import collections.abc
import io
import os
import sys
import errno
import pathlib
import pickle
import socket
import stat
import tempfile
import unittest
from unittest import mock

from test import support
from test.support import TESTFN, FakePath

try:
    import grp, pwd
except ImportError:
    grp = pwd = None


class _BaseFlavourTest(object):

    def _check_parse_parts(self, arg, expected):
        f = self.flavour.parse_parts
        sep = self.flavour.sep
        altsep = self.flavour.altsep
        actual = f([x.replace('/', sep) for x in arg])
        self.assertEqual(actual, expected)
        if altsep:
            actual = f([x.replace('/', altsep) for x in arg])
            self.assertEqual(actual, expected)

    def test_parse_parts_common(self):
        check = self._check_parse_parts
        sep = self.flavour.sep
        # Unanchored parts.
        check([],                   ('', '', []))
        check(['a'],                ('', '', ['a']))
        check(['a/'],               ('', '', ['a']))
        check(['a', 'b'],           ('', '', ['a', 'b']))
        # Expansion.
        check(['a/b'],              ('', '', ['a', 'b']))
        check(['a/b/'],             ('', '', ['a', 'b']))
        check(['a', 'b/c', 'd'],    ('', '', ['a', 'b', 'c', 'd']))
        # Collapsing and stripping excess slashes.
        check(['a', 'b//c', 'd'],   ('', '', ['a', 'b', 'c', 'd']))
        check(['a', 'b/c/', 'd'],   ('', '', ['a', 'b', 'c', 'd']))
        # Eliminating standalone dots.
        check(['.'],                ('', '', []))
        check(['.', '.', 'b'],      ('', '', ['b']))
        check(['a', '.', 'b'],      ('', '', ['a', 'b']))
        check(['a', '.', '.'],      ('', '', ['a']))
        # The first part is anchored.
        check(['/a/b'],             ('', sep, [sep, 'a', 'b']))
        check(['/a', 'b'],          ('', sep, [sep, 'a', 'b']))
        check(['/a/', 'b'],         ('', sep, [sep, 'a', 'b']))
        # Ignoring parts before an anchored part.
        check(['a', '/b', 'c'],     ('', sep, [sep, 'b', 'c']))
        check(['a', '/b', '/c'],    ('', sep, [sep, 'c']))


class PosixFlavourTest(_BaseFlavourTest, unittest.TestCase):
    flavour = pathlib._posix_flavour

    def test_parse_parts(self):
        check = self._check_parse_parts
        # Collapsing of excess leading slashes, except for the double-slash
        # special case.
        check(['//a', 'b'],             ('', '//', ['//', 'a', 'b']))
        check(['///a', 'b'],            ('', '/', ['/', 'a', 'b']))
        check(['////a', 'b'],           ('', '/', ['/', 'a', 'b']))
        # Paths which look like NT paths aren't treated specially.
        check(['c:a'],                  ('', '', ['c:a']))
        check(['c:\\a'],                ('', '', ['c:\\a']))
        check(['\\a'],                  ('', '', ['\\a']))

    def test_splitroot(self):
        f = self.flavour.splitroot
        self.assertEqual(f(''), ('', '', ''))
        self.assertEqual(f('a'), ('', '', 'a'))
        self.assertEqual(f('a/b'), ('', '', 'a/b'))
        self.assertEqual(f('a/b/'), ('', '', 'a/b/'))
        self.assertEqual(f('/a'), ('', '/', 'a'))
        self.assertEqual(f('/a/b'), ('', '/', 'a/b'))
        self.assertEqual(f('/a/b/'), ('', '/', 'a/b/'))
        # The root is collapsed when there are redundant slashes
        # except when there are exactly two leading slashes, which
        # is a special case in POSIX.
        self.assertEqual(f('//a'), ('', '//', 'a'))
        self.assertEqual(f('///a'), ('', '/', 'a'))
        self.assertEqual(f('///a/b'), ('', '/', 'a/b'))
        # Paths which look like NT paths aren't treated specially.
        self.assertEqual(f('c:/a/b'), ('', '', 'c:/a/b'))
        self.assertEqual(f('\\/a/b'), ('', '', '\\/a/b'))
        self.assertEqual(f('\\a\\b'), ('', '', '\\a\\b'))


class NTFlavourTest(_BaseFlavourTest, unittest.TestCase):
    flavour = pathlib._windows_flavour

    def test_parse_parts(self):
        check = self._check_parse_parts
        # First part is anchored.
        check(['c:'],                   ('c:', '', ['c:']))
        check(['c:/'],                  ('c:', '\\', ['c:\\']))
        check(['/'],                    ('', '\\', ['\\']))
        check(['c:a'],                  ('c:', '', ['c:', 'a']))
        check(['c:/a'],                 ('c:', '\\', ['c:\\', 'a']))
        check(['/a'],                   ('', '\\', ['\\', 'a']))
        # UNC paths.
        check(['//a/b'],                ('\\\\a\\b', '\\', ['\\\\a\\b\\']))
        check(['//a/b/'],               ('\\\\a\\b', '\\', ['\\\\a\\b\\']))
        check(['//a/b/c'],              ('\\\\a\\b', '\\', ['\\\\a\\b\\', 'c']))
        # Second part is anchored, so that the first part is ignored.
        check(['a', 'Z:b', 'c'],        ('Z:', '', ['Z:', 'b', 'c']))
        check(['a', 'Z:/b', 'c'],       ('Z:', '\\', ['Z:\\', 'b', 'c']))
        # UNC paths.
        check(['a', '//b/c', 'd'],      ('\\\\b\\c', '\\', ['\\\\b\\c\\', 'd']))
        # Collapsing and stripping excess slashes.
        check(['a', 'Z://b//c/', 'd/'], ('Z:', '\\', ['Z:\\', 'b', 'c', 'd']))
        # UNC paths.
        check(['a', '//b/c//', 'd'],    ('\\\\b\\c', '\\', ['\\\\b\\c\\', 'd']))
        # Extended paths.
        check(['//?/c:/'],              ('\\\\?\\c:', '\\', ['\\\\?\\c:\\']))
        check(['//?/c:/a'],             ('\\\\?\\c:', '\\', ['\\\\?\\c:\\', 'a']))
        check(['//?/c:/a', '/b'],       ('\\\\?\\c:', '\\', ['\\\\?\\c:\\', 'b']))
        # Extended UNC paths (format is "\\?\UNC\server\share").
        check(['//?/UNC/b/c'],          ('\\\\?\\UNC\\b\\c', '\\', ['\\\\?\\UNC\\b\\c\\']))
        check(['//?/UNC/b/c/d'],        ('\\\\?\\UNC\\b\\c', '\\', ['\\\\?\\UNC\\b\\c\\', 'd']))
        # Second part has a root but not drive.
        check(['a', '/b', 'c'],         ('', '\\', ['\\', 'b', 'c']))
        check(['Z:/a', '/b', 'c'],      ('Z:', '\\', ['Z:\\', 'b', 'c']))
        check(['//?/Z:/a', '/b', 'c'],  ('\\\\?\\Z:', '\\', ['\\\\?\\Z:\\', 'b', 'c']))

    def test_splitroot(self):
        f = self.flavour.splitroot
        self.assertEqual(f(''), ('', '', ''))
        self.assertEqual(f('a'), ('', '', 'a'))
        self.assertEqual(f('a\\b'), ('', '', 'a\\b'))
        self.assertEqual(f('\\a'), ('', '\\', 'a'))
        self.assertEqual(f('\\a\\b'), ('', '\\', 'a\\b'))
        self.assertEqual(f('c:a\\b'), ('c:', '', 'a\\b'))
        self.assertEqual(f('c:\\a\\b'), ('c:', '\\', 'a\\b'))
        # Redundant slashes in the root are collapsed.
        self.assertEqual(f('\\\\a'), ('', '\\', 'a'))
        self.assertEqual(f('\\\\\\a/b'), ('', '\\', 'a/b'))
        self.assertEqual(f('c:\\\\a'), ('c:', '\\', 'a'))
        self.assertEqual(f('c:\\\\\\a/b'), ('c:', '\\', 'a/b'))
        # Valid UNC paths.
        self.assertEqual(f('\\\\a\\b'), ('\\\\a\\b', '\\', ''))
        self.assertEqual(f('\\\\a\\b\\'), ('\\\\a\\b', '\\', ''))
        self.assertEqual(f('\\\\a\\b\\c\\d'), ('\\\\a\\b', '\\', 'c\\d'))
        # These are non-UNC paths (according to ntpath.py and test_ntpath).
        # However, command.com says such paths are invalid, so it's
        # difficult to know what the right semantics are.
        self.assertEqual(f('\\\\\\a\\b'), ('', '\\', 'a\\b'))
        self.assertEqual(f('\\\\a'), ('', '\\', 'a'))


#
# Tests for the pure classes.
#

class _BasePurePathTest(object):

    # Keys are canonical paths, values are list of tuples of arguments
    # supposed to produce equal paths.
    equivalences = {
        'a/b': [
            ('a', 'b'), ('a/', 'b'), ('a', 'b/'), ('a/', 'b/'),
            ('a/b/',), ('a//b',), ('a//b//',),
            # Empty components get removed.
            ('', 'a', 'b'), ('a', '', 'b'), ('a', 'b', ''),
            ],
        '/b/c/d': [
            ('a', '/b/c', 'd'), ('a', '///b//c', 'd/'),
            ('/a', '/b/c', 'd'),
            # Empty components get removed.
            ('/', 'b', '', 'c/d'), ('/', '', 'b/c/d'), ('', '/b/c/d'),
            ],
    }

    def setUp(self):
        p = self.cls('a')
        self.flavour = p._flavour
        self.sep = self.flavour.sep
        self.altsep = self.flavour.altsep

    def test_constructor_common(self):
        P = self.cls
        p = P('a')
        self.assertIsInstance(p, P)
        P('a', 'b', 'c')
        P('/a', 'b', 'c')
        P('a/b/c')
        P('/a/b/c')
        P(FakePath("a/b/c"))
        self.assertEqual(P(P('a')), P('a'))
        self.assertEqual(P(P('a'), 'b'), P('a/b'))
        self.assertEqual(P(P('a'), P('b')), P('a/b'))
        self.assertEqual(P(P('a'), P('b'), P('c')), P(FakePath("a/b/c")))

    def _check_str_subclass(self, *args):
        # Issue #21127: it should be possible to construct a PurePath object
        # from a str subclass instance, and it then gets converted to
        # a pure str object.
        class StrSubclass(str):
            pass
        P = self.cls
        p = P(*(StrSubclass(x) for x in args))
        self.assertEqual(p, P(*args))
        for part in p.parts:
            self.assertIs(type(part), str)

    def test_str_subclass_common(self):
        self._check_str_subclass('')
        self._check_str_subclass('.')
        self._check_str_subclass('a')
        self._check_str_subclass('a/b.txt')
        self._check_str_subclass('/a/b.txt')

    def test_join_common(self):
        P = self.cls
        p = P('a/b')
        pp = p.joinpath('c')
        self.assertEqual(pp, P('a/b/c'))
        self.assertIs(type(pp), type(p))
        pp = p.joinpath('c', 'd')
        self.assertEqual(pp, P('a/b/c/d'))
        pp = p.joinpath(P('c'))
        self.assertEqual(pp, P('a/b/c'))
        pp = p.joinpath('/c')
        self.assertEqual(pp, P('/c'))

    def test_div_common(self):
        # Basically the same as joinpath().
        P = self.cls
        p = P('a/b')
        pp = p / 'c'
        self.assertEqual(pp, P('a/b/c'))
        self.assertIs(type(pp), type(p))
        pp = p / 'c/d'
        self.assertEqual(pp, P('a/b/c/d'))
        pp = p / 'c' / 'd'
        self.assertEqual(pp, P('a/b/c/d'))
        pp = 'c' / p / 'd'
        self.assertEqual(pp, P('c/a/b/d'))
        pp = p / P('c')
        self.assertEqual(pp, P('a/b/c'))
        pp = p/ '/c'
        self.assertEqual(pp, P('/c'))

    def _check_str(self, expected, args):
        p = self.cls(*args)
        self.assertEqual(str(p), expected.replace('/', self.sep))

    def test_str_common(self):
        # Canonicalized paths roundtrip.
        for pathstr in ('a', 'a/b', 'a/b/c', '/', '/a/b', '/a/b/c'):
            self._check_str(pathstr, (pathstr,))
        # Special case for the empty path.
        self._check_str('.', ('',))
        # Other tests for str() are in test_equivalences().

    def test_as_posix_common(self):
        P = self.cls
        for pathstr in ('a', 'a/b', 'a/b/c', '/', '/a/b', '/a/b/c'):
            self.assertEqual(P(pathstr).as_posix(), pathstr)
        # Other tests for as_posix() are in test_equivalences().

