diff --git a/Lib/test/test_genericpath.py b/Lib/test/test_genericpath.py
index 15f12e4..e54dd10 100644
--- a/Lib/test/test_genericpath.py
+++ b/Lib/test/test_genericpath.py
@@ -1,38 +1,72 @@
+"""
+Tests common to genericpath, macpath, ntpath and posixpath
+"""
+
 import unittest
 from test import test_support
 import os
 import genericpath
 
-class AllCommonTest(unittest.TestCase):
+
+def safe_rmdir(dirname):
+    try:
+        os.rmdir(dirname)
+    except OSError:
+        pass
+
+
+class GenericTest(unittest.TestCase):
+    # The path module to be tested
+    path = genericpath
+    common_attributes = ['commonprefix', 'getsize', 'getatime', 'getctime',
+                         'getmtime', 'exists', 'isdir', 'isfile']
+    attributes = []
+
+    def test_no_argument(self):
+        for attr in self.common_attributes + self.attributes:
+            with self.assertRaises(TypeError):
+                getattr(self.path, attr)()
+                raise self.fail("{}.{}() do not raise a TypeError"
+                                .format(self.path.__name__, attr))
 
     def test_commonprefix(self):
         self.assertEqual(
-            genericpath.commonprefix([]),
+            self.path.commonprefix([]),
             ""
         )
         self.assertEqual(
-            genericpath.commonprefix(["/home/swenson/spam", "/home/swen/spam"]),
+            self.path.commonprefix(["/home/swenson/spam", "/home/swen/spam"]),
             "/home/swen"
         )
         self.assertEqual(
-            genericpath.commonprefix(["/home/swen/spam", "/home/swen/eggs"]),
+            self.path.commonprefix(["/home/swen/spam", "/home/swen/eggs"]),
             "/home/swen/"
         )
         self.assertEqual(
-            genericpath.commonprefix(["/home/swen/spam", "/home/swen/spam"]),
+            self.path.commonprefix(["/home/swen/spam", "/home/swen/spam"]),
             "/home/swen/spam"
         )
 
+        testlist = ['', 'abc', 'Xbcd', 'Xb', 'XY', 'abcd', 'aXc', 'abd', 'ab', 'aX', 'abcX']
+        for s1 in testlist:
+            for s2 in testlist:
+                p = self.path.commonprefix([s1, s2])
+                self.assertTrue(s1.startswith(p))
+                self.assertTrue(s2.startswith(p))
+                if s1 != s2:
+                    n = len(p)
+                    self.assertNotEqual(s1[n:n+1], s2[n:n+1])
+
     def test_getsize(self):
         f = open(test_support.TESTFN, "wb")
         try:
             f.write("foo")
             f.close()
-            self.assertEqual(genericpath.getsize(test_support.TESTFN), 3)
+            self.assertEqual(self.path.getsize(test_support.TESTFN), 3)
         finally:
             if not f.closed:
                 f.close()
-            os.remove(test_support.TESTFN)
+            test_support.unlink(test_support.TESTFN)
 
     def test_time(self):
         f = open(test_support.TESTFN, "wb")
@@ -48,147 +82,150 @@
             self.assertEqual(d, "foobar")
 
             self.assertLessEqual(
-                genericpath.getctime(test_support.TESTFN),
-                genericpath.getmtime(test_support.TESTFN)
+                self.path.getctime(test_support.TESTFN),
+                self.path.getmtime(test_support.TESTFN)
             )
         finally:
             if not f.closed:
                 f.close()
-            os.remove(test_support.TESTFN)
+            test_support.unlink(test_support.TESTFN)
 
     def test_exists(self):
-        self.assertIs(genericpath.exists(test_support.TESTFN), False)
+        self.assertIs(self.path.exists(test_support.TESTFN), False)
         f = open(test_support.TESTFN, "wb")
         try:
             f.write("foo")
             f.close()
-            self.assertIs(genericpath.exists(test_support.TESTFN), True)
+            self.assertIs(self.path.exists(test_support.TESTFN), True)
+            if not self.path == genericpath:
+                self.assertIs(self.path.lexists(test_support.TESTFN), True)
         finally:
             if not f.close():
                 f.close()
-            try:
-                os.remove(test_support.TESTFN)
-            except os.error:
-                pass
-
-        self.assertRaises(TypeError, genericpath.exists)
+            test_support.unlink(test_support.TESTFN)
 
