Feature implementation from commits 7f8f40c..9f8af01

importlib_metadata/__init__.py

@@ -22,11 +22,12 @@
 import sys
 import textwrap
 import types
+from collections.abc import Iterable, Mapping
 from contextlib import suppress
 from importlib import import_module
 from importlib.abc import MetaPathFinder
 from itertools import starmap
-from typing import Any, Iterable, List, Mapping, Match, Optional, Set, cast
+from typing import Any, cast
 
 from . import _meta
 from ._collections import FreezableDefaultDict, Pair
@@ -133,6 +134,12 @@ def valid(line: str):
         return line and not line.startswith('#')
 
 
+class _EntryPointMatch(types.SimpleNamespace):
+    module: str
+    attr: str
+    extras: str
+
+
 class EntryPoint:
     """An entry point as defined by Python packaging conventions.
 
@@ -148,6 +155,30 @@ class EntryPoint:
     'attr'
     >>> ep.extras
     ['extra1', 'extra2']
+
+    If the value package or module are not valid identifiers, a
+    ValueError is raised on access.
+
+    >>> EntryPoint(name=None, group=None, value='invalid-name').module
+    Traceback (most recent call last):
+    ...
+    ValueError: ('Invalid object reference...invalid-name...
+    >>> EntryPoint(name=None, group=None, value='invalid-name').attr
+    Traceback (most recent call last):
+    ...
+    ValueError: ('Invalid object reference...invalid-name...
+    >>> EntryPoint(name=None, group=None, value='invalid-name').extras
+    Traceback (most recent call last):
+    ...
+    ValueError: ('Invalid object reference...invalid-name...
+
+    The same thing happens on construction.
+
+    >>> EntryPoint(name=None, group=None, value='invalid-name')
+    Traceback (most recent call last):
+    ...
+    ValueError: ('Invalid object reference...invalid-name...
+
     """
 
     pattern = re.compile(
@@ -175,38 +206,44 @@ class EntryPoint:
     value: str
     group: str
 
-    dist: Optional[Distribution] = None
+    dist: Distribution | None = None
 
     def __init__(self, name: str, value: str, group: str) -> None:
         vars(self).update(name=name, value=value, group=group)
+        self.module
 
     def load(self) -> Any:
         """Load the entry point from its definition. If only a module
         is indicated by the value, return that module. Otherwise,
         return the named object.
         """
-        match = cast(Match, self.pattern.match(self.value))
-        module = import_module(match.group('module'))
-        attrs = filter(None, (match.group('attr') or '').split('.'))
+        module = import_module(self.module)
+        attrs = filter(None, (self.attr or '').split('.'))
         return functools.reduce(getattr, attrs, module)
 
     @property
     def module(self) -> str:
-        match = self.pattern.match(self.value)
-        assert match is not None
-        return match.group('module')
+        return self._match.module
 
     @property
     def attr(self) -> str:
-        match = self.pattern.match(self.value)
-        assert match is not None
-        return match.group('attr')
+        return self._match.attr
 
     @property
-    def extras(self) -> List[str]:
+    def extras(self) -> list[str]:
+        return re.findall(r'\w+', self._match.extras or '')
+
+    @functools.cached_property
+    def _match(self) -> _EntryPointMatch:
         match = self.pattern.match(self.value)
-        assert match is not None
-        return re.findall(r'\w+', match.group('extras') or '')
+        if not match:
+            raise ValueError(
+                'Invalid object reference. '
+                'See https://packaging.python.org'
+                '/en/latest/specifications/entry-points/#data-model',
+                self.value,
+            )
+        return _EntryPointMatch(**match.groupdict())
 
     def _for(self, dist):
         vars(self).update(dist=dist)
@@ -305,14 +342,14 @@ def select(self, **params) -> EntryPoints:
         return EntryPoints(ep for ep in self if py39.ep_matches(ep, **params))
 