    def test_as_bytes_common(self):
        sep = os.fsencode(self.sep)
        P = self.cls
        self.assertEqual(bytes(P('a/b')), b'a' + sep + b'b')

    def test_as_uri_common(self):
        P = self.cls
        with self.assertRaises(ValueError):
            P('a').as_uri()
        with self.assertRaises(ValueError):
            P().as_uri()

    def test_repr_common(self):
        for pathstr in ('a', 'a/b', 'a/b/c', '/', '/a/b', '/a/b/c'):
            p = self.cls(pathstr)
            clsname = p.__class__.__name__
            r = repr(p)
            # The repr() is in the form ClassName("forward-slashes path").
            self.assertTrue(r.startswith(clsname + '('), r)
            self.assertTrue(r.endswith(')'), r)
            inner = r[len(clsname) + 1 : -1]
            self.assertEqual(eval(inner), p.as_posix())
            # The repr() roundtrips.
            q = eval(r, pathlib.__dict__)
            self.assertIs(q.__class__, p.__class__)
            self.assertEqual(q, p)
            self.assertEqual(repr(q), r)

    def test_eq_common(self):
        P = self.cls
        self.assertEqual(P('a/b'), P('a/b'))
        self.assertEqual(P('a/b'), P('a', 'b'))
        self.assertNotEqual(P('a/b'), P('a'))
        self.assertNotEqual(P('a/b'), P('/a/b'))
        self.assertNotEqual(P('a/b'), P())
        self.assertNotEqual(P('/a/b'), P('/'))
        self.assertNotEqual(P(), P('/'))
        self.assertNotEqual(P(), "")
        self.assertNotEqual(P(), {})
        self.assertNotEqual(P(), int)

    def test_match_common(self):
        P = self.cls
        self.assertRaises(ValueError, P('a').match, '')
        self.assertRaises(ValueError, P('a').match, '.')
        # Simple relative pattern.
        self.assertTrue(P('b.py').match('b.py'))
        self.assertTrue(P('a/b.py').match('b.py'))
        self.assertTrue(P('/a/b.py').match('b.py'))
        self.assertFalse(P('a.py').match('b.py'))
        self.assertFalse(P('b/py').match('b.py'))
        self.assertFalse(P('/a.py').match('b.py'))
        self.assertFalse(P('b.py/c').match('b.py'))
        # Wilcard relative pattern.
        self.assertTrue(P('b.py').match('*.py'))
        self.assertTrue(P('a/b.py').match('*.py'))
        self.assertTrue(P('/a/b.py').match('*.py'))
        self.assertFalse(P('b.pyc').match('*.py'))
        self.assertFalse(P('b./py').match('*.py'))
        self.assertFalse(P('b.py/c').match('*.py'))
        # Multi-part relative pattern.
        self.assertTrue(P('ab/c.py').match('a*/*.py'))
        self.assertTrue(P('/d/ab/c.py').match('a*/*.py'))
        self.assertFalse(P('a.py').match('a*/*.py'))
        self.assertFalse(P('/dab/c.py').match('a*/*.py'))
        self.assertFalse(P('ab/c.py/d').match('a*/*.py'))
        # Absolute pattern.
        self.assertTrue(P('/b.py').match('/*.py'))
        self.assertFalse(P('b.py').match('/*.py'))
        self.assertFalse(P('a/b.py').match('/*.py'))
        self.assertFalse(P('/a/b.py').match('/*.py'))
        # Multi-part absolute pattern.
        self.assertTrue(P('/a/b.py').match('/a/*.py'))
        self.assertFalse(P('/ab.py').match('/a/*.py'))
        self.assertFalse(P('/a/b/c.py').match('/a/*.py'))
        # Multi-part glob-style pattern.
        self.assertFalse(P('/a/b/c.py').match('/**/*.py'))
        self.assertTrue(P('/a/b/c.py').match('/a/**/*.py'))

    def test_ordering_common(self):
        # Ordering is tuple-alike.
        def assertLess(a, b):
            self.assertLess(a, b)
            self.assertGreater(b, a)
        P = self.cls
        a = P('a')
        b = P('a/b')
        c = P('abc')
        d = P('b')
        assertLess(a, b)
        assertLess(a, c)
        assertLess(a, d)
        assertLess(b, c)
        assertLess(c, d)
        P = self.cls
        a = P('/a')
        b = P('/a/b')
        c = P('/abc')
        d = P('/b')
        assertLess(a, b)
        assertLess(a, c)
        assertLess(a, d)
        assertLess(b, c)
        assertLess(c, d)
        with self.assertRaises(TypeError):
            P() < {}

    def test_parts_common(self):
        # `parts` returns a tuple.
        sep = self.sep
        P = self.cls
        p = P('a/b')
        parts = p.parts
        self.assertEqual(parts, ('a', 'b'))
        # The object gets reused.
        self.assertIs(parts, p.parts)
        # When the path is absolute, the anchor is a separate part.
        p = P('/a/b')
        parts = p.parts
        self.assertEqual(parts, (sep, 'a', 'b'))

    def test_fspath_common(self):
        P = self.cls
        p = P('a/b')
        self._check_str(p.__fspath__(), ('a/b',))
        self._check_str(os.fspath(p), ('a/b',))

    def test_equivalences(self):
        for k, tuples in self.equivalences.items():
            canon = k.replace('/', self.sep)
            posix = k.replace(self.sep, '/')
            if canon != posix:
                tuples = tuples + [
                    tuple(part.replace('/', self.sep) for part in t)
                    for t in tuples
                    ]
                tuples.append((posix, ))
            pcanon = self.cls(canon)
            for t in tuples:
                p = self.cls(*t)
                self.assertEqual(p, pcanon, "failed with args {}".format(t))
                self.assertEqual(hash(p), hash(pcanon))
                self.assertEqual(str(p), canon)
                self.assertEqual(p.as_posix(), posix)

    def test_parent_common(self):
        # Relative
        P = self.cls
        p = P('a/b/c')
        self.assertEqual(p.parent, P('a/b'))
        self.assertEqual(p.parent.parent, P('a'))
        self.assertEqual(p.parent.parent.parent, P())
        self.assertEqual(p.parent.parent.parent.parent, P())
        # Anchored
        p = P('/a/b/c')
        self.assertEqual(p.parent, P('/a/b'))
        self.assertEqual(p.parent.parent, P('/a'))
        self.assertEqual(p.parent.parent.parent, P('/'))
        self.assertEqual(p.parent.parent.parent.parent, P('/'))

    def test_parents_common(self):
        # Relative
        P = self.cls
        p = P('a/b/c')
        par = p.parents
        self.assertEqual(len(par), 3)
        self.assertEqual(par[0], P('a/b'))
        self.assertEqual(par[1], P('a'))
        self.assertEqual(par[2], P('.'))
        self.assertEqual(list(par), [P('a/b'), P('a'), P('.')])
        with self.assertRaises(IndexError):
            par[-1]
        with self.assertRaises(IndexError):
            par[3]
        with self.assertRaises(TypeError):
            par[0] = p
        # Anchored
        p = P('/a/b/c')
        par = p.parents
        self.assertEqual(len(par), 3)
        self.assertEqual(par[0], P('/a/b'))
        self.assertEqual(par[1], P('/a'))
        self.assertEqual(par[2], P('/'))
        self.assertEqual(list(par), [P('/a/b'), P('/a'), P('/')])
        with self.assertRaises(IndexError):
            par[3]

    def test_drive_common(self):
        P = self.cls
        self.assertEqual(P('a/b').drive, '')
        self.assertEqual(P('/a/b').drive, '')
        self.assertEqual(P('').drive, '')

    def test_root_common(self):
        P = self.cls
        sep = self.sep
        self.assertEqual(P('').root, '')
        self.assertEqual(P('a/b').root, '')
        self.assertEqual(P('/').root, sep)
        self.assertEqual(P('/a/b').root, sep)

    def test_anchor_common(self):
        P = self.cls
        sep = self.sep
        self.assertEqual(P('').anchor, '')
        self.assertEqual(P('a/b').anchor, '')
        self.assertEqual(P('/').anchor, sep)
        self.assertEqual(P('/a/b').anchor, sep)

    def test_name_common(self):
        P = self.cls
        self.assertEqual(P('').name, '')
        self.assertEqual(P('.').name, '')
        self.assertEqual(P('/').name, '')
        self.assertEqual(P('a/b').name, 'b')
        self.assertEqual(P('/a/b').name, 'b')
        self.assertEqual(P('/a/b/.').name, 'b')
        self.assertEqual(P('a/b.py').name, 'b.py')
        self.assertEqual(P('/a/b.py').name, 'b.py')

    def test_suffix_common(self):
        P = self.cls
        self.assertEqual(P('').suffix, '')
        self.assertEqual(P('.').suffix, '')
        self.assertEqual(P('..').suffix, '')
        self.assertEqual(P('/').suffix, '')
        self.assertEqual(P('a/b').suffix, '')
        self.assertEqual(P('/a/b').suffix, '')
        self.assertEqual(P('/a/b/.').suffix, '')
        self.assertEqual(P('a/b.py').suffix, '.py')
        self.assertEqual(P('/a/b.py').suffix, '.py')
        self.assertEqual(P('a/.hgrc').suffix, '')
        self.assertEqual(P('/a/.hgrc').suffix, '')
        self.assertEqual(P('a/.hg.rc').suffix, '.rc')
        self.assertEqual(P('/a/.hg.rc').suffix, '.rc')
        self.assertEqual(P('a/b.tar.gz').suffix, '.gz')
        self.assertEqual(P('/a/b.tar.gz').suffix, '.gz')
        self.assertEqual(P('a/Some name. Ending with a dot.').suffix, '')
        self.assertEqual(P('/a/Some name. Ending with a dot.').suffix, '')

    def test_suffixes_common(self):
        P = self.cls
        self.assertEqual(P('').suffixes, [])
        self.assertEqual(P('.').suffixes, [])
        self.assertEqual(P('/').suffixes, [])
        self.assertEqual(P('a/b').suffixes, [])
        self.assertEqual(P('/a/b').suffixes, [])
        self.assertEqual(P('/a/b/.').suffixes, [])
        self.assertEqual(P('a/b.py').suffixes, ['.py'])
        self.assertEqual(P('/a/b.py').suffixes, ['.py'])
        self.assertEqual(P('a/.hgrc').suffixes, [])
        self.assertEqual(P('/a/.hgrc').suffixes, [])
        self.assertEqual(P('a/.hg.rc').suffixes, ['.rc'])
        self.assertEqual(P('/a/.hg.rc').suffixes, ['.rc'])
        self.assertEqual(P('a/b.tar.gz').suffixes, ['.tar', '.gz'])
        self.assertEqual(P('/a/b.tar.gz').suffixes, ['.tar', '.gz'])
        self.assertEqual(P('a/Some name. Ending with a dot.').suffixes, [])
        self.assertEqual(P('/a/Some name. Ending with a dot.').suffixes, [])

    def test_stem_common(self):
        P = self.cls
        self.assertEqual(P('').stem, '')
        self.assertEqual(P('.').stem, '')
        self.assertEqual(P('..').stem, '..')
        self.assertEqual(P('/').stem, '')
        self.assertEqual(P('a/b').stem, 'b')
        self.assertEqual(P('a/b.py').stem, 'b')
        self.assertEqual(P('a/.hgrc').stem, '.hgrc')
        self.assertEqual(P('a/.hg.rc').stem, '.hg')
        self.assertEqual(P('a/b.tar.gz').stem, 'b.tar')
        self.assertEqual(P('a/Some name. Ending with a dot.').stem,
                         'Some name. Ending with a dot.')

    def test_with_name_common(self):
        P = self.cls
        self.assertEqual(P('a/b').with_name('d.xml'), P('a/d.xml'))
        self.assertEqual(P('/a/b').with_name('d.xml'), P('/a/d.xml'))
        self.assertEqual(P('a/b.py').with_name('d.xml'), P('a/d.xml'))
        self.assertEqual(P('/a/b.py').with_name('d.xml'), P('/a/d.xml'))
        self.assertEqual(P('a/Dot ending.').with_name('d.xml'), P('a/d.xml'))
        self.assertEqual(P('/a/Dot ending.').with_name('d.xml'), P('/a/d.xml'))
        self.assertRaises(ValueError, P('').with_name, 'd.xml')
        self.assertRaises(ValueError, P('.').with_name, 'd.xml')
        self.assertRaises(ValueError, P('/').with_name, 'd.xml')
        self.assertRaises(ValueError, P('a/b').with_name, '')
        self.assertRaises(ValueError, P('a/b').with_name, '/c')
        self.assertRaises(ValueError, P('a/b').with_name, 'c/')
        self.assertRaises(ValueError, P('a/b').with_name, 'c/d')

    def test_with_suffix_common(self):
        P = self.cls
        self.assertEqual(P('a/b').with_suffix('.gz'), P('a/b.gz'))
        self.assertEqual(P('/a/b').with_suffix('.gz'), P('/a/b.gz'))
        self.assertEqual(P('a/b.py').with_suffix('.gz'), P('a/b.gz'))
        self.assertEqual(P('/a/b.py').with_suffix('.gz'), P('/a/b.gz'))
        # Stripping suffix.
        self.assertEqual(P('a/b.py').with_suffix(''), P('a/b'))
        self.assertEqual(P('/a/b').with_suffix(''), P('/a/b'))
        # Path doesn't have a "filename" component.
        self.assertRaises(ValueError, P('').with_suffix, '.gz')
        self.assertRaises(ValueError, P('.').with_suffix, '.gz')
        self.assertRaises(ValueError, P('/').with_suffix, '.gz')
        # Invalid suffix.
        self.assertRaises(ValueError, P('a/b').with_suffix, 'gz')
        self.assertRaises(ValueError, P('a/b').with_suffix, '/')
        self.assertRaises(ValueError, P('a/b').with_suffix, '.')
        self.assertRaises(ValueError, P('a/b').with_suffix, '/.gz')
        self.assertRaises(ValueError, P('a/b').with_suffix, 'c/d')
        self.assertRaises(ValueError, P('a/b').with_suffix, '.c/.d')
        self.assertRaises(ValueError, P('a/b').with_suffix, './.d')
        self.assertRaises(ValueError, P('a/b').with_suffix, '.d/.')
        self.assertRaises(ValueError, P('a/b').with_suffix,
                          (self.flavour.sep, 'd'))

