Apply changes from importlib_metadata 6.5.0

Author: jaraco

Lib/importlib/metadata/__init__.py

@@ -343,7 +343,26 @@ def __repr__(self):
         return f'<FileHash mode: {self.mode} value: {self.value}>'
 
 
-class Distribution(metaclass=abc.ABCMeta):
+class DeprecatedNonAbstract:
+    def __new__(cls, *args, **kwargs):
+        all_names = {
+            name for subclass in inspect.getmro(cls) for name in vars(subclass)
+        }
+        abstract = {
+            name
+            for name in all_names
+            if getattr(getattr(cls, name), '__isabstractmethod__', False)
+        }
+        if abstract:
+            warnings.warn(
+                f"Unimplemented abstract methods {abstract}",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+        return super().__new__(cls)
+
+
+class Distribution(DeprecatedNonAbstract):
     """A Python distribution package."""
 
     @abc.abstractmethod

Lib/test/test_importlib/test_main.py

@@ -1,7 +1,9 @@
 import re
 import pickle
 import unittest
+import warnings
 import importlib.metadata
+import contextlib
 import itertools
 
 try:
@@ -10,6 +12,7 @@
     from .stubs import fake_filesystem_unittest as ffs
 
 from . import fixtures
+from ._context import suppress
 from importlib.metadata import (
     Distribution,
     EntryPoint,
@@ -23,6 +26,13 @@
 )
 
 
+@contextlib.contextmanager
+def suppress_known_deprecation():
+    with warnings.catch_warnings(record=True) as ctx:
+        warnings.simplefilter('default', category=DeprecationWarning)
+        yield ctx
+
+
 class BasicTests(fixtures.DistInfoPkg, unittest.TestCase):
     version_pattern = r'\d+\.\d+(\.\d)?'
 
@@ -47,6 +57,9 @@ def test_package_not_found_mentions_metadata(self):
 
         assert "metadata" in str(ctx.exception)
 
+    # expected to fail until ABC is enforced
+    @suppress(AssertionError)
+    @suppress_known_deprecation()
     def test_abc_enforced(self):
         with self.assertRaises(TypeError):
             type('DistributionSubclass', (Distribution,), {})()

Misc/NEWS.d/next/Library/2023-04-16-19-48-21.gh-issue-103584.3mBTuM.rst

@@ -1,12 +1,12 @@
 Updated ``importlib.metadata`` with changes from ``importlib_metadata`` 5.2
-through 6.4.1, including: Support ``installed-files.txt`` for
+through 6.5.0, including: Support ``installed-files.txt`` for
 ``Distribution.files`` when present. ``PackageMetadata`` now stipulates an
 additional ``get`` method allowing for easy querying of metadata keys that
 may not be present. ``packages_distributions`` now honors packages and
 modules with Python modules that not ``.py`` sources (e.g. ``.pyc``,
 ``.so``). Expand protocol for ``PackageMetadata.get_all`` to match the
 upstream implementation of ``email.message.Message.get_all`` in
-python/typeshed#9620. Declared ``Distribution`` as an abstract class,
-enforcing definition of abstract methods in instantiated subclasses.
-Deprecated expectation that ``PackageMetadata.__getitem__`` will return
-``None`` for missing keys. In the future, it will raise a ``KeyError``.
+python/typeshed#9620. Deprecated use of ``Distribution`` without defining
+abstract methods. Deprecated expectation that
+``PackageMetadata.__getitem__`` will return ``None`` for missing keys. In
+the future, it will raise a ``KeyError``.