Revert "Remove importlib-metadata and importlib-resources"

This reverts commit 38435ae81c.

lib/importlib_metadata/__init__.py

@@ -0,0 +1,904 @@
+import os
+import re
+import abc
+import csv
+import sys
+import zipp
+import email
+import pathlib
+import operator
+import textwrap
+import warnings
+import functools
+import itertools
+import posixpath
+import collections
+
+from . import _adapters, _meta, _py39compat
+from ._collections import FreezableDefaultDict, Pair
+from ._compat import (
+    NullFinder,
+    install,
+    pypy_partial,
+)
+from ._functools import method_cache, pass_none
+from ._itertools import always_iterable, unique_everseen
+from ._meta import PackageMetadata, SimplePath
+
+from contextlib import suppress
+from importlib import import_module
+from importlib.abc import MetaPathFinder
+from itertools import starmap
+from typing import List, Mapping, Optional
+
+
+__all__ = [
+    'Distribution',
+    'DistributionFinder',
+    'PackageMetadata',
+    'PackageNotFoundError',
+    'distribution',
+    'distributions',
+    'entry_points',
+    'files',
+    'metadata',
+    'packages_distributions',
+    'requires',
+    'version',
+]
+
+
+class PackageNotFoundError(ModuleNotFoundError):
+    """The package was not found."""
+
+    def __str__(self):
+        return f"No package metadata was found for {self.name}"
+
+    @property
+    def name(self):
+        (name,) = self.args
+        return name
+
+
+class Sectioned:
+    """
+    A simple entry point config parser for performance
+
+    >>> for item in Sectioned.read(Sectioned._sample):
+    ...     print(item)
+    Pair(name='sec1', value='# comments ignored')
+    Pair(name='sec1', value='a = 1')
+    Pair(name='sec1', value='b = 2')
+    Pair(name='sec2', value='a = 2')
+
+    >>> res = Sectioned.section_pairs(Sectioned._sample)
+    >>> item = next(res)
+    >>> item.name
+    'sec1'
+    >>> item.value
+    Pair(name='a', value='1')
+    >>> item = next(res)
+    >>> item.value
+    Pair(name='b', value='2')
+    >>> item = next(res)
+    >>> item.name
+    'sec2'
+    >>> item.value
+    Pair(name='a', value='2')
+    >>> list(res)
+    []
+    """
+
+    _sample = textwrap.dedent(
+        """
+        [sec1]
+        # comments ignored
+        a = 1
+        b = 2
+
+        [sec2]
+        a = 2
+        """
+    ).lstrip()
+
+    @classmethod
+    def section_pairs(cls, text):
+        return (
+            section._replace(value=Pair.parse(section.value))
+            for section in cls.read(text, filter_=cls.valid)
+            if section.name is not None
+        )
+
+    @staticmethod
+    def read(text, filter_=None):
+        lines = filter(filter_, map(str.strip, text.splitlines()))
+        name = None
+        for value in lines:
+            section_match = value.startswith('[') and value.endswith(']')
+            if section_match:
+                name = value.strip('[]')
+                continue
+            yield Pair(name, value)
+
+    @staticmethod
+    def valid(line):
+        return line and not line.startswith('#')
+
+
+class DeprecatedTuple:
+    """
+    Provide subscript item access for backward compatibility.
+
+    >>> recwarn = getfixture('recwarn')
+    >>> ep = EntryPoint(name='name', value='value', group='group')
+    >>> ep[:]
+    ('name', 'value', 'group')
+    >>> ep[0]
+    'name'
+    >>> len(recwarn)
+    1
+    """
+
+    # Do not remove prior to 2023-05-01 or Python 3.13
+    _warn = functools.partial(
+        warnings.warn,
+        "EntryPoint tuple interface is deprecated. Access members by name.",
+        DeprecationWarning,
+        stacklevel=pypy_partial(2),
+    )
+
+    def __getitem__(self, item):
+        self._warn()
+        return self._key()[item]
+
+
+class EntryPoint(DeprecatedTuple):
+    """An entry point as defined by Python packaging conventions.
+
+    See `the packaging docs on entry points
+    <https://packaging.python.org/specifications/entry-points/>`_
+    for more information.
+
+    >>> ep = EntryPoint(
+    ...     name=None, group=None, value='package.module:attr [extra1, extra2]')
+    >>> ep.module
+    'package.module'
+    >>> ep.attr
+    'attr'
+    >>> ep.extras
+    ['extra1', 'extra2']
+    """
+
+    pattern = re.compile(
+        r'(?P<module>[\w.]+)\s*'
+        r'(:\s*(?P<attr>[\w.]+)\s*)?'
+        r'((?P<extras>\[.*\])\s*)?$'
+    )
+    """
+    A regular expression describing the syntax for an entry point,
+    which might look like:
+
+        - module
+        - package.module
+        - package.module:attribute
+        - package.module:object.attribute
+        - package.module:attr [extra1, extra2]
+
+    Other combinations are possible as well.
+
+    The expression is lenient about whitespace around the ':',
+    following the attr, and following any extras.
+    """
+
+    name: str
+    value: str
+    group: str
+
+    dist: Optional['Distribution'] = None
+
+    def __init__(self, name, value, group):
+        vars(self).update(name=name, value=value, group=group)
+
+    def load(self):
+        """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 = self.pattern.match(self.value)
+        module = import_module(match.group('module'))
+        attrs = filter(None, (match.group('attr') or '').split('.'))
+        return functools.reduce(getattr, attrs, module)
+
+    @property
+    def module(self):
+        match = self.pattern.match(self.value)
+        return match.group('module')
+
+    @property
+    def attr(self):
+        match = self.pattern.match(self.value)
+        return match.group('attr')
+
+    @property
+    def extras(self):
+        match = self.pattern.match(self.value)
+        return re.findall(r'\w+', match.group('extras') or '')
+
+    def _for(self, dist):
+        vars(self).update(dist=dist)
+        return self
+
+    def matches(self, **params):
+        """
+        EntryPoint matches the given parameters.
+
+        >>> ep = EntryPoint(group='foo', name='bar', value='bing:bong [extra1, extra2]')
+        >>> ep.matches(group='foo')
+        True
+        >>> ep.matches(name='bar', value='bing:bong [extra1, extra2]')
+        True
+        >>> ep.matches(group='foo', name='other')
+        False
+        >>> ep.matches()
+        True
+        >>> ep.matches(extras=['extra1', 'extra2'])
+        True
+        >>> ep.matches(module='bing')
+        True
+        >>> ep.matches(attr='bong')
+        True
+        """
+        attrs = (getattr(self, param) for param in params)
+        return all(map(operator.eq, params.values(), attrs))
+
+    def _key(self):
+        return self.name, self.value, self.group
+
+    def __lt__(self, other):
+        return self._key() < other._key()
+
+    def __eq__(self, other):
+        return self._key() == other._key()
+
+    def __setattr__(self, name, value):
+        raise AttributeError("EntryPoint objects are immutable.")
+
+    def __repr__(self):
+        return (
+            f'EntryPoint(name={self.name!r}, value={self.value!r}, '
+            f'group={self.group!r})'
+        )
+
+    def __hash__(self):
+        return hash(self._key())
+
+
+class EntryPoints(tuple):
+    """
+    An immutable collection of selectable EntryPoint objects.
+    """
+
+    __slots__ = ()
+
+    def __getitem__(self, name):  # -> EntryPoint:
+        """
+        Get the EntryPoint in self matching name.
+        """
+        try:
+            return next(iter(self.select(name=name)))
+        except StopIteration:
+            raise KeyError(name)
+
+    def select(self, **params):
+        """
+        Select entry points from self that match the
+        given parameters (typically group and/or name).
+        """
+        return EntryPoints(ep for ep in self if _py39compat.ep_matches(ep, **params))
+
+    @property
+    def names(self):
+        """
+        Return the set of all names of all entry points.
+        """
+        return {ep.name for ep in self}
+
+    @property
+    def groups(self):
+        """
+        Return the set of all groups of all entry points.
+        """
+        return {ep.group for ep in self}
+
+    @classmethod
+    def _from_text_for(cls, text, dist):
+        return cls(ep._for(dist) for ep in cls._from_text(text))
+
+    @staticmethod
+    def _from_text(text):
+        return (
+            EntryPoint(name=item.value.name, value=item.value.value, group=item.name)
+            for item in Sectioned.section_pairs(text or '')
+        )
+
+
+class PackagePath(pathlib.PurePosixPath):
+    """A reference to a path in a package"""
+
+    def read_text(self, encoding='utf-8'):
+        with self.locate().open(encoding=encoding) as stream:
+            return stream.read()
+
+    def read_binary(self):
+        with self.locate().open('rb') as stream:
+            return stream.read()
+
+    def locate(self):
+        """Return a path-like object for this path"""
+        return self.dist.locate_file(self)
+
+
+class FileHash:
+    def __init__(self, spec):
+        self.mode, _, self.value = spec.partition('=')
+
+    def __repr__(self):
+        return f'<FileHash mode: {self.mode} value: {self.value}>'
+
+
+class Distribution(metaclass=abc.ABCMeta):
+    """A Python distribution package."""
+
+    @abc.abstractmethod
+    def read_text(self, filename):
+        """Attempt to load metadata file given by the name.
+
+        :param filename: The name of the file in the distribution info.
+        :return: The text if found, otherwise None.
+        """
+
+    @abc.abstractmethod
+    def locate_file(self, path):
+        """
+        Given a path to a file in this distribution, return a path
+        to it.
+        """
+
+    @classmethod
+    def from_name(cls, name: str):
+        """Return the Distribution for the given package name.
+
+        :param name: The name of the distribution package to search for.
+        :return: The Distribution instance (or subclass thereof) for the named
+            package, if found.
+        :raises PackageNotFoundError: When the named package's distribution
+            metadata cannot be found.
+        :raises ValueError: When an invalid value is supplied for name.
+        """
+        if not name:
+            raise ValueError("A distribution name is required.")
+        try:
+            return next(cls.discover(name=name))
+        except StopIteration:
+            raise PackageNotFoundError(name)
+
+    @classmethod
+    def discover(cls, **kwargs):
+        """Return an iterable of Distribution objects for all packages.
+
+        Pass a ``context`` or pass keyword arguments for constructing
+        a context.
+
+        :context: A ``DistributionFinder.Context`` object.
+        :return: Iterable of Distribution objects for all packages.
+        """
+        context = kwargs.pop('context', None)
+        if context and kwargs:
+            raise ValueError("cannot accept context and kwargs")
+        context = context or DistributionFinder.Context(**kwargs)
+        return itertools.chain.from_iterable(
+            resolver(context) for resolver in cls._discover_resolvers()
+        )
+
+    @staticmethod
+    def at(path):
+        """Return a Distribution for the indicated metadata path
+
+        :param path: a string or path-like object
+        :return: a concrete Distribution instance for the path
+        """
+        return PathDistribution(pathlib.Path(path))
+
+    @staticmethod
+    def _discover_resolvers():
+        """Search the meta_path for resolvers."""
+        declared = (
+            getattr(finder, 'find_distributions', None) for finder in sys.meta_path
+        )
+        return filter(None, declared)
+
+    @property
+    def metadata(self) -> _meta.PackageMetadata:
+        """Return the parsed metadata for this Distribution.
+
+        The returned object will have keys that name the various bits of
+        metadata.  See PEP 566 for details.
+        """
+        text = (
+            self.read_text('METADATA')
+            or self.read_text('PKG-INFO')
+            # This last clause is here to support old egg-info files.  Its
+            # effect is to just end up using the PathDistribution's self._path
+            # (which points to the egg-info file) attribute unchanged.
+            or self.read_text('')
+        )
+        return _adapters.Message(email.message_from_string(text))
+
+    @property
+    def name(self):
+        """Return the 'Name' metadata for the distribution package."""
+        return self.metadata['Name']
+
+    @property
+    def _normalized_name(self):
+        """Return a normalized version of the name."""
+        return Prepared.normalize(self.name)
+
+    @property
+    def version(self):
+        """Return the 'Version' metadata for the distribution package."""
+        return self.metadata['Version']
+
+    @property
+    def entry_points(self):
+        return EntryPoints._from_text_for(self.read_text('entry_points.txt'), self)
+
+    @property
+    def files(self):
+        """Files in this distribution.
+
+        :return: List of PackagePath for this distribution or None
+
+        Result is `None` if the metadata file that enumerates files
+        (i.e. RECORD for dist-info or SOURCES.txt for egg-info) is
+        missing.
+        Result may be empty if the metadata exists but is empty.
+        """
+
+        def make_file(name, hash=None, size_str=None):
+            result = PackagePath(name)
+            result.hash = FileHash(hash) if hash else None
+            result.size = int(size_str) if size_str else None
+            result.dist = self
+            return result
+
+        @pass_none
+        def make_files(lines):
+            return list(starmap(make_file, csv.reader(lines)))
+
+        return make_files(self._read_files_distinfo() or self._read_files_egginfo())
+
+    def _read_files_distinfo(self):
+        """
+        Read the lines of RECORD
+        """
+        text = self.read_text('RECORD')
+        return text and text.splitlines()
+
+    def _read_files_egginfo(self):
+        """
+        SOURCES.txt might contain literal commas, so wrap each line
+        in quotes.
+        """
+        text = self.read_text('SOURCES.txt')
+        return text and map('"{}"'.format, text.splitlines())
+
+    @property
+    def requires(self):
+        """Generated requirements specified for this Distribution"""
+        reqs = self._read_dist_info_reqs() or self._read_egg_info_reqs()
+        return reqs and list(reqs)
+
+    def _read_dist_info_reqs(self):
+        return self.metadata.get_all('Requires-Dist')
+
+    def _read_egg_info_reqs(self):
+        source = self.read_text('requires.txt')
+        return pass_none(self._deps_from_requires_text)(source)
+
+    @classmethod
+    def _deps_from_requires_text(cls, source):
+        return cls._convert_egg_info_reqs_to_simple_reqs(Sectioned.read(source))
+
+    @staticmethod
+    def _convert_egg_info_reqs_to_simple_reqs(sections):
+        """
+        Historically, setuptools would solicit and store 'extra'
+        requirements, including those with environment markers,
+        in separate sections. More modern tools expect each
+        dependency to be defined separately, with any relevant
+        extras and environment markers attached directly to that
+        requirement. This method converts the former to the
+        latter. See _test_deps_from_requires_text for an example.
+        """
+
+        def make_condition(name):
+            return name and f'extra == "{name}"'
+
+        def quoted_marker(section):
+            section = section or ''
+            extra, sep, markers = section.partition(':')
+            if extra and markers:
+                markers = f'({markers})'
+            conditions = list(filter(None, [markers, make_condition(extra)]))
+            return '; ' + ' and '.join(conditions) if conditions else ''
+
+        def url_req_space(req):
+            """
+            PEP 508 requires a space between the url_spec and the quoted_marker.
+            Ref python/importlib_metadata#357.
+            """
+            # '@' is uniquely indicative of a url_req.
+            return ' ' * ('@' in req)
+
+        for section in sections:
+            space = url_req_space(section.value)
+            yield section.value + space + quoted_marker(section.name)
+
+
+class DistributionFinder(MetaPathFinder):
+    """
+    A MetaPathFinder capable of discovering installed distributions.
+    """
+
+    class Context:
+        """
+        Keyword arguments presented by the caller to
+        ``distributions()`` or ``Distribution.discover()``
+        to narrow the scope of a search for distributions
+        in all DistributionFinders.
+
+        Each DistributionFinder may expect any parameters
+        and should attempt to honor the canonical
+        parameters defined below when appropriate.
+        """
+
+        name = None
+        """
+        Specific name for which a distribution finder should match.
+        A name of ``None`` matches all distributions.
+        """
+
+        def __init__(self, **kwargs):
+            vars(self).update(kwargs)
+
+        @property
+        def path(self):
+            """
+            The sequence of directory path that a distribution finder
+            should search.
+
+            Typically refers to Python installed package paths such as
+            "site-packages" directories and defaults to ``sys.path``.
+            """
+            return vars(self).get('path', sys.path)
+
+    @abc.abstractmethod
+    def find_distributions(self, context=Context()):
+        """
+        Find distributions.
+
+        Return an iterable of all Distribution instances capable of
+        loading the metadata for packages matching the ``context``,
+        a DistributionFinder.Context instance.
+        """
+
+
+class FastPath:
+    """
+    Micro-optimized class for searching a path for
+    children.
+
+    >>> FastPath('').children()
+    ['...']
+    """
+
+    @functools.lru_cache()  # type: ignore
+    def __new__(cls, root):
+        return super().__new__(cls)
+
+    def __init__(self, root):
+        self.root = root
+
+    def joinpath(self, child):
+        return pathlib.Path(self.root, child)
+
+    def children(self):
+        with suppress(Exception):
+            return os.listdir(self.root or '.')
+        with suppress(Exception):
+            return self.zip_children()
+        return []
+
+    def zip_children(self):
+        zip_path = zipp.Path(self.root)
+        names = zip_path.root.namelist()
+        self.joinpath = zip_path.joinpath
+
+        return dict.fromkeys(child.split(posixpath.sep, 1)[0] for child in names)
+
+    def search(self, name):
+        return self.lookup(self.mtime).search(name)
+
+    @property
+    def mtime(self):
+        with suppress(OSError):
+            return os.stat(self.root).st_mtime
+        self.lookup.cache_clear()
+
+    @method_cache
+    def lookup(self, mtime):
+        return Lookup(self)
+
+
+class Lookup:
+    def __init__(self, path: FastPath):
+        base = os.path.basename(path.root).lower()
+        base_is_egg = base.endswith(".egg")
+        self.infos = FreezableDefaultDict(list)
+        self.eggs = FreezableDefaultDict(list)
+
+        for child in path.children():
+            low = child.lower()
+            if low.endswith((".dist-info", ".egg-info")):
+                # rpartition is faster than splitext and suitable for this purpose.
+                name = low.rpartition(".")[0].partition("-")[0]
+                normalized = Prepared.normalize(name)
+                self.infos[normalized].append(path.joinpath(child))
+            elif base_is_egg and low == "egg-info":
+                name = base.rpartition(".")[0].partition("-")[0]
+                legacy_normalized = Prepared.legacy_normalize(name)
+                self.eggs[legacy_normalized].append(path.joinpath(child))
+
+        self.infos.freeze()
+        self.eggs.freeze()
+
+    def search(self, prepared):
+        infos = (
+            self.infos[prepared.normalized]
+            if prepared
+            else itertools.chain.from_iterable(self.infos.values())
+        )
+        eggs = (
+            self.eggs[prepared.legacy_normalized]
+            if prepared
+            else itertools.chain.from_iterable(self.eggs.values())
+        )
+        return itertools.chain(infos, eggs)
+
+
+class Prepared:
+    """
+    A prepared search for metadata on a possibly-named package.
+    """
+
+    normalized = None
+    legacy_normalized = None
+
+    def __init__(self, name):
+        self.name = name
+        if name is None:
+            return
+        self.normalized = self.normalize(name)
+        self.legacy_normalized = self.legacy_normalize(name)
+
+    @staticmethod
+    def normalize(name):
+        """
+        PEP 503 normalization plus dashes as underscores.
+        """
+        return re.sub(r"[-_.]+", "-", name).lower().replace('-', '_')
+
+    @staticmethod
+    def legacy_normalize(name):
+        """
+        Normalize the package name as found in the convention in
+        older packaging tools versions and specs.
+        """
+        return name.lower().replace('-', '_')
+
+    def __bool__(self):
+        return bool(self.name)
+
+
+@install
+class MetadataPathFinder(NullFinder, DistributionFinder):
+    """A degenerate finder for distribution packages on the file system.
+
+    This finder supplies only a find_distributions() method for versions
+    of Python that do not have a PathFinder find_distributions().
+    """
+
+    def find_distributions(self, context=DistributionFinder.Context()):
+        """
+        Find distributions.
+
+        Return an iterable of all Distribution instances capable of
+        loading the metadata for packages matching ``context.name``
+        (or all names if ``None`` indicated) along the paths in the list
+        of directories ``context.path``.
+        """
+        found = self._search_paths(context.name, context.path)
+        return map(PathDistribution, found)
+
+    @classmethod
+    def _search_paths(cls, name, paths):
+        """Find metadata directories in paths heuristically."""
+        prepared = Prepared(name)
+        return itertools.chain.from_iterable(
+            path.search(prepared) for path in map(FastPath, paths)
+        )
+
+    def invalidate_caches(cls):
+        FastPath.__new__.cache_clear()
+
+
+class PathDistribution(Distribution):
+    def __init__(self, path: SimplePath):
+        """Construct a distribution.
+
+        :param path: SimplePath indicating the metadata directory.
+        """
+        self._path = path
+
+    def read_text(self, filename):
+        with suppress(
+            FileNotFoundError,
+            IsADirectoryError,
+            KeyError,
+            NotADirectoryError,
+            PermissionError,
+        ):
+            return self._path.joinpath(filename).read_text(encoding='utf-8')
+
+    read_text.__doc__ = Distribution.read_text.__doc__
+
+    def locate_file(self, path):
+        return self._path.parent / path
+
+    @property
+    def _normalized_name(self):
+        """
+        Performance optimization: where possible, resolve the
+        normalized name from the file system path.
+        """
+        stem = os.path.basename(str(self._path))
+        return (
+            pass_none(Prepared.normalize)(self._name_from_stem(stem))
+            or super()._normalized_name
+        )
+
+    @staticmethod
+    def _name_from_stem(stem):
+        """
+        >>> PathDistribution._name_from_stem('foo-3.0.egg-info')
+        'foo'
+        >>> PathDistribution._name_from_stem('CherryPy-3.0.dist-info')
+        'CherryPy'
+        >>> PathDistribution._name_from_stem('face.egg-info')
+        'face'
+        >>> PathDistribution._name_from_stem('foo.bar')
+        """
+        filename, ext = os.path.splitext(stem)
+        if ext not in ('.dist-info', '.egg-info'):
+            return
+        name, sep, rest = filename.partition('-')
+        return name
+
+
+def distribution(distribution_name):
+    """Get the ``Distribution`` instance for the named package.
+
+    :param distribution_name: The name of the distribution package as a string.
+    :return: A ``Distribution`` instance (or subclass thereof).
+    """
+    return Distribution.from_name(distribution_name)
+
+
+def distributions(**kwargs):
+    """Get all ``Distribution`` instances in the current environment.
+
+    :return: An iterable of ``Distribution`` instances.
+    """
+    return Distribution.discover(**kwargs)
+
+
+def metadata(distribution_name) -> _meta.PackageMetadata:
+    """Get the metadata for the named package.
+
+    :param distribution_name: The name of the distribution package to query.
+    :return: A PackageMetadata containing the parsed metadata.
+    """
+    return Distribution.from_name(distribution_name).metadata
+
+
+def version(distribution_name):
+    """Get the version string for the named package.
+
+    :param distribution_name: The name of the distribution package to query.
+    :return: The version string for the package as defined in the package's
+        "Version" metadata key.
+    """
+    return distribution(distribution_name).version
+
+
+_unique = functools.partial(
+    unique_everseen,
+    key=_py39compat.normalized_name,
+)
+"""
+Wrapper for ``distributions`` to return unique distributions by name.
+"""
+
+
+def entry_points(**params) -> EntryPoints:
+    """Return EntryPoint objects for all installed packages.
+
+    Pass selection parameters (group or name) to filter the
+    result to entry points matching those properties (see
+    EntryPoints.select()).
+
+    :return: EntryPoints for all installed packages.
+    """
+    eps = itertools.chain.from_iterable(
+        dist.entry_points for dist in _unique(distributions())
+    )
+    return EntryPoints(eps).select(**params)
+
+
+def files(distribution_name):
+    """Return a list of files for the named package.
+
+    :param distribution_name: The name of the distribution package to query.
+    :return: List of files composing the distribution.
+    """
+    return distribution(distribution_name).files
+
+
+def requires(distribution_name):
+    """
+    Return a list of requirements for the named package.
+
+    :return: An iterator of requirements, suitable for
+        packaging.requirement.Requirement.
+    """
+    return distribution(distribution_name).requires
+
+
+def packages_distributions() -> Mapping[str, List[str]]:
+    """
+    Return a mapping of top-level packages to their
+    distributions.
+
+    >>> import collections.abc
+    >>> pkgs = packages_distributions()
+    >>> all(isinstance(dist, collections.abc.Sequence) for dist in pkgs.values())
+    True
+    """
+    pkg_to_dist = collections.defaultdict(list)
+    for dist in distributions():
+        for pkg in _top_level_declared(dist) or _top_level_inferred(dist):
+            pkg_to_dist[pkg].append(dist.metadata['Name'])
+    return dict(pkg_to_dist)
+
+
+def _top_level_declared(dist):
+    return (dist.read_text('top_level.txt') or '').split()
+
+
+def _top_level_inferred(dist):
+    return {
+        f.parts[0] if len(f.parts) > 1 else f.with_suffix('').name
+        for f in always_iterable(dist.files)
+        if f.suffix == ".py"
+    }