    def test_relative_to_common(self):
        P = self.cls
        p = P('a/b')
        self.assertRaises(TypeError, p.relative_to)
        self.assertRaises(TypeError, p.relative_to, b'a')
        self.assertEqual(p.relative_to(P()), P('a/b'))
        self.assertEqual(p.relative_to(''), P('a/b'))
        self.assertEqual(p.relative_to(P('a')), P('b'))
        self.assertEqual(p.relative_to('a'), P('b'))
        self.assertEqual(p.relative_to('a/'), P('b'))
        self.assertEqual(p.relative_to(P('a/b')), P())
        self.assertEqual(p.relative_to('a/b'), P())
        # With several args.
        self.assertEqual(p.relative_to('a', 'b'), P())
        # Unrelated paths.
        self.assertRaises(ValueError, p.relative_to, P('c'))
        self.assertRaises(ValueError, p.relative_to, P('a/b/c'))
        self.assertRaises(ValueError, p.relative_to, P('a/c'))
        self.assertRaises(ValueError, p.relative_to, P('/a'))
        p = P('/a/b')
        self.assertEqual(p.relative_to(P('/')), P('a/b'))
        self.assertEqual(p.relative_to('/'), P('a/b'))
        self.assertEqual(p.relative_to(P('/a')), P('b'))
        self.assertEqual(p.relative_to('/a'), P('b'))
        self.assertEqual(p.relative_to('/a/'), P('b'))
        self.assertEqual(p.relative_to(P('/a/b')), P())
        self.assertEqual(p.relative_to('/a/b'), P())
        # Unrelated paths.
        self.assertRaises(ValueError, p.relative_to, P('/c'))
        self.assertRaises(ValueError, p.relative_to, P('/a/b/c'))
        self.assertRaises(ValueError, p.relative_to, P('/a/c'))
        self.assertRaises(ValueError, p.relative_to, P())
        self.assertRaises(ValueError, p.relative_to, '')
        self.assertRaises(ValueError, p.relative_to, P('a'))

    def test_is_relative_to_common(self):
        P = self.cls
        p = P('a/b')
        self.assertRaises(TypeError, p.is_relative_to)
        self.assertRaises(TypeError, p.is_relative_to, b'a')
        self.assertTrue(p.is_relative_to(P()))
        self.assertTrue(p.is_relative_to(''))
        self.assertTrue(p.is_relative_to(P('a')))
        self.assertTrue(p.is_relative_to('a/'))
        self.assertTrue(p.is_relative_to(P('a/b')))
        self.assertTrue(p.is_relative_to('a/b'))
        # With several args.
        self.assertTrue(p.is_relative_to('a', 'b'))
        # Unrelated paths.
        self.assertFalse(p.is_relative_to(P('c')))
        self.assertFalse(p.is_relative_to(P('a/b/c')))
        self.assertFalse(p.is_relative_to(P('a/c')))
        self.assertFalse(p.is_relative_to(P('/a')))
        p = P('/a/b')
        self.assertTrue(p.is_relative_to(P('/')))
        self.assertTrue(p.is_relative_to('/'))
        self.assertTrue(p.is_relative_to(P('/a')))
        self.assertTrue(p.is_relative_to('/a'))
        self.assertTrue(p.is_relative_to('/a/'))
        self.assertTrue(p.is_relative_to(P('/a/b')))
        self.assertTrue(p.is_relative_to('/a/b'))
        # Unrelated paths.
        self.assertFalse(p.is_relative_to(P('/c')))
        self.assertFalse(p.is_relative_to(P('/a/b/c')))
        self.assertFalse(p.is_relative_to(P('/a/c')))
        self.assertFalse(p.is_relative_to(P()))
        self.assertFalse(p.is_relative_to(''))
        self.assertFalse(p.is_relative_to(P('a')))

    def test_pickling_common(self):
        P = self.cls
        p = P('/a/b')
        for proto in range(0, pickle.HIGHEST_PROTOCOL + 1):
            dumped = pickle.dumps(p, proto)
            pp = pickle.loads(dumped)
            self.assertIs(pp.__class__, p.__class__)
            self.assertEqual(pp, p)
            self.assertEqual(hash(pp), hash(p))
            self.assertEqual(str(pp), str(p))


class PurePosixPathTest(_BasePurePathTest, unittest.TestCase):
    cls = pathlib.PurePosixPath

    def test_root(self):
        P = self.cls
        self.assertEqual(P('/a/b').root, '/')
        self.assertEqual(P('///a/b').root, '/')
        # POSIX special case for two leading slashes.
        self.assertEqual(P('//a/b').root, '//')

    def test_eq(self):
        P = self.cls
        self.assertNotEqual(P('a/b'), P('A/b'))
        self.assertEqual(P('/a'), P('///a'))
        self.assertNotEqual(P('/a'), P('//a'))

    def test_as_uri(self):
        P = self.cls
        self.assertEqual(P('/').as_uri(), 'file:///')
        self.assertEqual(P('/a/b.c').as_uri(), 'file:///a/b.c')
        self.assertEqual(P('/a/b%#c').as_uri(), 'file:///a/b%25%23c')

    def test_as_uri_non_ascii(self):
        from urllib.parse import quote_from_bytes
        P = self.cls
        try:
            os.fsencode('\xe9')
        except UnicodeEncodeError:
            self.skipTest("\\xe9 cannot be encoded to the filesystem encoding")
        self.assertEqual(P('/a/b\xe9').as_uri(),
                         'file:///a/b' + quote_from_bytes(os.fsencode('\xe9')))

    def test_match(self):
        P = self.cls
        self.assertFalse(P('A.py').match('a.PY'))

    def test_is_absolute(self):
        P = self.cls
        self.assertFalse(P().is_absolute())
        self.assertFalse(P('a').is_absolute())
        self.assertFalse(P('a/b/').is_absolute())
        self.assertTrue(P('/').is_absolute())
        self.assertTrue(P('/a').is_absolute())
        self.assertTrue(P('/a/b/').is_absolute())
        self.assertTrue(P('//a').is_absolute())
        self.assertTrue(P('//a/b').is_absolute())

    def test_is_reserved(self):
        P = self.cls
        self.assertIs(False, P('').is_reserved())
        self.assertIs(False, P('/').is_reserved())
        self.assertIs(False, P('/foo/bar').is_reserved())
        self.assertIs(False, P('/dev/con/PRN/NUL').is_reserved())

    def test_join(self):
        P = self.cls
        p = P('//a')
        pp = p.joinpath('b')
        self.assertEqual(pp, P('//a/b'))
        pp = P('/a').joinpath('//c')
        self.assertEqual(pp, P('//c'))
        pp = P('//a').joinpath('/c')
        self.assertEqual(pp, P('/c'))

    def test_div(self):
        # Basically the same as joinpath().
        P = self.cls
        p = P('//a')
        pp = p / 'b'
        self.assertEqual(pp, P('//a/b'))
        pp = P('/a') / '//c'
        self.assertEqual(pp, P('//c'))
        pp = P('//a') / '/c'
        self.assertEqual(pp, P('/c'))


class PureWindowsPathTest(_BasePurePathTest, unittest.TestCase):
    cls = pathlib.PureWindowsPath

    equivalences = _BasePurePathTest.equivalences.copy()
    equivalences.update({
        'c:a': [ ('c:', 'a'), ('c:', 'a/'), ('/', 'c:', 'a') ],
        'c:/a': [
            ('c:/', 'a'), ('c:', '/', 'a'), ('c:', '/a'),
            ('/z', 'c:/', 'a'), ('//x/y', 'c:/', 'a'),
            ],
        '//a/b/': [ ('//a/b',) ],
        '//a/b/c': [
            ('//a/b', 'c'), ('//a/b/', 'c'),
            ],
    })

    def test_str(self):
        p = self.cls('a/b/c')
        self.assertEqual(str(p), 'a\\b\\c')
        p = self.cls('c:/a/b/c')
        self.assertEqual(str(p), 'c:\\a\\b\\c')
        p = self.cls('//a/b')
        self.assertEqual(str(p), '\\\\a\\b\\')
        p = self.cls('//a/b/c')
        self.assertEqual(str(p), '\\\\a\\b\\c')
        p = self.cls('//a/b/c/d')
        self.assertEqual(str(p), '\\\\a\\b\\c\\d')

    def test_str_subclass(self):
        self._check_str_subclass('c:')
        self._check_str_subclass('c:a')
        self._check_str_subclass('c:a\\b.txt')
        self._check_str_subclass('c:\\')
        self._check_str_subclass('c:\\a')
        self._check_str_subclass('c:\\a\\b.txt')
        self._check_str_subclass('\\\\some\\share')
        self._check_str_subclass('\\\\some\\share\\a')
        self._check_str_subclass('\\\\some\\share\\a\\b.txt')

    def test_eq(self):
        P = self.cls
        self.assertEqual(P('c:a/b'), P('c:a/b'))
        self.assertEqual(P('c:a/b'), P('c:', 'a', 'b'))
        self.assertNotEqual(P('c:a/b'), P('d:a/b'))
        self.assertNotEqual(P('c:a/b'), P('c:/a/b'))
        self.assertNotEqual(P('/a/b'), P('c:/a/b'))
        # Case-insensitivity.
        self.assertEqual(P('a/B'), P('A/b'))
        self.assertEqual(P('C:a/B'), P('c:A/b'))
        self.assertEqual(P('//Some/SHARE/a/B'), P('//somE/share/A/b'))

    def test_as_uri(self):
        P = self.cls
        with self.assertRaises(ValueError):
            P('/a/b').as_uri()
        with self.assertRaises(ValueError):
            P('c:a/b').as_uri()
        self.assertEqual(P('c:/').as_uri(), 'file:///c:/')
        self.assertEqual(P('c:/a/b.c').as_uri(), 'file:///c:/a/b.c')
        self.assertEqual(P('c:/a/b%#c').as_uri(), 'file:///c:/a/b%25%23c')
        self.assertEqual(P('c:/a/b\xe9').as_uri(), 'file:///c:/a/b%C3%A9')
        self.assertEqual(P('//some/share/').as_uri(), 'file://some/share/')
        self.assertEqual(P('//some/share/a/b.c').as_uri(),
                         'file://some/share/a/b.c')
        self.assertEqual(P('//some/share/a/b%#c\xe9').as_uri(),
                         'file://some/share/a/b%25%23c%C3%A9')

    def test_match_common(self):
        P = self.cls
        # Absolute patterns.
        self.assertTrue(P('c:/b.py').match('/*.py'))
        self.assertTrue(P('c:/b.py').match('c:*.py'))
        self.assertTrue(P('c:/b.py').match('c:/*.py'))
        self.assertFalse(P('d:/b.py').match('c:/*.py'))  # wrong drive
        self.assertFalse(P('b.py').match('/*.py'))
        self.assertFalse(P('b.py').match('c:*.py'))
        self.assertFalse(P('b.py').match('c:/*.py'))
        self.assertFalse(P('c:b.py').match('/*.py'))
        self.assertFalse(P('c:b.py').match('c:/*.py'))
        self.assertFalse(P('/b.py').match('c:*.py'))
        self.assertFalse(P('/b.py').match('c:/*.py'))
        # UNC patterns.
        self.assertTrue(P('//some/share/a.py').match('/*.py'))
        self.assertTrue(P('//some/share/a.py').match('//some/share/*.py'))
        self.assertFalse(P('//other/share/a.py').match('//some/share/*.py'))
        self.assertFalse(P('//some/share/a/b.py').match('//some/share/*.py'))
        # Case-insensitivity.
        self.assertTrue(P('B.py').match('b.PY'))
        self.assertTrue(P('c:/a/B.Py').match('C:/A/*.pY'))
        self.assertTrue(P('//Some/Share/B.Py').match('//somE/sharE/*.pY'))

    def test_ordering_common(self):
        # Case-insensitivity.
        def assertOrderedEqual(a, b):
            self.assertLessEqual(a, b)
            self.assertGreaterEqual(b, a)
        P = self.cls
        p = P('c:A/b')
        q = P('C:a/B')
        assertOrderedEqual(p, q)
        self.assertFalse(p < q)
        self.assertFalse(p > q)
        p = P('//some/Share/A/b')
        q = P('//Some/SHARE/a/B')
        assertOrderedEqual(p, q)
        self.assertFalse(p < q)
        self.assertFalse(p > q)

    def test_parts(self):
        P = self.cls
        p = P('c:a/b')
        parts = p.parts
        self.assertEqual(parts, ('c:', 'a', 'b'))
        p = P('c:/a/b')
        parts = p.parts
        self.assertEqual(parts, ('c:\\', 'a', 'b'))
        p = P('//a/b/c/d')
        parts = p.parts
        self.assertEqual(parts, ('\\\\a\\b\\', 'c', 'd'))

    def test_parent(self):
        # Anchored
        P = self.cls
        p = P('z:a/b/c')
        self.assertEqual(p.parent, P('z:a/b'))
        self.assertEqual(p.parent.parent, P('z:a'))
        self.assertEqual(p.parent.parent.parent, P('z:'))
        self.assertEqual(p.parent.parent.parent.parent, P('z:'))
        p = P('z:/a/b/c')
        self.assertEqual(p.parent, P('z:/a/b'))
        self.assertEqual(p.parent.parent, P('z:/a'))
        self.assertEqual(p.parent.parent.parent, P('z:/'))
        self.assertEqual(p.parent.parent.parent.parent, P('z:/'))
        p = P('//a/b/c/d')
        self.assertEqual(p.parent, P('//a/b/c'))
        self.assertEqual(p.parent.parent, P('//a/b'))
        self.assertEqual(p.parent.parent.parent, P('//a/b'))

