bpo-40275: Use new test.support helper submodules in tests (GH-21449)

20 files changed, 154 insertions, 132 deletions

diff --git a/Lib/test/test__opcode.py b/Lib/test/test__opcode.py
index 0fb39ee..3bb64a7 100644
--- a/Lib/test/test__opcode.py
+++ b/Lib/test/test__opcode.py
@@ -1,5 +1,5 @@
 import dis
-from test.support import import_module
+from test.support.import_helper import import_module
 import unittest
 
 _opcode = import_module("_opcode")
diff --git a/Lib/test/test_asyncore.py b/Lib/test/test_asyncore.py
index 2cee6fb..06c6bc2 100644
--- a/Lib/test/test_asyncore.py
+++ b/Lib/test/test_asyncore.py
@@ -10,8 +10,10 @@ import struct
 import threading
 
 from test import support
+from test.support import os_helper
 from test.support import socket_helper
 from test.support import threading_helper
+from test.support import warnings_helper
 from io import BytesIO
 
 if support.PGO:
@@ -92,7 +94,7 @@ def bind_af_aware(sock, addr):
     """Helper function to bind a socket according to its family."""
     if HAS_UNIX_SOCKETS and sock.family == socket.AF_UNIX:
         # Make sure the path doesn't exist.
-        support.unlink(addr)
+        os_helper.unlink(addr)
         socket_helper.bind_unix_socket(sock, addr)
     else:
         sock.bind(addr)
@@ -369,14 +371,14 @@ class DispatcherWithSendTests(unittest.TestCase):
 class FileWrapperTest(unittest.TestCase):
     def setUp(self):
         self.d = b"It's not dead, it's sleeping!"
-        with open(support.TESTFN, 'wb') as file:
+        with open(os_helper.TESTFN, 'wb') as file:
             file.write(self.d)
 
     def tearDown(self):
-        support.unlink(support.TESTFN)
+        os_helper.unlink(os_helper.TESTFN)
 
     def test_recv(self):
-        fd = os.open(support.TESTFN, os.O_RDONLY)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY)
         w = asyncore.file_wrapper(fd)
         os.close(fd)
 
@@ -390,20 +392,20 @@ class FileWrapperTest(unittest.TestCase):
     def test_send(self):
         d1 = b"Come again?"
         d2 = b"I want to buy some cheese."
-        fd = os.open(support.TESTFN, os.O_WRONLY | os.O_APPEND)
+        fd = os.open(os_helper.TESTFN, os.O_WRONLY | os.O_APPEND)
         w = asyncore.file_wrapper(fd)
         os.close(fd)
 
         w.write(d1)
         w.send(d2)
         w.close()
-        with open(support.TESTFN, 'rb') as file:
+        with open(os_helper.TESTFN, 'rb') as file:
             self.assertEqual(file.read(), self.d + d1 + d2)
 
     @unittest.skipUnless(hasattr(asyncore, 'file_dispatcher'),
                          'asyncore.file_dispatcher required')
     def test_dispatcher(self):
-        fd = os.open(support.TESTFN, os.O_RDONLY)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY)
         data = []
         class FileDispatcher(asyncore.file_dispatcher):
             def handle_read(self):
@@ -415,16 +417,16 @@ class FileWrapperTest(unittest.TestCase):
 
     def test_resource_warning(self):
         # Issue #11453
-        fd = os.open(support.TESTFN, os.O_RDONLY)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY)
         f = asyncore.file_wrapper(fd)
 
         os.close(fd)
-        with support.check_warnings(('', ResourceWarning)):
+        with warnings_helper.check_warnings(('', ResourceWarning)):
             f = None
             support.gc_collect()
 
     def test_close_twice(self):
-        fd = os.open(support.TESTFN, os.O_RDONLY)
+        fd = os.open(os_helper.TESTFN, os.O_RDONLY)
         f = asyncore.file_wrapper(fd)
         os.close(fd)
 
@@ -804,10 +806,10 @@ class TestAPI_UseIPv6Sockets(BaseTestAPI):
 class TestAPI_UseUnixSockets(BaseTestAPI):
     if HAS_UNIX_SOCKETS:
         family = socket.AF_UNIX
-    addr = support.TESTFN
+    addr = os_helper.TESTFN
 
     def tearDown(self):
-        support.unlink(self.addr)
+        os_helper.unlink(self.addr)
         BaseTestAPI.tearDown(self)
 
 class TestAPI_UseIPv4Select(TestAPI_UseIPv4Sockets, unittest.TestCase):
diff --git a/Lib/test/test_binascii.py b/Lib/test/test_binascii.py
index 4532795..4d1bf2c 100644
--- a/Lib/test/test_binascii.py
+++ b/Lib/test/test_binascii.py
@@ -4,7 +4,8 @@ import unittest
 import binascii
 import array
 import re
-from test import support
+from test.support import warnings_helper
+
 
