bpo-42129: Add support for resources in namespaces (GH-24670)

* Unify behavior in ResourceReaderDefaultsTests and align with the behavior found in importlib_resources.
* Equip NamespaceLoader with a NamespaceReader.
* Apply changes from importlib_resources 5.0.4

Lib/test/test_importlib/namespacedata01/utf-8.file

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

Lib/test/test_importlib/test_abc.py

@@ -338,7 +338,9 @@ class ResourceReaderDefaultsTests(ABCTestHarness):
             self.ins.is_resource('dummy_file')
 
     def test_contents(self):
-        self.assertEqual([], list(self.ins.contents()))
+        with self.assertRaises(FileNotFoundError):
+            self.ins.contents()
+
 
 (Frozen_RRDefaultTests,
  Source_RRDefaultsTests

Lib/test/test_importlib/test_files.py

@@ -21,7 +21,7 @@ class FilesTests:
     @unittest.skipUnless(
         hasattr(typing, 'runtime_checkable'),
         "Only suitable when typing supports runtime_checkable",
-        )
+    )
     def test_traversable(self):
         assert isinstance(resources.files(self.data), Traversable)
 

Lib/test/test_importlib/test_open.py

@@ -29,34 +29,32 @@ class OpenTests:
             self.assertEqual(result, 'Hello, UTF-8 world!\n')
 
     def test_open_text_given_encoding(self):
-        with resources.open_text(
-                self.data, 'utf-16.file', 'utf-16', 'strict') as fp:
+        with resources.open_text(self.data, 'utf-16.file', 'utf-16', '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.
-        with resources.open_text(
-                self.data, 'utf-16.file', 'utf-8', 'strict') as fp:
+        with resources.open_text(self.data, 'utf-16.file', 'utf-8', 'strict') as fp:
             self.assertRaises(UnicodeError, fp.read)
-        with resources.open_text(
-                self.data, 'utf-16.file', 'utf-8', 'ignore') as fp:
+        with resources.open_text(self.data, 'utf-16.file', 'utf-8', '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')
+            '\x00w\x00o\x00r\x00l\x00d\x00!\x00\n\x00',
+        )
 
     def test_open_binary_FileNotFoundError(self):
         self.assertRaises(
-            FileNotFoundError,
-            resources.open_binary, self.data, 'does-not-exist')
+            FileNotFoundError, resources.open_binary, self.data, 'does-not-exist'
+        )
 
     def test_open_text_FileNotFoundError(self):
         self.assertRaises(
-            FileNotFoundError,
-            resources.open_text, self.data, 'does-not-exist')
+            FileNotFoundError, resources.open_text, self.data, 'does-not-exist'
+        )
 
 
 class OpenDiskTests(OpenTests, unittest.TestCase):
@@ -64,6 +62,13 @@ class OpenDiskTests(OpenTests, unittest.TestCase):
         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
 

Lib/test/test_importlib/test_path.py

@@ -1,3 +1,4 @@
+import io
 import unittest
 
 from importlib import resources
@@ -37,6 +38,17 @@ class PathDiskTests(PathTests, unittest.TestCase):
             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

Lib/test/test_importlib/test_read.py

@@ -25,20 +25,19 @@ class ReadTests:
         self.assertEqual(result, 'Hello, UTF-8 world!\n')
 
     def test_read_text_given_encoding(self):
-        result = resources.read_text(
-            self.data, 'utf-16.file', encoding='utf-16')
+        result = resources.read_text(self.data, 'utf-16.file', encoding='utf-16')
         self.assertEqual(result, 'Hello, UTF-16 world!\n')
 
     def test_read_text_with_errors(self):
         # Raises UnicodeError without the 'errors' argument.
-        self.assertRaises(
-            UnicodeError, resources.read_text, self.data, 'utf-16.file')
+        self.assertRaises(UnicodeError, resources.read_text, self.data, 'utf-16.file')
         result = resources.read_text(self.data, 'utf-16.file', 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')
+            '\x00w\x00o\x00r\x00l\x00d\x00!\x00\n\x00',
+        )
 