     def test_isdir(self):
-        self.assertIs(genericpath.isdir(test_support.TESTFN), False)
+        self.assertIs(self.path.isdir(test_support.TESTFN), False)
         f = open(test_support.TESTFN, "wb")
         try:
             f.write("foo")
             f.close()
-            self.assertIs(genericpath.isdir(test_support.TESTFN), False)
+            self.assertIs(self.path.isdir(test_support.TESTFN), False)
             os.remove(test_support.TESTFN)
             os.mkdir(test_support.TESTFN)
-            self.assertIs(genericpath.isdir(test_support.TESTFN), True)
+            self.assertIs(self.path.isdir(test_support.TESTFN), True)
             os.rmdir(test_support.TESTFN)
         finally:
             if not f.close():
                 f.close()
-            try:
-                os.remove(test_support.TESTFN)
-            except os.error:
-                pass
-            try:
-                os.rmdir(test_support.TESTFN)
-            except os.error:
-                pass
-
-        self.assertRaises(TypeError, genericpath.isdir)
+            test_support.unlink(test_support.TESTFN)
+            safe_rmdir(test_support.TESTFN)
 
     def test_isfile(self):
-        self.assertIs(genericpath.isfile(test_support.TESTFN), False)
+        self.assertIs(self.path.isfile(test_support.TESTFN), False)
         f = open(test_support.TESTFN, "wb")
         try:
             f.write("foo")
             f.close()
-            self.assertIs(genericpath.isfile(test_support.TESTFN), True)
+            self.assertIs(self.path.isfile(test_support.TESTFN), True)
             os.remove(test_support.TESTFN)
             os.mkdir(test_support.TESTFN)
-            self.assertIs(genericpath.isfile(test_support.TESTFN), False)
+            self.assertIs(self.path.isfile(test_support.TESTFN), False)
             os.rmdir(test_support.TESTFN)
         finally:
             if not f.close():
                 f.close()
-            try:
-                os.remove(test_support.TESTFN)
-            except os.error:
-                pass
-            try:
-                os.rmdir(test_support.TESTFN)
-            except os.error:
-                pass
-
-        self.assertRaises(TypeError, genericpath.isdir)
-
-        def test_samefile(self):
-            f = open(test_support.TESTFN + "1", "wb")
-            try:
-                f.write("foo")
-                f.close()
-                self.assertIs(
-                    genericpath.samefile(
-                        test_support.TESTFN + "1",
-                        test_support.TESTFN + "1"
-                    ),
-                    True
-                )
-                # If we don't have links, assume that os.stat doesn't return resonable
-                # inode information and thus, that samefile() doesn't work
-                if hasattr(os, "symlink"):
-                    os.symlink(
-                        test_support.TESTFN + "1",
-                        test_support.TESTFN + "2"
-                    )
-                    self.assertIs(
-                        genericpath.samefile(
-                            test_support.TESTFN + "1",
-                            test_support.TESTFN + "2"
-                        ),
-                        True
-                    )
-                    os.remove(test_support.TESTFN + "2")
-                    f = open(test_support.TESTFN + "2", "wb")
-                    f.write("bar")
-                    f.close()
-                    self.assertIs(
-                        genericpath.samefile(
-                            test_support.TESTFN + "1",
-                            test_support.TESTFN + "2"
-                        ),
-                        False
-                    )
-            finally:
-                if not f.close():
-                    f.close()
-                try:
-                    os.remove(test_support.TESTFN + "1")
-                except os.error:
-                    pass
-                try:
-                    os.remove(test_support.TESTFN + "2")
-                except os.error:
-                    pass
-
-            self.assertRaises(TypeError, genericpath.samefile)
+            test_support.unlink(test_support.TESTFN)
+            safe_rmdir(test_support.TESTFN)
 