 # Note: "*_hex" functions are aliases for "(un)hexlify"
 b2a_functions = ['b2a_base64', 'b2a_hex', 'b2a_hqx', 'b2a_qp', 'b2a_uu',
@@ -37,7 +38,7 @@ class BinASCIITest(unittest.TestCase):
             self.assertTrue(hasattr(getattr(binascii, name), '__call__'))
             self.assertRaises(TypeError, getattr(binascii, name))
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_returned_value(self):
         # Limit to the minimum of all limits (b2a_uu)
         MAX_ALL = 45
@@ -181,7 +182,7 @@ class BinASCIITest(unittest.TestCase):
         with self.assertRaises(TypeError):
             binascii.b2a_uu(b"", True)
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_crc_hqx(self):
         crc = binascii.crc_hqx(self.type2test(b"Test the CRC-32 of"), 0)
         crc = binascii.crc_hqx(self.type2test(b" this string."), crc)
@@ -201,7 +202,7 @@ class BinASCIITest(unittest.TestCase):
 
         self.assertRaises(TypeError, binascii.crc32)
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_hqx(self):
         # Perform binhex4 style RLE-compression
         # Then calculate the hexbin4 binary-to-ASCII translation
@@ -212,7 +213,7 @@ class BinASCIITest(unittest.TestCase):
         res = binascii.rledecode_hqx(b)
         self.assertEqual(res, self.rawdata)
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_rle(self):
         # test repetition with a repetition longer than the limit of 255
         data = (b'a' * 100 + b'b' + b'c' * 300)
@@ -359,7 +360,7 @@ class BinASCIITest(unittest.TestCase):
         self.assertEqual(b2a_qp(type2test(b'a.\n')), b'a.\n')
         self.assertEqual(b2a_qp(type2test(b'.a')[:-1]), b'=2E')
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_empty_string(self):
         # A test for SF bug #1022953.  Make sure SystemError is not raised.
         empty = self.type2test(b'')
@@ -384,7 +385,7 @@ class BinASCIITest(unittest.TestCase):
         # crc_hqx needs 2 arguments
         self.assertRaises(TypeError, binascii.crc_hqx, "test", 0)
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_unicode_a2b(self):
         # Unicode strings are accepted by a2b_* functions.
         MAX_ALL = 45
diff --git a/Lib/test/test_bisect.py b/Lib/test/test_bisect.py
index 580a963..fc7990d 100644
--- a/Lib/test/test_bisect.py
+++ b/Lib/test/test_bisect.py
@@ -1,10 +1,11 @@
 import sys
 import unittest
-from test import support
+from test.support import import_helper
 from collections import UserList
 
-py_bisect = support.import_fresh_module('bisect', blocked=['_bisect'])
-c_bisect = support.import_fresh_module('bisect', fresh=['_bisect'])
+
+py_bisect = import_helper.import_fresh_module('bisect', blocked=['_bisect'])
+c_bisect = import_helper.import_fresh_module('bisect', fresh=['_bisect'])
 
 class Range(object):
     """A trivial range()-like object that has an insert() method."""
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 3bc1a3e..edb4ec0 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -26,10 +26,10 @@ from textwrap import dedent
 from types import AsyncGeneratorType, FunctionType
 from operator import neg
 from test import support
-from test.support import (
-    EnvironmentVarGuard, TESTFN, check_warnings, swap_attr, unlink,
-    maybe_get_event_loop_policy)
+from test.support import (swap_attr, maybe_get_event_loop_policy)
+from test.support.os_helper import (EnvironmentVarGuard, TESTFN, unlink)
 from test.support.script_helper import assert_python_ok
+from test.support.warnings_helper import check_warnings
 from unittest.mock import MagicMock, patch
 try:
     import pty, signal
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
index 7da967e..a182b14 100644
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -1,8 +1,9 @@
 from test import support
+from test.support import import_helper
 from test.support import threading_helper
 
