Revert "Remove importlib-metadata and importlib-resources"

This reverts commit 38435ae81c.

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()