 
-# XXX at some point this should probably go in some class that contains common
-# tests for all test_*path modules.
-def _issue3426(self, cwd, abspath):
-    # Issue 3426: check that abspath retuns unicode when the arg is unicode
-    # and str when it's str, with both ASCII and non-ASCII cwds
-    with test_support.temp_cwd(cwd):
+class CommonTest(GenericTest):
+    # The path module to be tested
+    path = None
+    common_attributes = GenericTest.common_attributes + [
+        # Properties
+        'curdir', 'pardir', 'extsep', 'sep',
+        'pathsep', 'defpath', 'altsep', 'devnull',
+        # Methods
+        'normcase', 'splitdrive', 'expandvars', 'normpath', 'abspath',
+        'join', 'split', 'splitext', 'isabs', 'basename', 'dirname',
+        'lexists', 'islink', 'ismount', 'expanduser', 'normpath', 'realpath',
+    ]
+
+    def test_normcase(self):
+        # Check that normcase() is idempotent
+        p = "FoO/./BaR"
+        p = self.path.normcase(p)
+        self.assertEqual(p, self.path.normcase(p))
+
+    def test_splitdrive(self):
+        # splitdrive for non-NT paths
+        self.assertEqual(self.path.splitdrive("/foo/bar"), ("", "/foo/bar"))
+        self.assertEqual(self.path.splitdrive("foo:bar"), ('', 'foo:bar'))
+        self.assertEqual(self.path.splitdrive(":foo:bar"), ('', ':foo:bar'))
+
+    def test_expandvars(self):
+        if self.path.__name__ == 'macpath':
+            raise unittest.SkipTest('macpath.expandvars is a stub')
+        with test_support.EnvironmentVarGuard() as env:
+            env.clear()
+            env["foo"] = "bar"
+            env["{foo"] = "baz1"
+            env["{foo}"] = "baz2"
+            self.assertEqual(self.path.expandvars("foo"), "foo")
+            self.assertEqual(self.path.expandvars("$foo bar"), "bar bar")
+            self.assertEqual(self.path.expandvars("${foo}bar"), "barbar")
+            self.assertEqual(self.path.expandvars("$[foo]bar"), "$[foo]bar")
+            self.assertEqual(self.path.expandvars("$bar bar"), "$bar bar")
+            self.assertEqual(self.path.expandvars("$?bar"), "$?bar")
+            self.assertEqual(self.path.expandvars("${foo}bar"), "barbar")
+            self.assertEqual(self.path.expandvars("$foo}bar"), "bar}bar")
+            self.assertEqual(self.path.expandvars("${foo"), "${foo")
+            self.assertEqual(self.path.expandvars("${{foo}}"), "baz1}")
+            self.assertEqual(self.path.expandvars("$foo$foo"), "barbar")
+            self.assertEqual(self.path.expandvars("$bar$bar"), "$bar$bar")
+
+    def test_abspath(self):
+        self.assertIn("foo", self.path.abspath("foo"))
+
+        # Abspath returns bytes when the arg is bytes
         for path in ('', 'foo', 'f\xf2\xf2', '/foo', 'C:\\'):
-            self.assertIsInstance(abspath(path), str)
-        for upath in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
-            self.assertIsInstance(abspath(upath), unicode)
+            self.assertIsInstance(self.path.abspath(path), str)
+
+    def test_realpath(self):
+        self.assertIn("foo", self.path.realpath("foo"))
+
+    def test_normpath_issue5827(self):
+        # Make sure normpath preserves unicode
+        for path in (u'', u'.', u'/', u'\\', u'///foo/.//bar//'):
+            self.assertIsInstance(self.path.normpath(path), unicode)
+
+    def test_abspath_issue3426(self):
+        # Check that abspath returns unicode when the arg is unicode
+        # with both ASCII and non-ASCII cwds.
+        for path in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
+            self.assertIsInstance(self.path.abspath(path), unicode)
+
+        unicwd = u'\xe7w\xf0'
+        try:
+            fsencoding = test_support.TESTFN_ENCODING or "ascii"
+            unicwd.encode(fsencoding)
+        except (AttributeError, UnicodeEncodeError):
+            # FS encoding is probably ASCII
+            pass
+        else:
+            with test_support.temp_cwd(unicwd):
+                for path in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
+                    self.assertIsInstance(self.path.abspath(path), unicode)
+
+        # Test non-ASCII, non-UTF8 bytes in the path.
+        with test_support.temp_cwd('\xe7w\xf0'):
+            self.test_abspath()
 