lib/importlib_metadata/_adapters.py

@@ -0,0 +1,90 @@
+import functools
+import warnings
+import re
+import textwrap
+import email.message
+
+from ._text import FoldedCase
+from ._compat import pypy_partial
+
+
+# Do not remove prior to 2024-01-01 or Python 3.14
+_warn = functools.partial(
+    warnings.warn,
+    "Implicit None on return values is deprecated and will raise KeyErrors.",
+    DeprecationWarning,
+    stacklevel=pypy_partial(2),
+)
+
+
+class Message(email.message.Message):
+    multiple_use_keys = set(
+        map(
+            FoldedCase,
+            [
+                'Classifier',
+                'Obsoletes-Dist',
+                'Platform',
+                'Project-URL',
+                'Provides-Dist',
+                'Provides-Extra',
+                'Requires-Dist',
+                'Requires-External',
+                'Supported-Platform',
+                'Dynamic',
+            ],
+        )
+    )
+    """
+    Keys that may be indicated multiple times per PEP 566.
+    """
+
+    def __new__(cls, orig: email.message.Message):
+        res = super().__new__(cls)
+        vars(res).update(vars(orig))
+        return res
+
+    def __init__(self, *args, **kwargs):
+        self._headers = self._repair_headers()
+
+    # suppress spurious error from mypy
+    def __iter__(self):
+        return super().__iter__()
+
+    def __getitem__(self, item):
+        """
+        Warn users that a ``KeyError`` can be expected when a
+        mising key is supplied. Ref python/importlib_metadata#371.
+        """
+        res = super().__getitem__(item)
+        if res is None:
+            _warn()
+        return res
+
+    def _repair_headers(self):
+        def redent(value):
+            "Correct for RFC822 indentation"
+            if not value or '\n' not in value:
+                return value
+            return textwrap.dedent(' ' * 8 + value)
+
+        headers = [(key, redent(value)) for key, value in vars(self)['_headers']]
+        if self._payload:
+            headers.append(('Description', self.get_payload()))
+        return headers
+
+    @property
+    def json(self):
+        """
+        Convert PackageMetadata to a JSON-compatible format
+        per PEP 0566.
+        """
+
+        def transform(key):
+            value = self.get_all(key) if key in self.multiple_use_keys else self[key]
+            if key == 'Keywords':
+                value = re.split(r'\s+', value)
+            tk = key.lower().replace('-', '_')
+            return tk, value
+
+        return dict(map(transform, map(FoldedCase, self)))