 # Skip tests if _multiprocessing wasn't built.
-support.import_module('_multiprocessing')
+import_helper.import_module('_multiprocessing')
 # Skip tests if sem_open implementation is broken.
 support.skip_if_broken_multiprocessing_synchronize()
 
diff --git a/Lib/test/test_configparser.py b/Lib/test/test_configparser.py
index f16da11..230ffc1 100644
--- a/Lib/test/test_configparser.py
+++ b/Lib/test/test_configparser.py
@@ -8,6 +8,7 @@ import unittest
 import warnings
 
 from test import support
+from test.support import os_helper
 
 
 class SortedDict(collections.UserDict):
@@ -1063,17 +1064,17 @@ class MultilineValuesTestCase(BasicTestCase, unittest.TestCase):
             cf.add_section(s)
             for j in range(10):
                 cf.set(s, 'lovely_spam{}'.format(j), self.wonderful_spam)
-        with open(support.TESTFN, 'w') as f:
+        with open(os_helper.TESTFN, 'w') as f:
             cf.write(f)
 
     def tearDown(self):
-        os.unlink(support.TESTFN)
+        os.unlink(os_helper.TESTFN)
 
     def test_dominating_multiline_values(self):
         # We're reading from file because this is where the code changed
         # during performance updates in Python 3.2
         cf_from_file = self.newconfig()
-        with open(support.TESTFN) as f:
+        with open(os_helper.TESTFN) as f:
             cf_from_file.read_file(f)
         self.assertEqual(cf_from_file.get('section8', 'lovely_spam4'),
                          self.wonderful_spam.replace('\t\n', '\n'))
diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
index 8d1e069..145adb6 100644
--- a/Lib/test/test_coroutines.py
+++ b/Lib/test/test_coroutines.py
@@ -7,6 +7,8 @@ import types
 import unittest
 import warnings
 from test import support
+from test.support import import_helper
+from test.support import warnings_helper
 from test.support.script_helper import assert_python_ok
 
 
@@ -2117,7 +2119,7 @@ class CoroAsyncIOCompatTest(unittest.TestCase):
     def test_asyncio_1(self):
         # asyncio cannot be imported when Python is compiled without thread
         # support
-        asyncio = support.import_module('asyncio')
+        asyncio = import_helper.import_module('asyncio')
 
         class MyException(Exception):
             pass
@@ -2258,8 +2260,9 @@ class OriginTrackingTest(unittest.TestCase):
         try:
             warnings._warn_unawaited_coroutine = lambda coro: 1/0
             with support.catch_unraisable_exception() as cm, \
-                 support.check_warnings((r'coroutine .* was never awaited',
-                                         RuntimeWarning)):
+                 warnings_helper.check_warnings(
+                         (r'coroutine .* was never awaited',
+                          RuntimeWarning)):
                 # only store repr() to avoid keeping the coroutine alive
                 coro = corofn()
                 coro_repr = repr(coro)
@@ -2272,8 +2275,8 @@ class OriginTrackingTest(unittest.TestCase):
                 self.assertEqual(cm.unraisable.exc_type, ZeroDivisionError)
 
             del warnings._warn_unawaited_coroutine
-            with support.check_warnings((r'coroutine .* was never awaited',
-                                         RuntimeWarning)):
+            with warnings_helper.check_warnings(
+                    (r'coroutine .* was never awaited', RuntimeWarning)):
                 corofn()
                 support.gc_collect()
 
diff --git a/Lib/test/test_curses.py b/Lib/test/test_curses.py
index 5e619d1..2c6d14c 100644
--- a/Lib/test/test_curses.py
+++ b/Lib/test/test_curses.py
@@ -15,7 +15,8 @@ import sys
 import tempfile
 import unittest
 
-from test.support import requires, import_module, verbose, SaveSignals
+from test.support import requires, verbose, SaveSignals
+from test.support.import_helper import import_module
 
 # Optionally test curses module.  This currently requires that the
 # 'curses' resource be given on the regrtest command line using the -u
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index d659f36..bdb9f02 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -1,7 +1,9 @@
 import unittest
 import sys
 
-from test.support import import_fresh_module, run_unittest
+from test.support import run_unittest
+from test.support.import_helper import import_fresh_module
+
 
 TESTS = 'test.datetimetester'
 
