From bb0424b122e3d222a558bd4177ce37befd3e0347 Mon Sep 17 00:00:00 2001
From: Hai Shi <shihai1992@gmail.com>
Date: Tue, 4 Aug 2020 00:47:42 +0800
Subject: bpo-40275: Use new test.support helper submodules in tests (GH-21451)

---
 Lib/test/test_bdb.py                    |   7 +-
 Lib/test/test_code_module.py            |   5 +-
 Lib/test/test_embed.py                  |  10 +-
 Lib/test/test_gzip.py                   |  24 ++-
 Lib/test/test_largefile.py              |   3 +-
 Lib/test/test_lltrace.py                |   8 +-
 Lib/test/test_ordered_dict.py           |   7 +-
 Lib/test/test_pathlib.py                |  72 +++----
 Lib/test/test_pipes.py                  |   4 +-
 Lib/test/test_posix.py                  | 358 +++++++++++++++++---------------
 Lib/test/test_pydoc.py                  |  15 +-
 Lib/test/test_resource.py               |   8 +-
 Lib/test/test_runpy.py                  |   6 +-
 Lib/test/test_sax.py                    |  30 +--
 Lib/test/test_sys.py                    |   7 +-
 Lib/test/test_syslog.py                 |   5 +-
 Lib/test/test_ttk_textonly.py           |   4 +-
 Lib/test/test_unicode_file_functions.py |  20 +-
 Lib/test/test_urllib2.py                |   6 +-
 Lib/test/test_venv.py                   |   3 +-
 20 files changed, 324 insertions(+), 278 deletions(-)

diff --git a/Lib/test/test_bdb.py b/Lib/test/test_bdb.py
index ae16880..9bce780 100644
--- a/Lib/test/test_bdb.py
+++ b/Lib/test/test_bdb.py
@@ -58,6 +58,9 @@ import linecache
 from contextlib import contextmanager
 from itertools import islice, repeat
 import test.support
+from test.support import import_helper
+from test.support import os_helper
+
 
 class BdbException(Exception): pass
 class BdbError(BdbException): """Error raised by the Bdb instance."""
@@ -531,7 +534,7 @@ def run_test(modules, set_list, skip=None):
 
 @contextmanager
 def create_modules(modules):
-    with test.support.temp_cwd():
+    with os_helper.temp_cwd():
         sys.path.append(os.getcwd())
         try:
             for m in modules:
@@ -543,7 +546,7 @@ def create_modules(modules):
             yield
         finally:
             for m in modules:
-                test.support.forget(m)
+                import_helper.forget(m)
             sys.path.pop()
 
 def break_in_func(funcname, fname=__file__, temporary=False, cond=None):
diff --git a/Lib/test/test_code_module.py b/Lib/test/test_code_module.py
index 24db0ac..226bc3a 100644
--- a/Lib/test/test_code_module.py
+++ b/Lib/test/test_code_module.py
@@ -4,9 +4,10 @@ import unittest
 from textwrap import dedent
 from contextlib import ExitStack
 from unittest import mock
-from test import support
+from test.support import import_helper
 
-code = support.import_module('code')
+
+code = import_helper.import_module('code')
 
 
 class TestInteractiveConsole(unittest.TestCase):
diff --git a/Lib/test/test_embed.py b/Lib/test/test_embed.py
index 2b74052..31dc39f 100644
--- a/Lib/test/test_embed.py
+++ b/Lib/test/test_embed.py
@@ -1,5 +1,7 @@
 # Run the tests in Programs/_testembed.c (tests for the CPython embedding APIs)
 from test import support
+from test.support import import_helper
+from test.support import os_helper
 import unittest
 
 from collections import namedtuple
@@ -1339,8 +1341,8 @@ class InitConfigTests(EmbeddingTestsMixin, unittest.TestCase):
         #
         # The global path configuration (_Py_path_config) must be a copy
         # of the path configuration of PyInterpreter.config (PyConfig).
-        ctypes = support.import_module('ctypes')
-        _testinternalcapi = support.import_module('_testinternalcapi')
+        ctypes = import_helper.import_module('ctypes')
+        _testinternalcapi = import_helper.import_module('_testinternalcapi')
 
         def get_func(name):
             func = getattr(ctypes.pythonapi, name)
@@ -1418,7 +1420,7 @@ class AuditingTests(EmbeddingTestsMixin, unittest.TestCase):
                                       returncode=1)
 
     def test_audit_run_interactivehook(self):
-        startup = os.path.join(self.oldcwd, support.TESTFN) + ".py"
+        startup = os.path.join(self.oldcwd, os_helper.TESTFN) + ".py"
         with open(startup, "w", encoding="utf-8") as f:
             print("import sys", file=f)
             print("sys.__interactivehook__ = lambda: None", file=f)
@@ -1431,7 +1433,7 @@ class AuditingTests(EmbeddingTestsMixin, unittest.TestCase):
             os.unlink(startup)
 
     def test_audit_run_startup(self):
-        startup = os.path.join(self.oldcwd, support.TESTFN) + ".py"
+        startup = os.path.join(self.oldcwd, os_helper.TESTFN) + ".py"
         with open(startup, "w", encoding="utf-8") as f:
             print("pass", file=f)
         try:
diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py
index 0f235d1..c3fa9b0 100644
--- a/Lib/test/test_gzip.py
+++ b/Lib/test/test_gzip.py
@@ -11,10 +11,12 @@ import sys
 import unittest
 from subprocess import PIPE, Popen
 from test import support
+from test.support import import_helper
+from test.support import os_helper
 from test.support import _4G, bigmemtest
 from test.support.script_helper import assert_python_ok, assert_python_failure
 
-gzip = support.import_module('gzip')
+gzip = import_helper.import_module('gzip')
 
 data1 = b"""  int length=DEFAULTALLOC, err = Z_OK;
   PyObject *RetVal;
@@ -29,7 +31,7 @@ data2 = b"""/* zlibmodule.c -- gzip-compatible data compression */
 """
 
 
-TEMPDIR = os.path.abspath(support.TESTFN) + '-gzdir'
+TEMPDIR = os.path.abspath(os_helper.TESTFN) + '-gzdir'
 
 
 class UnseekableIO(io.BytesIO):
@@ -44,13 +46,13 @@ class UnseekableIO(io.BytesIO):
 
 
 class BaseTest(unittest.TestCase):
-    filename = support.TESTFN
+    filename = os_helper.TESTFN
 
     def setUp(self):
-        support.unlink(self.filename)
+        os_helper.unlink(self.filename)
 
     def tearDown(self):
-        support.unlink(self.filename)
+        os_helper.unlink(self.filename)
 
 
 class TestGzip(BaseTest):
@@ -286,7 +288,7 @@ class TestGzip(BaseTest):
         self.test_write()
         with gzip.GzipFile(self.filename, 'r') as f:
             self.assertEqual(f.myfileobj.mode, 'rb')
-        support.unlink(self.filename)
+        os_helper.unlink(self.filename)
         with gzip.GzipFile(self.filename, 'x') as f:
             self.assertEqual(f.myfileobj.mode, 'xb')
 
@@ -365,7 +367,7 @@ class TestGzip(BaseTest):
             self.assertEqual(isizeBytes, struct.pack('<i', len(data1)))
 
     def test_metadata_ascii_name(self):
-        self.filename = support.TESTFN_ASCII
+        self.filename = os_helper.TESTFN_ASCII
         self.test_metadata()
 
     def test_compresslevel_metadata(self):
@@ -497,7 +499,7 @@ class TestGzip(BaseTest):
                     self.assertEqual(g.mode, gzip.READ)
         for mode in "wb", "ab", "xb":
             if "x" in mode:
-                support.unlink(self.filename)
+                os_helper.unlink(self.filename)
             with open(self.filename, mode) as f:
                 with self.assertWarns(FutureWarning):
                     g = gzip.GzipFile(fileobj=f)
@@ -611,7 +613,7 @@ class TestOpen(BaseTest):
 
         with self.assertRaises(FileExistsError):
             gzip.open(self.filename, "xb")
-        support.unlink(self.filename)
+        os_helper.unlink(self.filename)
         with gzip.open(self.filename, "xb") as f:
             f.write(uncompressed)
         with open(self.filename, "rb") as f:
@@ -648,7 +650,7 @@ class TestOpen(BaseTest):
 
         with self.assertRaises(FileExistsError):
             gzip.open(self.filename, "x")
-        support.unlink(self.filename)
+        os_helper.unlink(self.filename)
         with gzip.open(self.filename, "x") as f:
             f.write(uncompressed)
         with open(self.filename, "rb") as f:
@@ -734,7 +736,7 @@ def create_and_remove_directory(directory):
             try:
                 return function(*args, **kwargs)
             finally:
-                support.rmtree(directory)
+                os_helper.rmtree(directory)
         return wrapper
     return decorator
 
diff --git a/Lib/test/test_largefile.py b/Lib/test/test_largefile.py
index a99b4ba..8f6bec1 100644
--- a/Lib/test/test_largefile.py
+++ b/Lib/test/test_largefile.py
@@ -8,9 +8,10 @@ import unittest
 import socket
 import shutil
 import threading
-from test.support import TESTFN, requires, unlink, bigmemtest
+from test.support import requires, bigmemtest
 from test.support import SHORT_TIMEOUT
 from test.support import socket_helper
+from test.support.os_helper import TESTFN, unlink
 import io  # C implementation of io
 import _pyio as pyio # Python implementation of io
 
diff --git a/Lib/test/test_lltrace.py b/Lib/test/test_lltrace.py
index 49fae81..5f7d564 100644
--- a/Lib/test/test_lltrace.py
+++ b/Lib/test/test_lltrace.py
@@ -2,7 +2,7 @@ import os
 import textwrap
 import unittest
 
-from test import support
+from test.support import os_helper
 from test.support.script_helper import assert_python_ok
 