    def test_parents(self):
        # Anchored
        P = self.cls
        p = P('z:a/b/')
        par = p.parents
        self.assertEqual(len(par), 2)
        self.assertEqual(par[0], P('z:a'))
        self.assertEqual(par[1], P('z:'))
        self.assertEqual(list(par), [P('z:a'), P('z:')])
        with self.assertRaises(IndexError):
            par[2]
        p = P('z:/a/b/')
        par = p.parents
        self.assertEqual(len(par), 2)
        self.assertEqual(par[0], P('z:/a'))
        self.assertEqual(par[1], P('z:/'))
        self.assertEqual(list(par), [P('z:/a'), P('z:/')])
        with self.assertRaises(IndexError):
            par[2]
        p = P('//a/b/c/d')
        par = p.parents
        self.assertEqual(len(par), 2)
        self.assertEqual(par[0], P('//a/b/c'))
        self.assertEqual(par[1], P('//a/b'))
        self.assertEqual(list(par), [P('//a/b/c'), P('//a/b')])
        with self.assertRaises(IndexError):
            par[2]

    def test_drive(self):
        P = self.cls
        self.assertEqual(P('c:').drive, 'c:')
        self.assertEqual(P('c:a/b').drive, 'c:')
        self.assertEqual(P('c:/').drive, 'c:')
        self.assertEqual(P('c:/a/b/').drive, 'c:')
        self.assertEqual(P('//a/b').drive, '\\\\a\\b')
        self.assertEqual(P('//a/b/').drive, '\\\\a\\b')
        self.assertEqual(P('//a/b/c/d').drive, '\\\\a\\b')

    def test_root(self):
        P = self.cls
        self.assertEqual(P('c:').root, '')
        self.assertEqual(P('c:a/b').root, '')
        self.assertEqual(P('c:/').root, '\\')
        self.assertEqual(P('c:/a/b/').root, '\\')
        self.assertEqual(P('//a/b').root, '\\')
        self.assertEqual(P('//a/b/').root, '\\')
        self.assertEqual(P('//a/b/c/d').root, '\\')

    def test_anchor(self):
        P = self.cls
        self.assertEqual(P('c:').anchor, 'c:')
        self.assertEqual(P('c:a/b').anchor, 'c:')
        self.assertEqual(P('c:/').anchor, 'c:\\')
        self.assertEqual(P('c:/a/b/').anchor, 'c:\\')
        self.assertEqual(P('//a/b').anchor, '\\\\a\\b\\')
        self.assertEqual(P('//a/b/').anchor, '\\\\a\\b\\')
        self.assertEqual(P('//a/b/c/d').anchor, '\\\\a\\b\\')

    def test_name(self):
        P = self.cls
        self.assertEqual(P('c:').name, '')
        self.assertEqual(P('c:/').name, '')
        self.assertEqual(P('c:a/b').name, 'b')
        self.assertEqual(P('c:/a/b').name, 'b')
        self.assertEqual(P('c:a/b.py').name, 'b.py')
        self.assertEqual(P('c:/a/b.py').name, 'b.py')
        self.assertEqual(P('//My.py/Share.php').name, '')
        self.assertEqual(P('//My.py/Share.php/a/b').name, 'b')

    def test_suffix(self):
        P = self.cls
        self.assertEqual(P('c:').suffix, '')
        self.assertEqual(P('c:/').suffix, '')
        self.assertEqual(P('c:a/b').suffix, '')
        self.assertEqual(P('c:/a/b').suffix, '')
        self.assertEqual(P('c:a/b.py').suffix, '.py')
        self.assertEqual(P('c:/a/b.py').suffix, '.py')
        self.assertEqual(P('c:a/.hgrc').suffix, '')
        self.assertEqual(P('c:/a/.hgrc').suffix, '')
        self.assertEqual(P('c:a/.hg.rc').suffix, '.rc')
        self.assertEqual(P('c:/a/.hg.rc').suffix, '.rc')
        self.assertEqual(P('c:a/b.tar.gz').suffix, '.gz')
        self.assertEqual(P('c:/a/b.tar.gz').suffix, '.gz')
        self.assertEqual(P('c:a/Some name. Ending with a dot.').suffix, '')
        self.assertEqual(P('c:/a/Some name. Ending with a dot.').suffix, '')
        self.assertEqual(P('//My.py/Share.php').suffix, '')
        self.assertEqual(P('//My.py/Share.php/a/b').suffix, '')

    def test_suffixes(self):
        P = self.cls
        self.assertEqual(P('c:').suffixes, [])
        self.assertEqual(P('c:/').suffixes, [])
        self.assertEqual(P('c:a/b').suffixes, [])
        self.assertEqual(P('c:/a/b').suffixes, [])
        self.assertEqual(P('c:a/b.py').suffixes, ['.py'])
        self.assertEqual(P('c:/a/b.py').suffixes, ['.py'])
        self.assertEqual(P('c:a/.hgrc').suffixes, [])
        self.assertEqual(P('c:/a/.hgrc').suffixes, [])
        self.assertEqual(P('c:a/.hg.rc').suffixes, ['.rc'])
        self.assertEqual(P('c:/a/.hg.rc').suffixes, ['.rc'])
        self.assertEqual(P('c:a/b.tar.gz').suffixes, ['.tar', '.gz'])
        self.assertEqual(P('c:/a/b.tar.gz').suffixes, ['.tar', '.gz'])
        self.assertEqual(P('//My.py/Share.php').suffixes, [])
        self.assertEqual(P('//My.py/Share.php/a/b').suffixes, [])
        self.assertEqual(P('c:a/Some name. Ending with a dot.').suffixes, [])
        self.assertEqual(P('c:/a/Some name. Ending with a dot.').suffixes, [])

    def test_stem(self):
        P = self.cls
        self.assertEqual(P('c:').stem, '')
        self.assertEqual(P('c:.').stem, '')
        self.assertEqual(P('c:..').stem, '..')
        self.assertEqual(P('c:/').stem, '')
        self.assertEqual(P('c:a/b').stem, 'b')
        self.assertEqual(P('c:a/b.py').stem, 'b')
        self.assertEqual(P('c:a/.hgrc').stem, '.hgrc')
        self.assertEqual(P('c:a/.hg.rc').stem, '.hg')
        self.assertEqual(P('c:a/b.tar.gz').stem, 'b.tar')
        self.assertEqual(P('c:a/Some name. Ending with a dot.').stem,
                         'Some name. Ending with a dot.')

    def test_with_name(self):
        P = self.cls
        self.assertEqual(P('c:a/b').with_name('d.xml'), P('c:a/d.xml'))
        self.assertEqual(P('c:/a/b').with_name('d.xml'), P('c:/a/d.xml'))
        self.assertEqual(P('c:a/Dot ending.').with_name('d.xml'), P('c:a/d.xml'))
        self.assertEqual(P('c:/a/Dot ending.').with_name('d.xml'), P('c:/a/d.xml'))
        self.assertRaises(ValueError, P('c:').with_name, 'd.xml')
        self.assertRaises(ValueError, P('c:/').with_name, 'd.xml')
        self.assertRaises(ValueError, P('//My/Share').with_name, 'd.xml')
        self.assertRaises(ValueError, P('c:a/b').with_name, 'd:')
        self.assertRaises(ValueError, P('c:a/b').with_name, 'd:e')
        self.assertRaises(ValueError, P('c:a/b').with_name, 'd:/e')
        self.assertRaises(ValueError, P('c:a/b').with_name, '//My/Share')

    def test_with_suffix(self):
        P = self.cls
        self.assertEqual(P('c:a/b').with_suffix('.gz'), P('c:a/b.gz'))
        self.assertEqual(P('c:/a/b').with_suffix('.gz'), P('c:/a/b.gz'))
        self.assertEqual(P('c:a/b.py').with_suffix('.gz'), P('c:a/b.gz'))
        self.assertEqual(P('c:/a/b.py').with_suffix('.gz'), P('c:/a/b.gz'))
        # Path doesn't have a "filename" component.
        self.assertRaises(ValueError, P('').with_suffix, '.gz')
        self.assertRaises(ValueError, P('.').with_suffix, '.gz')
        self.assertRaises(ValueError, P('/').with_suffix, '.gz')
        self.assertRaises(ValueError, P('//My/Share').with_suffix, '.gz')
        # Invalid suffix.
        self.assertRaises(ValueError, P('c:a/b').with_suffix, 'gz')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, '/')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, '\\')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, 'c:')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, '/.gz')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, '\\.gz')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, 'c:.gz')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, 'c/d')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, 'c\\d')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, '.c/d')
        self.assertRaises(ValueError, P('c:a/b').with_suffix, '.c\\d')

    def test_relative_to(self):
        P = self.cls
        p = P('C:Foo/Bar')
        self.assertEqual(p.relative_to(P('c:')), P('Foo/Bar'))
        self.assertEqual(p.relative_to('c:'), P('Foo/Bar'))
        self.assertEqual(p.relative_to(P('c:foO')), P('Bar'))
        self.assertEqual(p.relative_to('c:foO'), P('Bar'))
        self.assertEqual(p.relative_to('c:foO/'), P('Bar'))
        self.assertEqual(p.relative_to(P('c:foO/baR')), P())
        self.assertEqual(p.relative_to('c:foO/baR'), P())
        # Unrelated paths.
        self.assertRaises(ValueError, p.relative_to, P())
        self.assertRaises(ValueError, p.relative_to, '')
        self.assertRaises(ValueError, p.relative_to, P('d:'))
        self.assertRaises(ValueError, p.relative_to, P('/'))
        self.assertRaises(ValueError, p.relative_to, P('Foo'))
        self.assertRaises(ValueError, p.relative_to, P('/Foo'))
        self.assertRaises(ValueError, p.relative_to, P('C:/Foo'))
        self.assertRaises(ValueError, p.relative_to, P('C:Foo/Bar/Baz'))
        self.assertRaises(ValueError, p.relative_to, P('C:Foo/Baz'))
        p = P('C:/Foo/Bar')
        self.assertEqual(p.relative_to(P('c:')), P('/Foo/Bar'))
        self.assertEqual(p.relative_to('c:'), P('/Foo/Bar'))
        self.assertEqual(str(p.relative_to(P('c:'))), '\\Foo\\Bar')
        self.assertEqual(str(p.relative_to('c:')), '\\Foo\\Bar')
        self.assertEqual(p.relative_to(P('c:/')), P('Foo/Bar'))
        self.assertEqual(p.relative_to('c:/'), P('Foo/Bar'))
        self.assertEqual(p.relative_to(P('c:/foO')), P('Bar'))
        self.assertEqual(p.relative_to('c:/foO'), P('Bar'))
        self.assertEqual(p.relative_to('c:/foO/'), P('Bar'))
        self.assertEqual(p.relative_to(P('c:/foO/baR')), P())
        self.assertEqual(p.relative_to('c:/foO/baR'), P())
        # Unrelated paths.
        self.assertRaises(ValueError, p.relative_to, P('C:/Baz'))
        self.assertRaises(ValueError, p.relative_to, P('C:/Foo/Bar/Baz'))
        self.assertRaises(ValueError, p.relative_to, P('C:/Foo/Baz'))
        self.assertRaises(ValueError, p.relative_to, P('C:Foo'))
        self.assertRaises(ValueError, p.relative_to, P('d:'))
        self.assertRaises(ValueError, p.relative_to, P('d:/'))
        self.assertRaises(ValueError, p.relative_to, P('/'))
        self.assertRaises(ValueError, p.relative_to, P('/Foo'))
        self.assertRaises(ValueError, p.relative_to, P('//C/Foo'))
        # UNC paths.
        p = P('//Server/Share/Foo/Bar')
        self.assertEqual(p.relative_to(P('//sErver/sHare')), P('Foo/Bar'))
        self.assertEqual(p.relative_to('//sErver/sHare'), P('Foo/Bar'))
        self.assertEqual(p.relative_to('//sErver/sHare/'), P('Foo/Bar'))
        self.assertEqual(p.relative_to(P('//sErver/sHare/Foo')), P('Bar'))
        self.assertEqual(p.relative_to('//sErver/sHare/Foo'), P('Bar'))
        self.assertEqual(p.relative_to('//sErver/sHare/Foo/'), P('Bar'))
        self.assertEqual(p.relative_to(P('//sErver/sHare/Foo/Bar')), P())
        self.assertEqual(p.relative_to('//sErver/sHare/Foo/Bar'), P())
        # Unrelated paths.
        self.assertRaises(ValueError, p.relative_to, P('/Server/Share/Foo'))
        self.assertRaises(ValueError, p.relative_to, P('c:/Server/Share/Foo'))
        self.assertRaises(ValueError, p.relative_to, P('//z/Share/Foo'))
        self.assertRaises(ValueError, p.relative_to, P('//Server/z/Foo'))