lib/importlib_metadata/_collections.py

@@ -0,0 +1,30 @@
+import collections
+
+
+# from jaraco.collections 3.3
+class FreezableDefaultDict(collections.defaultdict):
+    """
+    Often it is desirable to prevent the mutation of
+    a default dict after its initial construction, such
+    as to prevent mutation during iteration.
+
+    >>> dd = FreezableDefaultDict(list)
+    >>> dd[0].append('1')
+    >>> dd.freeze()
+    >>> dd[1]
+    []
+    >>> len(dd)
+    1
+    """
+
+    def __missing__(self, key):
+        return getattr(self, '_frozen', super().__missing__)(key)
+
+    def freeze(self):
+        self._frozen = lambda key: self.default_factory()
+
+
+class Pair(collections.namedtuple('Pair', 'name value')):
+    @classmethod
+    def parse(cls, text):
+        return cls(*map(str.strip, text.split("=", 1)))

lib/importlib_metadata/_compat.py

@@ -0,0 +1,72 @@
+import sys
+import platform
+
+
+__all__ = ['install', 'NullFinder', 'Protocol']
+
+
+try:
+    from typing import Protocol
+except ImportError:  # pragma: no cover
+    # Python 3.7 compatibility
+    from typing_extensions import Protocol  # type: ignore
+
+
+def install(cls):
+    """
+    Class decorator for installation on sys.meta_path.
+
+    Adds the backport DistributionFinder to sys.meta_path and
+    attempts to disable the finder functionality of the stdlib
+    DistributionFinder.
+    """
+    sys.meta_path.append(cls())
+    disable_stdlib_finder()
+    return cls
+
+
+def disable_stdlib_finder():
+    """
+    Give the backport primacy for discovering path-based distributions
+    by monkey-patching the stdlib O_O.
+
+    See #91 for more background for rationale on this sketchy
+    behavior.
+    """
+
+    def matches(finder):
+        return getattr(
+            finder, '__module__', None
+        ) == '_frozen_importlib_external' and hasattr(finder, 'find_distributions')
+
+    for finder in filter(matches, sys.meta_path):  # pragma: nocover
+        del finder.find_distributions
+
+
+class NullFinder:
+    """
+    A "Finder" (aka "MetaClassFinder") that never finds any modules,
+    but may find distributions.
+    """
+
+    @staticmethod
+    def find_spec(*args, **kwargs):
+        return None
+
+    # In Python 2, the import system requires finders
+    # to have a find_module() method, but this usage
+    # is deprecated in Python 3 in favor of find_spec().
+    # For the purposes of this finder (i.e. being present
+    # on sys.meta_path but having no other import
+    # system functionality), the two methods are identical.
+    find_module = find_spec
+
+
+def pypy_partial(val):
+    """
+    Adjust for variable stacklevel on partial under PyPy.
+
+    Workaround for #327.
+    """
+    is_pypy = platform.python_implementation() == 'PyPy'
+    return val + is_pypy

lib/importlib_metadata/_functools.py

@@ -0,0 +1,104 @@
+import types
+import functools
+
+
+# from jaraco.functools 3.3
+def method_cache(method, cache_wrapper=None):
+    """
+    Wrap lru_cache to support storing the cache data in the object instances.
+
+    Abstracts the common paradigm where the method explicitly saves an
+    underscore-prefixed protected property on first call and returns that
+    subsequently.
+
+    >>> class MyClass:
+    ...     calls = 0
+    ...
+    ...     @method_cache
+    ...     def method(self, value):
+    ...         self.calls += 1
+    ...         return value
+
+    >>> a = MyClass()
+    >>> a.method(3)
+    3
+    >>> for x in range(75):
+    ...     res = a.method(x)
+    >>> a.calls
+    75
+
+    Note that the apparent behavior will be exactly like that of lru_cache
+    except that the cache is stored on each instance, so values in one
+    instance will not flush values from another, and when an instance is
+    deleted, so are the cached values for that instance.
+
+    >>> b = MyClass()
+    >>> for x in range(35):
+    ...     res = b.method(x)
+    >>> b.calls
+    35
+    >>> a.method(0)
+    0
+    >>> a.calls
+    75
+
+    Note that if method had been decorated with ``functools.lru_cache()``,
+    a.calls would have been 76 (due to the cached value of 0 having been
+    flushed by the 'b' instance).
+
+    Clear the cache with ``.cache_clear()``
+
+    >>> a.method.cache_clear()
+
+    Same for a method that hasn't yet been called.
+
+    >>> c = MyClass()
+    >>> c.method.cache_clear()
+
+    Another cache wrapper may be supplied:
+
+    >>> cache = functools.lru_cache(maxsize=2)
+    >>> MyClass.method2 = method_cache(lambda self: 3, cache_wrapper=cache)
+    >>> a = MyClass()
+    >>> a.method2()
+    3
+
+    Caution - do not subsequently wrap the method with another decorator, such
+    as ``@property``, which changes the semantics of the function.
+
+    See also
+    http://code.activestate.com/recipes/577452-a-memoize-decorator-for-instance-methods/
+    for another implementation and additional justification.
+    """
+    cache_wrapper = cache_wrapper or functools.lru_cache()
+
+    def wrapper(self, *args, **kwargs):
+        # it's the first call, replace the method with a cached, bound method
+        bound_method = types.MethodType(method, self)
+        cached_method = cache_wrapper(bound_method)
+        setattr(self, method.__name__, cached_method)
+        return cached_method(*args, **kwargs)
+
+    # Support cache clear even before cache has been created.
+    wrapper.cache_clear = lambda: None
+
+    return wrapper
+
+
+# From jaraco.functools 3.3
+def pass_none(func):
+    """
+    Wrap func so it's not called if its first param is None
+
+    >>> print_text = pass_none(print)
+    >>> print_text('text')
+    text
+    >>> print_text(None)
+    """
+
+    @functools.wraps(func)
+    def wrapper(param, *args, **kwargs):
+        if param is not None:
+            return func(param, *args, **kwargs)
+
+    return wrapper

lib/importlib_metadata/_itertools.py

@@ -0,0 +1,73 @@
+from itertools import filterfalse
+
+
+def unique_everseen(iterable, key=None):
+    "List unique elements, preserving order. Remember all elements ever seen."
+    # unique_everseen('AAAABBBCCDAABBB') --> A B C D
+    # unique_everseen('ABBCcAD', str.lower) --> A B C D
+    seen = set()
+    seen_add = seen.add
+    if key is None:
+        for element in filterfalse(seen.__contains__, iterable):
+            seen_add(element)
+            yield element
+    else:
+        for element in iterable:
+            k = key(element)
+            if k not in seen:
+                seen_add(k)
+                yield element
+
+
+# copied from more_itertools 8.8
+def always_iterable(obj, base_type=(str, bytes)):
+    """If *obj* is iterable, return an iterator over its items::
+
+        >>> obj = (1, 2, 3)
+        >>> list(always_iterable(obj))
+        [1, 2, 3]
+
+    If *obj* is not iterable, return a one-item iterable containing *obj*::
+
+        >>> obj = 1
+        >>> list(always_iterable(obj))
+        [1]
+
+    If *obj* is ``None``, return an empty iterable:
+
+        >>> obj = None
+        >>> list(always_iterable(None))
+        []
+
+    By default, binary and text strings are not considered iterable::
+
+        >>> obj = 'foo'
+        >>> list(always_iterable(obj))
+        ['foo']
+
+    If *base_type* is set, objects for which ``isinstance(obj, base_type)``
+    returns ``True`` won't be considered iterable.
+
+        >>> obj = {'a': 1}
+        >>> list(always_iterable(obj))  # Iterate over the dict's keys
+        ['a']
+        >>> list(always_iterable(obj, base_type=dict))  # Treat dicts as a unit
+        [{'a': 1}]
+
+    Set *base_type* to ``None`` to avoid any special handling and treat objects
+    Python considers iterable as iterable:
+
+        >>> obj = 'foo'
+        >>> list(always_iterable(obj, base_type=None))
+        ['f', 'o', 'o']
+    """
+    if obj is None:
+        return iter(())
+
+    if (base_type is not None) and isinstance(obj, base_type):
+        return iter((obj,))
+
+    try:
+        return iter(obj)
+    except TypeError:
+        return iter((obj,))

lib/importlib_metadata/_meta.py

@@ -0,0 +1,49 @@
+from ._compat import Protocol
+from typing import Any, Dict, Iterator, List, TypeVar, Union
+
+
+_T = TypeVar("_T")
+
+
+class PackageMetadata(Protocol):
+    def __len__(self) -> int:
+        ...  # pragma: no cover
+
+    def __contains__(self, item: str) -> bool:
+        ...  # pragma: no cover
+
+    def __getitem__(self, key: str) -> str:
+        ...  # pragma: no cover
+
+    def __iter__(self) -> Iterator[str]:
+        ...  # pragma: no cover
+
+    def get_all(self, name: str, failobj: _T = ...) -> Union[List[Any], _T]:
+        """
+        Return all values associated with a possibly multi-valued key.
+        """
+
+    @property
+    def json(self) -> Dict[str, Union[str, List[str]]]:
+        """
+        A JSON-compatible form of the metadata.
+        """
+
+
+class SimplePath(Protocol[_T]):
+    """
+    A minimal subset of pathlib.Path required by PathDistribution.
+    """
+
+    def joinpath(self) -> _T:
+        ...  # pragma: no cover
+
+    def __truediv__(self, other: Union[str, _T]) -> _T:
+        ...  # pragma: no cover
+
+    @property
+    def parent(self) -> _T:
+        ...  # pragma: no cover
+
+    def read_text(self) -> str:
+        ...  # pragma: no cover

lib/importlib_metadata/_py39compat.py

@@ -0,0 +1,35 @@
+"""
+Compatibility layer with Python 3.8/3.9
+"""
+from typing import TYPE_CHECKING, Any, Optional
+
+if TYPE_CHECKING:  # pragma: no cover
+    # Prevent circular imports on runtime.
+    from . import Distribution, EntryPoint
+else:
+    Distribution = EntryPoint = Any
+
+
+def normalized_name(dist: Distribution) -> Optional[str]:
+    """
+    Honor name normalization for distributions that don't provide ``_normalized_name``.
+    """
+    try:
+        return dist._normalized_name
+    except AttributeError:
+        from . import Prepared  # -> delay to prevent circular imports.
+
+        return Prepared.normalize(getattr(dist, "name", None) or dist.metadata['Name'])
+
+
+def ep_matches(ep: EntryPoint, **params) -> bool:
+    """
+    Workaround for ``EntryPoint`` objects without the ``matches`` method.
+    """
+    try:
+        return ep.matches(**params)
+    except AttributeError:
+        from . import EntryPoint  # -> delay to prevent circular imports.
+
+        # Reconstruct the EntryPoint object to make sure it is compatible.
+        return EntryPoint(ep.name, ep.value, ep.group).matches(**params)

lib/importlib_metadata/_text.py

@@ -0,0 +1,99 @@
+import re
+
+from ._functools import method_cache
+
+
+# from jaraco.text 3.5
+class FoldedCase(str):
+    """
+    A case insensitive string class; behaves just like str
+    except compares equal when the only variation is case.
+
+    >>> s = FoldedCase('hello world')
+
+    >>> s == 'Hello World'
+    True
+
+    >>> 'Hello World' == s
+    True
+
+    >>> s != 'Hello World'
+    False
+
+    >>> s.index('O')
+    4
+
+    >>> s.split('O')
+    ['hell', ' w', 'rld']
+
+    >>> sorted(map(FoldedCase, ['GAMMA', 'alpha', 'Beta']))
+    ['alpha', 'Beta', 'GAMMA']
+
+    Sequence membership is straightforward.
+
+    >>> "Hello World" in [s]
+    True
+    >>> s in ["Hello World"]
+    True
+
+    You may test for set inclusion, but candidate and elements
+    must both be folded.
+
+    >>> FoldedCase("Hello World") in {s}
+    True
+    >>> s in {FoldedCase("Hello World")}
+    True
+
+    String inclusion works as long as the FoldedCase object
+    is on the right.
+
+    >>> "hello" in FoldedCase("Hello World")
+    True
+
+    But not if the FoldedCase object is on the left:
+
+    >>> FoldedCase('hello') in 'Hello World'
+    False
+
+    In that case, use in_:
+
+    >>> FoldedCase('hello').in_('Hello World')
+    True
+
+    >>> FoldedCase('hello') > FoldedCase('Hello')
+    False
+    """
+
+    def __lt__(self, other):
+        return self.lower() < other.lower()
+
+    def __gt__(self, other):
+        return self.lower() > other.lower()
+
+    def __eq__(self, other):
+        return self.lower() == other.lower()
+
+    def __ne__(self, other):
+        return self.lower() != other.lower()
+
+    def __hash__(self):
+        return hash(self.lower())
+
+    def __contains__(self, other):
+        return super().lower().__contains__(other.lower())
+
+    def in_(self, other):
+        "Does self appear in other?"
+        return self in FoldedCase(other)
+
+    # cache lower since it's likely to be called frequently.
+    @method_cache
+    def lower(self):
+        return super().lower()
+
+    def index(self, sub):
+        return self.lower().index(sub.lower())
+
+    def split(self, splitter=' ', maxsplit=0):
+        pattern = re.compile(re.escape(splitter), re.I)
+        return pattern.split(self, maxsplit)