 
@@ -13,8 +13,8 @@ class TestLLTrace(unittest.TestCase):
         # bpo-34113. The crash happened at the command line console of
         # debug Python builds with __ltrace__ enabled (only possible in console),
         # when the interal Python stack was negatively adjusted
-        with open(support.TESTFN, 'w') as fd:
-            self.addCleanup(os.unlink, support.TESTFN)
+        with open(os_helper.TESTFN, 'w') as fd:
+            self.addCleanup(os_helper.unlink, os_helper.TESTFN)
             fd.write(textwrap.dedent("""\
             import code
 
@@ -25,7 +25,7 @@ class TestLLTrace(unittest.TestCase):
             print('unreachable if bug exists')
             """))
 
-            assert_python_ok(support.TESTFN)
+            assert_python_ok(os_helper.TESTFN)
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_ordered_dict.py b/Lib/test/test_ordered_dict.py
index fdea44e..1f27c0e 100644
--- a/Lib/test/test_ordered_dict.py
+++ b/Lib/test/test_ordered_dict.py
@@ -10,10 +10,13 @@ import unittest
 import weakref
 from collections.abc import MutableMapping
 from test import mapping_tests, support
+from test.support import import_helper
 
 
-py_coll = support.import_fresh_module('collections', blocked=['_collections'])
-c_coll = support.import_fresh_module('collections', fresh=['_collections'])
+py_coll = import_helper.import_fresh_module('collections',
+                                            blocked=['_collections'])
+c_coll = import_helper.import_fresh_module('collections',
+                                           fresh=['_collections'])
 
 
 @contextlib.contextmanager
diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py
index 1589282..04f7c3d 100644
--- a/Lib/test/test_pathlib.py
+++ b/Lib/test/test_pathlib.py
@@ -11,8 +11,9 @@ import tempfile
 import unittest
 from unittest import mock
 
-from test import support
-from test.support import TESTFN, FakePath
+from test.support import import_helper
+from test.support import os_helper
+from test.support.os_helper import TESTFN, FakePath
 
 try:
     import grp, pwd
@@ -1346,7 +1347,7 @@ class _BasePathTest(object):
     def setUp(self):
         def cleanup():
             os.chmod(join('dirE'), 0o777)
-            support.rmtree(BASE)
+            os_helper.rmtree(BASE)
         self.addCleanup(cleanup)
         os.mkdir(BASE)
         os.mkdir(join('dirA'))
@@ -1363,7 +1364,7 @@ class _BasePathTest(object):
         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():
+        if os_helper.can_symlink():
             # Relative symlinks.
             os.symlink('fileA', join('linkA'))
             os.symlink('non-existing', join('brokenLink'))
@@ -1414,7 +1415,7 @@ class _BasePathTest(object):
         self.assertTrue(p.is_absolute())
 
     def test_home(self):
-        with support.EnvironmentVarGuard() as env:
+        with os_helper.EnvironmentVarGuard() as env:
             self._test_home(self.cls.home())
 
             env.clear()
@@ -1470,7 +1471,7 @@ class _BasePathTest(object):
         self.assertIs(True, (p / 'dirA').exists())
         self.assertIs(True, (p / 'fileA').exists())
         self.assertIs(False, (p / 'fileA' / 'bah').exists())
-        if support.can_symlink():
+        if os_helper.can_symlink():
             self.assertIs(True, (p / 'linkA').exists())
             self.assertIs(True, (p / 'linkB').exists())
             self.assertIs(True, (p / 'linkB' / 'fileB').exists())
@@ -1515,11 +1516,11 @@ class _BasePathTest(object):
         it = p.iterdir()
         paths = set(it)
         expected = ['dirA', 'dirB', 'dirC', 'dirE', 'fileA']
-        if support.can_symlink():
+        if os_helper.can_symlink():
             expected += ['linkA', 'linkB', 'brokenLink', 'brokenLinkLoop']
         self.assertEqual(paths, { P(BASE, q) for q in expected })
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_iterdir_symlink(self):
         # __iter__ on a symlink to a directory.
         P = self.cls
@@ -1548,16 +1549,16 @@ class _BasePathTest(object):
         _check(it, ["fileA"])
         _check(p.glob("fileB"), [])
         _check(p.glob("dir*/file*"), ["dirB/fileB", "dirC/fileC"])
-        if not support.can_symlink():
+        if not os_helper.can_symlink():
             _check(p.glob("*A"), ['dirA', 'fileA'])
         else:
             _check(p.glob("*A"), ['dirA', 'fileA', 'linkA'])
-        if not support.can_symlink():
+        if not os_helper.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():
+        if not os_helper.can_symlink():
             _check(p.glob("*/fileB"), ['dirB/fileB'])
         else:
             _check(p.glob("*/fileB"), ['dirB/fileB', 'linkB/fileB'])
@@ -1572,7 +1573,7 @@ class _BasePathTest(object):
         _check(it, ["fileA"])
         _check(p.rglob("fileB"), ["dirB/fileB"])
         _check(p.rglob("*/fileA"), [])
-        if not support.can_symlink():
+        if not os_helper.can_symlink():
             _check(p.rglob("*/fileB"), ["dirB/fileB"])
         else:
             _check(p.rglob("*/fileB"), ["dirB/fileB", "dirB/linkD/fileB",
@@ -1583,7 +1584,7 @@ class _BasePathTest(object):
         _check(p.rglob("file*"), ["dirC/fileC", "dirC/dirD/fileD"])
         _check(p.rglob("*/*"), ["dirC/dirD/fileD"])
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_rglob_symlink_loop(self):
         # Don't get fooled by symlink loops (Issue #26012).
         P = self.cls
@@ -1626,7 +1627,7 @@ class _BasePathTest(object):
         self.assertEqual(set(p.glob("dirA/../file*")), { P(BASE, "dirA/../fileA") })
         self.assertEqual(set(p.glob("../xyzzy")), set())
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_glob_permissions(self):
         # See bpo-38894
         P = self.cls
@@ -1670,7 +1671,7 @@ class _BasePathTest(object):
     # This can be used to check both relative and absolute resolutions.
     _check_resolve_relative = _check_resolve_absolute = _check_resolve
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_resolve_common(self):
         P = self.cls
         p = P(BASE, 'foo')
@@ -1710,8 +1711,9 @@ class _BasePathTest(object):
             # 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)
+        d = os_helper._longpath(tempfile.mkdtemp(suffix='-dirD',
+                                                 dir=os.getcwd()))
+        self.addCleanup(os_helper.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')
@@ -1730,7 +1732,7 @@ class _BasePathTest(object):
             # 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
+    @os_helper.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)
@@ -1784,7 +1786,7 @@ class _BasePathTest(object):
         self.addCleanup(p.chmod, st.st_mode)
         self.assertNotEqual(p.stat(), st)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_lstat(self):
         p = self.cls(BASE)/ 'linkA'
         st = p.stat()
@@ -1899,7 +1901,7 @@ class _BasePathTest(object):
         self.assertEqual(os.stat(r).st_size, size)
         self.assertFileNotFound(q.stat)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_readlink(self):
         P = self.cls(BASE)
         self.assertEqual((P / 'linkA').readlink(), self.cls('fileA'))
@@ -2074,7 +2076,7 @@ class _BasePathTest(object):
                 self.assertNotIn(str(p12), concurrently_created)
             self.assertTrue(p.exists())
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_symlink_to(self):
         P = self.cls(BASE)
         target = P / 'fileA'
@@ -2104,7 +2106,7 @@ class _BasePathTest(object):
         self.assertFalse((P / 'fileA').is_dir())
         self.assertFalse((P / 'non-existing').is_dir())
         self.assertFalse((P / 'fileA' / 'bah').is_dir())
-        if support.can_symlink():
+        if os_helper.can_symlink():
             self.assertFalse((P / 'linkA').is_dir())
             self.assertTrue((P / 'linkB').is_dir())
             self.assertFalse((P/ 'brokenLink').is_dir(), False)
@@ -2117,7 +2119,7 @@ class _BasePathTest(object):
         self.assertFalse((P / 'dirA').is_file())
         self.assertFalse((P / 'non-existing').is_file())
         self.assertFalse((P / 'fileA' / 'bah').is_file())
-        if support.can_symlink():
+        if os_helper.can_symlink():
             self.assertTrue((P / 'linkA').is_file())
             self.assertFalse((P / 'linkB').is_file())
             self.assertFalse((P/ 'brokenLink').is_file())
@@ -2133,7 +2135,7 @@ class _BasePathTest(object):
         self.assertFalse((P / 'non-existing').is_mount())
         self.assertFalse((P / 'fileA' / 'bah').is_mount())
         self.assertTrue(R.is_mount())
-        if support.can_symlink():
+        if os_helper.can_symlink():
             self.assertFalse((P / 'linkA').is_mount())
         self.assertIs(self.cls('/\udfff').is_mount(), False)
         self.assertIs(self.cls('/\x00').is_mount(), False)
@@ -2144,13 +2146,13 @@ class _BasePathTest(object):
         self.assertFalse((P / 'dirA').is_symlink())
         self.assertFalse((P / 'non-existing').is_symlink())
         self.assertFalse((P / 'fileA' / 'bah').is_symlink())
-        if support.can_symlink():
+        if os_helper.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():
+        if os_helper.can_symlink():
             self.assertIs((P / 'linkA\udfff').is_file(), False)
             self.assertIs((P / 'linkA\x00').is_file(), False)
 
@@ -2288,15 +2290,15 @@ class _BasePathTest(object):
         finally:
             os.chdir(old_path)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_complex_symlinks_absolute(self):
         self._check_complex_symlinks(BASE)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_complex_symlinks_relative(self):
         self._check_complex_symlinks('.')
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_complex_symlinks_relative_dot_dot(self):
         self._check_complex_symlinks(os.path.join('dirA', '..'))
 