    def test_is_relative_to(self):
        P = self.cls
        p = P('C:Foo/Bar')
        self.assertTrue(p.is_relative_to(P('c:')))
        self.assertTrue(p.is_relative_to('c:'))
        self.assertTrue(p.is_relative_to(P('c:foO')))
        self.assertTrue(p.is_relative_to('c:foO'))
        self.assertTrue(p.is_relative_to('c:foO/'))
        self.assertTrue(p.is_relative_to(P('c:foO/baR')))
        self.assertTrue(p.is_relative_to('c:foO/baR'))
        # Unrelated paths.
        self.assertFalse(p.is_relative_to(P()))
        self.assertFalse(p.is_relative_to(''))
        self.assertFalse(p.is_relative_to(P('d:')))
        self.assertFalse(p.is_relative_to(P('/')))
        self.assertFalse(p.is_relative_to(P('Foo')))
        self.assertFalse(p.is_relative_to(P('/Foo')))
        self.assertFalse(p.is_relative_to(P('C:/Foo')))
        self.assertFalse(p.is_relative_to(P('C:Foo/Bar/Baz')))
        self.assertFalse(p.is_relative_to(P('C:Foo/Baz')))
        p = P('C:/Foo/Bar')
        self.assertTrue(p.is_relative_to('c:'))
        self.assertTrue(p.is_relative_to(P('c:/')))
        self.assertTrue(p.is_relative_to(P('c:/foO')))
        self.assertTrue(p.is_relative_to('c:/foO/'))
        self.assertTrue(p.is_relative_to(P('c:/foO/baR')))
        self.assertTrue(p.is_relative_to('c:/foO/baR'))
        # Unrelated paths.
        self.assertFalse(p.is_relative_to(P('C:/Baz')))
        self.assertFalse(p.is_relative_to(P('C:/Foo/Bar/Baz')))
        self.assertFalse(p.is_relative_to(P('C:/Foo/Baz')))
        self.assertFalse(p.is_relative_to(P('C:Foo')))
        self.assertFalse(p.is_relative_to(P('d:')))
        self.assertFalse(p.is_relative_to(P('d:/')))
        self.assertFalse(p.is_relative_to(P('/')))
        self.assertFalse(p.is_relative_to(P('/Foo')))
        self.assertFalse(p.is_relative_to(P('//C/Foo')))
        # UNC paths.
        p = P('//Server/Share/Foo/Bar')
        self.assertTrue(p.is_relative_to(P('//sErver/sHare')))
        self.assertTrue(p.is_relative_to('//sErver/sHare'))
        self.assertTrue(p.is_relative_to('//sErver/sHare/'))
        self.assertTrue(p.is_relative_to(P('//sErver/sHare/Foo')))
        self.assertTrue(p.is_relative_to('//sErver/sHare/Foo'))
        self.assertTrue(p.is_relative_to('//sErver/sHare/Foo/'))
        self.assertTrue(p.is_relative_to(P('//sErver/sHare/Foo/Bar')))
        self.assertTrue(p.is_relative_to('//sErver/sHare/Foo/Bar'))
        # Unrelated paths.
        self.assertFalse(p.is_relative_to(P('/Server/Share/Foo')))
        self.assertFalse(p.is_relative_to(P('c:/Server/Share/Foo')))
        self.assertFalse(p.is_relative_to(P('//z/Share/Foo')))
        self.assertFalse(p.is_relative_to(P('//Server/z/Foo')))

    def test_is_absolute(self):
        P = self.cls
        # Under NT, only paths with both a drive and a root are absolute.
        self.assertFalse(P().is_absolute())
        self.assertFalse(P('a').is_absolute())
        self.assertFalse(P('a/b/').is_absolute())
        self.assertFalse(P('/').is_absolute())
        self.assertFalse(P('/a').is_absolute())
        self.assertFalse(P('/a/b/').is_absolute())
        self.assertFalse(P('c:').is_absolute())
        self.assertFalse(P('c:a').is_absolute())
        self.assertFalse(P('c:a/b/').is_absolute())
        self.assertTrue(P('c:/').is_absolute())
        self.assertTrue(P('c:/a').is_absolute())
        self.assertTrue(P('c:/a/b/').is_absolute())
        # UNC paths are absolute by definition.
        self.assertTrue(P('//a/b').is_absolute())
        self.assertTrue(P('//a/b/').is_absolute())
        self.assertTrue(P('//a/b/c').is_absolute())
        self.assertTrue(P('//a/b/c/d').is_absolute())

    def test_join(self):
        P = self.cls
        p = P('C:/a/b')
        pp = p.joinpath('x/y')
        self.assertEqual(pp, P('C:/a/b/x/y'))
        pp = p.joinpath('/x/y')
        self.assertEqual(pp, P('C:/x/y'))
        # Joining with a different drive => the first path is ignored, even
        # if the second path is relative.
        pp = p.joinpath('D:x/y')
        self.assertEqual(pp, P('D:x/y'))
        pp = p.joinpath('D:/x/y')
        self.assertEqual(pp, P('D:/x/y'))
        pp = p.joinpath('//host/share/x/y')
        self.assertEqual(pp, P('//host/share/x/y'))
        # Joining with the same drive => the first path is appended to if
        # the second path is relative.
        pp = p.joinpath('c:x/y')
        self.assertEqual(pp, P('C:/a/b/x/y'))
        pp = p.joinpath('c:/x/y')
        self.assertEqual(pp, P('C:/x/y'))

    def test_div(self):
        # Basically the same as joinpath().
        P = self.cls
        p = P('C:/a/b')
        self.assertEqual(p / 'x/y', P('C:/a/b/x/y'))
        self.assertEqual(p / 'x' / 'y', P('C:/a/b/x/y'))
        self.assertEqual(p / '/x/y', P('C:/x/y'))
        self.assertEqual(p / '/x' / 'y', P('C:/x/y'))
        # Joining with a different drive => the first path is ignored, even
        # if the second path is relative.
        self.assertEqual(p / 'D:x/y', P('D:x/y'))
        self.assertEqual(p / 'D:' / 'x/y', P('D:x/y'))
        self.assertEqual(p / 'D:/x/y', P('D:/x/y'))
        self.assertEqual(p / 'D:' / '/x/y', P('D:/x/y'))
        self.assertEqual(p / '//host/share/x/y', P('//host/share/x/y'))
        # Joining with the same drive => the first path is appended to if
        # the second path is relative.
        self.assertEqual(p / 'c:x/y', P('C:/a/b/x/y'))
        self.assertEqual(p / 'c:/x/y', P('C:/x/y'))

    def test_is_reserved(self):
        P = self.cls
        self.assertIs(False, P('').is_reserved())
        self.assertIs(False, P('/').is_reserved())
        self.assertIs(False, P('/foo/bar').is_reserved())
        self.assertIs(True, P('con').is_reserved())
        self.assertIs(True, P('NUL').is_reserved())
        self.assertIs(True, P('NUL.txt').is_reserved())
        self.assertIs(True, P('com1').is_reserved())
        self.assertIs(True, P('com9.bar').is_reserved())
        self.assertIs(False, P('bar.com9').is_reserved())
        self.assertIs(True, P('lpt1').is_reserved())
        self.assertIs(True, P('lpt9.bar').is_reserved())
        self.assertIs(False, P('bar.lpt9').is_reserved())
        # Only the last component matters.
        self.assertIs(False, P('c:/NUL/con/baz').is_reserved())
        # UNC paths are never reserved.
        self.assertIs(False, P('//my/share/nul/con/aux').is_reserved())

class PurePathTest(_BasePurePathTest, unittest.TestCase):
    cls = pathlib.PurePath

    def test_concrete_class(self):
        p = self.cls('a')
        self.assertIs(type(p),
            pathlib.PureWindowsPath if os.name == 'nt' else pathlib.PurePosixPath)

    def test_different_flavours_unequal(self):
        p = pathlib.PurePosixPath('a')
        q = pathlib.PureWindowsPath('a')
        self.assertNotEqual(p, q)

    def test_different_flavours_unordered(self):
        p = pathlib.PurePosixPath('a')
        q = pathlib.PureWindowsPath('a')
        with self.assertRaises(TypeError):
            p < q
        with self.assertRaises(TypeError):
            p <= q
        with self.assertRaises(TypeError):
            p > q
        with self.assertRaises(TypeError):
            p >= q


#
# Tests for the concrete classes.
#

# Make sure any symbolic links in the base test path are resolved.
BASE = os.path.realpath(TESTFN)
join = lambda *x: os.path.join(BASE, *x)
rel_join = lambda *x: os.path.join(TESTFN, *x)

only_nt = unittest.skipIf(os.name != 'nt',
                          'test requires a Windows-compatible system')
only_posix = unittest.skipIf(os.name == 'nt',
                             'test requires a POSIX-compatible system')

@only_posix
class PosixPathAsPureTest(PurePosixPathTest):
    cls = pathlib.PosixPath

@only_nt
class WindowsPathAsPureTest(PureWindowsPathTest):
    cls = pathlib.WindowsPath

    def test_owner(self):
        P = self.cls
        with self.assertRaises(NotImplementedError):
            P('c:/').owner()

    def test_group(self):
        P = self.cls
        with self.assertRaises(NotImplementedError):
            P('c:/').group()


class _BasePathTest(object):
    """Tests for the FS-accessing functionalities of the Path classes."""

    # (BASE)
    #  |
    #  |-- brokenLink -> non-existing
    #  |-- dirA
    #  |   `-- linkC -> ../dirB
    #  |-- dirB
    #  |   |-- fileB
    #  |   `-- linkD -> ../dirB
    #  |-- dirC
    #  |   |-- dirD
    #  |   |   `-- fileD
    #  |   `-- fileC
    #  |-- dirE  # No permissions
    #  |-- fileA
    #  |-- linkA -> fileA
    #  |-- linkB -> dirB
    #  `-- brokenLinkLoop -> brokenLinkLoop
    #

    def setUp(self):
        def cleanup():
            os.chmod(join('dirE'), 0o777)
            support.rmtree(BASE)
        self.addCleanup(cleanup)
        os.mkdir(BASE)
        os.mkdir(join('dirA'))
        os.mkdir(join('dirB'))
        os.mkdir(join('dirC'))
        os.mkdir(join('dirC', 'dirD'))
        os.mkdir(join('dirE'))
        with open(join('fileA'), 'wb') as f:
            f.write(b"this is file A\n")
        with open(join('dirB', 'fileB'), 'wb') as f:
            f.write(b"this is file B\n")
        with open(join('dirC', 'fileC'), 'wb') as f:
            f.write(b"this is file C\n")
        with open(join('dirC', 'dirD', 'fileD'), 'wb') as f:
            f.write(b"this is file D\n")
        os.chmod(join('dirE'), 0)
        if support.can_symlink():
            # Relative symlinks.
            os.symlink('fileA', join('linkA'))
            os.symlink('non-existing', join('brokenLink'))
            self.dirlink('dirB', join('linkB'))
            self.dirlink(os.path.join('..', 'dirB'), join('dirA', 'linkC'))
            # This one goes upwards, creating a loop.
            self.dirlink(os.path.join('..', 'dirB'), join('dirB', 'linkD'))
            # Broken symlink (pointing to itself).
            os.symlink('brokenLinkLoop',  join('brokenLinkLoop'))

    if os.name == 'nt':
        # Workaround for http://bugs.python.org/issue13772.
        def dirlink(self, src, dest):
            os.symlink(src, dest, target_is_directory=True)
    else:
        def dirlink(self, src, dest):
            os.symlink(src, dest)

    def assertSame(self, path_a, path_b):
        self.assertTrue(os.path.samefile(str(path_a), str(path_b)),
                        "%r and %r don't point to the same file" %
                        (path_a, path_b))

    def assertFileNotFound(self, func, *args, **kwargs):
        with self.assertRaises(FileNotFoundError) as cm:
            func(*args, **kwargs)
        self.assertEqual(cm.exception.errno, errno.ENOENT)

    def assertEqualNormCase(self, path_a, path_b):
        self.assertEqual(os.path.normcase(path_a), os.path.normcase(path_b))

    def _test_cwd(self, p):
        q = self.cls(os.getcwd())
        self.assertEqual(p, q)
        self.assertEqualNormCase(str(p), str(q))
        self.assertIs(type(p), type(q))
        self.assertTrue(p.is_absolute())

    def test_cwd(self):
        p = self.cls.cwd()
        self._test_cwd(p)

    def _test_home(self, p):
        q = self.cls(os.path.expanduser('~'))
        self.assertEqual(p, q)
        self.assertEqualNormCase(str(p), str(q))
        self.assertIs(type(p), type(q))
        self.assertTrue(p.is_absolute())

    def test_home(self):
        p = self.cls.home()
        self._test_home(p)

    def test_samefile(self):
        fileA_path = os.path.join(BASE, 'fileA')
        fileB_path = os.path.join(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 = os.path.join(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_empty_path(self):
        # The empty path points to '.'
        p = self.cls('')
        self.assertEqual(p.stat(), os.stat('.'))