lib/importlib_resources/__init__.py

@@ -0,0 +1,17 @@
+"""Read resources contained within a package."""
+
+from ._common import (
+    as_file,
+    files,
+    Package,
+)
+
+from .abc import ResourceReader
+
+
+__all__ = [
+    'Package',
+    'ResourceReader',
+    'as_file',
+    'files',
+]

lib/importlib_resources/_adapters.py

@@ -0,0 +1,168 @@
+from contextlib import suppress
+from io import TextIOWrapper
+
+from . import abc
+
+
+class SpecLoaderAdapter:
+    """
+    Adapt a package spec to adapt the underlying loader.
+    """
+
+    def __init__(self, spec, adapter=lambda spec: spec.loader):
+        self.spec = spec
+        self.loader = adapter(spec)
+
+    def __getattr__(self, name):
+        return getattr(self.spec, name)
+
+
+class TraversableResourcesLoader:
+    """
+    Adapt a loader to provide TraversableResources.
+    """
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    def get_resource_reader(self, name):
+        return CompatibilityFiles(self.spec)._native()
+
+
+def _io_wrapper(file, mode='r', *args, **kwargs):
+    if mode == 'r':
+        return TextIOWrapper(file, *args, **kwargs)
+    elif mode == 'rb':
+        return file
+    raise ValueError(f"Invalid mode value '{mode}', only 'r' and 'rb' are supported")
+
+
+class CompatibilityFiles:
+    """
+    Adapter for an existing or non-existent resource reader
+    to provide a compatibility .files().
+    """
+
+    class SpecPath(abc.Traversable):
+        """
+        Path tied to a module spec.
+        Can be read and exposes the resource reader children.
+        """
+
+        def __init__(self, spec, reader):
+            self._spec = spec
+            self._reader = reader
+
+        def iterdir(self):
+            if not self._reader:
+                return iter(())
+            return iter(
+                CompatibilityFiles.ChildPath(self._reader, path)
+                for path in self._reader.contents()
+            )
+
+        def is_file(self):
+            return False
+
+        is_dir = is_file
+
+        def joinpath(self, other):
+            if not self._reader:
+                return CompatibilityFiles.OrphanPath(other)
+            return CompatibilityFiles.ChildPath(self._reader, other)
+
+        @property
+        def name(self):
+            return self._spec.name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(self._reader.open_resource(None), mode, *args, **kwargs)
+
+    class ChildPath(abc.Traversable):
+        """
+        Path tied to a resource reader child.
+        Can be read but doesn't expose any meaningful children.
+        """
+
+        def __init__(self, reader, name):
+            self._reader = reader
+            self._name = name
+
+        def iterdir(self):
+            return iter(())
+
+        def is_file(self):
+            return self._reader.is_resource(self.name)
+
+        def is_dir(self):
+            return not self.is_file()
+
+        def joinpath(self, other):
+            return CompatibilityFiles.OrphanPath(self.name, other)
+
+        @property
+        def name(self):
+            return self._name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(
+                self._reader.open_resource(self.name), mode, *args, **kwargs
+            )
+
+    class OrphanPath(abc.Traversable):
+        """
+        Orphan path, not tied to a module spec or resource reader.
+        Can't be read and doesn't expose any meaningful children.
+        """
+
+        def __init__(self, *path_parts):
+            if len(path_parts) < 1:
+                raise ValueError('Need at least one path part to construct a path')
+            self._path = path_parts
+
+        def iterdir(self):
+            return iter(())
+
+        def is_file(self):
+            return False
+
+        is_dir = is_file
+
+        def joinpath(self, other):
+            return CompatibilityFiles.OrphanPath(*self._path, other)
+
+        @property
+        def name(self):
+            return self._path[-1]
+
+        def open(self, mode='r', *args, **kwargs):
+            raise FileNotFoundError("Can't open orphan path")
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    @property
+    def _reader(self):
+        with suppress(AttributeError):
+            return self.spec.loader.get_resource_reader(self.spec.name)
+
+    def _native(self):
+        """
+        Return the native reader if it supports files().
+        """
+        reader = self._reader
+        return reader if hasattr(reader, 'files') else self
+
+    def __getattr__(self, attr):
+        return getattr(self._reader, attr)
+
+    def files(self):
+        return CompatibilityFiles.SpecPath(self.spec, self._reader)
+
+
+def wrap_spec(package):
+    """
+    Construct a package spec with traversable compatibility
+    on the spec/loader/reader.
+    """
+    return SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)

lib/importlib_resources/_common.py

@@ -0,0 +1,207 @@
+import os
+import pathlib
+import tempfile
+import functools
+import contextlib
+import types
+import importlib
+import inspect
+import warnings
+import itertools
+
+from typing import Union, Optional, cast
+from .abc import ResourceReader, Traversable
+
+from ._compat import wrap_spec
+
+Package = Union[types.ModuleType, str]
+Anchor = Package
+
+
+def package_to_anchor(func):
+    """
+    Replace 'package' parameter as 'anchor' and warn about the change.
+
+    Other errors should fall through.
+
+    >>> files('a', 'b')
+    Traceback (most recent call last):
+    TypeError: files() takes from 0 to 1 positional arguments but 2 were given
+    """
+    undefined = object()
+
+    @functools.wraps(func)
+    def wrapper(anchor=undefined, package=undefined):
+        if package is not undefined:
+            if anchor is not undefined:
+                return func(anchor, package)
+            warnings.warn(
+                "First parameter to files is renamed to 'anchor'",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            return func(package)
+        elif anchor is undefined:
+            return func()
+        return func(anchor)
+
+    return wrapper
+
+
+@package_to_anchor
+def files(anchor: Optional[Anchor] = None) -> Traversable:
+    """
+    Get a Traversable resource for an anchor.
+    """
+    return from_package(resolve(anchor))
+
+
+def get_resource_reader(package: types.ModuleType) -> Optional[ResourceReader]:
+    """
+    Return the package's loader if it's a ResourceReader.
+    """
+    # We can't use
+    # a issubclass() check here because apparently abc.'s __subclasscheck__()
+    # hook wants to create a weak reference to the object, but
+    # zipimport.zipimporter does not support weak references, resulting in a
+    # TypeError.  That seems terrible.
+    spec = package.__spec__
+    reader = getattr(spec.loader, 'get_resource_reader', None)  # type: ignore
+    if reader is None:
+        return None
+    return reader(spec.name)  # type: ignore
+
+
+@functools.singledispatch
+def resolve(cand: Optional[Anchor]) -> types.ModuleType:
+    return cast(types.ModuleType, cand)
+
+
+@resolve.register
+def _(cand: str) -> types.ModuleType:
+    return importlib.import_module(cand)
+
+
+@resolve.register
+def _(cand: None) -> types.ModuleType:
+    return resolve(_infer_caller().f_globals['__name__'])
+
+
+def _infer_caller():
+    """
+    Walk the stack and find the frame of the first caller not in this module.
+    """
+
+    def is_this_file(frame_info):
+        return frame_info.filename == __file__
+
+    def is_wrapper(frame_info):
+        return frame_info.function == 'wrapper'
+
+    not_this_file = itertools.filterfalse(is_this_file, inspect.stack())
+    # also exclude 'wrapper' due to singledispatch in the call stack
+    callers = itertools.filterfalse(is_wrapper, not_this_file)
+    return next(callers).frame
+
+
+def from_package(package: types.ModuleType):
+    """
+    Return a Traversable object for the given package.
+
+    """
+    spec = wrap_spec(package)
+    reader = spec.loader.get_resource_reader(spec.name)
+    return reader.files()
+
+
+@contextlib.contextmanager
+def _tempfile(
+    reader,
+    suffix='',
+    # gh-93353: Keep a reference to call os.remove() in late Python
+    # finalization.
+    *,
+    _os_remove=os.remove,
+):
+    # Not using tempfile.NamedTemporaryFile as it leads to deeper 'try'
+    # blocks due to the need to close the temporary file to work on Windows
+    # properly.
+    fd, raw_path = tempfile.mkstemp(suffix=suffix)
+    try:
+        try:
+            os.write(fd, reader())
+        finally:
+            os.close(fd)
+        del reader
+        yield pathlib.Path(raw_path)
+    finally:
+        try:
+            _os_remove(raw_path)
+        except FileNotFoundError:
+            pass
+
+
+def _temp_file(path):
+    return _tempfile(path.read_bytes, suffix=path.name)
+
+
+def _is_present_dir(path: Traversable) -> bool:
+    """
+    Some Traversables implement ``is_dir()`` to raise an
+    exception (i.e. ``FileNotFoundError``) when the
+    directory doesn't exist. This function wraps that call
+    to always return a boolean and only return True
+    if there's a dir and it exists.
+    """
+    with contextlib.suppress(FileNotFoundError):
+        return path.is_dir()
+    return False
+
+
+@functools.singledispatch
+def as_file(path):
+    """
+    Given a Traversable object, return that object as a
+    path on the local file system in a context manager.
+    """
+    return _temp_dir(path) if _is_present_dir(path) else _temp_file(path)
+
+
+@as_file.register(pathlib.Path)
+@contextlib.contextmanager
+def _(path):
+    """
+    Degenerate behavior for pathlib.Path objects.
+    """
+    yield path
+
+
+@contextlib.contextmanager
+def _temp_path(dir: tempfile.TemporaryDirectory):
+    """
+    Wrap tempfile.TemporyDirectory to return a pathlib object.
+    """
+    with dir as result:
+        yield pathlib.Path(result)
+
+
+@contextlib.contextmanager
+def _temp_dir(path):
+    """
+    Given a traversable dir, recursively replicate the whole tree
+    to the file system in a context manager.
+    """
+    assert path.is_dir()
+    with _temp_path(tempfile.TemporaryDirectory()) as temp_dir:
+        yield _write_contents(temp_dir, path)
+
+
+def _write_contents(target, source):
+    child = target.joinpath(source.name)
+    if source.is_dir():
+        child.mkdir()
+        for item in source.iterdir():
+            _write_contents(child, item)
+    else:
+        child.write_bytes(source.read_bytes())
+    return child

lib/importlib_resources/_compat.py

@@ -0,0 +1,109 @@
+# flake8: noqa
+
+import abc
+import os
+import sys
+import pathlib
+from contextlib import suppress
+from typing import Union
+
+
+if sys.version_info >= (3, 10):
+    from zipfile import Path as ZipPath  # type: ignore
+else:
+    from zipp import Path as ZipPath  # type: ignore
+
+
+try:
+    from typing import runtime_checkable  # type: ignore
+except ImportError:
+
+    def runtime_checkable(cls):  # type: ignore
+        return cls
+
+
+try:
+    from typing import Protocol  # type: ignore
+except ImportError:
+    Protocol = abc.ABC  # type: ignore
+
+
+class TraversableResourcesLoader:
+    """
+    Adapt loaders to provide TraversableResources and other
+    compatibility.
+
+    Used primarily for Python 3.9 and earlier where the native
+    loaders do not yet implement TraversableResources.
+    """
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    @property
+    def path(self):
+        return self.spec.origin
+
+    def get_resource_reader(self, name):
+        from . import readers, _adapters
+
+        def _zip_reader(spec):
+            with suppress(AttributeError):
+                return readers.ZipReader(spec.loader, spec.name)
+
+        def _namespace_reader(spec):
+            with suppress(AttributeError, ValueError):
+                return readers.NamespaceReader(spec.submodule_search_locations)
+
+        def _available_reader(spec):
+            with suppress(AttributeError):
+                return spec.loader.get_resource_reader(spec.name)
+
+        def _native_reader(spec):
+            reader = _available_reader(spec)
+            return reader if hasattr(reader, 'files') else None
+
+        def _file_reader(spec):
+            try:
+                path = pathlib.Path(self.path)
+            except TypeError:
+                return None
+            if path.exists():
+                return readers.FileReader(self)
+
+        return (
+            # local ZipReader if a zip module
+            _zip_reader(self.spec)
+            or
+            # local NamespaceReader if a namespace module
+            _namespace_reader(self.spec)
+            or
+            # local FileReader
+            _file_reader(self.spec)
+            or
+            # native reader if it supplies 'files'
+            _native_reader(self.spec)
+            or
+            # fallback - adapt the spec ResourceReader to TraversableReader
+            _adapters.CompatibilityFiles(self.spec)
+        )
+
+
+def wrap_spec(package):
+    """
+    Construct a package spec with traversable compatibility
+    on the spec/loader/reader.
+
+    Supersedes _adapters.wrap_spec to use TraversableResourcesLoader
+    from above for older Python compatibility (<3.10).
+    """
+    from . import _adapters
+
+    return _adapters.SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)
+
+
+if sys.version_info >= (3, 9):
+    StrPath = Union[str, os.PathLike[str]]
+else:
+    # PathLike is only subscriptable at runtime in 3.9+
+    StrPath = Union[str, "os.PathLike[str]"]