@@ -2362,7 +2364,7 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
         st = os.stat(join('masked_new_file'))
         self.assertEqual(stat.S_IMODE(st.st_mode), 0o750)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_resolve_loop(self):
         # Loops with relative symlinks.
         os.symlink('linkX/inside', join('linkX'))
@@ -2387,7 +2389,7 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
         P = self.cls
         p = P(BASE)
         given = set(p.glob("FILEa"))
-        expect = set() if not support.fs_is_case_insensitive(BASE) else given
+        expect = set() if not os_helper.fs_is_case_insensitive(BASE) else given
         self.assertEqual(given, expect)
         self.assertEqual(set(p.glob("FILEa*")), set())
 
@@ -2395,7 +2397,7 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
         P = self.cls
         p = P(BASE, "dirC")
         given = set(p.rglob("FILEd"))
-        expect = set() if not support.fs_is_case_insensitive(BASE) else given
+        expect = set() if not os_helper.fs_is_case_insensitive(BASE) else given
         self.assertEqual(given, expect)
         self.assertEqual(set(p.rglob("FILEd*")), set())
 
@@ -2403,7 +2405,7 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
                          'pwd module does not expose getpwall()')
     def test_expanduser(self):
         P = self.cls
-        support.import_module('pwd')
+        import_helper.import_module('pwd')
         import pwd
         pwdent = pwd.getpwuid(os.getuid())
         username = pwdent.pw_name
@@ -2426,7 +2428,7 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
         p6 = P('')
         p7 = P('~fakeuser/Documents')
 
-        with support.EnvironmentVarGuard() as env:
+        with os_helper.EnvironmentVarGuard() as env:
             env.pop('HOME', None)
 
             self.assertEqual(p1.expanduser(), P(userhome) / 'Documents')
@@ -2490,7 +2492,7 @@ class WindowsPathTest(_BasePathTest, unittest.TestCase):
 
     def test_expanduser(self):
         P = self.cls
-        with support.EnvironmentVarGuard() as env:
+        with os_helper.EnvironmentVarGuard() as env:
             env.pop('HOME', None)
             env.pop('USERPROFILE', None)
             env.pop('HOMEPATH', None)
diff --git a/Lib/test/test_pipes.py b/Lib/test/test_pipes.py
index 1d538b9..7d8cd54 100644
--- a/Lib/test/test_pipes.py
+++ b/Lib/test/test_pipes.py
@@ -3,7 +3,9 @@ import os
 import string
 import unittest
 import shutil
-from test.support import TESTFN, run_unittest, unlink, reap_children
+from test.support import run_unittest, reap_children
+from test.support.os_helper import TESTFN, unlink
+
 
 if os.name != 'posix':
     raise unittest.SkipTest('pipes module only works on posix')
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index be121ae..f57c882 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -1,10 +1,13 @@
 "Test posix functions"
 
 from test import support
+from test.support import import_helper
+from test.support import os_helper
+from test.support import warnings_helper
 from test.support.script_helper import assert_python_ok
 
 # Skip these tests if there is no posix module.
-posix = support.import_module('posix')
+posix = import_helper.import_module('posix')
 
 import errno
 import sys
@@ -20,7 +23,7 @@ import warnings
 import textwrap
 
 _DUMMY_SYMLINK = os.path.join(tempfile.gettempdir(),
-                              support.TESTFN + '-dummy-symlink')
+                              os_helper.TESTFN + '-dummy-symlink')
 
 requires_32b = unittest.skipUnless(sys.maxsize < 2**32,
         'test is only meaningful on 32-bit builds')
@@ -42,17 +45,17 @@ class PosixTester(unittest.TestCase):
 
     def setUp(self):
         # create empty file
-        fp = open(support.TESTFN, 'w+')
+        fp = open(os_helper.TESTFN, 'w+')
         fp.close()
-        self.teardown_files = [ support.TESTFN ]
-        self._warnings_manager = support.check_warnings()
+        self.teardown_files = [ os_helper.TESTFN ]
+        self._warnings_manager = warnings_helper.check_warnings()
         self._warnings_manager.__enter__()
         warnings.filterwarnings('ignore', '.* potential security risk .*',
                                 RuntimeWarning)
 
     def tearDown(self):
         for teardown_file in self.teardown_files:
-            support.unlink(teardown_file)
+            os_helper.unlink(teardown_file)
         self._warnings_manager.__exit__(None, None, None)
 
     def testNoArgFunctions(self):
@@ -153,7 +156,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'fstatvfs'),
                          'test needs posix.fstatvfs()')
     def test_fstatvfs(self):
-        fp = open(support.TESTFN)
+        fp = open(os_helper.TESTFN)
         try:
             self.assertTrue(posix.fstatvfs(fp.fileno()))
             self.assertTrue(posix.statvfs(fp.fileno()))
@@ -163,7 +166,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'ftruncate'),
                          'test needs posix.ftruncate()')
     def test_ftruncate(self):
-        fp = open(support.TESTFN, 'w+')
+        fp = open(os_helper.TESTFN, 'w+')
         try:
             # we need to have some data to truncate
             fp.write('test')
@@ -174,10 +177,10 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'truncate'), "test needs posix.truncate()")
     def test_truncate(self):
-        with open(support.TESTFN, 'w') as fp:
+        with open(os_helper.TESTFN, 'w') as fp:
             fp.write('test')
             fp.flush()
-        posix.truncate(support.TESTFN, 0)
+        posix.truncate(os_helper.TESTFN, 0)
 
     @unittest.skipUnless(getattr(os, 'execve', None) in os.supports_fd, "test needs execve() to support the fd parameter")
     @unittest.skipUnless(hasattr(os, 'fork'), "test needs os.fork()")
@@ -268,7 +271,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'lockf'), "test needs posix.lockf()")
     def test_lockf(self):
-        fd = os.open(support.TESTFN, os.O_WRONLY | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_WRONLY | os.O_CREAT)
         try:
             os.write(fd, b'test')
             os.lseek(fd, 0, os.SEEK_SET)
@@ -280,7 +283,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'pread'), "test needs posix.pread()")
     def test_pread(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd, b'test')
             os.lseek(fd, 0, os.SEEK_SET)
@@ -292,7 +295,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'preadv'), "test needs posix.preadv()")
     def test_preadv(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd, b'test1tt2t3t5t6t6t8')
             buf = [bytearray(i) for i in [5, 3, 2]]
@@ -304,7 +307,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'preadv'), "test needs posix.preadv()")
     @unittest.skipUnless(hasattr(posix, 'RWF_HIPRI'), "test needs posix.RWF_HIPRI")
     def test_preadv_flags(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd, b'test1tt2t3t5t6t6t8')
             buf = [bytearray(i) for i in [5, 3, 2]]
@@ -326,7 +329,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'preadv'), "test needs posix.preadv()")
     @requires_32b
     def test_preadv_overflow_32bits(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             buf = [bytearray(2**16)] * 2**15
             with self.assertRaises(OSError) as cm:
@@ -338,7 +341,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'pwrite'), "test needs posix.pwrite()")
     def test_pwrite(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd, b'test')
             os.lseek(fd, 0, os.SEEK_SET)
@@ -349,7 +352,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'pwritev'), "test needs posix.pwritev()")
     def test_pwritev(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd, b"xx")
             os.lseek(fd, 0, os.SEEK_SET)
@@ -364,7 +367,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'pwritev'), "test needs posix.pwritev()")
     @unittest.skipUnless(hasattr(posix, 'os.RWF_SYNC'), "test needs os.RWF_SYNC")
     def test_pwritev_flags(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd,b"xx")
             os.lseek(fd, 0, os.SEEK_SET)
@@ -379,7 +382,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'pwritev'), "test needs posix.pwritev()")
     @requires_32b
     def test_pwritev_overflow_32bits(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             with self.assertRaises(OSError) as cm:
                 os.pwritev(fd, [b"x" * 2**16] * 2**15, 0)
@@ -390,7 +393,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'posix_fallocate'),
         "test needs posix.posix_fallocate()")
     def test_posix_fallocate(self):
-        fd = os.open(support.TESTFN, os.O_WRONLY | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_WRONLY | os.O_CREAT)
         try:
             posix.posix_fallocate(fd, 0, 10)
         except OSError as inst:
@@ -419,7 +422,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'posix_fadvise'),
         "test needs posix.posix_fadvise()")
     def test_posix_fadvise(self):
-        fd = os.open(support.TESTFN, os.O_RDONLY)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY)
         try:
             posix.posix_fadvise(fd, 0, 0, posix.POSIX_FADV_WILLNEED)
         finally:
@@ -437,7 +440,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(os.utime in os.supports_fd, "test needs fd support in os.utime")
     def test_utime_with_fd(self):
         now = time.time()
-        fd = os.open(support.TESTFN, os.O_RDONLY)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY)
         try:
             posix.utime(fd)
             posix.utime(fd, None)
@@ -458,17 +461,21 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(os.utime in os.supports_follow_symlinks, "test needs follow_symlinks support in os.utime")
     def test_utime_nofollow_symlinks(self):
         now = time.time()
-        posix.utime(support.TESTFN, None, follow_symlinks=False)
-        self.assertRaises(TypeError, posix.utime, support.TESTFN, (None, None), follow_symlinks=False)
-        self.assertRaises(TypeError, posix.utime, support.TESTFN, (now, None), follow_symlinks=False)
-        self.assertRaises(TypeError, posix.utime, support.TESTFN, (None, now), follow_symlinks=False)
-        posix.utime(support.TESTFN, (int(now), int(now)), follow_symlinks=False)
-        posix.utime(support.TESTFN, (now, now), follow_symlinks=False)
-        posix.utime(support.TESTFN, follow_symlinks=False)
+        posix.utime(os_helper.TESTFN, None, follow_symlinks=False)
+        self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                          (None, None), follow_symlinks=False)
+        self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                          (now, None), follow_symlinks=False)
+        self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                          (None, now), follow_symlinks=False)
+        posix.utime(os_helper.TESTFN, (int(now), int(now)),
+                    follow_symlinks=False)
+        posix.utime(os_helper.TESTFN, (now, now), follow_symlinks=False)
+        posix.utime(os_helper.TESTFN, follow_symlinks=False)
 