    def test_expanduser_common(self):
        P = self.cls
        p = P('~')
        self.assertEqual(p.expanduser(), P(os.path.expanduser('~')))
        p = P('foo')
        self.assertEqual(p.expanduser(), p)
        p = P('/~')
        self.assertEqual(p.expanduser(), p)
        p = P('../~')
        self.assertEqual(p.expanduser(), p)
        p = P(P('').absolute().anchor) / '~'
        self.assertEqual(p.expanduser(), p)

    def test_exists(self):
        P = self.cls
        p = P(BASE)
        self.assertIs(True, p.exists())
        self.assertIs(True, (p / 'dirA').exists())
        self.assertIs(True, (p / 'fileA').exists())
        self.assertIs(False, (p / 'fileA' / 'bah').exists())
        if support.can_symlink():
            self.assertIs(True, (p / 'linkA').exists())
            self.assertIs(True, (p / 'linkB').exists())
            self.assertIs(True, (p / 'linkB' / 'fileB').exists())
            self.assertIs(False, (p / 'linkA' / 'bah').exists())
        self.assertIs(False, (p / 'foo').exists())
        self.assertIs(False, P('/xyzzy').exists())
        self.assertIs(False, P(BASE + '\udfff').exists())
        self.assertIs(False, P(BASE + '\x00').exists())

    def test_open_common(self):
        p = self.cls(BASE)
        with (p / 'fileA').open('r') as f:
            self.assertIsInstance(f, io.TextIOBase)
            self.assertEqual(f.read(), "this is file A\n")
        with (p / 'fileA').open('rb') as f:
            self.assertIsInstance(f, io.BufferedIOBase)
            self.assertEqual(f.read().strip(), b"this is file A")
        with (p / 'fileA').open('rb', buffering=0) as f:
            self.assertIsInstance(f, io.RawIOBase)
            self.assertEqual(f.read().strip(), b"this is file A")

    def test_read_write_bytes(self):
        p = self.cls(BASE)
        (p / 'fileA').write_bytes(b'abcdefg')
        self.assertEqual((p / 'fileA').read_bytes(), b'abcdefg')
        # Check that trying to write str does not truncate the file.
        self.assertRaises(TypeError, (p / 'fileA').write_bytes, 'somestr')
        self.assertEqual((p / 'fileA').read_bytes(), b'abcdefg')

    def test_read_write_text(self):
        p = self.cls(BASE)
        (p / 'fileA').write_text('äbcdefg', encoding='latin-1')
        self.assertEqual((p / 'fileA').read_text(
            encoding='utf-8', errors='ignore'), 'bcdefg')
        # Check that trying to write bytes does not truncate the file.
        self.assertRaises(TypeError, (p / 'fileA').write_text, b'somebytes')
        self.assertEqual((p / 'fileA').read_text(encoding='latin-1'), 'äbcdefg')

    def test_iterdir(self):
        P = self.cls
        p = P(BASE)
        it = p.iterdir()
        paths = set(it)
        expected = ['dirA', 'dirB', 'dirC', 'dirE', 'fileA']
        if support.can_symlink():
            expected += ['linkA', 'linkB', 'brokenLink', 'brokenLinkLoop']
        self.assertEqual(paths, { P(BASE, q) for q in expected })

    @support.skip_unless_symlink
    def test_iterdir_symlink(self):
        # __iter__ on a symlink to a directory.
        P = self.cls
        p = P(BASE, 'linkB')
        paths = set(p.iterdir())
        expected = { P(BASE, 'linkB', q) for q in ['fileB', 'linkD'] }
        self.assertEqual(paths, expected)

    def test_iterdir_nodir(self):
        # __iter__ on something that is not a directory.
        p = self.cls(BASE, 'fileA')
        with self.assertRaises(OSError) as cm:
            next(p.iterdir())
        # ENOENT or EINVAL under Windows, ENOTDIR otherwise
        # (see issue #12802).
        self.assertIn(cm.exception.errno, (errno.ENOTDIR,
                                           errno.ENOENT, errno.EINVAL))

    def test_glob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.glob("fileA")
        self.assertIsInstance(it, collections.abc.Iterator)
        _check(it, ["fileA"])
        _check(p.glob("fileB"), [])
        _check(p.glob("dir*/file*"), ["dirB/fileB", "dirC/fileC"])
        if not support.can_symlink():
            _check(p.glob("*A"), ['dirA', 'fileA'])
        else:
            _check(p.glob("*A"), ['dirA', 'fileA', 'linkA'])
        if not support.can_symlink():
            _check(p.glob("*B/*"), ['dirB/fileB'])
        else:
            _check(p.glob("*B/*"), ['dirB/fileB', 'dirB/linkD',
                                    'linkB/fileB', 'linkB/linkD'])
        if not support.can_symlink():
            _check(p.glob("*/fileB"), ['dirB/fileB'])
        else:
            _check(p.glob("*/fileB"), ['dirB/fileB', 'linkB/fileB'])

    def test_rglob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.rglob("fileA")
        self.assertIsInstance(it, collections.abc.Iterator)
        _check(it, ["fileA"])
        _check(p.rglob("fileB"), ["dirB/fileB"])
        _check(p.rglob("*/fileA"), [])
        if not support.can_symlink():
            _check(p.rglob("*/fileB"), ["dirB/fileB"])
        else:
            _check(p.rglob("*/fileB"), ["dirB/fileB", "dirB/linkD/fileB",
                                        "linkB/fileB", "dirA/linkC/fileB"])
        _check(p.rglob("file*"), ["fileA", "dirB/fileB",
                                  "dirC/fileC", "dirC/dirD/fileD"])
        p = P(BASE, "dirC")
        _check(p.rglob("file*"), ["dirC/fileC", "dirC/dirD/fileD"])
        _check(p.rglob("*/*"), ["dirC/dirD/fileD"])

    @support.skip_unless_symlink
    def test_rglob_symlink_loop(self):
        # Don't get fooled by symlink loops (Issue #26012).
        P = self.cls
        p = P(BASE)
        given = set(p.rglob('*'))
        expect = {'brokenLink',
                  'dirA', 'dirA/linkC',
                  'dirB', 'dirB/fileB', 'dirB/linkD',
                  'dirC', 'dirC/dirD', 'dirC/dirD/fileD', 'dirC/fileC',
                  'dirE',
                  'fileA',
                  'linkA',
                  'linkB',
                  'brokenLinkLoop',
                  }
        self.assertEqual(given, {p / x for x in expect})

    def test_glob_many_open_files(self):
        depth = 30
        P = self.cls
        base = P(BASE) / 'deep'
        p = P(base, *(['d']*depth))
        p.mkdir(parents=True)
        pattern = '/'.join(['*'] * depth)
        iters = [base.glob(pattern) for j in range(100)]
        for it in iters:
            self.assertEqual(next(it), p)
        iters = [base.rglob('d') for j in range(100)]
        p = base
        for i in range(depth):
            p = p / 'd'
            for it in iters:
                self.assertEqual(next(it), p)

    def test_glob_dotdot(self):
        # ".." is not special in globs.
        P = self.cls
        p = P(BASE)
        self.assertEqual(set(p.glob("..")), { P(BASE, "..") })
        self.assertEqual(set(p.glob("dirA/../file*")), { P(BASE, "dirA/../fileA") })
        self.assertEqual(set(p.glob("../xyzzy")), set())


    def _check_resolve(self, p, expected, strict=True):
        q = p.resolve(strict)
        self.assertEqual(q, expected)

    # This can be used to check both relative and absolute resolutions.
    _check_resolve_relative = _check_resolve_absolute = _check_resolve

    @support.skip_unless_symlink
    def test_resolve_common(self):
        P = self.cls
        p = P(BASE, 'foo')
        with self.assertRaises(OSError) as cm:
            p.resolve(strict=True)
        self.assertEqual(cm.exception.errno, errno.ENOENT)
        # Non-strict
        self.assertEqualNormCase(str(p.resolve(strict=False)),
                                 os.path.join(BASE, 'foo'))
        p = P(BASE, 'foo', 'in', 'spam')
        self.assertEqualNormCase(str(p.resolve(strict=False)),
                                 os.path.join(BASE, 'foo', 'in', 'spam'))
        p = P(BASE, '..', 'foo', 'in', 'spam')
        self.assertEqualNormCase(str(p.resolve(strict=False)),
                                 os.path.abspath(os.path.join('foo', 'in', 'spam')))
        # These are all relative symlinks.
        p = P(BASE, 'dirB', 'fileB')
        self._check_resolve_relative(p, p)
        p = P(BASE, 'linkA')
        self._check_resolve_relative(p, P(BASE, 'fileA'))
        p = P(BASE, 'dirA', 'linkC', 'fileB')
        self._check_resolve_relative(p, P(BASE, 'dirB', 'fileB'))
        p = P(BASE, 'dirB', 'linkD', 'fileB')
        self._check_resolve_relative(p, P(BASE, 'dirB', 'fileB'))
        # Non-strict
        p = P(BASE, 'dirA', 'linkC', 'fileB', 'foo', 'in', 'spam')
        self._check_resolve_relative(p, P(BASE, 'dirB', 'fileB', 'foo', 'in',
                                          'spam'), False)
        p = P(BASE, 'dirA', 'linkC', '..', 'foo', 'in', 'spam')
        if os.name == 'nt':
            # In Windows, if linkY points to dirB, 'dirA\linkY\..'
            # resolves to 'dirA' without resolving linkY first.
            self._check_resolve_relative(p, P(BASE, 'dirA', 'foo', 'in',
                                              'spam'), False)
        else:
            # In Posix, if linkY points to dirB, 'dirA/linkY/..'
            # resolves to 'dirB/..' first before resolving to parent of dirB.
            self._check_resolve_relative(p, P(BASE, 'foo', 'in', 'spam'), False)
        # Now create absolute symlinks.
        d = support._longpath(tempfile.mkdtemp(suffix='-dirD', dir=os.getcwd()))
        self.addCleanup(support.rmtree, d)
        os.symlink(os.path.join(d), join('dirA', 'linkX'))
        os.symlink(join('dirB'), os.path.join(d, 'linkY'))
        p = P(BASE, 'dirA', 'linkX', 'linkY', 'fileB')
        self._check_resolve_absolute(p, P(BASE, 'dirB', 'fileB'))
        # Non-strict
        p = P(BASE, 'dirA', 'linkX', 'linkY', 'foo', 'in', 'spam')
        self._check_resolve_relative(p, P(BASE, 'dirB', 'foo', 'in', 'spam'),
                                     False)
        p = P(BASE, 'dirA', 'linkX', 'linkY', '..', 'foo', 'in', 'spam')
        if os.name == 'nt':
            # In Windows, if linkY points to dirB, 'dirA\linkY\..'
            # resolves to 'dirA' without resolving linkY first.
            self._check_resolve_relative(p, P(d, 'foo', 'in', 'spam'), False)
        else:
            # In Posix, if linkY points to dirB, 'dirA/linkY/..'
            # resolves to 'dirB/..' first before resolving to parent of dirB.
            self._check_resolve_relative(p, P(BASE, 'foo', 'in', 'spam'), False)

    @support.skip_unless_symlink
    def test_resolve_dot(self):
        # See https://bitbucket.org/pitrou/pathlib/issue/9/pathresolve-fails-on-complex-symlinks
        p = self.cls(BASE)
        self.dirlink('.', join('0'))
        self.dirlink(os.path.join('0', '0'), join('1'))
        self.dirlink(os.path.join('1', '1'), join('2'))
        q = p / '2'
        self.assertEqual(q.resolve(strict=True), p)
        r = q / '3' / '4'
        self.assertRaises(FileNotFoundError, r.resolve, strict=True)
        # Non-strict
        self.assertEqual(r.resolve(strict=False), p / '3' / '4')

    def test_with(self):
        p = self.cls(BASE)
        it = p.iterdir()
        it2 = p.iterdir()
        next(it2)
        with p:
            pass
        # I/O operation on closed path.
        self.assertRaises(ValueError, next, it)
        self.assertRaises(ValueError, next, it2)
        self.assertRaises(ValueError, p.open)
        self.assertRaises(ValueError, p.resolve)
        self.assertRaises(ValueError, p.absolute)
        self.assertRaises(ValueError, p.__enter__)

    def test_chmod(self):
        p = self.cls(BASE) / 'fileA'
        mode = p.stat().st_mode
        # Clear writable bit.
        new_mode = mode & ~0o222
        p.chmod(new_mode)
        self.assertEqual(p.stat().st_mode, new_mode)
        # Set writable bit.
        new_mode = mode | 0o222
        p.chmod(new_mode)
        self.assertEqual(p.stat().st_mode, new_mode)

    # XXX also need a test for lchmod.

    def test_stat(self):
        p = self.cls(BASE) / 'fileA'
        st = p.stat()
        self.assertEqual(p.stat(), st)
        # Change file mode by flipping write bit.
        p.chmod(st.st_mode ^ 0o222)
        self.addCleanup(p.chmod, st.st_mode)
        self.assertNotEqual(p.stat(), st)

    @support.skip_unless_symlink
    def test_lstat(self):
        p = self.cls(BASE)/ 'linkA'
        st = p.stat()
        self.assertNotEqual(st, p.lstat())

    def test_lstat_nosymlink(self):
        p = self.cls(BASE) / 'fileA'
        st = p.stat()
        self.assertEqual(st, p.lstat())

    @unittest.skipUnless(pwd, "the pwd module is needed for this test")
    def test_owner(self):
        p = self.cls(BASE) / 'fileA'
        uid = p.stat().st_uid
        try:
            name = pwd.getpwuid(uid).pw_name
        except KeyError:
            self.skipTest(
                "user %d doesn't have an entry in the system database" % uid)
        self.assertEqual(name, p.owner())

