GH-127381: pathlib ABCs: remove `PathBase.samefile()` and rarer `is_*()` (#127709)

Remove `PathBase.samefile()`, which is fairly specific to the local FS, and
relies on `stat()`, which we're aiming to remove from `PathBase`.

Also remove `PathBase.is_mount()`, `is_junction()`, `is_block_device()`,
`is_char_device()`, `is_fifo()` and `is_socket()`. These rely on POSIX
file type numbers that we're aiming to remove from the `PathBase` API.

2 files changed, 75 insertions, 83 deletions

diff --git a/Lib/test/test_pathlib/test_pathlib.py b/Lib/test/test_pathlib/test_pathlib.py
index ce0f474..b57ef42 100644
--- a/Lib/test/test_pathlib/test_pathlib.py
+++ b/Lib/test/test_pathlib/test_pathlib.py
@@ -1786,13 +1786,31 @@ class PathTest(test_pathlib_abc.DummyPathTest, PurePathTest):
         st = p.stat()
         self.assertEqual(st, p.lstat())
 
-    def test_is_junction(self):
+    def test_is_junction_false(self):
+        P = self.cls(self.base)
+        self.assertFalse((P / 'fileA').is_junction())
+        self.assertFalse((P / 'dirA').is_junction())
+        self.assertFalse((P / 'non-existing').is_junction())
+        self.assertFalse((P / 'fileA' / 'bah').is_junction())
+        self.assertFalse((P / 'fileA\udfff').is_junction())
+        self.assertFalse((P / 'fileA\x00').is_junction())
+
+    def test_is_junction_true(self):
         P = self.cls(self.base)
 
         with mock.patch.object(P.parser, 'isjunction'):
             self.assertEqual(P.is_junction(), P.parser.isjunction.return_value)
             P.parser.isjunction.assert_called_once_with(P)
 
+    def test_is_fifo_false(self):
+        P = self.cls(self.base)
+        self.assertFalse((P / 'fileA').is_fifo())
+        self.assertFalse((P / 'dirA').is_fifo())
+        self.assertFalse((P / 'non-existing').is_fifo())
+        self.assertFalse((P / 'fileA' / 'bah').is_fifo())
+        self.assertIs((P / 'fileA\udfff').is_fifo(), False)
+        self.assertIs((P / 'fileA\x00').is_fifo(), False)
+
     @unittest.skipUnless(hasattr(os, "mkfifo"), "os.mkfifo() required")
     @unittest.skipIf(sys.platform == "vxworks",
                     "fifo requires special path on VxWorks")
@@ -1808,6 +1826,15 @@ class PathTest(test_pathlib_abc.DummyPathTest, PurePathTest):
         self.assertIs(self.cls(self.base, 'myfifo\udfff').is_fifo(), False)
         self.assertIs(self.cls(self.base, 'myfifo\x00').is_fifo(), False)
 
+    def test_is_socket_false(self):
+        P = self.cls(self.base)
+        self.assertFalse((P / 'fileA').is_socket())
+        self.assertFalse((P / 'dirA').is_socket())
+        self.assertFalse((P / 'non-existing').is_socket())
+        self.assertFalse((P / 'fileA' / 'bah').is_socket())
+        self.assertIs((P / 'fileA\udfff').is_socket(), False)
+        self.assertIs((P / 'fileA\x00').is_socket(), False)
+
     @unittest.skipUnless(hasattr(socket, "AF_UNIX"), "Unix sockets required")
     @unittest.skipIf(
         is_emscripten, "Unix sockets are not implemented on Emscripten."
@@ -1831,6 +1858,24 @@ class PathTest(test_pathlib_abc.DummyPathTest, PurePathTest):
         self.assertIs(self.cls(self.base, 'mysock\udfff').is_socket(), False)
         self.assertIs(self.cls(self.base, 'mysock\x00').is_socket(), False)
 