     @unittest.skipUnless(hasattr(posix, 'writev'), "test needs posix.writev()")
     def test_writev(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             n = os.writev(fd, (b'test1', b'tt2', b't3'))
             self.assertEqual(n, 10)
@@ -491,7 +498,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'writev'), "test needs posix.writev()")
     @requires_32b
     def test_writev_overflow_32bits(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             with self.assertRaises(OSError) as cm:
                 os.writev(fd, [b"x" * 2**16] * 2**15)
@@ -501,7 +508,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'readv'), "test needs posix.readv()")
     def test_readv(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             os.write(fd, b'test1tt2t3')
             os.lseek(fd, 0, os.SEEK_SET)
@@ -524,7 +531,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'readv'), "test needs posix.readv()")
     @requires_32b
     def test_readv_overflow_32bits(self):
-        fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+        fd = os.open(os_helper.TESTFN, os.O_RDWR | os.O_CREAT)
         try:
             buf = [bytearray(2**16)] * 2**15
             with self.assertRaises(OSError) as cm:
@@ -537,7 +544,7 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'dup'),
                          'test needs posix.dup()')
     def test_dup(self):
-        fp = open(support.TESTFN)
+        fp = open(os_helper.TESTFN)
         try:
             fd = posix.dup(fp.fileno())
             self.assertIsInstance(fd, int)
@@ -554,8 +561,8 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'dup2'),
                          'test needs posix.dup2()')
     def test_dup2(self):
-        fp1 = open(support.TESTFN)
-        fp2 = open(support.TESTFN)
+        fp1 = open(os_helper.TESTFN)
+        fp2 = open(os_helper.TESTFN)
         try:
             posix.dup2(fp1.fileno(), fp2.fileno())
         finally:
@@ -565,47 +572,47 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(os, 'O_CLOEXEC'), "needs os.O_CLOEXEC")
     @support.requires_linux_version(2, 6, 23)
     def test_oscloexec(self):
-        fd = os.open(support.TESTFN, os.O_RDONLY|os.O_CLOEXEC)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY|os.O_CLOEXEC)
         self.addCleanup(os.close, fd)
         self.assertFalse(os.get_inheritable(fd))
 
     @unittest.skipUnless(hasattr(posix, 'O_EXLOCK'),
                          'test needs posix.O_EXLOCK')
     def test_osexlock(self):
-        fd = os.open(support.TESTFN,
+        fd = os.open(os_helper.TESTFN,
                      os.O_WRONLY|os.O_EXLOCK|os.O_CREAT)
-        self.assertRaises(OSError, os.open, support.TESTFN,
+        self.assertRaises(OSError, os.open, os_helper.TESTFN,
                           os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
         os.close(fd)
 
         if hasattr(posix, "O_SHLOCK"):
-            fd = os.open(support.TESTFN,
+            fd = os.open(os_helper.TESTFN,
                          os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-            self.assertRaises(OSError, os.open, support.TESTFN,
+            self.assertRaises(OSError, os.open, os_helper.TESTFN,
                               os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
             os.close(fd)
 
     @unittest.skipUnless(hasattr(posix, 'O_SHLOCK'),
                          'test needs posix.O_SHLOCK')
     def test_osshlock(self):
-        fd1 = os.open(support.TESTFN,
+        fd1 = os.open(os_helper.TESTFN,
                      os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-        fd2 = os.open(support.TESTFN,
+        fd2 = os.open(os_helper.TESTFN,
                       os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
         os.close(fd2)
         os.close(fd1)
 
         if hasattr(posix, "O_EXLOCK"):
-            fd = os.open(support.TESTFN,
+            fd = os.open(os_helper.TESTFN,
                          os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-            self.assertRaises(OSError, os.open, support.TESTFN,
+            self.assertRaises(OSError, os.open, os_helper.TESTFN,
                               os.O_RDONLY|os.O_EXLOCK|os.O_NONBLOCK)
             os.close(fd)
 
     @unittest.skipUnless(hasattr(posix, 'fstat'),
                          'test needs posix.fstat()')
     def test_fstat(self):
-        fp = open(support.TESTFN)
+        fp = open(os_helper.TESTFN)
         try:
             self.assertTrue(posix.fstat(fp.fileno()))
             self.assertTrue(posix.stat(fp.fileno()))
@@ -617,58 +624,58 @@ class PosixTester(unittest.TestCase):
             fp.close()
 
     def test_stat(self):
-        self.assertTrue(posix.stat(support.TESTFN))
-        self.assertTrue(posix.stat(os.fsencode(support.TESTFN)))
+        self.assertTrue(posix.stat(os_helper.TESTFN))
+        self.assertTrue(posix.stat(os.fsencode(os_helper.TESTFN)))
 
         self.assertWarnsRegex(DeprecationWarning,
                 'should be string, bytes, os.PathLike or integer, not',
-                posix.stat, bytearray(os.fsencode(support.TESTFN)))
+                posix.stat, bytearray(os.fsencode(os_helper.TESTFN)))
         self.assertRaisesRegex(TypeError,
                 'should be string, bytes, os.PathLike or integer, not',
                 posix.stat, None)
         self.assertRaisesRegex(TypeError,
                 'should be string, bytes, os.PathLike or integer, not',
-                posix.stat, list(support.TESTFN))
+                posix.stat, list(os_helper.TESTFN))
         self.assertRaisesRegex(TypeError,
                 'should be string, bytes, os.PathLike or integer, not',
-                posix.stat, list(os.fsencode(support.TESTFN)))
+                posix.stat, list(os.fsencode(os_helper.TESTFN)))
 
     @unittest.skipUnless(hasattr(posix, 'mkfifo'), "don't have mkfifo()")
     def test_mkfifo(self):
-        support.unlink(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
         try:
-            posix.mkfifo(support.TESTFN, stat.S_IRUSR | stat.S_IWUSR)
+            posix.mkfifo(os_helper.TESTFN, stat.S_IRUSR | stat.S_IWUSR)
         except PermissionError as e:
             self.skipTest('posix.mkfifo(): %s' % e)
-        self.assertTrue(stat.S_ISFIFO(posix.stat(support.TESTFN).st_mode))
+        self.assertTrue(stat.S_ISFIFO(posix.stat(os_helper.TESTFN).st_mode))
 
     @unittest.skipUnless(hasattr(posix, 'mknod') and hasattr(stat, 'S_IFIFO'),
                          "don't have mknod()/S_IFIFO")
     def test_mknod(self):
         # Test using mknod() to create a FIFO (the only use specified
         # by POSIX).
-        support.unlink(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
         mode = stat.S_IFIFO | stat.S_IRUSR | stat.S_IWUSR
         try:
-            posix.mknod(support.TESTFN, mode, 0)
+            posix.mknod(os_helper.TESTFN, mode, 0)
         except OSError as e:
             # Some old systems don't allow unprivileged users to use
             # mknod(), or only support creating device nodes.
             self.assertIn(e.errno, (errno.EPERM, errno.EINVAL, errno.EACCES))
         else:
-            self.assertTrue(stat.S_ISFIFO(posix.stat(support.TESTFN).st_mode))
+            self.assertTrue(stat.S_ISFIFO(posix.stat(os_helper.TESTFN).st_mode))
 
         # Keyword arguments are also supported
-        support.unlink(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
         try:
-            posix.mknod(path=support.TESTFN, mode=mode, device=0,
+            posix.mknod(path=os_helper.TESTFN, mode=mode, device=0,
                 dir_fd=None)
         except OSError as e:
             self.assertIn(e.errno, (errno.EPERM, errno.EINVAL, errno.EACCES))
 
     @unittest.skipUnless(hasattr(posix, 'makedev'), 'test needs posix.makedev()')
     def test_makedev(self):
-        st = posix.stat(support.TESTFN)
+        st = posix.stat(os_helper.TESTFN)
         dev = st.st_dev
         self.assertIsInstance(dev, int)
         self.assertGreaterEqual(dev, 0)
@@ -757,19 +764,19 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'chown'), "test needs os.chown()")
     def test_chown(self):
         # raise an OSError if the file does not exist
-        os.unlink(support.TESTFN)
-        self.assertRaises(OSError, posix.chown, support.TESTFN, -1, -1)
+        os.unlink(os_helper.TESTFN)
+        self.assertRaises(OSError, posix.chown, os_helper.TESTFN, -1, -1)
 
         # re-create the file
-        support.create_empty_file(support.TESTFN)
-        self._test_all_chown_common(posix.chown, support.TESTFN, posix.stat)
+        os_helper.create_empty_file(os_helper.TESTFN)
+        self._test_all_chown_common(posix.chown, os_helper.TESTFN, posix.stat)
 
     @unittest.skipUnless(hasattr(posix, 'fchown'), "test needs os.fchown()")
     def test_fchown(self):
-        os.unlink(support.TESTFN)
+        os.unlink(os_helper.TESTFN)
 
         # re-create the file
-        test_file = open(support.TESTFN, 'w')
+        test_file = open(os_helper.TESTFN, 'w')
         try:
             fd = test_file.fileno()
             self._test_all_chown_common(posix.fchown, fd,
@@ -779,35 +786,35 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'lchown'), "test needs os.lchown()")
     def test_lchown(self):
-        os.unlink(support.TESTFN)
+        os.unlink(os_helper.TESTFN)
         # create a symlink
-        os.symlink(_DUMMY_SYMLINK, support.TESTFN)
-        self._test_all_chown_common(posix.lchown, support.TESTFN,
+        os.symlink(_DUMMY_SYMLINK, os_helper.TESTFN)
+        self._test_all_chown_common(posix.lchown, os_helper.TESTFN,
                                     getattr(posix, 'lstat', None))
 