 
 def test_main():
-    test_support.run_unittest(AllCommonTest)
+    test_support.run_unittest(GenericTest)
+
 
 if __name__=="__main__":
     test_main()
diff --git a/Lib/test/test_macpath.py b/Lib/test/test_macpath.py
index 564def7..e81fba2 100644
--- a/Lib/test/test_macpath.py
+++ b/Lib/test/test_macpath.py
@@ -1,7 +1,6 @@
 import macpath
-from test import test_support
+from test import test_support, test_genericpath
 import unittest
-import test_genericpath
 
 
 class MacPathTestCase(unittest.TestCase):
@@ -9,12 +8,6 @@
     def test_abspath(self):
         self.assertEqual(macpath.abspath("xx:yy"), "xx:yy")
 
-    def test_abspath_with_ascii_cwd(self):
-        test_genericpath._issue3426(self, u'cwd', macpath.abspath)
-
-    def test_abspath_with_nonascii_cwd(self):
-        test_genericpath._issue3426(self, u'\xe7w\xf0', macpath.abspath)
-
     def test_isabs(self):
         isabs = macpath.isabs
         self.assertTrue(isabs("xx:yy"))
@@ -46,11 +39,6 @@
         self.assertEqual(split(":conky:mountpoint:"),
                           (':conky:mountpoint', ''))
 
-    def test_splitdrive(self):
-        splitdrive = macpath.splitdrive
-        self.assertEqual(splitdrive("foo:bar"), ('', 'foo:bar'))
-        self.assertEqual(splitdrive(":foo:bar"), ('', ':foo:bar'))
-
     def test_splitext(self):
         splitext = macpath.splitext
         self.assertEqual(splitext(":foo.ext"), (':foo', '.ext'))
@@ -67,9 +55,12 @@
             self.assertIsInstance(macpath.normpath(path), unicode,
                                   'normpath() returned str instead of unicode')
 
+class MacCommonTest(test_genericpath.CommonTest):
+    path = macpath
+
 
 def test_main():
-    test_support.run_unittest(MacPathTestCase)
+    test_support.run_unittest(MacPathTestCase, MacCommonTest)
 
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index f5bc952..d8c576a 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -1,7 +1,7 @@
 import ntpath
 import os
 from test.test_support import TestFailed
-import test.test_support as test_support
+from test import test_support, test_genericpath
 import unittest
 
 
@@ -123,11 +123,6 @@
         tester("ntpath.normpath('C:////a/b')", r'C:\a\b')
         tester("ntpath.normpath('//machine/share//a/b')", r'\\machine\share\a\b')
 
-        # Issue 5827: Make sure normpath preserves unicode
-        for path in (u'', u'.', u'/', u'\\', u'///foo/.//bar//'):
-            self.assertIsInstance(ntpath.normpath(path), unicode,
-                                  'normpath() returned str instead of unicode')
-
     def test_expandvars(self):
         with test_support.EnvironmentVarGuard() as env:
             env.clear()
@@ -169,16 +164,6 @@
         else:
             tester('ntpath.abspath("C:\\")', "C:\\")
 
-            # Issue 3426: check that abspath retuns unicode when the arg is
-            # unicode and str when it's str, with both ASCII and non-ASCII cwds
-            for cwd in (u'cwd', u'\xe7w\xf0'):
-                with test_support.temp_cwd(cwd):
-                    for path in ('', 'foo', 'f\xf2\xf2', '/foo', 'C:\\'):
-                        self.assertIsInstance(ntpath.abspath(path), str)
-                    for upath in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
-                        self.assertIsInstance(ntpath.abspath(upath), unicode)
-
-
     def test_relpath(self):
         currentdir = os.path.split(os.getcwd())[-1]
         tester('ntpath.relpath("a")', 'a')
@@ -192,8 +177,13 @@
         tester('ntpath.relpath("a", "a")', '.')
 