lib/importlib_resources/_itertools.py

@@ -0,0 +1,38 @@
+# from more_itertools 9.0
+def only(iterable, default=None, too_long=None):
+    """If *iterable* has only one item, return it.
+    If it has zero items, return *default*.
+    If it has more than one item, raise the exception given by *too_long*,
+    which is ``ValueError`` by default.
+    >>> only([], default='missing')
+    'missing'
+    >>> only([1])
+    1
+    >>> only([1, 2])  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+    ...
+    ValueError: Expected exactly one item in iterable, but got 1, 2,
+     and perhaps more.'
+    >>> only([1, 2], too_long=TypeError)  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+    ...
+    TypeError
+    Note that :func:`only` attempts to advance *iterable* twice to ensure there
+    is only one item.  See :func:`spy` or :func:`peekable` to check
+    iterable contents less destructively.
+    """
+    it = iter(iterable)
+    first_value = next(it, default)
+
+    try:
+        second_value = next(it)
+    except StopIteration:
+        pass
+    else:
+        msg = (
+            'Expected exactly one item in iterable, but got {!r}, {!r}, '
+            'and perhaps more.'.format(first_value, second_value)
+        )
+        raise too_long or ValueError(msg)
+
+    return first_value

lib/importlib_resources/abc.py

@@ -0,0 +1,170 @@
+import abc
+import io
+import itertools
+import pathlib
+from typing import Any, BinaryIO, Iterable, Iterator, NoReturn, Text, Optional
+
+from ._compat import runtime_checkable, Protocol, StrPath
+
+
+__all__ = ["ResourceReader", "Traversable", "TraversableResources"]
+
+
+class ResourceReader(metaclass=abc.ABCMeta):
+    """Abstract base class for loaders to provide resource reading support."""
+
+    @abc.abstractmethod
+    def open_resource(self, resource: Text) -> BinaryIO:
+        """Return an opened, file-like object for binary reading.
+
+        The 'resource' argument is expected to represent only a file name.
+        If the resource cannot be found, FileNotFoundError is raised.
+        """
+        # This deliberately raises FileNotFoundError instead of
+        # NotImplementedError so that if this method is accidentally called,
+        # it'll still do the right thing.
+        raise FileNotFoundError
+
+    @abc.abstractmethod
+    def resource_path(self, resource: Text) -> Text:
+        """Return the file system path to the specified resource.
+
+        The 'resource' argument is expected to represent only a file name.
+        If the resource does not exist on the file system, raise
+        FileNotFoundError.
+        """
+        # This deliberately raises FileNotFoundError instead of
+        # NotImplementedError so that if this method is accidentally called,
+        # it'll still do the right thing.
+        raise FileNotFoundError
+
+    @abc.abstractmethod
+    def is_resource(self, path: Text) -> bool:
+        """Return True if the named 'path' is a resource.
+
+        Files are resources, directories are not.
+        """
+        raise FileNotFoundError
+
+    @abc.abstractmethod
+    def contents(self) -> Iterable[str]:
+        """Return an iterable of entries in `package`."""
+        raise FileNotFoundError
+
+
+class TraversalError(Exception):
+    pass
+
+
+@runtime_checkable
+class Traversable(Protocol):
+    """
+    An object with a subset of pathlib.Path methods suitable for
+    traversing directories and opening files.
+
+    Any exceptions that occur when accessing the backing resource
+    may propagate unaltered.
+    """
+
+    @abc.abstractmethod
+    def iterdir(self) -> Iterator["Traversable"]:
+        """
+        Yield Traversable objects in self
+        """
+
+    def read_bytes(self) -> bytes:
+        """
+        Read contents of self as bytes
+        """
+        with self.open('rb') as strm:
+            return strm.read()
+
+    def read_text(self, encoding: Optional[str] = None) -> str:
+        """
+        Read contents of self as text
+        """
+        with self.open(encoding=encoding) as strm:
+            return strm.read()
+
+    @abc.abstractmethod
+    def is_dir(self) -> bool:
+        """
+        Return True if self is a directory
+        """
+
+    @abc.abstractmethod
+    def is_file(self) -> bool:
+        """
+        Return True if self is a file
+        """
+
+    def joinpath(self, *descendants: StrPath) -> "Traversable":
+        """
+        Return Traversable resolved with any descendants applied.
+
+        Each descendant should be a path segment relative to self
+        and each may contain multiple levels separated by
+        ``posixpath.sep`` (``/``).
+        """
+        if not descendants:
+            return self
+        names = itertools.chain.from_iterable(
+            path.parts for path in map(pathlib.PurePosixPath, descendants)
+        )
+        target = next(names)
+        matches = (
+            traversable for traversable in self.iterdir() if traversable.name == target
+        )
+        try:
+            match = next(matches)
+        except StopIteration:
+            raise TraversalError(
+                "Target not found during traversal.", target, list(names)
+            )
+        return match.joinpath(*names)
+
+    def __truediv__(self, child: StrPath) -> "Traversable":
+        """
+        Return Traversable child in self
+        """
+        return self.joinpath(child)
+
+    @abc.abstractmethod
+    def open(self, mode='r', *args, **kwargs):
+        """
+        mode may be 'r' or 'rb' to open as text or binary. Return a handle
+        suitable for reading (same as pathlib.Path.open).
+
+        When opening as text, accepts encoding parameters such as those
+        accepted by io.TextIOWrapper.
+        """
+
+    @property
+    @abc.abstractmethod
+    def name(self) -> str:
+        """
+        The base name of this object without any parent references.
+        """
+
+
+class TraversableResources(ResourceReader):
+    """
+    The required interface for providing traversable
+    resources.
+    """
+
+    @abc.abstractmethod
+    def files(self) -> "Traversable":
+        """Return a Traversable object for the loaded package."""
+
+    def open_resource(self, resource: StrPath) -> io.BufferedReader:
+        return self.files().joinpath(resource).open('rb')
+
+    def resource_path(self, resource: Any) -> NoReturn:
+        raise FileNotFoundError(resource)
+
+    def is_resource(self, path: StrPath) -> bool:
+        return self.files().joinpath(path).is_file()
+
+    def contents(self) -> Iterator[str]:
+        return (item.name for item in self.files().iterdir())

lib/importlib_resources/readers.py

@@ -0,0 +1,144 @@
+import collections
+import itertools
+import pathlib
+import operator
+
+from . import abc
+
+from ._itertools import only
+from ._compat import ZipPath
+
+
+def remove_duplicates(items):
+    return iter(collections.OrderedDict.fromkeys(items))
+
+
+class FileReader(abc.TraversableResources):
+    def __init__(self, loader):
+        self.path = pathlib.Path(loader.path).parent
+
+    def resource_path(self, resource):
+        """
+        Return the file system path to prevent
+        `resources.path()` from creating a temporary
+        copy.
+        """
+        return str(self.path.joinpath(resource))
+
+    def files(self):
+        return self.path
+
+
+class ZipReader(abc.TraversableResources):
+    def __init__(self, loader, module):
+        _, _, name = module.rpartition('.')
+        self.prefix = loader.prefix.replace('\\', '/') + name + '/'
+        self.archive = loader.archive
+
+    def open_resource(self, resource):
+        try:
+            return super().open_resource(resource)
+        except KeyError as exc:
+            raise FileNotFoundError(exc.args[0])
+
+    def is_resource(self, path):
+        """
+        Workaround for `zipfile.Path.is_file` returning true
+        for non-existent paths.
+        """
+        target = self.files().joinpath(path)
+        return target.is_file() and target.exists()
+
+    def files(self):
+        return ZipPath(self.archive, self.prefix)
+
+
+class MultiplexedPath(abc.Traversable):
+    """
+    Given a series of Traversable objects, implement a merged
+    version of the interface across all objects. Useful for
+    namespace packages which may be multihomed at a single
+    name.
+    """
+
+    def __init__(self, *paths):
+        self._paths = list(map(pathlib.Path, remove_duplicates(paths)))
+        if not self._paths:
+            message = 'MultiplexedPath must contain at least one path'
+            raise FileNotFoundError(message)
+        if not all(path.is_dir() for path in self._paths):
+            raise NotADirectoryError('MultiplexedPath only supports directories')
+
+    def iterdir(self):
+        children = (child for path in self._paths for child in path.iterdir())
+        by_name = operator.attrgetter('name')
+        groups = itertools.groupby(sorted(children, key=by_name), key=by_name)
+        return map(self._follow, (locs for name, locs in groups))
+
+    def read_bytes(self):
+        raise FileNotFoundError(f'{self} is not a file')
+
+    def read_text(self, *args, **kwargs):
+        raise FileNotFoundError(f'{self} is not a file')
+
+    def is_dir(self):
+        return True
+
+    def is_file(self):
+        return False
+
+    def joinpath(self, *descendants):
+        try:
+            return super().joinpath(*descendants)
+        except abc.TraversalError:
+            # One of the paths did not resolve (a directory does not exist).
+            # Just return something that will not exist.
+            return self._paths[0].joinpath(*descendants)
+
+    @classmethod
+    def _follow(cls, children):
+        """
+        Construct a MultiplexedPath if needed.
+
+        If children contains a sole element, return it.
+        Otherwise, return a MultiplexedPath of the items.
+        Unless one of the items is not a Directory, then return the first.
+        """
+        subdirs, one_dir, one_file = itertools.tee(children, 3)
+
+        try:
+            return only(one_dir)
+        except ValueError:
+            try:
+                return cls(*subdirs)
+            except NotADirectoryError:
+                return next(one_file)
+
+    def open(self, *args, **kwargs):
+        raise FileNotFoundError(f'{self} is not a file')
+
+    @property
+    def name(self):
+        return self._paths[0].name
+
+    def __repr__(self):
+        paths = ', '.join(f"'{path}'" for path in self._paths)
+        return f'MultiplexedPath({paths})'
+
+
+class NamespaceReader(abc.TraversableResources):
+    def __init__(self, namespace_path):
+        if 'NamespacePath' not in str(namespace_path):
+            raise ValueError('Invalid path')
+        self.path = MultiplexedPath(*list(namespace_path))
+
+    def resource_path(self, resource):
+        """
+        Return the file system path to prevent
+        `resources.path()` from creating a temporary
+        copy.
+        """
+        return str(self.path.joinpath(resource))
+
+    def files(self):
+        return self.path

lib/importlib_resources/simple.py

@@ -0,0 +1,106 @@
+"""
+Interface adapters for low-level readers.
+"""
+
+import abc
+import io
+import itertools
+from typing import BinaryIO, List
+
+from .abc import Traversable, TraversableResources
+
+
+class SimpleReader(abc.ABC):
+    """
+    The minimum, low-level interface required from a resource
+    provider.
+    """
+
+    @property
+    @abc.abstractmethod
+    def package(self) -> str:
+        """
+        The name of the package for which this reader loads resources.
+        """
+
+    @abc.abstractmethod
+    def children(self) -> List['SimpleReader']:
+        """
+        Obtain an iterable of SimpleReader for available
+        child containers (e.g. directories).
+        """
+
+    @abc.abstractmethod
+    def resources(self) -> List[str]:
+        """
+        Obtain available named resources for this virtual package.
+        """
+
+    @abc.abstractmethod
+    def open_binary(self, resource: str) -> BinaryIO:
+        """
+        Obtain a File-like for a named resource.
+        """
+
+    @property
+    def name(self):
+        return self.package.split('.')[-1]
+
+
+class ResourceContainer(Traversable):
+    """
+    Traversable container for a package's resources via its reader.
+    """
+
+    def __init__(self, reader: SimpleReader):
+        self.reader = reader
+
+    def is_dir(self):
+        return True
+
+    def is_file(self):
+        return False
+
+    def iterdir(self):
+        files = (ResourceHandle(self, name) for name in self.reader.resources)
+        dirs = map(ResourceContainer, self.reader.children())
+        return itertools.chain(files, dirs)
+
+    def open(self, *args, **kwargs):
+        raise IsADirectoryError()
+
+
+class ResourceHandle(Traversable):
+    """
+    Handle to a named resource in a ResourceReader.
+    """
+
+    def __init__(self, parent: ResourceContainer, name: str):
+        self.parent = parent
+        self.name = name  # type: ignore
+
+    def is_file(self):
+        return True
+
+    def is_dir(self):
+        return False
+
+    def open(self, mode='r', *args, **kwargs):
+        stream = self.parent.reader.open_binary(self.name)
+        if 'b' not in mode:
+            stream = io.TextIOWrapper(*args, **kwargs)
+        return stream
+
+    def joinpath(self, name):
+        raise RuntimeError("Cannot traverse into a resource")
+
+
+class TraversableReader(TraversableResources, SimpleReader):
+    """
+    A TraversableResources based on SimpleReader. Resource providers
+    may derive from this class to provide the TraversableResources
+    interface by supplying the SimpleReader interface.
+    """
+
+    def files(self):
+        return ResourceContainer(self)

lib/importlib_resources/tests/_compat.py

@@ -0,0 +1,32 @@
+import os
+
+
+try:
+    from test.support import import_helper  # type: ignore
+except ImportError:
+    # Python 3.9 and earlier
+    class import_helper:  # type: ignore
+        from test.support import (
+            modules_setup,
+            modules_cleanup,
+            DirsOnSysPath,
+            CleanImport,
+        )
+
+
+try:
+    from test.support import os_helper  # type: ignore
+except ImportError:
+    # Python 3.9 compat
+    class os_helper:  # type:ignore
+        from test.support import temp_dir
+
+
+try:
+    # Python 3.10
+    from test.support.os_helper import unlink
+except ImportError:
+    from test.support import unlink as _unlink
+
+    def unlink(target):
+        return _unlink(os.fspath(target))

lib/importlib_resources/tests/_path.py

@@ -0,0 +1,56 @@
+import pathlib
+import functools
+
+from typing import Dict, Union
+
+
+####
+# from jaraco.path 3.4.1
+
+FilesSpec = Dict[str, Union[str, bytes, 'FilesSpec']]  # type: ignore
+
+
+def build(spec: FilesSpec, prefix=pathlib.Path()):
+    """
+    Build a set of files/directories, as described by the spec.
+
+    Each key represents a pathname, and the value represents
+    the content. Content may be a nested directory.
+
+    >>> spec = {
+    ...     'README.txt': "A README file",
+    ...     "foo": {
+    ...         "__init__.py": "",
+    ...         "bar": {
+    ...             "__init__.py": "",
+    ...         },
+    ...         "baz.py": "# Some code",
+    ...     }
+    ... }
+    >>> target = getfixture('tmp_path')
+    >>> build(spec, target)
+    >>> target.joinpath('foo/baz.py').read_text(encoding='utf-8')
+    '# Some code'
+    """
+    for name, contents in spec.items():
+        create(contents, pathlib.Path(prefix) / name)
+
+
+@functools.singledispatch
+def create(content: Union[str, bytes, FilesSpec], path):
+    path.mkdir(exist_ok=True)
+    build(content, prefix=path)  # type: ignore
+
+
+@create.register
+def _(content: bytes, path):
+    path.write_bytes(content)
+
+
+@create.register
+def _(content: str, path):
+    path.write_text(content, encoding='utf-8')
+
+
+# end from jaraco.path
+####

lib/importlib_resources/tests/data01/utf-8.file

@@ -0,0 +1 @@
+Hello, UTF-8 world!