 
 class ReadDiskTests(ReadTests, unittest.TestCase):
@@ -48,13 +47,11 @@ class ReadDiskTests(ReadTests, unittest.TestCase):
 class ReadZipTests(ReadTests, util.ZipSetup, unittest.TestCase):
     def test_read_submodule_resource(self):
         submodule = import_module('ziptestdata.subdirectory')
-        result = resources.read_binary(
-            submodule, 'binary.file')
+        result = resources.read_binary(submodule, 'binary.file')
         self.assertEqual(result, b'\0\1\2\3')
 
     def test_read_submodule_resource_by_name(self):
-        result = resources.read_binary(
-            'ziptestdata.subdirectory', 'binary.file')
+        result = resources.read_binary('ziptestdata.subdirectory', 'binary.file')
         self.assertEqual(result, b'\0\1\2\3')
 
 

Lib/test/test_importlib/test_reader.py

@@ -0,0 +1,123 @@
+import os.path
+import sys
+import pathlib
+import unittest
+
+from importlib import import_module
+from importlib.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):
+        print('test_join_path')
+        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'),
+        )
+
+    def test_repr(self):
+        self.assertEqual(
+            repr(MultiplexedPath(self.folder)),
+            "MultiplexedPath('{}')".format(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()), "MultiplexedPath('{}')".format(root))
+
+
+if __name__ == '__main__':
+    unittest.main()

Lib/test/test_importlib/test_resource.py

@@ -27,20 +27,21 @@ class ResourceTests:
     def test_contents(self):
         contents = set(resources.contents(self.data))
         # There may be cruft in the directory listing of the data directory.
-        # Under Python 3 we could have a __pycache__ directory, and under
-        # Python 2 we could have .pyc files.  These are both artifacts of the
-        # test suite importing these modules and writing these caches.  They
-        # aren't germane to this test, so just filter them out.
+        # It could have a __pycache__ directory,
+        # an artifact of the
+        # test suite importing these modules, which
+        # are not germane to this test, so just filter them out.
         contents.discard('__pycache__')
-        contents.discard('__init__.pyc')
-        contents.discard('__init__.pyo')
-        self.assertEqual(contents, {
-            '__init__.py',
-            'subdirectory',
-            'utf-8.file',
-            'binary.file',
-            'utf-16.file',
-            })
+        self.assertEqual(
+            contents,
+            {
+                '__init__.py',
+                'subdirectory',
+                'utf-8.file',
+                'binary.file',
+                'utf-16.file',
+            },
+        )
 
 
 class ResourceDiskTests(ResourceTests, unittest.TestCase):
@@ -55,27 +56,26 @@ class ResourceZipTests(ResourceTests, util.ZipSetup, unittest.TestCase):
 class ResourceLoaderTests(unittest.TestCase):
     def test_resource_contents(self):
         package = util.create_package(
-            file=data01, path=data01.__file__, contents=['A', 'B', 'C'])
-        self.assertEqual(
-            set(resources.contents(package)),
-            {'A', 'B', 'C'})
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C']
+        )
+        self.assertEqual(set(resources.contents(package)), {'A', 'B', 'C'})
 
     def test_resource_is_resource(self):
         package = util.create_package(
-            file=data01, path=data01.__file__,
-            contents=['A', 'B', 'C', 'D/E', 'D/F'])
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C', 'D/E', 'D/F']
+        )
         self.assertTrue(resources.is_resource(package, 'B'))
 
     def test_resource_directory_is_not_resource(self):
         package = util.create_package(
-            file=data01, path=data01.__file__,
-            contents=['A', 'B', 'C', 'D/E', 'D/F'])
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C', 'D/E', 'D/F']
+        )
         self.assertFalse(resources.is_resource(package, 'D'))
 
     def test_resource_missing_is_not_resource(self):
         package = util.create_package(
-            file=data01, path=data01.__file__,
-            contents=['A', 'B', 'C', 'D/E', 'D/F'])
+            file=data01, path=data01.__file__, contents=['A', 'B', 'C', 'D/E', 'D/F']
+        )
         self.assertFalse(resources.is_resource(package, 'Z'))
 
 
@@ -86,90 +86,63 @@ class ResourceCornerCaseTests(unittest.TestCase):
         # 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'])
+            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'
-        if sys.version_info >= (3,):
-            module.__spec__.loader = module.__loader__
-            module.__spec__.origin = module.__file__
+        module.__spec__.loader = module.__loader__
+        module.__spec__.origin = module.__file__
         self.assertFalse(resources.is_resource(module, 'A'))
 
