pathlib tests: create test hierarchy without using class under test (#128200)

In the pathlib tests, avoid using the path class under test (`self.cls`) in
test setup. Instead we use `os` functions in `test_pathlib`, and direct
manipulation of `DummyPath` internal data in `test_pathlib_abc`.

1 files changed, 36 insertions, 2 deletions

diff --git a/Lib/test/test_pathlib/test_pathlib.py b/Lib/test/test_pathlib/test_pathlib.py
index ef482c31154..fac8cbdf65a 100644
--- a/Lib/test/test_pathlib/test_pathlib.py
+++ b/Lib/test/test_pathlib/test_pathlib.py
@@ -578,10 +578,44 @@ class PathTest(test_pathlib_abc.DummyPathTest, PurePathTest):
         if name in _tests_needing_symlinks and not self.can_symlink:
             self.skipTest('requires symlinks')
         super().setUp()
-        os.chmod(self.parser.join(self.base, 'dirE'), 0)
+
+    def createTestHierarchy(self):
+        os.mkdir(self.base)
+        os.mkdir(os.path.join(self.base, 'dirA'))
+        os.mkdir(os.path.join(self.base, 'dirB'))
+        os.mkdir(os.path.join(self.base, 'dirC'))
+        os.mkdir(os.path.join(self.base, 'dirC', 'dirD'))
+        os.mkdir(os.path.join(self.base, 'dirE'))
+        with open(os.path.join(self.base, 'fileA'), 'wb') as f:
+            f.write(b"this is file A\n")
+        with open(os.path.join(self.base, 'dirB', 'fileB'), 'wb') as f:
+            f.write(b"this is file B\n")
+        with open(os.path.join(self.base, 'dirC', 'fileC'), 'wb') as f:
+            f.write(b"this is file C\n")
+        with open(os.path.join(self.base, 'dirC', 'novel.txt'), 'wb') as f:
+            f.write(b"this is a novel\n")
+        with open(os.path.join(self.base, 'dirC', 'dirD', 'fileD'), 'wb') as f:
+            f.write(b"this is file D\n")
+        os.chmod(os.path.join(self.base, 'dirE'), 0)
+        if self.can_symlink:
+            # Relative symlinks.
+            os.symlink('fileA', os.path.join(self.base, 'linkA'))
+            os.symlink('non-existing', os.path.join(self.base, 'brokenLink'))
+            os.symlink('dirB',
+                       os.path.join(self.base, 'linkB'),
+                       target_is_directory=True)
+            os.symlink(os.path.join('..', 'dirB'),
+                       os.path.join(self.base, 'dirA', 'linkC'),
+                       target_is_directory=True)
+            # This one goes upwards, creating a loop.
+            os.symlink(os.path.join('..', 'dirB'),
+                       os.path.join(self.base, 'dirB', 'linkD'),
+                       target_is_directory=True)
+            # Broken symlink (pointing to itself).
+            os.symlink('brokenLinkLoop', os.path.join(self.base, 'brokenLinkLoop'))
 
     def tearDown(self):
-        os.chmod(self.parser.join(self.base, 'dirE'), 0o777)
+        os.chmod(os.path.join(self.base, 'dirE'), 0o777)
         os_helper.rmtree(self.base)
 
     def tempdir(self):