     @property
-    def names(self) -> Set[str]:
+    def names(self) -> set[str]:
         """
         Return the set of all names of all entry points.
         """
         return {ep.name for ep in self}
 
     @property
-    def groups(self) -> Set[str]:
+    def groups(self) -> set[str]:
         """
         Return the set of all groups of all entry points.
         """
@@ -333,7 +370,7 @@ def _from_text(text):
 class PackagePath(pathlib.PurePosixPath):
     """A reference to a path in a package"""
 
-    hash: Optional[FileHash]
+    hash: FileHash | None
     size: int
     dist: Distribution
 
@@ -368,7 +405,7 @@ class Distribution(metaclass=abc.ABCMeta):
     """
 
     @abc.abstractmethod
-    def read_text(self, filename) -> Optional[str]:
+    def read_text(self, filename) -> str | None:
         """Attempt to load metadata file given by the name.
 
         Python distribution metadata is organized by blobs of text
@@ -428,7 +465,7 @@ def from_name(cls, name: str) -> Distribution:
 
     @classmethod
     def discover(
-        cls, *, context: Optional[DistributionFinder.Context] = None, **kwargs
+        cls, *, context: DistributionFinder.Context | None = None, **kwargs
     ) -> Iterable[Distribution]:
         """Return an iterable of Distribution objects for all packages.
 
@@ -524,7 +561,7 @@ def entry_points(self) -> EntryPoints:
         return EntryPoints._from_text_for(self.read_text('entry_points.txt'), self)
 
     @property
-    def files(self) -> Optional[List[PackagePath]]:
+    def files(self) -> list[PackagePath] | None:
         """Files in this distribution.
 
         :return: List of PackagePath for this distribution or None
@@ -616,7 +653,7 @@ def _read_files_egginfo_sources(self):
         return text and map('"{}"'.format, text.splitlines())
 
     @property
-    def requires(self) -> Optional[List[str]]:
+    def requires(self) -> list[str] | None:
         """Generated requirements specified for this Distribution"""
         reqs = self._read_dist_info_reqs() or self._read_egg_info_reqs()
         return reqs and list(reqs)
@@ -722,7 +759,7 @@ def __init__(self, **kwargs):
             vars(self).update(kwargs)
 
         @property
-        def path(self) -> List[str]:
+        def path(self) -> list[str]:
             """
             The sequence of directory path that a distribution finder
             should search.
@@ -874,7 +911,7 @@ class Prepared:
     normalized = None
     legacy_normalized = None
 
-    def __init__(self, name: Optional[str]):
+    def __init__(self, name: str | None):
         self.name = name
         if name is None:
             return
@@ -944,7 +981,7 @@ def __init__(self, path: SimplePath) -> None:
         """
         self._path = path
 
-    def read_text(self, filename: str | os.PathLike[str]) -> Optional[str]:
+    def read_text(self, filename: str | os.PathLike[str]) -> str | None:
         with suppress(
             FileNotFoundError,
             IsADirectoryError,
@@ -1051,7 +1088,7 @@ def entry_points(**params) -> EntryPoints:
     return EntryPoints(eps).select(**params)
 
 
-def files(distribution_name: str) -> Optional[List[PackagePath]]:
+def files(distribution_name: str) -> list[PackagePath] | None:
     """Return a list of files for the named package.
 
     :param distribution_name: The name of the distribution package to query.
@@ -1060,7 +1097,7 @@ def files(distribution_name: str) -> Optional[List[PackagePath]]:
     return distribution(distribution_name).files
 
 
-def requires(distribution_name: str) -> Optional[List[str]]:
+def requires(distribution_name: str) -> list[str] | None:
     """
     Return a list of requirements for the named package.
 