+    def test_is_block_device_false(self):
+        P = self.cls(self.base)
+        self.assertFalse((P / 'fileA').is_block_device())
+        self.assertFalse((P / 'dirA').is_block_device())
+        self.assertFalse((P / 'non-existing').is_block_device())
+        self.assertFalse((P / 'fileA' / 'bah').is_block_device())
+        self.assertIs((P / 'fileA\udfff').is_block_device(), False)
+        self.assertIs((P / 'fileA\x00').is_block_device(), False)
+
+    def test_is_char_device_false(self):
+        P = self.cls(self.base)
+        self.assertFalse((P / 'fileA').is_char_device())
+        self.assertFalse((P / 'dirA').is_char_device())
+        self.assertFalse((P / 'non-existing').is_char_device())
+        self.assertFalse((P / 'fileA' / 'bah').is_char_device())
+        self.assertIs((P / 'fileA\udfff').is_char_device(), False)
+        self.assertIs((P / 'fileA\x00').is_char_device(), False)
+
     def test_is_char_device_true(self):
         # os.devnull should generally be a char device.
         P = self.cls(os.devnull)
@@ -1842,7 +1887,14 @@ class PathTest(test_pathlib_abc.DummyPathTest, PurePathTest):
         self.assertIs(self.cls(f'{os.devnull}\udfff').is_char_device(), False)
         self.assertIs(self.cls(f'{os.devnull}\x00').is_char_device(), False)
 
-    def test_is_mount_root(self):
+    def test_is_mount(self):
+        P = self.cls(self.base)
+        self.assertFalse((P / 'fileA').is_mount())
+        self.assertFalse((P / 'dirA').is_mount())
+        self.assertFalse((P / 'non-existing').is_mount())
+        self.assertFalse((P / 'fileA' / 'bah').is_mount())
+        if self.can_symlink:
+            self.assertFalse((P / 'linkA').is_mount())
         if os.name == 'nt':
             R = self.cls('c:\\')
         else:
@@ -1850,6 +1902,27 @@ class PathTest(test_pathlib_abc.DummyPathTest, PurePathTest):
         self.assertTrue(R.is_mount())
         self.assertFalse((R / '\udfff').is_mount())
 
+    def test_samefile(self):
+        parser = self.parser
+        fileA_path = parser.join(self.base, 'fileA')
+        fileB_path = parser.join(self.base, 'dirB', 'fileB')
+        p = self.cls(fileA_path)
+        pp = self.cls(fileA_path)
+        q = self.cls(fileB_path)
+        self.assertTrue(p.samefile(fileA_path))
+        self.assertTrue(p.samefile(pp))
+        self.assertFalse(p.samefile(fileB_path))
+        self.assertFalse(p.samefile(q))
+        # Test the non-existent file case
+        non_existent = parser.join(self.base, 'foo')
+        r = self.cls(non_existent)
+        self.assertRaises(FileNotFoundError, p.samefile, r)
+        self.assertRaises(FileNotFoundError, p.samefile, non_existent)
+        self.assertRaises(FileNotFoundError, r.samefile, p)
+        self.assertRaises(FileNotFoundError, r.samefile, non_existent)
+        self.assertRaises(FileNotFoundError, r.samefile, r)
+        self.assertRaises(FileNotFoundError, r.samefile, non_existent)
+
     def test_passing_kwargs_errors(self):
         with self.assertRaises(TypeError):
             self.cls(foo="bar")
diff --git a/Lib/test/test_pathlib/test_pathlib_abc.py b/Lib/test/test_pathlib/test_pathlib_abc.py
index dd9425c..f4c364c 100644
--- a/Lib/test/test_pathlib/test_pathlib_abc.py
+++ b/Lib/test/test_pathlib/test_pathlib_abc.py
@@ -1300,15 +1300,9 @@ class PathBaseTest(PurePathBaseTest):
         e = UnsupportedOperation
         self.assertRaises(e, p.stat)
         self.assertRaises(e, p.exists)
-        self.assertRaises(e, p.samefile, 'foo')
         self.assertRaises(e, p.is_dir)
         self.assertRaises(e, p.is_file)
-        self.assertRaises(e, p.is_mount)
         self.assertRaises(e, p.is_symlink)
-        self.assertRaises(e, p.is_block_device)
-        self.assertRaises(e, p.is_char_device)
-        self.assertRaises(e, p.is_fifo)
-        self.assertRaises(e, p.is_socket)
         self.assertRaises(e, p.open)
         self.assertRaises(e, p.read_bytes)
         self.assertRaises(e, p.read_text)
@@ -1535,27 +1529,6 @@ class DummyPathTest(DummyPurePathTest):
         normcase = self.parser.normcase
         self.assertEqual(normcase(path_a), normcase(path_b))
 