 
+class NtCommonTest(test_genericpath.CommonTest):
+    path = ntpath
+    attributes = ['relpath', 'splitunc']
+
+
 def test_main():
-    test_support.run_unittest(TestNtpath)
+    test_support.run_unittest(TestNtpath, NtCommonTest)
 
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index 23a88e3..3af646f 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -1,7 +1,5 @@
 import unittest
-from test import test_support
-
-import test_genericpath
+from test import test_support, test_genericpath
 
 import posixpath, os
 from posixpath import realpath, abspath, dirname, basename
@@ -27,26 +25,11 @@
             test_support.unlink(test_support.TESTFN + suffix)
             safe_rmdir(test_support.TESTFN + suffix)
 
-    def test_normcase(self):
-        # Check that normcase() is idempotent
-        p = "FoO/./BaR"
-        p = posixpath.normcase(p)
-        self.assertEqual(p, posixpath.normcase(p))
-
-        self.assertRaises(TypeError, posixpath.normcase)
-
     def test_join(self):
         self.assertEqual(posixpath.join("/foo", "bar", "/bar", "baz"), "/bar/baz")
         self.assertEqual(posixpath.join("/foo", "bar", "baz"), "/foo/bar/baz")
         self.assertEqual(posixpath.join("/foo/", "bar/", "baz/"), "/foo/bar/baz/")
 
-        self.assertRaises(TypeError, posixpath.join)
-
-    def test_splitdrive(self):
-        self.assertEqual(posixpath.splitdrive("/foo/bar"), ("", "/foo/bar"))
-
-        self.assertRaises(TypeError, posixpath.splitdrive)
-
     def test_split(self):
         self.assertEqual(posixpath.split("/foo/bar"), ("/foo", "bar"))
         self.assertEqual(posixpath.split("/"), ("/", ""))
@@ -54,8 +37,6 @@
         self.assertEqual(posixpath.split("////foo"), ("////", "foo"))
         self.assertEqual(posixpath.split("//foo//bar"), ("//foo", "bar"))
 
-        self.assertRaises(TypeError, posixpath.split)
-
     def splitextTest(self, path, filename, ext):
         self.assertEqual(posixpath.splitext(path), (filename, ext))
         self.assertEqual(posixpath.splitext("/" + path), ("/" + filename, ext))
@@ -77,7 +58,6 @@
         self.splitextTest("..", "..", "")
         self.splitextTest("........", "........", "")
         self.splitextTest("", "", "")
-        self.assertRaises(TypeError, posixpath.splitext)
 
     def test_isabs(self):
         self.assertIs(posixpath.isabs(""), False)
@@ -86,8 +66,6 @@
         self.assertIs(posixpath.isabs("/foo/bar"), True)
         self.assertIs(posixpath.isabs("foo/bar"), False)
 
-        self.assertRaises(TypeError, posixpath.isabs)
-
     def test_basename(self):
         self.assertEqual(posixpath.basename("/foo/bar"), "bar")
         self.assertEqual(posixpath.basename("/"), "")
@@ -95,8 +73,6 @@
         self.assertEqual(posixpath.basename("////foo"), "foo")
         self.assertEqual(posixpath.basename("//foo//bar"), "bar")
 
-        self.assertRaises(TypeError, posixpath.basename)
-
     def test_dirname(self):
         self.assertEqual(posixpath.dirname("/foo/bar"), "/foo")
         self.assertEqual(posixpath.dirname("/"), "/")
@@ -104,67 +80,6 @@
         self.assertEqual(posixpath.dirname("////foo"), "////")
         self.assertEqual(posixpath.dirname("//foo//bar"), "//foo")
 