     @unittest.skipUnless(hasattr(posix, 'chdir'), 'test needs posix.chdir()')
     def test_chdir(self):
         posix.chdir(os.curdir)
-        self.assertRaises(OSError, posix.chdir, support.TESTFN)
+        self.assertRaises(OSError, posix.chdir, os_helper.TESTFN)
 
     def test_listdir(self):
-        self.assertIn(support.TESTFN, posix.listdir(os.curdir))
+        self.assertIn(os_helper.TESTFN, posix.listdir(os.curdir))
 
     def test_listdir_default(self):
         # When listdir is called without argument,
         # it's the same as listdir(os.curdir).
-        self.assertIn(support.TESTFN, posix.listdir())
+        self.assertIn(os_helper.TESTFN, posix.listdir())
 
     def test_listdir_bytes(self):
         # When listdir is called with a bytes object,
         # the returned strings are of type bytes.
-        self.assertIn(os.fsencode(support.TESTFN), posix.listdir(b'.'))
+        self.assertIn(os.fsencode(os_helper.TESTFN), posix.listdir(b'.'))
 
     def test_listdir_bytes_like(self):
         for cls in bytearray, memoryview:
             with self.assertWarns(DeprecationWarning):
                 names = posix.listdir(cls(b'.'))
-            self.assertIn(os.fsencode(support.TESTFN), names)
+            self.assertIn(os.fsencode(os_helper.TESTFN), names)
             for name in names:
                 self.assertIs(type(name), bytes)
 
@@ -828,7 +835,7 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'access'), 'test needs posix.access()')
     def test_access(self):
-        self.assertTrue(posix.access(support.TESTFN, os.R_OK))
+        self.assertTrue(posix.access(os_helper.TESTFN, os.R_OK))
 
     @unittest.skipUnless(hasattr(posix, 'umask'), 'test needs posix.umask()')
     def test_umask(self):
@@ -887,12 +894,15 @@ class PosixTester(unittest.TestCase):
     @unittest.skipUnless(hasattr(posix, 'utime'), 'test needs posix.utime()')
     def test_utime(self):
         now = time.time()
-        posix.utime(support.TESTFN, None)
-        self.assertRaises(TypeError, posix.utime, support.TESTFN, (None, None))
-        self.assertRaises(TypeError, posix.utime, support.TESTFN, (now, None))
-        self.assertRaises(TypeError, posix.utime, support.TESTFN, (None, now))
-        posix.utime(support.TESTFN, (int(now), int(now)))
-        posix.utime(support.TESTFN, (now, now))
+        posix.utime(os_helper.TESTFN, None)
+        self.assertRaises(TypeError, posix.utime,
+                          os_helper.TESTFN, (None, None))
+        self.assertRaises(TypeError, posix.utime,
+                          os_helper.TESTFN, (now, None))
+        self.assertRaises(TypeError, posix.utime,
+                          os_helper.TESTFN, (None, now))
+        posix.utime(os_helper.TESTFN, (int(now), int(now)))
+        posix.utime(os_helper.TESTFN, (now, now))
 
     def _test_chflags_regular_file(self, chflags_func, target_file, **kwargs):
         st = os.stat(target_file)
@@ -920,20 +930,21 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(hasattr(posix, 'chflags'), 'test needs os.chflags()')
     def test_chflags(self):
-        self._test_chflags_regular_file(posix.chflags, support.TESTFN)
+        self._test_chflags_regular_file(posix.chflags, os_helper.TESTFN)
 
     @unittest.skipUnless(hasattr(posix, 'lchflags'), 'test needs os.lchflags()')
     def test_lchflags_regular_file(self):
-        self._test_chflags_regular_file(posix.lchflags, support.TESTFN)
-        self._test_chflags_regular_file(posix.chflags, support.TESTFN, follow_symlinks=False)
+        self._test_chflags_regular_file(posix.lchflags, os_helper.TESTFN)
+        self._test_chflags_regular_file(posix.chflags, os_helper.TESTFN,
+                                        follow_symlinks=False)
 
     @unittest.skipUnless(hasattr(posix, 'lchflags'), 'test needs os.lchflags()')
     def test_lchflags_symlink(self):
-        testfn_st = os.stat(support.TESTFN)
+        testfn_st = os.stat(os_helper.TESTFN)
 
         self.assertTrue(hasattr(testfn_st, 'st_flags'))
 
-        os.symlink(support.TESTFN, _DUMMY_SYMLINK)
+        os.symlink(os_helper.TESTFN, _DUMMY_SYMLINK)
         self.teardown_files.append(_DUMMY_SYMLINK)
         dummy_symlink_st = os.lstat(_DUMMY_SYMLINK)
 
@@ -951,7 +962,7 @@ class PosixTester(unittest.TestCase):
                 msg = 'chflag UF_IMMUTABLE not supported by underlying fs'
                 self.skipTest(msg)
             try:
-                new_testfn_st = os.stat(support.TESTFN)
+                new_testfn_st = os.stat(os_helper.TESTFN)
                 new_dummy_symlink_st = os.lstat(_DUMMY_SYMLINK)
 
                 self.assertEqual(testfn_st.st_flags, new_testfn_st.st_flags)
@@ -987,7 +998,7 @@ class PosixTester(unittest.TestCase):
     def test_getcwd_long_pathnames(self):
         dirname = 'getcwd-test-directory-0123456789abcdef-01234567890abcdef'
         curdir = os.getcwd()
-        base_path = os.path.abspath(support.TESTFN) + '.getcwd'
+        base_path = os.path.abspath(os_helper.TESTFN) + '.getcwd'
 
         try:
             os.mkdir(base_path)
@@ -1017,7 +1028,7 @@ class PosixTester(unittest.TestCase):
 
         finally:
             os.chdir(curdir)
-            support.rmtree(base_path)
+            os_helper.rmtree(base_path)
 
     @unittest.skipUnless(hasattr(posix, 'getgrouplist'), "test needs posix.getgrouplist()")
     @unittest.skipUnless(hasattr(pwd, 'getpwuid'), "test needs pwd.getpwuid()")
@@ -1061,53 +1072,53 @@ class PosixTester(unittest.TestCase):
     def test_access_dir_fd(self):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            self.assertTrue(posix.access(support.TESTFN, os.R_OK, dir_fd=f))
+            self.assertTrue(posix.access(os_helper.TESTFN, os.R_OK, dir_fd=f))
         finally:
             posix.close(f)
 
     @unittest.skipUnless(os.chmod in os.supports_dir_fd, "test needs dir_fd support in os.chmod()")
     def test_chmod_dir_fd(self):
-        os.chmod(support.TESTFN, stat.S_IRUSR)
+        os.chmod(os_helper.TESTFN, stat.S_IRUSR)
 
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.chmod(support.TESTFN, stat.S_IRUSR | stat.S_IWUSR, dir_fd=f)
+            posix.chmod(os_helper.TESTFN, stat.S_IRUSR | stat.S_IWUSR, dir_fd=f)
 
-            s = posix.stat(support.TESTFN)
+            s = posix.stat(os_helper.TESTFN)
             self.assertEqual(s[0] & stat.S_IRWXU, stat.S_IRUSR | stat.S_IWUSR)
         finally:
             posix.close(f)
 
     @unittest.skipUnless(os.chown in os.supports_dir_fd, "test needs dir_fd support in os.chown()")
     def test_chown_dir_fd(self):
-        support.unlink(support.TESTFN)
-        support.create_empty_file(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
+        os_helper.create_empty_file(os_helper.TESTFN)
 
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.chown(support.TESTFN, os.getuid(), os.getgid(), dir_fd=f)
+            posix.chown(os_helper.TESTFN, os.getuid(), os.getgid(), dir_fd=f)
         finally:
             posix.close(f)
 
     @unittest.skipUnless(os.stat in os.supports_dir_fd, "test needs dir_fd support in os.stat()")
     def test_stat_dir_fd(self):
-        support.unlink(support.TESTFN)
-        with open(support.TESTFN, 'w') as outfile:
+        os_helper.unlink(os_helper.TESTFN)
+        with open(os_helper.TESTFN, 'w') as outfile:
             outfile.write("testline\n")
 
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            s1 = posix.stat(support.TESTFN)
-            s2 = posix.stat(support.TESTFN, dir_fd=f)
+            s1 = posix.stat(os_helper.TESTFN)
+            s2 = posix.stat(os_helper.TESTFN, dir_fd=f)
             self.assertEqual(s1, s2)
-            s2 = posix.stat(support.TESTFN, dir_fd=None)
+            s2 = posix.stat(os_helper.TESTFN, dir_fd=None)
             self.assertEqual(s1, s2)
             self.assertRaisesRegex(TypeError, 'should be integer or None, not',
-                    posix.stat, support.TESTFN, dir_fd=posix.getcwd())
+                    posix.stat, os_helper.TESTFN, dir_fd=posix.getcwd())
             self.assertRaisesRegex(TypeError, 'should be integer or None, not',
-                    posix.stat, support.TESTFN, dir_fd=float(f))
+                    posix.stat, os_helper.TESTFN, dir_fd=float(f))
             self.assertRaises(OverflowError,
-                    posix.stat, support.TESTFN, dir_fd=10**20)
+                    posix.stat, os_helper.TESTFN, dir_fd=10**20)
         finally:
             posix.close(f)
 