lib/importlib_resources/tests/data02/one/resource1.txt

@@ -0,0 +1 @@
+one resource

lib/importlib_resources/tests/data02/subdirectory/subsubdir/resource.txt

@@ -0,0 +1 @@
+a resource

lib/importlib_resources/tests/data02/two/resource2.txt

@@ -0,0 +1 @@
+two resource

lib/importlib_resources/tests/namespacedata01/utf-8.file

@@ -0,0 +1 @@
+Hello, UTF-8 world!

lib/importlib_resources/tests/test_compatibilty_files.py

@@ -0,0 +1,104 @@
+import io
+import unittest
+
+import importlib_resources as resources
+
+from importlib_resources._adapters import (
+    CompatibilityFiles,
+    wrap_spec,
+)
+
+from . import util
+
+
+class CompatibilityFilesTests(unittest.TestCase):
+    @property
+    def package(self):
+        bytes_data = io.BytesIO(b'Hello, world!')
+        return util.create_package(
+            file=bytes_data,
+            path='some_path',
+            contents=('a', 'b', 'c'),
+        )
+
+    @property
+    def files(self):
+        return resources.files(self.package)
+
+    def test_spec_path_iter(self):
+        self.assertEqual(
+            sorted(path.name for path in self.files.iterdir()),
+            ['a', 'b', 'c'],
+        )
+
+    def test_child_path_iter(self):
+        self.assertEqual(list((self.files / 'a').iterdir()), [])
+
+    def test_orphan_path_iter(self):
+        self.assertEqual(list((self.files / 'a' / 'a').iterdir()), [])
+        self.assertEqual(list((self.files / 'a' / 'a' / 'a').iterdir()), [])
+
+    def test_spec_path_is(self):
+        self.assertFalse(self.files.is_file())
+        self.assertFalse(self.files.is_dir())
+
+    def test_child_path_is(self):
+        self.assertTrue((self.files / 'a').is_file())
+        self.assertFalse((self.files / 'a').is_dir())
+
+    def test_orphan_path_is(self):
+        self.assertFalse((self.files / 'a' / 'a').is_file())
+        self.assertFalse((self.files / 'a' / 'a').is_dir())
+        self.assertFalse((self.files / 'a' / 'a' / 'a').is_file())
+        self.assertFalse((self.files / 'a' / 'a' / 'a').is_dir())
+
+    def test_spec_path_name(self):
+        self.assertEqual(self.files.name, 'testingpackage')
+
+    def test_child_path_name(self):
+        self.assertEqual((self.files / 'a').name, 'a')
+
+    def test_orphan_path_name(self):
+        self.assertEqual((self.files / 'a' / 'b').name, 'b')
+        self.assertEqual((self.files / 'a' / 'b' / 'c').name, 'c')
+
+    def test_spec_path_open(self):
+        self.assertEqual(self.files.read_bytes(), b'Hello, world!')
+        self.assertEqual(self.files.read_text(encoding='utf-8'), 'Hello, world!')
+
+    def test_child_path_open(self):
+        self.assertEqual((self.files / 'a').read_bytes(), b'Hello, world!')
+        self.assertEqual(
+            (self.files / 'a').read_text(encoding='utf-8'), 'Hello, world!'
+        )
+
+    def test_orphan_path_open(self):
+        with self.assertRaises(FileNotFoundError):
+            (self.files / 'a' / 'b').read_bytes()
+        with self.assertRaises(FileNotFoundError):
+            (self.files / 'a' / 'b' / 'c').read_bytes()
+
+    def test_open_invalid_mode(self):
+        with self.assertRaises(ValueError):
+            self.files.open('0')
+
+    def test_orphan_path_invalid(self):
+        with self.assertRaises(ValueError):
+            CompatibilityFiles.OrphanPath()
+
+    def test_wrap_spec(self):
+        spec = wrap_spec(self.package)
+        self.assertIsInstance(spec.loader.get_resource_reader(None), CompatibilityFiles)
+
+
+class CompatibilityFilesNoReaderTests(unittest.TestCase):
+    @property
+    def package(self):
+        return util.create_package_from_loader(None)
+
+    @property
+    def files(self):
+        return resources.files(self.package)
+
+    def test_spec_path_joinpath(self):
+        self.assertIsInstance(self.files / 'a', CompatibilityFiles.OrphanPath)

lib/importlib_resources/tests/test_contents.py

@@ -0,0 +1,43 @@
+import unittest
+import importlib_resources as resources
+
+from . import data01
+from . import util
+
+
+class ContentsTests:
+    expected = {
+        '__init__.py',
+        'binary.file',
+        'subdirectory',
+        'utf-16.file',
+        'utf-8.file',
+    }
+
+    def test_contents(self):
+        contents = {path.name for path in resources.files(self.data).iterdir()}
+        assert self.expected <= contents
+
+
+class ContentsDiskTests(ContentsTests, unittest.TestCase):
+    def setUp(self):
+        self.data = data01
+
+
+class ContentsZipTests(ContentsTests, util.ZipSetup, unittest.TestCase):
+    pass
+
+
+class ContentsNamespaceTests(ContentsTests, unittest.TestCase):
+    expected = {
+        # no __init__ because of namespace design
+        # no subdirectory as incidental difference in fixture
+        'binary.file',
+        'utf-16.file',
+        'utf-8.file',
+    }
+
+    def setUp(self):
+        from . import namespacedata01
+
+        self.data = namespacedata01

lib/importlib_resources/tests/test_custom.py

@@ -0,0 +1,45 @@
+import unittest
+import contextlib
+import pathlib
+
+import importlib_resources as resources
+from ..abc import TraversableResources, ResourceReader
+from . import util
+from ._compat import os_helper
+
+
+class SimpleLoader:
+    """
+    A simple loader that only implements a resource reader.
+    """
+
+    def __init__(self, reader: ResourceReader):
+        self.reader = reader
+
+    def get_resource_reader(self, package):
+        return self.reader
+
+
+class MagicResources(TraversableResources):
+    """
+    Magically returns the resources at path.
+    """
+
+    def __init__(self, path: pathlib.Path):
+        self.path = path
+
+    def files(self):
+        return self.path
+
+
+class CustomTraversableResourcesTests(unittest.TestCase):
+    def setUp(self):
+        self.fixtures = contextlib.ExitStack()
+        self.addCleanup(self.fixtures.close)
+
+    def test_custom_loader(self):
+        temp_dir = self.fixtures.enter_context(os_helper.temp_dir())
+        loader = SimpleLoader(MagicResources(temp_dir))
+        pkg = util.create_package_from_loader(loader)
+        files = resources.files(pkg)
+        assert files is temp_dir

lib/importlib_resources/tests/test_files.py

@@ -0,0 +1,112 @@
+import typing
+import textwrap
+import unittest
+import warnings
+import importlib
+import contextlib
+
+import importlib_resources as resources
+from ..abc import Traversable
+from . import data01
+from . import util
+from . import _path
+from ._compat import os_helper, import_helper
+
+
+@contextlib.contextmanager
+def suppress_known_deprecation():
+    with warnings.catch_warnings(record=True) as ctx:
+        warnings.simplefilter('default', category=DeprecationWarning)
+        yield ctx
+
+
+class FilesTests:
+    def test_read_bytes(self):
+        files = resources.files(self.data)
+        actual = files.joinpath('utf-8.file').read_bytes()
+        assert actual == b'Hello, UTF-8 world!\n'
+
+    def test_read_text(self):
+        files = resources.files(self.data)
+        actual = files.joinpath('utf-8.file').read_text(encoding='utf-8')
+        assert actual == 'Hello, UTF-8 world!\n'
+
+    @unittest.skipUnless(
+        hasattr(typing, 'runtime_checkable'),
+        "Only suitable when typing supports runtime_checkable",
+    )
+    def test_traversable(self):
+        assert isinstance(resources.files(self.data), Traversable)
+
+    def test_old_parameter(self):
+        """
+        Files used to take a 'package' parameter. Make sure anyone
+        passing by name is still supported.
+        """
+        with suppress_known_deprecation():
+            resources.files(package=self.data)
+
+
+class OpenDiskTests(FilesTests, unittest.TestCase):
+    def setUp(self):
+        self.data = data01
+
+
+class OpenZipTests(FilesTests, util.ZipSetup, unittest.TestCase):
+    pass
+
+
+class OpenNamespaceTests(FilesTests, unittest.TestCase):
+    def setUp(self):
+        from . import namespacedata01
+
+        self.data = namespacedata01
+
+
+class SiteDir:
+    def setUp(self):
+        self.fixtures = contextlib.ExitStack()
+        self.addCleanup(self.fixtures.close)
+        self.site_dir = self.fixtures.enter_context(os_helper.temp_dir())
+        self.fixtures.enter_context(import_helper.DirsOnSysPath(self.site_dir))
+        self.fixtures.enter_context(import_helper.CleanImport())
+
+
+class ModulesFilesTests(SiteDir, unittest.TestCase):
+    def test_module_resources(self):
+        """
+        A module can have resources found adjacent to the module.
+        """
+        spec = {
+            'mod.py': '',
+            'res.txt': 'resources are the best',
+        }
+        _path.build(spec, self.site_dir)
+        import mod
+
+        actual = resources.files(mod).joinpath('res.txt').read_text(encoding='utf-8')
+        assert actual == spec['res.txt']
+
+
+class ImplicitContextFilesTests(SiteDir, unittest.TestCase):
+    def test_implicit_files(self):
+        """
+        Without any parameter, files() will infer the location as the caller.
+        """
+        spec = {
+            'somepkg': {
+                '__init__.py': textwrap.dedent(
+                    """
+                    import importlib_resources as res
+                    val = res.files().joinpath('res.txt').read_text(encoding='utf-8')
+                    """
+                ),
+                'res.txt': 'resources are the best',
+            },
+        }
+        _path.build(spec, self.site_dir)
+        assert importlib.import_module('somepkg').val == 'resources are the best'
+
+
+if __name__ == '__main__':
+    unittest.main()

lib/importlib_resources/tests/test_open.py

@@ -0,0 +1,85 @@
+import unittest
+
+import importlib_resources as resources
+from . import data01
+from . import util
+
+
+class CommonBinaryTests(util.CommonTests, unittest.TestCase):
+    def execute(self, package, path):
+        target = resources.files(package).joinpath(path)
+        with target.open('rb'):
+            pass
+
+
+class CommonTextTests(util.CommonTests, unittest.TestCase):
+    def execute(self, package, path):
+        target = resources.files(package).joinpath(path)
+        with target.open(encoding='utf-8'):
+            pass
+
+
+class OpenTests:
+    def test_open_binary(self):
+        target = resources.files(self.data) / 'binary.file'
+        with target.open('rb') as fp:
+            result = fp.read()
+            self.assertEqual(result, b'\x00\x01\x02\x03')
+
+    def test_open_text_default_encoding(self):
+        target = resources.files(self.data) / 'utf-8.file'
+        with target.open(encoding='utf-8') as fp:
+            result = fp.read()
+            self.assertEqual(result, 'Hello, UTF-8 world!\n')
+
+    def test_open_text_given_encoding(self):
+        target = resources.files(self.data) / 'utf-16.file'
+        with target.open(encoding='utf-16', errors='strict') as fp:
+            result = fp.read()
+        self.assertEqual(result, 'Hello, UTF-16 world!\n')
+
+    def test_open_text_with_errors(self):
+        """
+        Raises UnicodeError without the 'errors' argument.
+        """
+        target = resources.files(self.data) / 'utf-16.file'
+        with target.open(encoding='utf-8', errors='strict') as fp:
+            self.assertRaises(UnicodeError, fp.read)
+        with target.open(encoding='utf-8', errors='ignore') as fp:
+            result = fp.read()
+        self.assertEqual(
+            result,
+            'H\x00e\x00l\x00l\x00o\x00,\x00 '
+            '\x00U\x00T\x00F\x00-\x001\x006\x00 '
+            '\x00w\x00o\x00r\x00l\x00d\x00!\x00\n\x00',
+        )
+
+    def test_open_binary_FileNotFoundError(self):
+        target = resources.files(self.data) / 'does-not-exist'
+        with self.assertRaises(FileNotFoundError):
+            target.open('rb')
+
+    def test_open_text_FileNotFoundError(self):
+        target = resources.files(self.data) / 'does-not-exist'
+        with self.assertRaises(FileNotFoundError):
+            target.open(encoding='utf-8')
+
+
+class OpenDiskTests(OpenTests, unittest.TestCase):
+    def setUp(self):
+        self.data = data01
+
+
+class OpenDiskNamespaceTests(OpenTests, unittest.TestCase):
+    def setUp(self):
+        from . import namespacedata01
+
+        self.data = namespacedata01
+
+
+class OpenZipTests(OpenTests, util.ZipSetup, unittest.TestCase):
+    pass
+
+
+if __name__ == '__main__':
+    unittest.main()