-    def test_samefile(self):
-        parser = self.parser
-        fileA_path = parser.join(self.base, 'fileA')
-        fileB_path = parser.join(self.base, 'dirB', 'fileB')
-        p = self.cls(fileA_path)
-        pp = self.cls(fileA_path)
-        q = self.cls(fileB_path)
-        self.assertTrue(p.samefile(fileA_path))
-        self.assertTrue(p.samefile(pp))
-        self.assertFalse(p.samefile(fileB_path))
-        self.assertFalse(p.samefile(q))
-        # Test the non-existent file case
-        non_existent = parser.join(self.base, 'foo')
-        r = self.cls(non_existent)
-        self.assertRaises(FileNotFoundError, p.samefile, r)
-        self.assertRaises(FileNotFoundError, p.samefile, non_existent)
-        self.assertRaises(FileNotFoundError, r.samefile, p)
-        self.assertRaises(FileNotFoundError, r.samefile, non_existent)
-        self.assertRaises(FileNotFoundError, r.samefile, r)
-        self.assertRaises(FileNotFoundError, r.samefile, non_existent)
-
     def test_exists(self):
         P = self.cls
         p = P(self.base)
@@ -2115,15 +2088,6 @@ class DummyPathTest(DummyPurePathTest):
         self.assertFalse((P / 'fileA\udfff').is_file(follow_symlinks=False))
         self.assertFalse((P / 'fileA\x00').is_file(follow_symlinks=False))
 
-    def test_is_mount(self):
-        P = self.cls(self.base)
-        self.assertFalse((P / 'fileA').is_mount())
-        self.assertFalse((P / 'dirA').is_mount())
-        self.assertFalse((P / 'non-existing').is_mount())
-        self.assertFalse((P / 'fileA' / 'bah').is_mount())
-        if self.can_symlink:
-            self.assertFalse((P / 'linkA').is_mount())
-
     def test_is_symlink(self):
         P = self.cls(self.base)
         self.assertFalse((P / 'fileA').is_symlink())
@@ -2140,51 +2104,6 @@ class DummyPathTest(DummyPurePathTest):
             self.assertIs((P / 'linkA\udfff').is_file(), False)
             self.assertIs((P / 'linkA\x00').is_file(), False)
 
-    def test_is_junction_false(self):
-        P = self.cls(self.base)
-        self.assertFalse((P / 'fileA').is_junction())
-        self.assertFalse((P / 'dirA').is_junction())
-        self.assertFalse((P / 'non-existing').is_junction())
-        self.assertFalse((P / 'fileA' / 'bah').is_junction())
-        self.assertFalse((P / 'fileA\udfff').is_junction())
-        self.assertFalse((P / 'fileA\x00').is_junction())
-
-    def test_is_fifo_false(self):
-        P = self.cls(self.base)
-        self.assertFalse((P / 'fileA').is_fifo())
-        self.assertFalse((P / 'dirA').is_fifo())
-        self.assertFalse((P / 'non-existing').is_fifo())
-        self.assertFalse((P / 'fileA' / 'bah').is_fifo())
-        self.assertIs((P / 'fileA\udfff').is_fifo(), False)
-        self.assertIs((P / 'fileA\x00').is_fifo(), False)
-
-    def test_is_socket_false(self):
-        P = self.cls(self.base)
-        self.assertFalse((P / 'fileA').is_socket())
-        self.assertFalse((P / 'dirA').is_socket())
-        self.assertFalse((P / 'non-existing').is_socket())
-        self.assertFalse((P / 'fileA' / 'bah').is_socket())
-        self.assertIs((P / 'fileA\udfff').is_socket(), False)
-        self.assertIs((P / 'fileA\x00').is_socket(), False)
-
-    def test_is_block_device_false(self):
-        P = self.cls(self.base)
-        self.assertFalse((P / 'fileA').is_block_device())
-        self.assertFalse((P / 'dirA').is_block_device())
-        self.assertFalse((P / 'non-existing').is_block_device())
-        self.assertFalse((P / 'fileA' / 'bah').is_block_device())
-        self.assertIs((P / 'fileA\udfff').is_block_device(), False)
-        self.assertIs((P / 'fileA\x00').is_block_device(), False)
-
-    def test_is_char_device_false(self):
-        P = self.cls(self.base)
-        self.assertFalse((P / 'fileA').is_char_device())
-        self.assertFalse((P / 'dirA').is_char_device())
-        self.assertFalse((P / 'non-existing').is_char_device())
-        self.assertFalse((P / 'fileA' / 'bah').is_char_device())
-        self.assertIs((P / 'fileA\udfff').is_char_device(), False)
-        self.assertIs((P / 'fileA\x00').is_char_device(), False)
-
     def test_delete_file(self):
         p = self.cls(self.base) / 'fileA'
         p._delete()