@@ -1116,24 +1127,30 @@ class PosixTester(unittest.TestCase):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
             now = time.time()
-            posix.utime(support.TESTFN, None, dir_fd=f)
-            posix.utime(support.TESTFN, dir_fd=f)
-            self.assertRaises(TypeError, posix.utime, support.TESTFN, now, dir_fd=f)
-            self.assertRaises(TypeError, posix.utime, support.TESTFN, (None, None), dir_fd=f)
-            self.assertRaises(TypeError, posix.utime, support.TESTFN, (now, None), dir_fd=f)
-            self.assertRaises(TypeError, posix.utime, support.TESTFN, (None, now), dir_fd=f)
-            self.assertRaises(TypeError, posix.utime, support.TESTFN, (now, "x"), dir_fd=f)
-            posix.utime(support.TESTFN, (int(now), int(now)), dir_fd=f)
-            posix.utime(support.TESTFN, (now, now), dir_fd=f)
-            posix.utime(support.TESTFN,
+            posix.utime(os_helper.TESTFN, None, dir_fd=f)
+            posix.utime(os_helper.TESTFN, dir_fd=f)
+            self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                              now, dir_fd=f)
+            self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                              (None, None), dir_fd=f)
+            self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                              (now, None), dir_fd=f)
+            self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                              (None, now), dir_fd=f)
+            self.assertRaises(TypeError, posix.utime, os_helper.TESTFN,
+                              (now, "x"), dir_fd=f)
+            posix.utime(os_helper.TESTFN, (int(now), int(now)), dir_fd=f)
+            posix.utime(os_helper.TESTFN, (now, now), dir_fd=f)
+            posix.utime(os_helper.TESTFN,
                     (int(now), int((now - int(now)) * 1e9)), dir_fd=f)
-            posix.utime(support.TESTFN, dir_fd=f,
+            posix.utime(os_helper.TESTFN, dir_fd=f,
                             times=(int(now), int((now - int(now)) * 1e9)))
 
             # try dir_fd and follow_symlinks together
             if os.utime in os.supports_follow_symlinks:
                 try:
-                    posix.utime(support.TESTFN, follow_symlinks=False, dir_fd=f)
+                    posix.utime(os_helper.TESTFN, follow_symlinks=False,
+                                dir_fd=f)
                 except ValueError:
                     # whoops!  using both together not supported on this platform.
                     pass
@@ -1145,53 +1162,54 @@ class PosixTester(unittest.TestCase):
     def test_link_dir_fd(self):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.link(support.TESTFN, support.TESTFN + 'link', src_dir_fd=f, dst_dir_fd=f)
+            posix.link(os_helper.TESTFN, os_helper.TESTFN + 'link',
+                       src_dir_fd=f, dst_dir_fd=f)
         except PermissionError as e:
             self.skipTest('posix.link(): %s' % e)
         else:
             # should have same inodes
-            self.assertEqual(posix.stat(support.TESTFN)[1],
-                posix.stat(support.TESTFN + 'link')[1])
+            self.assertEqual(posix.stat(os_helper.TESTFN)[1],
+                posix.stat(os_helper.TESTFN + 'link')[1])
         finally:
             posix.close(f)
-            support.unlink(support.TESTFN + 'link')
+            os_helper.unlink(os_helper.TESTFN + 'link')
 
     @unittest.skipUnless(os.mkdir in os.supports_dir_fd, "test needs dir_fd support in os.mkdir()")
     def test_mkdir_dir_fd(self):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.mkdir(support.TESTFN + 'dir', dir_fd=f)
-            posix.stat(support.TESTFN + 'dir') # should not raise exception
+            posix.mkdir(os_helper.TESTFN + 'dir', dir_fd=f)
+            posix.stat(os_helper.TESTFN + 'dir') # should not raise exception
         finally:
             posix.close(f)
-            support.rmtree(support.TESTFN + 'dir')
+            os_helper.rmtree(os_helper.TESTFN + 'dir')
 
     @unittest.skipUnless((os.mknod in os.supports_dir_fd) and hasattr(stat, 'S_IFIFO'),
                          "test requires both stat.S_IFIFO and dir_fd support for os.mknod()")
     def test_mknod_dir_fd(self):
         # Test using mknodat() to create a FIFO (the only use specified
         # by POSIX).
-        support.unlink(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
         mode = stat.S_IFIFO | stat.S_IRUSR | stat.S_IWUSR
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.mknod(support.TESTFN, mode, 0, dir_fd=f)
+            posix.mknod(os_helper.TESTFN, mode, 0, dir_fd=f)
         except OSError as e:
             # Some old systems don't allow unprivileged users to use
             # mknod(), or only support creating device nodes.
             self.assertIn(e.errno, (errno.EPERM, errno.EINVAL, errno.EACCES))
         else:
-            self.assertTrue(stat.S_ISFIFO(posix.stat(support.TESTFN).st_mode))
+            self.assertTrue(stat.S_ISFIFO(posix.stat(os_helper.TESTFN).st_mode))
         finally:
             posix.close(f)
 
     @unittest.skipUnless(os.open in os.supports_dir_fd, "test needs dir_fd support in os.open()")
     def test_open_dir_fd(self):
-        support.unlink(support.TESTFN)
-        with open(support.TESTFN, 'w') as outfile:
+        os_helper.unlink(os_helper.TESTFN)
+        with open(os_helper.TESTFN, 'w') as outfile:
             outfile.write("testline\n")
         a = posix.open(posix.getcwd(), posix.O_RDONLY)
-        b = posix.open(support.TESTFN, posix.O_RDONLY, dir_fd=a)
+        b = posix.open(os_helper.TESTFN, posix.O_RDONLY, dir_fd=a)
         try:
             res = posix.read(b, 9).decode(encoding="utf-8")
             self.assertEqual("testline\n", res)
@@ -1201,27 +1219,27 @@ class PosixTester(unittest.TestCase):
 
     @unittest.skipUnless(os.readlink in os.supports_dir_fd, "test needs dir_fd support in os.readlink()")
     def test_readlink_dir_fd(self):
-        os.symlink(support.TESTFN, support.TESTFN + 'link')
+        os.symlink(os_helper.TESTFN, os_helper.TESTFN + 'link')
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            self.assertEqual(posix.readlink(support.TESTFN + 'link'),
-                posix.readlink(support.TESTFN + 'link', dir_fd=f))
+            self.assertEqual(posix.readlink(os_helper.TESTFN + 'link'),
+                posix.readlink(os_helper.TESTFN + 'link', dir_fd=f))
         finally:
-            support.unlink(support.TESTFN + 'link')
+            os_helper.unlink(os_helper.TESTFN + 'link')
             posix.close(f)
 
     @unittest.skipUnless(os.rename in os.supports_dir_fd, "test needs dir_fd support in os.rename()")
     def test_rename_dir_fd(self):
-        support.unlink(support.TESTFN)
-        support.create_empty_file(support.TESTFN + 'ren')
+        os_helper.unlink(os_helper.TESTFN)
+        os_helper.create_empty_file(os_helper.TESTFN + 'ren')
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.rename(support.TESTFN + 'ren', support.TESTFN, src_dir_fd=f, dst_dir_fd=f)
+            posix.rename(os_helper.TESTFN + 'ren', os_helper.TESTFN, src_dir_fd=f, dst_dir_fd=f)
         except:
-            posix.rename(support.TESTFN + 'ren', support.TESTFN)
+            posix.rename(os_helper.TESTFN + 'ren', os_helper.TESTFN)
             raise
         else:
-            posix.stat(support.TESTFN) # should not raise exception
+            posix.stat(os_helper.TESTFN) # should not raise exception
         finally:
             posix.close(f)
 
@@ -1239,38 +1257,40 @@ class PosixTester(unittest.TestCase):
     def test_symlink_dir_fd(self):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
-            posix.symlink(support.TESTFN, support.TESTFN + 'link', dir_fd=f)
-            self.assertEqual(posix.readlink(support.TESTFN + 'link'), support.TESTFN)
+            posix.symlink(os_helper.TESTFN, os_helper.TESTFN + 'link',
+                          dir_fd=f)
+            self.assertEqual(posix.readlink(os_helper.TESTFN + 'link'),
+                             os_helper.TESTFN)
         finally:
             posix.close(f)
-            support.unlink(support.TESTFN + 'link')
+            os_helper.unlink(os_helper.TESTFN + 'link')
 
     @unittest.skipUnless(os.unlink in os.supports_dir_fd, "test needs dir_fd support in os.unlink()")
     def test_unlink_dir_fd(self):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
-        support.create_empty_file(support.TESTFN + 'del')
-        posix.stat(support.TESTFN + 'del') # should not raise exception
+        os_helper.create_empty_file(os_helper.TESTFN + 'del')
+        posix.stat(os_helper.TESTFN + 'del') # should not raise exception
         try:
-            posix.unlink(support.TESTFN + 'del', dir_fd=f)
+            posix.unlink(os_helper.TESTFN + 'del', dir_fd=f)
         except:
-            support.unlink(support.TESTFN + 'del')
+            os_helper.unlink(os_helper.TESTFN + 'del')
             raise
         else:
-            self.assertRaises(OSError, posix.stat, support.TESTFN + 'link')
+            self.assertRaises(OSError, posix.stat, os_helper.TESTFN + 'link')
         finally:
             posix.close(f)
 
     @unittest.skipUnless(os.mkfifo in os.supports_dir_fd, "test needs dir_fd support in os.mkfifo()")
     def test_mkfifo_dir_fd(self):
-        support.unlink(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
         f = posix.open(posix.getcwd(), posix.O_RDONLY)
         try:
             try:
-                posix.mkfifo(support.TESTFN,
+                posix.mkfifo(os_helper.TESTFN,
                              stat.S_IRUSR | stat.S_IWUSR, dir_fd=f)
             except PermissionError as e:
                 self.skipTest('posix.mkfifo(): %s' % e)
-            self.assertTrue(stat.S_ISFIFO(posix.stat(support.TESTFN).st_mode))
+            self.assertTrue(stat.S_ISFIFO(posix.stat(os_helper.TESTFN).st_mode))
         finally:
             posix.close(f)
 