-        self.assertRaises(TypeError, posixpath.dirname)
-
-    def test_commonprefix(self):
-        self.assertEqual(
-            posixpath.commonprefix([]),
-            ""
-        )
-        self.assertEqual(
-            posixpath.commonprefix(["/home/swenson/spam", "/home/swen/spam"]),
-            "/home/swen"
-        )
-        self.assertEqual(
-            posixpath.commonprefix(["/home/swen/spam", "/home/swen/eggs"]),
-            "/home/swen/"
-        )
-        self.assertEqual(
-            posixpath.commonprefix(["/home/swen/spam", "/home/swen/spam"]),
-            "/home/swen/spam"
-        )
-
-        testlist = ['', 'abc', 'Xbcd', 'Xb', 'XY', 'abcd', 'aXc', 'abd', 'ab', 'aX', 'abcX']
-        for s1 in testlist:
-            for s2 in testlist:
-                p = posixpath.commonprefix([s1, s2])
-                self.assertTrue(s1.startswith(p))
-                self.assertTrue(s2.startswith(p))
-                if s1 != s2:
-                    n = len(p)
-                    self.assertNotEqual(s1[n:n+1], s2[n:n+1])
-
-    def test_getsize(self):
-        f = open(test_support.TESTFN, "wb")
-        try:
-            f.write("foo")
-            f.close()
-            self.assertEqual(posixpath.getsize(test_support.TESTFN), 3)
-        finally:
-            if not f.closed:
-                f.close()
-
-    def test_time(self):
-        f = open(test_support.TESTFN, "wb")
-        try:
-            f.write("foo")
-            f.close()
-            f = open(test_support.TESTFN, "ab")
-            f.write("bar")
-            f.close()
-            f = open(test_support.TESTFN, "rb")
-            d = f.read()
-            f.close()
-            self.assertEqual(d, "foobar")
-
-            self.assertLessEqual(
-                posixpath.getctime(test_support.TESTFN),
-                posixpath.getmtime(test_support.TESTFN)
-            )
-        finally:
-            if not f.closed:
-                f.close()
-
     def test_islink(self):
         self.assertIs(posixpath.islink(test_support.TESTFN + "1"), False)
         f = open(test_support.TESTFN + "1", "wb")
@@ -183,56 +98,6 @@
             if not f.close():
                 f.close()
 
-        self.assertRaises(TypeError, posixpath.islink)
-
-    def test_exists(self):
-        self.assertIs(posixpath.exists(test_support.TESTFN), False)
-        f = open(test_support.TESTFN, "wb")
-        try:
-            f.write("foo")
-            f.close()
-            self.assertIs(posixpath.exists(test_support.TESTFN), True)
-            self.assertIs(posixpath.lexists(test_support.TESTFN), True)
-        finally:
-            if not f.close():
-                f.close()
-
-        self.assertRaises(TypeError, posixpath.exists)
-
-    def test_isdir(self):
-        self.assertIs(posixpath.isdir(test_support.TESTFN), False)
-        f = open(test_support.TESTFN, "wb")
-        try:
-            f.write("foo")
-            f.close()
-            self.assertIs(posixpath.isdir(test_support.TESTFN), False)
-            os.remove(test_support.TESTFN)
-            os.mkdir(test_support.TESTFN)
-            self.assertIs(posixpath.isdir(test_support.TESTFN), True)
-            os.rmdir(test_support.TESTFN)
-        finally:
-            if not f.close():
-                f.close()
-
-        self.assertRaises(TypeError, posixpath.isdir)
-
-    def test_isfile(self):
-        self.assertIs(posixpath.isfile(test_support.TESTFN), False)
-        f = open(test_support.TESTFN, "wb")
-        try:
-            f.write("foo")
-            f.close()
-            self.assertIs(posixpath.isfile(test_support.TESTFN), True)
-            os.remove(test_support.TESTFN)
-            os.mkdir(test_support.TESTFN)
-            self.assertIs(posixpath.isfile(test_support.TESTFN), False)
-            os.rmdir(test_support.TESTFN)
-        finally:
-            if not f.close():
-                f.close()
-
-        self.assertRaises(TypeError, posixpath.isdir)
-
     def test_samefile(self):
         f = open(test_support.TESTFN + "1", "wb")
         try:
@@ -274,8 +139,6 @@
             if not f.close():
                 f.close()
 