    @unittest.skipUnless(grp, "the grp module is needed for this test")
    def test_group(self):
        p = self.cls(BASE) / 'fileA'
        gid = p.stat().st_gid
        try:
            name = grp.getgrgid(gid).gr_name
        except KeyError:
            self.skipTest(
                "group %d doesn't have an entry in the system database" % gid)
        self.assertEqual(name, p.group())

    def test_unlink(self):
        p = self.cls(BASE) / 'fileA'
        p.unlink()
        self.assertFileNotFound(p.stat)
        self.assertFileNotFound(p.unlink)

    def test_unlink_missing_ok(self):
        p = self.cls(BASE) / 'fileAAA'
        self.assertFileNotFound(p.unlink)
        p.unlink(missing_ok=True)

    def test_rmdir(self):
        p = self.cls(BASE) / 'dirA'
        for q in p.iterdir():
            q.unlink()
        p.rmdir()
        self.assertFileNotFound(p.stat)
        self.assertFileNotFound(p.unlink)

    def test_link_to(self):
        P = self.cls(BASE)
        p = P / 'fileA'
        size = p.stat().st_size
        # linking to another path.
        q = P / 'dirA' / 'fileAA'
        try:
            p.link_to(q)
        except PermissionError as e:
            self.skipTest('os.link(): %s' % e)
        self.assertEqual(q.stat().st_size, size)
        self.assertEqual(os.path.samefile(p, q), True)
        self.assertTrue(p.stat)
        # Linking to a str of a relative path.
        r = rel_join('fileAAA')
        q.link_to(r)
        self.assertEqual(os.stat(r).st_size, size)
        self.assertTrue(q.stat)

    def test_rename(self):
        P = self.cls(BASE)
        p = P / 'fileA'
        size = p.stat().st_size
        # Renaming to another path.
        q = P / 'dirA' / 'fileAA'
        renamed_p = p.rename(q)
        self.assertEqual(renamed_p, q)
        self.assertEqual(q.stat().st_size, size)
        self.assertFileNotFound(p.stat)
        # Renaming to a str of a relative path.
        r = rel_join('fileAAA')
        renamed_q = q.rename(r)
        self.assertEqual(renamed_q, self.cls(r))
        self.assertEqual(os.stat(r).st_size, size)
        self.assertFileNotFound(q.stat)

    def test_replace(self):
        P = self.cls(BASE)
        p = P / 'fileA'
        size = p.stat().st_size
        # Replacing a non-existing path.
        q = P / 'dirA' / 'fileAA'
        replaced_p = p.replace(q)
        self.assertEqual(replaced_p, q)
        self.assertEqual(q.stat().st_size, size)
        self.assertFileNotFound(p.stat)
        # Replacing another (existing) path.
        r = rel_join('dirB', 'fileB')
        replaced_q = q.replace(r)
        self.assertEqual(replaced_q, self.cls(r))
        self.assertEqual(os.stat(r).st_size, size)
        self.assertFileNotFound(q.stat)

    def test_touch_common(self):
        P = self.cls(BASE)
        p = P / 'newfileA'
        self.assertFalse(p.exists())
        p.touch()
        self.assertTrue(p.exists())
        st = p.stat()
        old_mtime = st.st_mtime
        old_mtime_ns = st.st_mtime_ns
        # Rewind the mtime sufficiently far in the past to work around
        # filesystem-specific timestamp granularity.
        os.utime(str(p), (old_mtime - 10, old_mtime - 10))
        # The file mtime should be refreshed by calling touch() again.
        p.touch()
        st = p.stat()
        self.assertGreaterEqual(st.st_mtime_ns, old_mtime_ns)
        self.assertGreaterEqual(st.st_mtime, old_mtime)
        # Now with exist_ok=False.
        p = P / 'newfileB'
        self.assertFalse(p.exists())
        p.touch(mode=0o700, exist_ok=False)
        self.assertTrue(p.exists())
        self.assertRaises(OSError, p.touch, exist_ok=False)

    def test_touch_nochange(self):
        P = self.cls(BASE)
        p = P / 'fileA'
        p.touch()
        with p.open('rb') as f:
            self.assertEqual(f.read().strip(), b"this is file A")

    def test_mkdir(self):
        P = self.cls(BASE)
        p = P / 'newdirA'
        self.assertFalse(p.exists())
        p.mkdir()
        self.assertTrue(p.exists())
        self.assertTrue(p.is_dir())
        with self.assertRaises(OSError) as cm:
            p.mkdir()
        self.assertEqual(cm.exception.errno, errno.EEXIST)

    def test_mkdir_parents(self):
        # Creating a chain of directories.
        p = self.cls(BASE, 'newdirB', 'newdirC')
        self.assertFalse(p.exists())
        with self.assertRaises(OSError) as cm:
            p.mkdir()
        self.assertEqual(cm.exception.errno, errno.ENOENT)
        p.mkdir(parents=True)
        self.assertTrue(p.exists())
        self.assertTrue(p.is_dir())
        with self.assertRaises(OSError) as cm:
            p.mkdir(parents=True)
        self.assertEqual(cm.exception.errno, errno.EEXIST)
        # Test `mode` arg.
        mode = stat.S_IMODE(p.stat().st_mode)  # Default mode.
        p = self.cls(BASE, 'newdirD', 'newdirE')
        p.mkdir(0o555, parents=True)
        self.assertTrue(p.exists())
        self.assertTrue(p.is_dir())
        if os.name != 'nt':
            # The directory's permissions follow the mode argument.
            self.assertEqual(stat.S_IMODE(p.stat().st_mode), 0o7555 & mode)
        # The parent's permissions follow the default process settings.
        self.assertEqual(stat.S_IMODE(p.parent.stat().st_mode), mode)

    def test_mkdir_exist_ok(self):
        p = self.cls(BASE, 'dirB')
        st_ctime_first = p.stat().st_ctime
        self.assertTrue(p.exists())
        self.assertTrue(p.is_dir())
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir()
        self.assertEqual(cm.exception.errno, errno.EEXIST)
        p.mkdir(exist_ok=True)
        self.assertTrue(p.exists())
        self.assertEqual(p.stat().st_ctime, st_ctime_first)

    def test_mkdir_exist_ok_with_parent(self):
        p = self.cls(BASE, 'dirC')
        self.assertTrue(p.exists())
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir()
        self.assertEqual(cm.exception.errno, errno.EEXIST)
        p = p / 'newdirC'
        p.mkdir(parents=True)
        st_ctime_first = p.stat().st_ctime
        self.assertTrue(p.exists())
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir(parents=True)
        self.assertEqual(cm.exception.errno, errno.EEXIST)
        p.mkdir(parents=True, exist_ok=True)
        self.assertTrue(p.exists())
        self.assertEqual(p.stat().st_ctime, st_ctime_first)

    def test_mkdir_exist_ok_root(self):
        # Issue #25803: A drive root could raise PermissionError on Windows.
        self.cls('/').resolve().mkdir(exist_ok=True)
        self.cls('/').resolve().mkdir(parents=True, exist_ok=True)

    @only_nt  # XXX: not sure how to test this on POSIX.
    def test_mkdir_with_unknown_drive(self):
        for d in 'ZYXWVUTSRQPONMLKJIHGFEDCBA':
            p = self.cls(d + ':\\')
            if not p.is_dir():
                break
        else:
            self.skipTest("cannot find a drive that doesn't exist")
        with self.assertRaises(OSError):
            (p / 'child' / 'path').mkdir(parents=True)

    def test_mkdir_with_child_file(self):
        p = self.cls(BASE, 'dirB', 'fileB')
        self.assertTrue(p.exists())
        # An exception is raised when the last path component is an existing
        # regular file, regardless of whether exist_ok is true or not.
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir(parents=True)
        self.assertEqual(cm.exception.errno, errno.EEXIST)
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir(parents=True, exist_ok=True)
        self.assertEqual(cm.exception.errno, errno.EEXIST)

    def test_mkdir_no_parents_file(self):
        p = self.cls(BASE, 'fileA')
        self.assertTrue(p.exists())
        # An exception is raised when the last path component is an existing
        # regular file, regardless of whether exist_ok is true or not.
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir()
        self.assertEqual(cm.exception.errno, errno.EEXIST)
        with self.assertRaises(FileExistsError) as cm:
            p.mkdir(exist_ok=True)
        self.assertEqual(cm.exception.errno, errno.EEXIST)

    def test_mkdir_concurrent_parent_creation(self):
        for pattern_num in range(32):
            p = self.cls(BASE, 'dirCPC%d' % pattern_num)
            self.assertFalse(p.exists())

            def my_mkdir(path, mode=0o777):
                path = str(path)
                # Emulate another process that would create the directory
                # just before we try to create it ourselves.  We do it
                # in all possible pattern combinations, assuming that this
                # function is called at most 5 times (dirCPC/dir1/dir2,
                # dirCPC/dir1, dirCPC, dirCPC/dir1, dirCPC/dir1/dir2).
                if pattern.pop():
                    os.mkdir(path, mode)  # From another process.
                    concurrently_created.add(path)
                os.mkdir(path, mode)  # Our real call.

            pattern = [bool(pattern_num & (1 << n)) for n in range(5)]
            concurrently_created = set()
            p12 = p / 'dir1' / 'dir2'
            try:
                with mock.patch("pathlib._normal_accessor.mkdir", my_mkdir):
                    p12.mkdir(parents=True, exist_ok=False)
            except FileExistsError:
                self.assertIn(str(p12), concurrently_created)
            else:
                self.assertNotIn(str(p12), concurrently_created)
            self.assertTrue(p.exists())

    @support.skip_unless_symlink
    def test_symlink_to(self):
        P = self.cls(BASE)
        target = P / 'fileA'
        # Symlinking a path target.
        link = P / 'dirA' / 'linkAA'
        link.symlink_to(target)
        self.assertEqual(link.stat(), target.stat())
        self.assertNotEqual(link.lstat(), target.stat())
        # Symlinking a str target.
        link = P / 'dirA' / 'linkAAA'
        link.symlink_to(str(target))
        self.assertEqual(link.stat(), target.stat())
        self.assertNotEqual(link.lstat(), target.stat())
        self.assertFalse(link.is_dir())
        # Symlinking to a directory.
        target = P / 'dirB'
        link = P / 'dirA' / 'linkAAAA'
        link.symlink_to(target, target_is_directory=True)
        self.assertEqual(link.stat(), target.stat())
        self.assertNotEqual(link.lstat(), target.stat())
        self.assertTrue(link.is_dir())
        self.assertTrue(list(link.iterdir()))

    def test_is_dir(self):
        P = self.cls(BASE)
        self.assertTrue((P / 'dirA').is_dir())
        self.assertFalse((P / 'fileA').is_dir())
        self.assertFalse((P / 'non-existing').is_dir())
        self.assertFalse((P / 'fileA' / 'bah').is_dir())
        if support.can_symlink():
            self.assertFalse((P / 'linkA').is_dir())
            self.assertTrue((P / 'linkB').is_dir())
            self.assertFalse((P/ 'brokenLink').is_dir(), False)
        self.assertIs((P / 'dirA\udfff').is_dir(), False)
        self.assertIs((P / 'dirA\x00').is_dir(), False)

    def test_is_file(self):
        P = self.cls(BASE)
        self.assertTrue((P / 'fileA').is_file())
        self.assertFalse((P / 'dirA').is_file())
        self.assertFalse((P / 'non-existing').is_file())
        self.assertFalse((P / 'fileA' / 'bah').is_file())
        if support.can_symlink():
            self.assertTrue((P / 'linkA').is_file())
            self.assertFalse((P / 'linkB').is_file())
            self.assertFalse((P/ 'brokenLink').is_file())
        self.assertIs((P / 'fileA\udfff').is_file(), False)
        self.assertIs((P / 'fileA\x00').is_file(), False)

    @only_posix
    def test_is_mount(self):
        P = self.cls(BASE)
        R = self.cls('/')  # TODO: Work out Windows.
        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())
        self.assertTrue(R.is_mount())
        if support.can_symlink():
            self.assertFalse((P / 'linkA').is_mount())
        self.assertIs(self.cls('/\udfff').is_mount(), False)
        self.assertIs(self.cls('/\x00').is_mount(), False)

    def test_is_symlink(self):
        P = self.cls(BASE)
        self.assertFalse((P / 'fileA').is_symlink())
        self.assertFalse((P / 'dirA').is_symlink())
        self.assertFalse((P / 'non-existing').is_symlink())
        self.assertFalse((P / 'fileA' / 'bah').is_symlink())
        if support.can_symlink():
            self.assertTrue((P / 'linkA').is_symlink())
            self.assertTrue((P / 'linkB').is_symlink())
            self.assertTrue((P/ 'brokenLink').is_symlink())
        self.assertIs((P / 'fileA\udfff').is_file(), False)
        self.assertIs((P / 'fileA\x00').is_file(), False)
        if support.can_symlink():
            self.assertIs((P / 'linkA\udfff').is_file(), False)
            self.assertIs((P / 'linkA\x00').is_file(), False)

    def test_is_fifo_false(self):
        P = self.cls(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")
    def test_is_fifo_true(self):
        P = self.cls(BASE, 'myfifo')
        try:
            os.mkfifo(str(P))
        except PermissionError as e:
            self.skipTest('os.mkfifo(): %s' % e)
        self.assertTrue(P.is_fifo())
        self.assertFalse(P.is_socket())
        self.assertFalse(P.is_file())
        self.assertIs(self.cls(BASE, 'myfifo\udfff').is_fifo(), False)
        self.assertIs(self.cls(BASE, 'myfifo\x00').is_fifo(), False)

    def test_is_socket_false(self):
        P = self.cls(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")
    def test_is_socket_true(self):
        P = self.cls(BASE, 'mysock')
        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
        self.addCleanup(sock.close)
        try:
            sock.bind(str(P))
        except OSError as e:
            if (isinstance(e, PermissionError) or
                    "AF_UNIX path too long" in str(e)):
                self.skipTest("cannot bind Unix socket: " + str(e))
        self.assertTrue(P.is_socket())
        self.assertFalse(P.is_fifo())
        self.assertFalse(P.is_file())
        self.assertIs(self.cls(BASE, 'mysock\udfff').is_socket(), False)
        self.assertIs(self.cls(BASE, 'mysock\x00').is_socket(), False)

    def test_is_block_device_false(self):
        P = self.cls(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(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):
        # Under Unix, /dev/null should generally be a char device.
        P = self.cls('/dev/null')
        if not P.exists():
            self.skipTest("/dev/null required")
        self.assertTrue(P.is_char_device())
        self.assertFalse(P.is_block_device())
        self.assertFalse(P.is_file())
        self.assertIs(self.cls('/dev/null\udfff').is_char_device(), False)
        self.assertIs(self.cls('/dev/null\x00').is_char_device(), False)

    def test_pickling_common(self):
        p = self.cls(BASE, 'fileA')
        for proto in range(0, pickle.HIGHEST_PROTOCOL + 1):
            dumped = pickle.dumps(p, proto)
            pp = pickle.loads(dumped)
            self.assertEqual(pp.stat(), p.stat())

    def test_parts_interning(self):
        P = self.cls
        p = P('/usr/bin/foo')
        q = P('/usr/local/bin')
        # 'usr'
        self.assertIs(p.parts[1], q.parts[1])
        # 'bin'
        self.assertIs(p.parts[2], q.parts[3])

    def _check_complex_symlinks(self, link0_target):
        # Test solving a non-looping chain of symlinks (issue #19887).
        P = self.cls(BASE)
        self.dirlink(os.path.join('link0', 'link0'), join('link1'))
        self.dirlink(os.path.join('link1', 'link1'), join('link2'))
        self.dirlink(os.path.join('link2', 'link2'), join('link3'))
        self.dirlink(link0_target, join('link0'))