@@ -1397,7 +1417,7 @@ class PosixTester(unittest.TestCase):
         # behaviour:
         # os.SEEK_DATA = current position
         # os.SEEK_HOLE = end of file position
-        with open(support.TESTFN, 'r+b') as fp:
+        with open(os_helper.TESTFN, 'r+b') as fp:
             fp.write(b"hello")
             fp.flush()
             size = fp.tell()
@@ -1424,7 +1444,7 @@ class PosixTester(unittest.TestCase):
             if function is None:
                 continue
 
-            for dst in ("noodly2", support.TESTFN):
+            for dst in ("noodly2", os_helper.TESTFN):
                 try:
                     function('doesnotexistfilename', dst)
                 except OSError as e:
@@ -1434,10 +1454,10 @@ class PosixTester(unittest.TestCase):
                 self.fail("No valid path_error2() test for os." + name)
 
     def test_path_with_null_character(self):
-        fn = support.TESTFN
+        fn = os_helper.TESTFN
         fn_with_NUL = fn + '\0'
-        self.addCleanup(support.unlink, fn)
-        support.unlink(fn)
+        self.addCleanup(os_helper.unlink, fn)
+        os_helper.unlink(fn)
         fd = None
         try:
             with self.assertRaises(ValueError):
@@ -1452,10 +1472,10 @@ class PosixTester(unittest.TestCase):
         self.assertRaises(ValueError, os.stat, fn_with_NUL)
 
     def test_path_with_null_byte(self):
-        fn = os.fsencode(support.TESTFN)
+        fn = os.fsencode(os_helper.TESTFN)
         fn_with_NUL = fn + b'\0'
-        self.addCleanup(support.unlink, fn)
-        support.unlink(fn)
+        self.addCleanup(os_helper.unlink, fn)
+        os_helper.unlink(fn)
         fd = None
         try:
             with self.assertRaises(ValueError):
@@ -1530,8 +1550,8 @@ class _PosixSpawnMixin:
         return (sys.executable, '-I', '-S', *args)
 
     def test_returns_pid(self):
-        pidfile = support.TESTFN
-        self.addCleanup(support.unlink, pidfile)
+        pidfile = os_helper.TESTFN
+        self.addCleanup(os_helper.unlink, pidfile)
         script = f"""if 1:
             import os
             with open({pidfile!r}, "w") as pidfile:
@@ -1559,8 +1579,8 @@ class _PosixSpawnMixin:
             self.assertNotEqual(status, 0)
 
     def test_specify_environment(self):
-        envfile = support.TESTFN
-        self.addCleanup(support.unlink, envfile)
+        envfile = os_helper.TESTFN
+        self.addCleanup(os_helper.unlink, envfile)
         script = f"""if 1:
             import os
             with open({envfile!r}, "w") as envfile:
@@ -1806,8 +1826,8 @@ class _PosixSpawnMixin:
                                            os.O_RDONLY, 0)])
 
     def test_open_file(self):
-        outfile = support.TESTFN
-        self.addCleanup(support.unlink, outfile)
+        outfile = os_helper.TESTFN
+        self.addCleanup(os_helper.unlink, outfile)
         script = """if 1:
             import sys
             sys.stdout.write("hello")
@@ -1826,8 +1846,8 @@ class _PosixSpawnMixin:
             self.assertEqual(f.read(), 'hello')
 
     def test_close_file(self):
-        closefile = support.TESTFN
-        self.addCleanup(support.unlink, closefile)
+        closefile = os_helper.TESTFN
+        self.addCleanup(os_helper.unlink, closefile)
         script = f"""if 1:
             import os
             try:
@@ -1845,8 +1865,8 @@ class _PosixSpawnMixin:
             self.assertEqual(f.read(), 'is closed %d' % errno.EBADF)
 
     def test_dup2(self):
-        dupfile = support.TESTFN
-        self.addCleanup(support.unlink, dupfile)
+        dupfile = os_helper.TESTFN
+        self.addCleanup(os_helper.unlink, dupfile)
         script = """if 1:
             import sys
             sys.stdout.write("hello")
@@ -1872,11 +1892,11 @@ class TestPosixSpawn(unittest.TestCase, _PosixSpawnMixin):
 class TestPosixSpawnP(unittest.TestCase, _PosixSpawnMixin):
     spawn_func = getattr(posix, 'posix_spawnp', None)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_posix_spawnp(self):
         # Use a symlink to create a program in its own temporary directory
         temp_dir = tempfile.mkdtemp()
-        self.addCleanup(support.rmtree, temp_dir)
+        self.addCleanup(os_helper.rmtree, temp_dir)
 
         program = 'posix_spawnp_test_program.exe'
         program_fullpath = os.path.join(temp_dir, program)
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index f0d7ffd..76d2af8 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -23,13 +23,12 @@ import xml.etree.ElementTree
 import textwrap
 from io import StringIO
 from collections import namedtuple
+from test.support import os_helper
 from test.support.script_helper import assert_python_ok
 from test.support import threading_helper
-from test.support import (
-    TESTFN, rmtree,
-    reap_children, captured_output, captured_stdout,
-    captured_stderr, unlink, requires_docstrings
-)
+from test.support import (reap_children, captured_output, captured_stdout,
+                          captured_stderr, requires_docstrings)
+from test.support.os_helper import (TESTFN, rmtree, unlink)
 from test import pydoc_mod
 
 
@@ -728,7 +727,7 @@ class PydocDocTest(unittest.TestCase):
         self.assertEqual(synopsis, expected)
 
     def test_synopsis_sourceless_empty_doc(self):
-        with test.support.temp_cwd() as test_dir:
+        with os_helper.temp_cwd() as test_dir:
             init_path = os.path.join(test_dir, 'foomod42.py')
             cached_path = importlib.util.cache_from_source(init_path)
             with open(init_path, 'w') as fobj:
@@ -745,11 +744,11 @@ class PydocDocTest(unittest.TestCase):
                          ('I Am A Doc', '\nHere is my description'))
 
     def test_is_package_when_not_package(self):
-        with test.support.temp_cwd() as test_dir:
+        with os_helper.temp_cwd() as test_dir:
             self.assertFalse(pydoc.ispackage(test_dir))
 
     def test_is_package_when_is_package(self):
-        with test.support.temp_cwd() as test_dir:
+        with os_helper.temp_cwd() as test_dir:
             init_path = os.path.join(test_dir, '__init__.py')
             open(init_path, 'w').close()
             self.assertTrue(pydoc.ispackage(test_dir))
diff --git a/Lib/test/test_resource.py b/Lib/test/test_resource.py
index e5ece52..d909e31 100644
--- a/Lib/test/test_resource.py
+++ b/Lib/test/test_resource.py
@@ -2,9 +2,11 @@ import contextlib
 import sys
 import unittest
 from test import support
+from test.support import import_helper
+from test.support import os_helper
 import time
 
-resource = support.import_module('resource')
+resource = import_helper.import_module('resource')
 
 # This test is checking a few specific problem spots with the resource module.
 
@@ -51,7 +53,7 @@ class ResourceTest(unittest.TestCase):
                     limit_set = True
                 except ValueError:
                     limit_set = False
-                f = open(support.TESTFN, "wb")
+                f = open(os_helper.TESTFN, "wb")
                 try:
                     f.write(b"X" * 1024)
                     try:
@@ -77,7 +79,7 @@ class ResourceTest(unittest.TestCase):
             finally:
                 if limit_set:
                     resource.setrlimit(resource.RLIMIT_FSIZE, (cur, max))
-                support.unlink(support.TESTFN)
+                os_helper.unlink(os_helper.TESTFN)
 
     def test_fsize_toobig(self):
         # Be sure that setrlimit is checking for really large values
diff --git a/Lib/test/test_runpy.py b/Lib/test/test_runpy.py
index 84834d3..f8274a9 100644
--- a/Lib/test/test_runpy.py
+++ b/Lib/test/test_runpy.py
@@ -9,9 +9,9 @@ import importlib, importlib.machinery, importlib.util
 import py_compile
 import warnings
 import pathlib
-from test.support import (
-    forget, make_legacy_pyc, unload, verbose, no_tracing,
-    create_empty_file, temp_dir)
+from test.support import verbose, no_tracing
+from test.support.import_helper import forget, make_legacy_pyc, unload
+from test.support.os_helper import create_empty_file, temp_dir
 from test.support.script_helper import make_script, make_zip_script
 
 
diff --git a/Lib/test/test_sax.py b/Lib/test/test_sax.py
index bc77103..cfc674b 100644
--- a/Lib/test/test_sax.py
+++ b/Lib/test/test_sax.py
@@ -22,8 +22,10 @@ import shutil
 import sys
 from urllib.error import URLError
 import urllib.request
-from test import support
-from test.support import findfile, run_unittest, FakePath, TESTFN
+from test.support import os_helper
+from test.support import findfile, run_unittest
+from test.support.os_helper import FakePath, TESTFN
+
 
 TEST_XMLFILE = findfile("test.xml", subdir="xmltestdata")
 TEST_XMLFILE_OUT = findfile("test.xml.out", subdir="xmltestdata")
@@ -36,7 +38,7 @@ except UnicodeEncodeError:
 supports_nonascii_filenames = True
 if not os.path.supports_unicode_filenames:
     try:
-        support.TESTFN_UNICODE.encode(sys.getfilesystemencoding())
+        os_helper.TESTFN_UNICODE.encode(sys.getfilesystemencoding())
     except (UnicodeError, TypeError):
         # Either the file system encoding is None, or the file name
         # cannot be encoded in the file system encoding.
@@ -121,7 +123,7 @@ class ParseTest(unittest.TestCase):
     data = '<money value="$\xa3\u20ac\U0001017b">$\xa3\u20ac\U0001017b</money>'
 
     def tearDown(self):
-        support.unlink(TESTFN)
+        os_helper.unlink(TESTFN)
 
     def check_parse(self, f):
         from xml.sax import parse
@@ -349,12 +351,12 @@ class SaxutilsTest(unittest.TestCase):
 class PrepareInputSourceTest(unittest.TestCase):
 
     def setUp(self):
-        self.file = support.TESTFN
+        self.file = os_helper.TESTFN
         with open(self.file, "w") as tmp:
             tmp.write("This was read from a file.")
 
