GH-128520: pathlib ABCs: allow tests to be run externally (#131315)

Adjust the tests for the `pathlib.types` module so that they can be run
against the `pathlib-abc` PyPI package, which is a backport of the module
for older Python versions.

Specifically, we add a `.support.is_pypi` switch that is false in the
stdlib and true in the pathlib-abc package. This controls which package
we import, and whether or not we run tests against `PurePath` and `Path`.

For compatibility with older Python versions, we stop using
`zipfile.ZipFile.mkdir()` and `zipfile.ZipInfo._for_archive()`.

1 files changed, 13 insertions, 7 deletions

diff --git a/Lib/test/test_pathlib/test_join.py b/Lib/test/test_pathlib/test_join.py
index 03a3ecf..f1a2420 100644
--- a/Lib/test/test_pathlib/test_join.py
+++ b/Lib/test/test_pathlib/test_join.py
@@ -4,9 +4,13 @@ Tests for pathlib.types._JoinablePath
 
 import unittest
 
-from pathlib import PurePath, Path
-from pathlib.types import _PathParser, _JoinablePath
-from test.test_pathlib.support.lexical_path import LexicalPath
+from .support import is_pypi
+from .support.lexical_path import LexicalPath
+
+if is_pypi:
+    from pathlib_abc import _PathParser, _JoinablePath
+else:
+    from pathlib.types import _PathParser, _JoinablePath
 
 
 class JoinTestBase:
@@ -355,12 +359,14 @@ class LexicalPathJoinTest(JoinTestBase, unittest.TestCase):
     cls = LexicalPath
 
 
-class PurePathJoinTest(JoinTestBase, unittest.TestCase):
-    cls = PurePath
+if not is_pypi:
+    from pathlib import PurePath, Path
 
+    class PurePathJoinTest(JoinTestBase, unittest.TestCase):
+        cls = PurePath
 
-class PathJoinTest(JoinTestBase, unittest.TestCase):
-    cls = Path
+    class PathJoinTest(JoinTestBase, unittest.TestCase):
+        cls = Path
 
 
 if __name__ == "__main__":