@@ -1070,7 +1107,7 @@ def requires(distribution_name: str) -> Optional[List[str]]:
     return distribution(distribution_name).requires
 
 
-def packages_distributions() -> Mapping[str, List[str]]:
+def packages_distributions() -> Mapping[str, list[str]]:
     """
     Return a mapping of top-level packages to their
     distributions.
@@ -1091,7 +1128,7 @@ def _top_level_declared(dist):
     return (dist.read_text('top_level.txt') or '').split()
 
 
-def _topmost(name: PackagePath) -> Optional[str]:
+def _topmost(name: PackagePath) -> str | None:
     """
     Return the top-most parent as long as there is a parent.
     """

importlib_metadata/_collections.py

@@ -1,4 +1,5 @@
 import collections
+import typing
 
 
 # from jaraco.collections 3.3
@@ -24,7 +25,10 @@ def freeze(self):
         self._frozen = lambda key: self.default_factory()
 
 
-class Pair(collections.namedtuple('Pair', 'name value')):
+class Pair(typing.NamedTuple):
+    name: str
+    value: str
+
     @classmethod
     def parse(cls, text):
         return cls(*map(str.strip, text.split("=", 1)))

importlib_metadata/_meta.py

@@ -1,15 +1,11 @@
 from __future__ import annotations
 
 import os
+from collections.abc import Iterator
 from typing import (
     Any,
-    Dict,
-    Iterator,
-    List,
-    Optional,
     Protocol,
     TypeVar,
-    Union,
     overload,
 )
 
@@ -28,25 +24,25 @@ def __iter__(self) -> Iterator[str]: ...  # pragma: no cover
     @overload
     def get(
         self, name: str, failobj: None = None
-    ) -> Optional[str]: ...  # pragma: no cover
+    ) -> str | None: ...  # pragma: no cover
 
     @overload
-    def get(self, name: str, failobj: _T) -> Union[str, _T]: ...  # pragma: no cover
+    def get(self, name: str, failobj: _T) -> str | _T: ...  # pragma: no cover
 
     # overload per python/importlib_metadata#435
     @overload
     def get_all(
         self, name: str, failobj: None = None
-    ) -> Optional[List[Any]]: ...  # pragma: no cover
+    ) -> list[Any] | None: ...  # pragma: no cover
 
     @overload
-    def get_all(self, name: str, failobj: _T) -> Union[List[Any], _T]:
+    def get_all(self, name: str, failobj: _T) -> list[Any] | _T:
         """
         Return all values associated with a possibly multi-valued key.
         """
 
     @property
-    def json(self) -> Dict[str, Union[str, List[str]]]:
+    def json(self) -> dict[str, str | list[str]]:
         """
         A JSON-compatible form of the metadata.
         """
@@ -58,11 +54,11 @@ class SimplePath(Protocol):
     """
 
     def joinpath(
-        self, other: Union[str, os.PathLike[str]]
+        self, other: str | os.PathLike[str]
     ) -> SimplePath: ...  # pragma: no cover
 
     def __truediv__(
-        self, other: Union[str, os.PathLike[str]]
+        self, other: str | os.PathLike[str]
     ) -> SimplePath: ...  # pragma: no cover
 
     @property

importlib_metadata/compat/py39.py

@@ -2,7 +2,9 @@
 Compatibility layer with Python 3.8/3.9
 """
 
-from typing import TYPE_CHECKING, Any, Optional
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any
 
 if TYPE_CHECKING:  # pragma: no cover
     # Prevent circular imports on runtime.
@@ -11,7 +13,7 @@
     Distribution = EntryPoint = Any
 
 
-def normalized_name(dist: Distribution) -> Optional[str]:
+def normalized_name(dist: Distribution) -> str | None:
     """
     Honor name normalization for distributions that don't provide ``_normalized_name``.
     """

tests/_path.py

@@ -4,7 +4,8 @@
 
 import functools
 import pathlib
-from typing import TYPE_CHECKING, Mapping, Protocol, Union, runtime_checkable
+from collections.abc import Mapping
+from typing import TYPE_CHECKING, Protocol, Union, runtime_checkable
 
 if TYPE_CHECKING:
     from typing_extensions import Self