lib/importlib_resources/tests/test_path.py

@@ -0,0 +1,69 @@
+import io
+import unittest
+
+import importlib_resources as resources
+from . import data01
+from . import util
+
+
+class CommonTests(util.CommonTests, unittest.TestCase):
+    def execute(self, package, path):
+        with resources.as_file(resources.files(package).joinpath(path)):
+            pass
+
+
+class PathTests:
+    def test_reading(self):
+        """
+        Path should be readable.
+
+        Test also implicitly verifies the returned object is a pathlib.Path
+        instance.
+        """
+        target = resources.files(self.data) / 'utf-8.file'
+        with resources.as_file(target) as path:
+            self.assertTrue(path.name.endswith("utf-8.file"), repr(path))
+            # pathlib.Path.read_text() was introduced in Python 3.5.
+            with path.open('r', encoding='utf-8') as file:
+                text = file.read()
+            self.assertEqual('Hello, UTF-8 world!\n', text)
+
+
+class PathDiskTests(PathTests, unittest.TestCase):
+    data = data01
+
+    def test_natural_path(self):
+        """
+        Guarantee the internal implementation detail that
+        file-system-backed resources do not get the tempdir
+        treatment.
+        """
+        target = resources.files(self.data) / 'utf-8.file'
+        with resources.as_file(target) as path:
+            assert 'data' in str(path)
+
+
+class PathMemoryTests(PathTests, unittest.TestCase):
+    def setUp(self):
+        file = io.BytesIO(b'Hello, UTF-8 world!\n')
+        self.addCleanup(file.close)
+        self.data = util.create_package(
+            file=file, path=FileNotFoundError("package exists only in memory")
+        )
+        self.data.__spec__.origin = None
+        self.data.__spec__.has_location = False
+
+
+class PathZipTests(PathTests, util.ZipSetup, unittest.TestCase):
+    def test_remove_in_context_manager(self):
+        """
+        It is not an error if the file that was temporarily stashed on the
+        file system is removed inside the `with` stanza.
+        """
+        target = resources.files(self.data) / 'utf-8.file'
+        with resources.as_file(target) as path:
+            path.unlink()
+
+
+if __name__ == '__main__':
+    unittest.main()

lib/importlib_resources/tests/test_read.py

@@ -0,0 +1,82 @@
+import unittest
+import importlib_resources as resources
+
+from . import data01
+from . import util
+from importlib import import_module
+
+
+class CommonBinaryTests(util.CommonTests, unittest.TestCase):
+    def execute(self, package, path):
+        resources.files(package).joinpath(path).read_bytes()
+
+
+class CommonTextTests(util.CommonTests, unittest.TestCase):
+    def execute(self, package, path):
+        resources.files(package).joinpath(path).read_text(encoding='utf-8')
+
+
+class ReadTests:
+    def test_read_bytes(self):
+        result = resources.files(self.data).joinpath('binary.file').read_bytes()
+        self.assertEqual(result, b'\0\1\2\3')
+
+    def test_read_text_default_encoding(self):
+        result = (
+            resources.files(self.data)
+            .joinpath('utf-8.file')
+            .read_text(encoding='utf-8')
+        )
+        self.assertEqual(result, 'Hello, UTF-8 world!\n')
+
+    def test_read_text_given_encoding(self):
+        result = (
+            resources.files(self.data)
+            .joinpath('utf-16.file')
+            .read_text(encoding='utf-16')
+        )
+        self.assertEqual(result, 'Hello, UTF-16 world!\n')
+
+    def test_read_text_with_errors(self):
+        """
+        Raises UnicodeError without the 'errors' argument.
+        """
+        target = resources.files(self.data) / 'utf-16.file'
+        self.assertRaises(UnicodeError, target.read_text, encoding='utf-8')
+        result = target.read_text(encoding='utf-8', errors='ignore')
+        self.assertEqual(
+            result,
+            'H\x00e\x00l\x00l\x00o\x00,\x00 '
+            '\x00U\x00T\x00F\x00-\x001\x006\x00 '
+            '\x00w\x00o\x00r\x00l\x00d\x00!\x00\n\x00',
+        )
+
+
+class ReadDiskTests(ReadTests, unittest.TestCase):
+    data = data01
+
+
+class ReadZipTests(ReadTests, util.ZipSetup, unittest.TestCase):
+    def test_read_submodule_resource(self):
+        submodule = import_module('ziptestdata.subdirectory')
+        result = resources.files(submodule).joinpath('binary.file').read_bytes()
+        self.assertEqual(result, b'\0\1\2\3')
+
+    def test_read_submodule_resource_by_name(self):
+        result = (
+            resources.files('ziptestdata.subdirectory')
+            .joinpath('binary.file')
+            .read_bytes()
+        )
+        self.assertEqual(result, b'\0\1\2\3')
+
+
+class ReadNamespaceTests(ReadTests, unittest.TestCase):
+    def setUp(self):
+        from . import namespacedata01
+
+        self.data = namespacedata01
+
+
+if __name__ == '__main__':
+    unittest.main()

lib/importlib_resources/tests/test_reader.py

@@ -0,0 +1,144 @@
+import os.path
+import sys
+import pathlib
+import unittest
+
+from importlib import import_module
+from importlib_resources.readers import MultiplexedPath, NamespaceReader
+
+
+class MultiplexedPathTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        path = pathlib.Path(__file__).parent / 'namespacedata01'
+        cls.folder = str(path)
+
+    def test_init_no_paths(self):
+        with self.assertRaises(FileNotFoundError):
+            MultiplexedPath()
+
+    def test_init_file(self):
+        with self.assertRaises(NotADirectoryError):
+            MultiplexedPath(os.path.join(self.folder, 'binary.file'))
+
+    def test_iterdir(self):
+        contents = {path.name for path in MultiplexedPath(self.folder).iterdir()}
+        try:
+            contents.remove('__pycache__')
+        except (KeyError, ValueError):
+            pass
+        self.assertEqual(contents, {'binary.file', 'utf-16.file', 'utf-8.file'})
+
+    def test_iterdir_duplicate(self):
+        data01 = os.path.abspath(os.path.join(__file__, '..', 'data01'))
+        contents = {
+            path.name for path in MultiplexedPath(self.folder, data01).iterdir()
+        }
+        for remove in ('__pycache__', '__init__.pyc'):
+            try:
+                contents.remove(remove)
+            except (KeyError, ValueError):
+                pass
+        self.assertEqual(
+            contents,
+            {'__init__.py', 'binary.file', 'subdirectory', 'utf-16.file', 'utf-8.file'},
+        )
+
+    def test_is_dir(self):
+        self.assertEqual(MultiplexedPath(self.folder).is_dir(), True)
+
+    def test_is_file(self):
+        self.assertEqual(MultiplexedPath(self.folder).is_file(), False)
+
+    def test_open_file(self):
+        path = MultiplexedPath(self.folder)
+        with self.assertRaises(FileNotFoundError):
+            path.read_bytes()
+        with self.assertRaises(FileNotFoundError):
+            path.read_text()
+        with self.assertRaises(FileNotFoundError):
+            path.open()
+
+    def test_join_path(self):
+        prefix = os.path.abspath(os.path.join(__file__, '..'))
+        data01 = os.path.join(prefix, 'data01')
+        path = MultiplexedPath(self.folder, data01)
+        self.assertEqual(
+            str(path.joinpath('binary.file'))[len(prefix) + 1 :],
+            os.path.join('namespacedata01', 'binary.file'),
+        )
+        self.assertEqual(
+            str(path.joinpath('subdirectory'))[len(prefix) + 1 :],
+            os.path.join('data01', 'subdirectory'),
+        )
+        self.assertEqual(
+            str(path.joinpath('imaginary'))[len(prefix) + 1 :],
+            os.path.join('namespacedata01', 'imaginary'),
+        )
+        self.assertEqual(path.joinpath(), path)
+
+    def test_join_path_compound(self):
+        path = MultiplexedPath(self.folder)
+        assert not path.joinpath('imaginary/foo.py').exists()
+
+    def test_join_path_common_subdir(self):
+        prefix = os.path.abspath(os.path.join(__file__, '..'))
+        data01 = os.path.join(prefix, 'data01')
+        data02 = os.path.join(prefix, 'data02')
+        path = MultiplexedPath(data01, data02)
+        self.assertIsInstance(path.joinpath('subdirectory'), MultiplexedPath)
+        self.assertEqual(
+            str(path.joinpath('subdirectory', 'subsubdir'))[len(prefix) + 1 :],
+            os.path.join('data02', 'subdirectory', 'subsubdir'),
+        )
+
+    def test_repr(self):
+        self.assertEqual(
+            repr(MultiplexedPath(self.folder)),
+            f"MultiplexedPath('{self.folder}')",
+        )
+
+    def test_name(self):
+        self.assertEqual(
+            MultiplexedPath(self.folder).name,
+            os.path.basename(self.folder),
+        )
+
+
+class NamespaceReaderTest(unittest.TestCase):
+    site_dir = str(pathlib.Path(__file__).parent)
+
+    @classmethod
+    def setUpClass(cls):
+        sys.path.append(cls.site_dir)
+
+    @classmethod
+    def tearDownClass(cls):
+        sys.path.remove(cls.site_dir)
+
+    def test_init_error(self):
+        with self.assertRaises(ValueError):
+            NamespaceReader(['path1', 'path2'])
+
+    def test_resource_path(self):
+        namespacedata01 = import_module('namespacedata01')
+        reader = NamespaceReader(namespacedata01.__spec__.submodule_search_locations)
+
+        root = os.path.abspath(os.path.join(__file__, '..', 'namespacedata01'))
+        self.assertEqual(
+            reader.resource_path('binary.file'), os.path.join(root, 'binary.file')
+        )
+        self.assertEqual(
+            reader.resource_path('imaginary'), os.path.join(root, 'imaginary')
+        )
+
+    def test_files(self):
+        namespacedata01 = import_module('namespacedata01')
+        reader = NamespaceReader(namespacedata01.__spec__.submodule_search_locations)
+        root = os.path.abspath(os.path.join(__file__, '..', 'namespacedata01'))
+        self.assertIsInstance(reader.files(), MultiplexedPath)
+        self.assertEqual(repr(reader.files()), f"MultiplexedPath('{root}')")
+
+
+if __name__ == '__main__':
+    unittest.main()

