.version_info.releaselevel in ('final', 'release'), + 'only applies to candidate or final python release levels' + ) + def test_magic_number(self): + """ + Each python minor release should generally have a MAGIC_NUMBER + that does not change once the release reaches candidate status. + + Once a release reaches candidate status, the value of the constant + EXPECTED_MAGIC_NUMBER in this test should be changed. + This test will then check that the actual MAGIC_NUMBER matches + the expected value for the release. + + In exceptional cases, it may be required to change the MAGIC_NUMBER + for a maintenance release. In this case the change should be + discussed in python-dev. If a change is required, community + stakeholders such as OS package maintainers must be notified + in advance. Such exceptional releases will then require an + adjustment to this test case. + """ + EXPECTED_MAGIC_NUMBER = 3379 + actual = int.from_bytes(importlib.util.MAGIC_NUMBER[:2], 'little') + + msg = ( + "To avoid breaking backwards compatibility with cached bytecode " + "files that can't be automatically regenerated by the current " + "user, candidate and final releases require the current " + "importlib.util.MAGIC_NUMBER to match the expected " + "magic number in this test. Set the expected " + "magic number in this test to the current MAGIC_NUMBER to " + "continue with the release.\n\n" + "Changing the MAGIC_NUMBER for a maintenance release " + "requires discussion in python-dev and notification of " + "community stakeholders." + ) + self.assertEqual(EXPECTED_MAGIC_NUMBER, actual, msg) + + if __name__ == '__main__': unittest.main() |