Revert "Remove importlib-metadata and importlib-resources"

This reverts commit 38435ae81c.

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