lib/importlib_resources/tests/test_resource.py

@@ -0,0 +1,252 @@
+import contextlib
+import sys
+import unittest
+import importlib_resources as resources
+import uuid
+import pathlib
+
+from . import data01
+from . import zipdata01, zipdata02
+from . import util
+from importlib import import_module
+from ._compat import import_helper, os_helper, unlink
+
+
+class ResourceTests:
+    # Subclasses are expected to set the `data` attribute.
+
+    def test_is_file_exists(self):
+        target = resources.files(self.data) / 'binary.file'
+        self.assertTrue(target.is_file())
+
+    def test_is_file_missing(self):
+        target = resources.files(self.data) / 'not-a-file'
+        self.assertFalse(target.is_file())
+
+    def test_is_dir(self):
+        target = resources.files(self.data) / 'subdirectory'
+        self.assertFalse(target.is_file())
+        self.assertTrue(target.is_dir())
+
+
+class ResourceDiskTests(ResourceTests, unittest.TestCase):
+    def setUp(self):
+        self.data = data01
+
+
+class ResourceZipTests(ResourceTests, util.ZipSetup, unittest.TestCase):
+    pass
+
+
+def names(traversable):
+    return {item.name for item in traversable.iterdir()}
+
+
+class ResourceLoaderTests(unittest.TestCase):
+    def test_resource_contents(self):
+        package = util.create_package(
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C']
+        )
+        self.assertEqual(names(resources.files(package)), {'A', 'B', 'C'})
+
+    def test_is_file(self):
+        package = util.create_package(
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C', 'D/E', 'D/F']
+        )
+        self.assertTrue(resources.files(package).joinpath('B').is_file())
+
+    def test_is_dir(self):
+        package = util.create_package(
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C', 'D/E', 'D/F']
+        )
+        self.assertTrue(resources.files(package).joinpath('D').is_dir())
+
+    def test_resource_missing(self):
+        package = util.create_package(
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C', 'D/E', 'D/F']
+        )
+        self.assertFalse(resources.files(package).joinpath('Z').is_file())
+
+
+class ResourceCornerCaseTests(unittest.TestCase):
+    def test_package_has_no_reader_fallback(self):
+        """
+        Test odd ball packages which:
+        # 1. Do not have a ResourceReader as a loader
+        # 2. Are not on the file system
+        # 3. Are not in a zip file
+        """
+        module = util.create_package(
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C']
+        )
+        # Give the module a dummy loader.
+        module.__loader__ = object()
+        # Give the module a dummy origin.
+        module.__file__ = '/path/which/shall/not/be/named'
+        module.__spec__.loader = module.__loader__
+        module.__spec__.origin = module.__file__
+        self.assertFalse(resources.files(module).joinpath('A').is_file())
+
+
+class ResourceFromZipsTest01(util.ZipSetupBase, unittest.TestCase):
+    ZIP_MODULE = zipdata01  # type: ignore
+
+    def test_is_submodule_resource(self):
+        submodule = import_module('ziptestdata.subdirectory')
+        self.assertTrue(resources.files(submodule).joinpath('binary.file').is_file())
+
+    def test_read_submodule_resource_by_name(self):
+        self.assertTrue(
+            resources.files('ziptestdata.subdirectory')
+            .joinpath('binary.file')
+            .is_file()
+        )
+
+    def test_submodule_contents(self):
+        submodule = import_module('ziptestdata.subdirectory')
+        self.assertEqual(
+            names(resources.files(submodule)), {'__init__.py', 'binary.file'}
+        )
+
+    def test_submodule_contents_by_name(self):
+        self.assertEqual(
+            names(resources.files('ziptestdata.subdirectory')),
+            {'__init__.py', 'binary.file'},
+        )
+
+    def test_as_file_directory(self):
+        with resources.as_file(resources.files('ziptestdata')) as data:
+            assert data.name == 'ziptestdata'
+            assert data.is_dir()
+            assert data.joinpath('subdirectory').is_dir()
+            assert len(list(data.iterdir()))
+        assert not data.parent.exists()
+
+
+class ResourceFromZipsTest02(util.ZipSetupBase, unittest.TestCase):
+    ZIP_MODULE = zipdata02  # type: ignore
+
+    def test_unrelated_contents(self):
+        """
+        Test thata zip with two unrelated subpackages return
+        distinct resources. Ref python/importlib_resources#44.
+        """
+        self.assertEqual(
+            names(resources.files('ziptestdata.one')),
+            {'__init__.py', 'resource1.txt'},
+        )
+        self.assertEqual(
+            names(resources.files('ziptestdata.two')),
+            {'__init__.py', 'resource2.txt'},
+        )
+
+
+@contextlib.contextmanager
+def zip_on_path(dir):
+    data_path = pathlib.Path(zipdata01.__file__)
+    source_zip_path = data_path.parent.joinpath('ziptestdata.zip')
+    zip_path = pathlib.Path(dir) / f'{uuid.uuid4()}.zip'
+    zip_path.write_bytes(source_zip_path.read_bytes())
+    sys.path.append(str(zip_path))
+    import_module('ziptestdata')
+
+    try:
+        yield
+    finally:
+        with contextlib.suppress(ValueError):
+            sys.path.remove(str(zip_path))
+
+        with contextlib.suppress(KeyError):
+            del sys.path_importer_cache[str(zip_path)]
+            del sys.modules['ziptestdata']
+
+        with contextlib.suppress(OSError):
+            unlink(zip_path)
+
+
+class DeletingZipsTest(unittest.TestCase):
+    """Having accessed resources in a zip file should not keep an open
+    reference to the zip.
+    """
+
+    def setUp(self):
+        self.fixtures = contextlib.ExitStack()
+        self.addCleanup(self.fixtures.close)
+
+        modules = import_helper.modules_setup()
+        self.addCleanup(import_helper.modules_cleanup, *modules)
+
+        temp_dir = self.fixtures.enter_context(os_helper.temp_dir())
+        self.fixtures.enter_context(zip_on_path(temp_dir))
+
+    def test_iterdir_does_not_keep_open(self):
+        [item.name for item in resources.files('ziptestdata').iterdir()]
+
+    def test_is_file_does_not_keep_open(self):
+        resources.files('ziptestdata').joinpath('binary.file').is_file()
+
+    def test_is_file_failure_does_not_keep_open(self):
+        resources.files('ziptestdata').joinpath('not-present').is_file()
+
+    @unittest.skip("Desired but not supported.")
+    def test_as_file_does_not_keep_open(self):  # pragma: no cover
+        resources.as_file(resources.files('ziptestdata') / 'binary.file')
+
+    def test_entered_path_does_not_keep_open(self):
+        """
+        Mimic what certifi does on import to make its bundle
+        available for the process duration.
+        """
+        resources.as_file(resources.files('ziptestdata') / 'binary.file').__enter__()
+
+    def test_read_binary_does_not_keep_open(self):
+        resources.files('ziptestdata').joinpath('binary.file').read_bytes()
+
+    def test_read_text_does_not_keep_open(self):
+        resources.files('ziptestdata').joinpath('utf-8.file').read_text(
+            encoding='utf-8'
+        )
+
+
+class ResourceFromNamespaceTest01(unittest.TestCase):
+    site_dir = str(pathlib.Path(__file__).parent)
+
+    @classmethod
+    def setUpClass(cls):
+        sys.path.append(cls.site_dir)
+
+    @classmethod
+    def tearDownClass(cls):
+        sys.path.remove(cls.site_dir)
+
+    def test_is_submodule_resource(self):
+        self.assertTrue(
+            resources.files(import_module('namespacedata01'))
+            .joinpath('binary.file')
+            .is_file()
+        )
+
+    def test_read_submodule_resource_by_name(self):
+        self.assertTrue(
+            resources.files('namespacedata01').joinpath('binary.file').is_file()
+        )
+
+    def test_submodule_contents(self):
+        contents = names(resources.files(import_module('namespacedata01')))
+        try:
+            contents.remove('__pycache__')
+        except KeyError:
+            pass
+        self.assertEqual(contents, {'binary.file', 'utf-8.file', 'utf-16.file'})
+
+    def test_submodule_contents_by_name(self):
+        contents = names(resources.files('namespacedata01'))
+        try:
+            contents.remove('__pycache__')
+        except KeyError:
+            pass
+        self.assertEqual(contents, {'binary.file', 'utf-8.file', 'utf-16.file'})
+
+
+if __name__ == '__main__':
+    unittest.main()

lib/importlib_resources/tests/update-zips.py

@@ -0,0 +1,53 @@
+"""
+Generate the zip test data files.
+
+Run to build the tests/zipdataNN/ziptestdata.zip files from
+files in tests/dataNN.
+
+Replaces the file with the working copy, but does commit anything
+to the source repo.
+"""
+
+import contextlib
+import os
+import pathlib
+import zipfile
+
+
+def main():
+    """
+    >>> from unittest import mock
+    >>> monkeypatch = getfixture('monkeypatch')
+    >>> monkeypatch.setattr(zipfile, 'ZipFile', mock.MagicMock())
+    >>> print(); main()  # print workaround for bpo-32509
+    <BLANKLINE>
+    ...data01... -> ziptestdata/...
+    ...
+    ...data02... -> ziptestdata/...
+    ...
+    """
+    suffixes = '01', '02'
+    tuple(map(generate, suffixes))
+
+
+def generate(suffix):
+    root = pathlib.Path(__file__).parent.relative_to(os.getcwd())
+    zfpath = root / f'zipdata{suffix}/ziptestdata.zip'
+    with zipfile.ZipFile(zfpath, 'w') as zf:
+        for src, rel in walk(root / f'data{suffix}'):
+            dst = 'ziptestdata' / pathlib.PurePosixPath(rel.as_posix())
+            print(src, '->', dst)
+            zf.write(src, dst)
+
+
+def walk(datapath):
+    for dirpath, dirnames, filenames in os.walk(datapath):
+        with contextlib.suppress(ValueError):
+            dirnames.remove('__pycache__')
+        for filename in filenames:
+            res = pathlib.Path(dirpath) / filename
+            rel = res.relative_to(datapath)
+            yield res, rel
+
+
+__name__ == '__main__' and main()

lib/importlib_resources/tests/util.py

@@ -0,0 +1,179 @@
+import abc
+import importlib
+import io
+import sys
+import types
+import pathlib
+
+from . import data01
+from . import zipdata01
+from ..abc import ResourceReader
+from ._compat import import_helper
+
+
+from importlib.machinery import ModuleSpec
+
+
+class Reader(ResourceReader):
+    def __init__(self, **kwargs):
+        vars(self).update(kwargs)
+
+    def get_resource_reader(self, package):
+        return self
+
+    def open_resource(self, path):
+        self._path = path
+        if isinstance(self.file, Exception):
+            raise self.file
+        return self.file
+
+    def resource_path(self, path_):
+        self._path = path_
+        if isinstance(self.path, Exception):
+            raise self.path
+        return self.path
+
+    def is_resource(self, path_):
+        self._path = path_
+        if isinstance(self.path, Exception):
+            raise self.path
+
+        def part(entry):
+            return entry.split('/')
+
+        return any(
+            len(parts) == 1 and parts[0] == path_ for parts in map(part, self._contents)
+        )
+
+    def contents(self):
+        if isinstance(self.path, Exception):
+            raise self.path
+        yield from self._contents
+
+
+def create_package_from_loader(loader, is_package=True):
+    name = 'testingpackage'
+    module = types.ModuleType(name)
+    spec = ModuleSpec(name, loader, origin='does-not-exist', is_package=is_package)
+    module.__spec__ = spec
+    module.__loader__ = loader
+    return module
+
+
+def create_package(file=None, path=None, is_package=True, contents=()):
+    return create_package_from_loader(
+        Reader(file=file, path=path, _contents=contents),
+        is_package,
+    )
+
+
+class CommonTests(metaclass=abc.ABCMeta):
+    """
+    Tests shared by test_open, test_path, and test_read.
+    """
+
+    @abc.abstractmethod
+    def execute(self, package, path):
+        """
+        Call the pertinent legacy API function (e.g. open_text, path)
+        on package and path.
+        """
+
+    def test_package_name(self):
+        """
+        Passing in the package name should succeed.
+        """
+        self.execute(data01.__name__, 'utf-8.file')
+
+    def test_package_object(self):
+        """
+        Passing in the package itself should succeed.
+        """
+        self.execute(data01, 'utf-8.file')
+
+    def test_string_path(self):
+        """
+        Passing in a string for the path should succeed.
+        """
+        path = 'utf-8.file'
+        self.execute(data01, path)
+
+    def test_pathlib_path(self):
+        """
+        Passing in a pathlib.PurePath object for the path should succeed.
+        """
+        path = pathlib.PurePath('utf-8.file')
+        self.execute(data01, path)
+
+    def test_importing_module_as_side_effect(self):
+        """
+        The anchor package can already be imported.
+        """
+        del sys.modules[data01.__name__]
+        self.execute(data01.__name__, 'utf-8.file')
+
+    def test_missing_path(self):
+        """
+        Attempting to open or read or request the path for a
+        non-existent path should succeed if open_resource
+        can return a viable data stream.
+        """
+        bytes_data = io.BytesIO(b'Hello, world!')
+        package = create_package(file=bytes_data, path=FileNotFoundError())
+        self.execute(package, 'utf-8.file')
+        self.assertEqual(package.__loader__._path, 'utf-8.file')
+
+    def test_extant_path(self):
+        # Attempting to open or read or request the path when the
+        # path does exist should still succeed. Does not assert
+        # anything about the result.
+        bytes_data = io.BytesIO(b'Hello, world!')
+        # any path that exists
+        path = __file__
+        package = create_package(file=bytes_data, path=path)
+        self.execute(package, 'utf-8.file')
+        self.assertEqual(package.__loader__._path, 'utf-8.file')
+
+    def test_useless_loader(self):
+        package = create_package(file=FileNotFoundError(), path=FileNotFoundError())
+        with self.assertRaises(FileNotFoundError):
+            self.execute(package, 'utf-8.file')
+
+
+class ZipSetupBase:
+    ZIP_MODULE = None
+
+    @classmethod
+    def setUpClass(cls):
+        data_path = pathlib.Path(cls.ZIP_MODULE.__file__)
+        data_dir = data_path.parent
+        cls._zip_path = str(data_dir / 'ziptestdata.zip')
+        sys.path.append(cls._zip_path)
+        cls.data = importlib.import_module('ziptestdata')
+
+    @classmethod
+    def tearDownClass(cls):
+        try:
+            sys.path.remove(cls._zip_path)
+        except ValueError:
+            pass
+
+        try:
+            del sys.path_importer_cache[cls._zip_path]
+            del sys.modules[cls.data.__name__]
+        except KeyError:
+            pass
+
+        try:
+            del cls.data
+            del cls._zip_path
+        except AttributeError:
+            pass
+
+    def setUp(self):
+        modules = import_helper.modules_setup()
+        self.addCleanup(import_helper.modules_cleanup, *modules)
+
+
+class ZipSetup(ZipSetupBase):
+    ZIP_MODULE = zipdata01  # type: ignore

requirements.txt

@@ -19,6 +19,8 @@ gntp==1.0.3
 html5lib==1.1
 httpagentparser==1.9.5
 idna==3.4
+importlib-metadata==6.8.0
+importlib-resources==6.0.1
 git+https://github.com/Tautulli/ipwhois.git@master#egg=ipwhois
 IPy==1.01
 Mako==1.2.4