     def tearDown(self):
-        support.unlink(self.file)
+        os_helper.unlink(self.file)
 
     def make_byte_stream(self):
         return BytesIO(b"This is a byte stream.")
@@ -824,14 +826,14 @@ class StreamWriterXmlgenTest(XmlgenTest, unittest.TestCase):
                 (encoding, doc)).encode('ascii', 'xmlcharrefreplace')
 
 class StreamReaderWriterXmlgenTest(XmlgenTest, unittest.TestCase):
-    fname = support.TESTFN + '-codecs'
+    fname = os_helper.TESTFN + '-codecs'
 
     def ioclass(self):
         writer = codecs.open(self.fname, 'w', encoding='ascii',
                              errors='xmlcharrefreplace', buffering=0)
         def cleanup():
             writer.close()
-            support.unlink(self.fname)
+            os_helper.unlink(self.fname)
         self.addCleanup(cleanup)
         def getvalue():
             # Windows will not let use reopen without first closing
@@ -901,9 +903,9 @@ class ExpatReaderTest(XmlTestBase):
 
     @requires_nonascii_filenames
     def test_expat_binary_file_nonascii(self):
-        fname = support.TESTFN_UNICODE
+        fname = os_helper.TESTFN_UNICODE
         shutil.copyfile(TEST_XMLFILE, fname)
-        self.addCleanup(support.unlink, fname)
+        self.addCleanup(os_helper.unlink, fname)
 
         parser = create_parser()
         result = BytesIO()
@@ -1137,9 +1139,9 @@ class ExpatReaderTest(XmlTestBase):
 
     @requires_nonascii_filenames
     def test_expat_inpsource_sysid_nonascii(self):
-        fname = support.TESTFN_UNICODE
+        fname = os_helper.TESTFN_UNICODE
         shutil.copyfile(TEST_XMLFILE, fname)
-        self.addCleanup(support.unlink, fname)
+        self.addCleanup(os_helper.unlink, fname)
 
         parser = create_parser()
         result = BytesIO()
@@ -1239,9 +1241,9 @@ class ExpatReaderTest(XmlTestBase):
 
     @requires_nonascii_filenames
     def test_expat_locator_withinfo_nonascii(self):
-        fname = support.TESTFN_UNICODE
+        fname = os_helper.TESTFN_UNICODE
         shutil.copyfile(TEST_XMLFILE, fname)
-        self.addCleanup(support.unlink, fname)
+        self.addCleanup(os_helper.unlink, fname)
 
         result = BytesIO()
         xmlgen = XMLGenerator(result)
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 7a5df46..30c29a2 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -10,6 +10,7 @@ import sys
 import sysconfig
 import test.support
 from test import support
+from test.support import os_helper
 from test.support.script_helper import assert_python_ok, assert_python_failure
 from test.support import threading_helper
 import textwrap
@@ -632,7 +633,7 @@ class SysModuleTest(unittest.TestCase):
         out = p.communicate()[0].strip()
         self.assertEqual(out, b'\xbd')
 
-    @unittest.skipUnless(test.support.FS_NONASCII,
+    @unittest.skipUnless(os_helper.FS_NONASCII,
                          'requires OS support of non-ASCII encodings')
     @unittest.skipUnless(sys.getfilesystemencoding() == locale.getpreferredencoding(False),
                          'requires FS encoding to match locale')
@@ -641,10 +642,10 @@ class SysModuleTest(unittest.TestCase):
 
         env["PYTHONIOENCODING"] = ""
         p = subprocess.Popen([sys.executable, "-c",
-                                'print(%a)' % test.support.FS_NONASCII],
+                                'print(%a)' % os_helper.FS_NONASCII],
                                 stdout=subprocess.PIPE, env=env)
         out = p.communicate()[0].strip()
-        self.assertEqual(out, os.fsencode(test.support.FS_NONASCII))
+        self.assertEqual(out, os.fsencode(os_helper.FS_NONASCII))
 
     @unittest.skipIf(sys.base_prefix != sys.prefix,
                      'Test is not venv-compatible')
diff --git a/Lib/test/test_syslog.py b/Lib/test/test_syslog.py
index 6f902f1..fe09bd3 100644
--- a/Lib/test/test_syslog.py
+++ b/Lib/test/test_syslog.py
@@ -1,6 +1,5 @@
-
-from test import support
-syslog = support.import_module("syslog") #skip if not supported
+from test.support import import_helper
+syslog = import_helper.import_module("syslog") #skip if not supported
 import unittest
 
 # XXX(nnorwitz): This test sucks.  I don't know of a platform independent way
diff --git a/Lib/test/test_ttk_textonly.py b/Lib/test/test_ttk_textonly.py
index 7540a431..013b0e9 100644
--- a/Lib/test/test_ttk_textonly.py
+++ b/Lib/test/test_ttk_textonly.py
@@ -1,7 +1,9 @@
 from test import support
+from test.support import import_helper
+
 
 # Skip this test if _tkinter does not exist.
-support.import_module('_tkinter')
+import_helper.import_module('_tkinter')
 
 from tkinter.test import runtktests
 
diff --git a/Lib/test/test_unicode_file_functions.py b/Lib/test/test_unicode_file_functions.py
index 1cd0d62..7ef11aa 100644
--- a/Lib/test/test_unicode_file_functions.py
+++ b/Lib/test/test_unicode_file_functions.py
@@ -6,6 +6,8 @@ import unittest
 import warnings
 from unicodedata import normalize
 from test import support
+from test.support import os_helper
+
 
 filenames = [
     '1_abc',
@@ -62,14 +64,14 @@ class UnicodeFileTests(unittest.TestCase):
 
     def setUp(self):
         try:
-            os.mkdir(support.TESTFN)
+            os.mkdir(os_helper.TESTFN)
         except FileExistsError:
             pass
-        self.addCleanup(support.rmtree, support.TESTFN)
+        self.addCleanup(os_helper.rmtree, os_helper.TESTFN)
 
         files = set()
         for name in self.files:
-            name = os.path.join(support.TESTFN, self.norm(name))
+            name = os.path.join(os_helper.TESTFN, self.norm(name))
             with open(name, 'wb') as f:
                 f.write((name+'\n').encode("utf-8"))
             os.stat(name)
@@ -144,9 +146,10 @@ class UnicodeFileTests(unittest.TestCase):
         sf0 = set(self.files)
         with warnings.catch_warnings():
             warnings.simplefilter("ignore", DeprecationWarning)
-            f1 = os.listdir(support.TESTFN.encode(sys.getfilesystemencoding()))
-        f2 = os.listdir(support.TESTFN)
-        sf2 = set(os.path.join(support.TESTFN, f) for f in f2)
+            f1 = os.listdir(os_helper.TESTFN.encode(
+                            sys.getfilesystemencoding()))
+        f2 = os.listdir(os_helper.TESTFN)
+        sf2 = set(os.path.join(os_helper.TESTFN, f) for f in f2)
         self.assertEqual(sf0, sf2, "%a != %a" % (sf0, sf2))
         self.assertEqual(len(f1), len(f2))
 
@@ -156,9 +159,10 @@ class UnicodeFileTests(unittest.TestCase):
             os.rename("tmp", name)
 
     def test_directory(self):
-        dirname = os.path.join(support.TESTFN, 'Gr\xfc\xdf-\u66e8\u66e9\u66eb')
+        dirname = os.path.join(os_helper.TESTFN,
+                               'Gr\xfc\xdf-\u66e8\u66e9\u66eb')
         filename = '\xdf-\u66e8\u66e9\u66eb'
-        with support.temp_cwd(dirname):
+        with os_helper.temp_cwd(dirname):
             with open(filename, 'wb') as f:
                 f.write((filename + '\n').encode("utf-8"))
             os.access(filename,os.R_OK)
diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index cbfa9ba..f202f97 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -1,6 +1,8 @@
 import unittest
 from test import support
+from test.support import os_helper
 from test.support import socket_helper
+from test.support import warnings_helper
 from test import test_urllib
 
 import os
@@ -765,7 +767,7 @@ class HandlerTests(unittest.TestCase):
         h = urllib.request.FileHandler()
         o = h.parent = MockOpener()
 
-        TESTFN = support.TESTFN
+        TESTFN = os_helper.TESTFN
         urlpath = sanepathname2url(os.path.abspath(TESTFN))
         towrite = b"hello, world\n"
         urls = [
@@ -1490,7 +1492,7 @@ class HandlerTests(unittest.TestCase):
             self.check_basic_auth(headers, realm)
 
         # no quote: expect a warning
-        with support.check_warnings(("Basic Auth Realm was unquoted",
+        with warnings_helper.check_warnings(("Basic Auth Realm was unquoted",
                                      UserWarning)):
             headers = [f'WWW-Authenticate: Basic realm={realm}']
             self.check_basic_auth(headers, realm)
diff --git a/Lib/test/test_venv.py b/Lib/test/test_venv.py
index ca003d5..5bb62cd 100644
--- a/Lib/test/test_venv.py
+++ b/Lib/test/test_venv.py
@@ -15,9 +15,8 @@ import subprocess
 import sys
 import tempfile
 from test.support import (captured_stdout, captured_stderr, requires_zlib,
-                          can_symlink, EnvironmentVarGuard, rmtree,
-                          import_module,
                           skip_if_broken_multiprocessing_synchronize)
+from test.support.os_helper import (can_symlink, EnvironmentVarGuard, rmtree)
 import unittest
 import venv
 from unittest.mock import patch
-- 
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