 
-class ResourceFromZipsTest(util.ZipSetupBase, unittest.TestCase):
-    ZIP_MODULE = zipdata02                          # type: ignore
-
-    def test_unrelated_contents(self):
-        # https://gitlab.com/python-devs/importlib_resources/issues/44
-        #
-        # Here we have a zip file with two unrelated subpackages.  The bug
-        # reports that getting the contents of a resource returns unrelated
-        # files.
-        self.assertEqual(
-            set(resources.contents('ziptestdata.one')),
-            {'__init__.py', 'resource1.txt'})
-        self.assertEqual(
-            set(resources.contents('ziptestdata.two')),
-            {'__init__.py', 'resource2.txt'})
-
-
-class SubdirectoryResourceFromZipsTest(util.ZipSetupBase, unittest.TestCase):
-    ZIP_MODULE = zipdata01                          # type: ignore
+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.is_resource(submodule, 'binary.file'))
+        self.assertTrue(resources.is_resource(submodule, 'binary.file'))
 
     def test_read_submodule_resource_by_name(self):
         self.assertTrue(
-            resources.is_resource('ziptestdata.subdirectory', 'binary.file'))
+            resources.is_resource('ziptestdata.subdirectory', 'binary.file')
+        )
 
     def test_submodule_contents(self):
         submodule = import_module('ziptestdata.subdirectory')
         self.assertEqual(
-            set(resources.contents(submodule)),
-            {'__init__.py', 'binary.file'})
+            set(resources.contents(submodule)), {'__init__.py', 'binary.file'}
+        )
 
     def test_submodule_contents_by_name(self):
         self.assertEqual(
             set(resources.contents('ziptestdata.subdirectory')),
-            {'__init__.py', 'binary.file'})
+            {'__init__.py', 'binary.file'},
+        )
 
 
-class NamespaceTest(unittest.TestCase):
-    def test_namespaces_cannot_have_resources(self):
-        contents = resources.contents('test.test_importlib.data03.namespace')
-        self.assertFalse(list(contents))
-        # Even though there is a file in the namespace directory, it is not
-        # considered a resource, since namespace packages can't have them.
-        self.assertFalse(resources.is_resource(
-            'test.test_importlib.data03.namespace',
-            'resource1.txt'))
-        # We should get an exception if we try to read it or open it.
-        self.assertRaises(
-            FileNotFoundError,
-            resources.open_text,
-            'test.test_importlib.data03.namespace', 'resource1.txt')
-        self.assertRaises(
-            FileNotFoundError,
-            resources.open_binary,
-            'test.test_importlib.data03.namespace', 'resource1.txt')
-        self.assertRaises(
-            FileNotFoundError,
-            resources.read_text,
-            'test.test_importlib.data03.namespace', 'resource1.txt')
-        self.assertRaises(
-            FileNotFoundError,
-            resources.read_binary,
-            'test.test_importlib.data03.namespace', 'resource1.txt')
+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(
+            set(resources.contents('ziptestdata.one')), {'__init__.py', 'resource1.txt'}
+        )
+        self.assertEqual(
+            set(resources.contents('ziptestdata.two')), {'__init__.py', 'resource2.txt'}
+        )
 
 
 class DeletingZipsTest(unittest.TestCase):
     """Having accessed resources in a zip file should not keep an open
     reference to the zip.
     """
+
     ZIP_MODULE = zipdata01
 
     def setUp(self):
@@ -241,5 +214,41 @@ class DeletingZipsTest(unittest.TestCase):
         del c
 
 
+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.is_resource(import_module('namespacedata01'), 'binary.file')
+        )
+
+    def test_read_submodule_resource_by_name(self):
+        self.assertTrue(resources.is_resource('namespacedata01', 'binary.file'))
+
+    def test_submodule_contents(self):
+        contents = set(resources.contents(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 = set(resources.contents('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/test/test_importlib/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(KeyError):
+            dirnames.remove('__pycache__')
+        for filename in filenames:
+            res = pathlib.Path(dirpath) / filename
+            rel = res.relative_to(datapath)
+            yield res, rel
+
+
+__name__ == '__main__' and main()