        # Resolve absolute paths.
        p = (P / 'link0').resolve()
        self.assertEqual(p, P)
        self.assertEqualNormCase(str(p), BASE)
        p = (P / 'link1').resolve()
        self.assertEqual(p, P)
        self.assertEqualNormCase(str(p), BASE)
        p = (P / 'link2').resolve()
        self.assertEqual(p, P)
        self.assertEqualNormCase(str(p), BASE)
        p = (P / 'link3').resolve()
        self.assertEqual(p, P)
        self.assertEqualNormCase(str(p), BASE)

        # Resolve relative paths.
        old_path = os.getcwd()
        os.chdir(BASE)
        try:
            p = self.cls('link0').resolve()
            self.assertEqual(p, P)
            self.assertEqualNormCase(str(p), BASE)
            p = self.cls('link1').resolve()
            self.assertEqual(p, P)
            self.assertEqualNormCase(str(p), BASE)
            p = self.cls('link2').resolve()
            self.assertEqual(p, P)
            self.assertEqualNormCase(str(p), BASE)
            p = self.cls('link3').resolve()
            self.assertEqual(p, P)
            self.assertEqualNormCase(str(p), BASE)
        finally:
            os.chdir(old_path)

    @support.skip_unless_symlink
    def test_complex_symlinks_absolute(self):
        self._check_complex_symlinks(BASE)

    @support.skip_unless_symlink
    def test_complex_symlinks_relative(self):
        self._check_complex_symlinks('.')

    @support.skip_unless_symlink
    def test_complex_symlinks_relative_dot_dot(self):
        self._check_complex_symlinks(os.path.join('dirA', '..'))


class PathTest(_BasePathTest, unittest.TestCase):
    cls = pathlib.Path

    def test_concrete_class(self):
        p = self.cls('a')
        self.assertIs(type(p),
            pathlib.WindowsPath if os.name == 'nt' else pathlib.PosixPath)

    def test_unsupported_flavour(self):
        if os.name == 'nt':
            self.assertRaises(NotImplementedError, pathlib.PosixPath)
        else:
            self.assertRaises(NotImplementedError, pathlib.WindowsPath)

    def test_glob_empty_pattern(self):
        p = self.cls()
        with self.assertRaisesRegex(ValueError, 'Unacceptable pattern'):
            list(p.glob(''))


@only_posix
class PosixPathTest(_BasePathTest, unittest.TestCase):
    cls = pathlib.PosixPath

    def _check_symlink_loop(self, *args, strict=True):
        path = self.cls(*args)
        with self.assertRaises(RuntimeError):
            print(path.resolve(strict))

    def test_open_mode(self):
        old_mask = os.umask(0)
        self.addCleanup(os.umask, old_mask)
        p = self.cls(BASE)
        with (p / 'new_file').open('wb'):
            pass
        st = os.stat(join('new_file'))
        self.assertEqual(stat.S_IMODE(st.st_mode), 0o666)
        os.umask(0o022)
        with (p / 'other_new_file').open('wb'):
            pass
        st = os.stat(join('other_new_file'))
        self.assertEqual(stat.S_IMODE(st.st_mode), 0o644)

    def test_touch_mode(self):
        old_mask = os.umask(0)
        self.addCleanup(os.umask, old_mask)
        p = self.cls(BASE)
        (p / 'new_file').touch()
        st = os.stat(join('new_file'))
        self.assertEqual(stat.S_IMODE(st.st_mode), 0o666)
        os.umask(0o022)
        (p / 'other_new_file').touch()
        st = os.stat(join('other_new_file'))
        self.assertEqual(stat.S_IMODE(st.st_mode), 0o644)
        (p / 'masked_new_file').touch(mode=0o750)
        st = os.stat(join('masked_new_file'))
        self.assertEqual(stat.S_IMODE(st.st_mode), 0o750)

    @support.skip_unless_symlink
    def test_resolve_loop(self):
        # Loops with relative symlinks.
        os.symlink('linkX/inside', join('linkX'))
        self._check_symlink_loop(BASE, 'linkX')
        os.symlink('linkY', join('linkY'))
        self._check_symlink_loop(BASE, 'linkY')
        os.symlink('linkZ/../linkZ', join('linkZ'))
        self._check_symlink_loop(BASE, 'linkZ')
        # Non-strict
        self._check_symlink_loop(BASE, 'linkZ', 'foo', strict=False)
        # Loops with absolute symlinks.
        os.symlink(join('linkU/inside'), join('linkU'))
        self._check_symlink_loop(BASE, 'linkU')
        os.symlink(join('linkV'), join('linkV'))
        self._check_symlink_loop(BASE, 'linkV')
        os.symlink(join('linkW/../linkW'), join('linkW'))
        self._check_symlink_loop(BASE, 'linkW')
        # Non-strict
        self._check_symlink_loop(BASE, 'linkW', 'foo', strict=False)

    def test_glob(self):
        P = self.cls
        p = P(BASE)
        given = set(p.glob("FILEa"))
        expect = set() if not support.fs_is_case_insensitive(BASE) else given
        self.assertEqual(given, expect)
        self.assertEqual(set(p.glob("FILEa*")), set())

    def test_rglob(self):
        P = self.cls
        p = P(BASE, "dirC")
        given = set(p.rglob("FILEd"))
        expect = set() if not support.fs_is_case_insensitive(BASE) else given
        self.assertEqual(given, expect)
        self.assertEqual(set(p.rglob("FILEd*")), set())

    @unittest.skipUnless(hasattr(pwd, 'getpwall'),
                         'pwd module does not expose getpwall()')
    def test_expanduser(self):
        P = self.cls
        support.import_module('pwd')
        import pwd
        pwdent = pwd.getpwuid(os.getuid())
        username = pwdent.pw_name
        userhome = pwdent.pw_dir.rstrip('/') or '/'
        # Find arbitrary different user (if exists).
        for pwdent in pwd.getpwall():
            othername = pwdent.pw_name
            otherhome = pwdent.pw_dir.rstrip('/')
            if othername != username and otherhome:
                break
        else:
            othername = username
            otherhome = userhome

        p1 = P('~/Documents')
        p2 = P('~' + username + '/Documents')
        p3 = P('~' + othername + '/Documents')
        p4 = P('../~' + username + '/Documents')
        p5 = P('/~' + username + '/Documents')
        p6 = P('')
        p7 = P('~fakeuser/Documents')

        with support.EnvironmentVarGuard() as env:
            env.pop('HOME', None)

            self.assertEqual(p1.expanduser(), P(userhome) / 'Documents')
            self.assertEqual(p2.expanduser(), P(userhome) / 'Documents')
            self.assertEqual(p3.expanduser(), P(otherhome) / 'Documents')
            self.assertEqual(p4.expanduser(), p4)
            self.assertEqual(p5.expanduser(), p5)
            self.assertEqual(p6.expanduser(), p6)
            self.assertRaises(RuntimeError, p7.expanduser)

            env['HOME'] = '/tmp'
            self.assertEqual(p1.expanduser(), P('/tmp/Documents'))
            self.assertEqual(p2.expanduser(), P(userhome) / 'Documents')
            self.assertEqual(p3.expanduser(), P(otherhome) / 'Documents')
            self.assertEqual(p4.expanduser(), p4)
            self.assertEqual(p5.expanduser(), p5)
            self.assertEqual(p6.expanduser(), p6)
            self.assertRaises(RuntimeError, p7.expanduser)

    @unittest.skipIf(sys.platform != "darwin",
                     "Bad file descriptor in /dev/fd affects only macOS")
    def test_handling_bad_descriptor(self):
        try:
            file_descriptors = list(pathlib.Path('/dev/fd').rglob("*"))[3:]
            if not file_descriptors:
                self.skipTest("no file descriptors - issue was not reproduced")
            # Checking all file descriptors because there is no guarantee
            # which one will fail.
            for f in file_descriptors:
                f.exists()
                f.is_dir()
                f.is_file()
                f.is_symlink()
                f.is_block_device()
                f.is_char_device()
                f.is_fifo()
                f.is_socket()
        except OSError as e:
            if e.errno == errno.EBADF:
                self.fail("Bad file descriptor not handled.")
            raise


@only_nt
class WindowsPathTest(_BasePathTest, unittest.TestCase):
    cls = pathlib.WindowsPath

    def test_glob(self):
        P = self.cls
        p = P(BASE)
        self.assertEqual(set(p.glob("FILEa")), { P(BASE, "fileA") })

    def test_rglob(self):
        P = self.cls
        p = P(BASE, "dirC")
        self.assertEqual(set(p.rglob("FILEd")), { P(BASE, "dirC/dirD/fileD") })

    def test_expanduser(self):
        P = self.cls
        with support.EnvironmentVarGuard() as env:
            env.pop('HOME', None)
            env.pop('USERPROFILE', None)
            env.pop('HOMEPATH', None)
            env.pop('HOMEDRIVE', None)
            env['USERNAME'] = 'alice'

            # test that the path returns unchanged
            p1 = P('~/My Documents')
            p2 = P('~alice/My Documents')
            p3 = P('~bob/My Documents')
            p4 = P('/~/My Documents')
            p5 = P('d:~/My Documents')
            p6 = P('')
            self.assertRaises(RuntimeError, p1.expanduser)
            self.assertRaises(RuntimeError, p2.expanduser)
            self.assertRaises(RuntimeError, p3.expanduser)
            self.assertEqual(p4.expanduser(), p4)
            self.assertEqual(p5.expanduser(), p5)
            self.assertEqual(p6.expanduser(), p6)

            def check():
                env.pop('USERNAME', None)
                self.assertEqual(p1.expanduser(),
                                 P('C:/Users/alice/My Documents'))
                self.assertRaises(KeyError, p2.expanduser)
                env['USERNAME'] = 'alice'
                self.assertEqual(p2.expanduser(),
                                 P('C:/Users/alice/My Documents'))
                self.assertEqual(p3.expanduser(),
                                 P('C:/Users/bob/My Documents'))
                self.assertEqual(p4.expanduser(), p4)
                self.assertEqual(p5.expanduser(), p5)
                self.assertEqual(p6.expanduser(), p6)

            # Test the first lookup key in the env vars.
            env['HOME'] = 'C:\\Users\\alice'
            check()

            # Test that HOMEPATH is available instead.
            env.pop('HOME', None)
            env['HOMEPATH'] = 'C:\\Users\\alice'
            check()

            env['HOMEDRIVE'] = 'C:\\'
            env['HOMEPATH'] = 'Users\\alice'
            check()

            env.pop('HOMEDRIVE', None)
            env.pop('HOMEPATH', None)
            env['USERPROFILE'] = 'C:\\Users\\alice'
            check()


class CompatiblePathTest(unittest.TestCase):
    """
    Test that a type can be made compatible with PurePath
    derivatives by implementing division operator overloads.
    """

    class CompatPath:
        """
        Minimum viable class to test PurePath compatibility.
        Simply uses the division operator to join a given
        string and the string value of another object with
        a forward slash.
        """
        def __init__(self, string):
            self.string = string

        def __truediv__(self, other):
            return type(self)(f"{self.string}/{other}")

        def __rtruediv__(self, other):
            return type(self)(f"{other}/{self.string}")

    def test_truediv(self):
        result = pathlib.PurePath("test") / self.CompatPath("right")
        self.assertIsInstance(result, self.CompatPath)
        self.assertEqual(result.string, "test/right")

        with self.assertRaises(TypeError):
            # Verify improper operations still raise a TypeError
            pathlib.PurePath("test") / 10

    def test_rtruediv(self):
        result = self.CompatPath("left") / pathlib.PurePath("test")
        self.assertIsInstance(result, self.CompatPath)
        self.assertEqual(result.string, "left/test")

        with self.assertRaises(TypeError):
            # Verify improper operations still raise a TypeError
            10 / pathlib.PurePath("test")


if __name__ == "__main__":
    unittest.main()