-        self.assertRaises(TypeError, posixpath.samefile)
-
     def test_samestat(self):
         f = open(test_support.TESTFN + "1", "wb")
         try:
@@ -315,13 +178,9 @@
             if not f.close():
                 f.close()
 
-        self.assertRaises(TypeError, posixpath.samestat)
-
     def test_ismount(self):
         self.assertIs(posixpath.ismount("/"), True)
 
-        self.assertRaises(TypeError, posixpath.ismount)
-
     def test_expanduser(self):
         self.assertEqual(posixpath.expanduser("foo"), "foo")
         try:
@@ -343,29 +202,6 @@
                 env['HOME'] = '/'
                 self.assertEqual(posixpath.expanduser("~"), "/")
 
-        self.assertRaises(TypeError, posixpath.expanduser)
-
-    def test_expandvars(self):
-        with test_support.EnvironmentVarGuard() as env:
-            env.clear()
-            env["foo"] = "bar"
-            env["{foo"] = "baz1"
-            env["{foo}"] = "baz2"
-            self.assertEqual(posixpath.expandvars("foo"), "foo")
-            self.assertEqual(posixpath.expandvars("$foo bar"), "bar bar")
-            self.assertEqual(posixpath.expandvars("${foo}bar"), "barbar")
-            self.assertEqual(posixpath.expandvars("$[foo]bar"), "$[foo]bar")
-            self.assertEqual(posixpath.expandvars("$bar bar"), "$bar bar")
-            self.assertEqual(posixpath.expandvars("$?bar"), "$?bar")
-            self.assertEqual(posixpath.expandvars("${foo}bar"), "barbar")
-            self.assertEqual(posixpath.expandvars("$foo}bar"), "bar}bar")
-            self.assertEqual(posixpath.expandvars("${foo"), "${foo")
-            self.assertEqual(posixpath.expandvars("${{foo}}"), "baz1}")
-            self.assertEqual(posixpath.expandvars("$foo$foo"), "barbar")
-            self.assertEqual(posixpath.expandvars("$bar$bar"), "$bar$bar")
-
-        self.assertRaises(TypeError, posixpath.expandvars)
-
     def test_normpath(self):
         self.assertEqual(posixpath.normpath(""), ".")
         self.assertEqual(posixpath.normpath("/"), "/")
@@ -375,27 +211,6 @@
         self.assertEqual(posixpath.normpath("///foo/.//bar//.//..//.//baz"), "/foo/baz")
         self.assertEqual(posixpath.normpath("///..//./foo/.//bar"), "/foo/bar")
 
-        # Issue 5827: Make sure normpath preserves unicode
-        for path in (u'', u'.', u'/', u'\\', u'///foo/.//bar//'):
-            self.assertIsInstance(posixpath.normpath(path), unicode,
-                                  'normpath() returned str instead of unicode')
-
-        self.assertRaises(TypeError, posixpath.normpath)
-
-    def test_abspath(self):
-        self.assertIn("foo", posixpath.abspath("foo"))
-        self.assertRaises(TypeError, posixpath.abspath)
-
-    def test_abspath_with_ascii_cwd(self):
-        test_genericpath._issue3426(self, u'cwd', posixpath.abspath)
-
-    def test_abspath_with_nonascii_cwd(self):
-        test_genericpath._issue3426(self, u'\xe7w\xf0', posixpath.abspath)
-
-    def test_realpath(self):
-        self.assertIn("foo", realpath("foo"))
-        self.assertRaises(TypeError, posixpath.realpath)
-
     if hasattr(os, "symlink"):
         def test_realpath_basic(self):
             # Basic operation.
@@ -510,8 +325,15 @@
         finally:
             os.getcwd = real_getcwd
 
+
+class PosixCommonTest(test_genericpath.CommonTest):
+    path = posixpath
+    attributes = ['relpath', 'samefile', 'sameopenfile', 'samestat']
+
+
 def test_main():
-    test_support.run_unittest(PosixPathTest)
+    test_support.run_unittest(PosixPathTest, PosixCommonTest)
+
 
 if __name__=="__main__":
     test_main()