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 5400f25..8f34c18 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -1,5 +1,6 @@
-from test.support import (TESTFN, import_module, unlink,
-                          requires, _2G, _4G, gc_collect, cpython_only)
+from test.support import (requires, _2G, _4G, gc_collect, cpython_only)
+from test.support.import_helper import import_module
+from test.support.os_helper import TESTFN, unlink
 import unittest
 import os
 import re
diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
index 45553a6..c656790 100644
--- a/Lib/test/test_signal.py
+++ b/Lib/test/test_signal.py
@@ -9,6 +9,7 @@ import sys
 import time
 import unittest
 from test import support
+from test.support import os_helper
 from test.support.script_helper import assert_python_ok, spawn_python
 try:
     import _testcapi
@@ -154,7 +155,7 @@ class WakeupFDTests(unittest.TestCase):
             signal.set_wakeup_fd(signal.SIGINT, False)
 
     def test_invalid_fd(self):
-        fd = support.make_bad_fd()
+        fd = os_helper.make_bad_fd()
         self.assertRaises((ValueError, OSError),
                           signal.set_wakeup_fd, fd)
 
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index de778d3..26eec96 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -4,8 +4,11 @@ import sys
 import unittest
 import unittest.mock
 from test import support
+from test.support import import_helper
+from test.support import os_helper
 from test.support import socket_helper
 from test.support import threading_helper
+from test.support import warnings_helper
 import socket
 import select
 import time
@@ -27,7 +30,7 @@ try:
 except ImportError:
     ctypes = None
 
-ssl = support.import_module("ssl")
+ssl = import_helper.import_module("ssl")
 
 from ssl import TLSVersion, _TLSContentType, _TLSMessageType
 
@@ -571,7 +574,7 @@ class BasicSocketTests(unittest.TestCase):
         s = socket.socket(socket.AF_INET)
         ss = test_wrap_socket(s)
         wr = weakref.ref(ss)
-        with support.check_warnings(("", ResourceWarning)):
+        with warnings_helper.check_warnings(("", ResourceWarning)):
             del ss
         self.assertEqual(wr(), None)
 
@@ -893,7 +896,7 @@ class BasicSocketTests(unittest.TestCase):
         self.assertEqual(len(paths), 6)
         self.assertIsInstance(paths, ssl.DefaultVerifyPaths)
 
-        with support.EnvironmentVarGuard() as env:
+        with os_helper.EnvironmentVarGuard() as env:
             env["SSL_CERT_DIR"] = CAPATH
             env["SSL_CERT_FILE"] = CERTFILE
             paths = ssl.get_default_verify_paths()
@@ -1605,7 +1608,7 @@ class ContextTests(unittest.TestCase):
     @unittest.skipIf(IS_LIBRESSL, "LibreSSL doesn't support env vars")
     def test_load_default_certs_env(self):
         ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
-        with support.EnvironmentVarGuard() as env:
+        with os_helper.EnvironmentVarGuard() as env:
             env["SSL_CERT_DIR"] = CAPATH
             env["SSL_CERT_FILE"] = CERTFILE
             ctx.load_default_certs()
@@ -1619,7 +1622,7 @@ class ContextTests(unittest.TestCase):
         stats = ctx.cert_store_stats()
 
         ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
-        with support.EnvironmentVarGuard() as env:
+        with os_helper.EnvironmentVarGuard() as env:
             env["SSL_CERT_DIR"] = CAPATH
             env["SSL_CERT_FILE"] = CERTFILE
             ctx.load_default_certs()
@@ -4266,9 +4269,9 @@ class ThreadedTests(unittest.TestCase):
 
     def test_sendfile(self):
         TEST_DATA = b"x" * 512
-        with open(support.TESTFN, 'wb') as f:
+        with open(os_helper.TESTFN, 'wb') as f:
             f.write(TEST_DATA)
-        self.addCleanup(support.unlink, support.TESTFN)
+        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
         context = ssl.SSLContext(ssl.PROTOCOL_TLS)
         context.verify_mode = ssl.CERT_REQUIRED
         context.load_verify_locations(SIGNING_CA)
@@ -4277,7 +4280,7 @@ class ThreadedTests(unittest.TestCase):
         with server:
             with context.wrap_socket(socket.socket()) as s:
                 s.connect((HOST, server.port))
-                with open(support.TESTFN, 'rb') as file:
+                with open(os_helper.TESTFN, 'rb') as file:
                     s.sendfile(file)
                     self.assertEqual(s.recv(1024), TEST_DATA)
 
@@ -4603,21 +4606,21 @@ requires_keylog = unittest.skipUnless(
 
 class TestSSLDebug(unittest.TestCase):
 
-    def keylog_lines(self, fname=support.TESTFN):
+    def keylog_lines(self, fname=os_helper.TESTFN):
         with open(fname) as f:
             return len(list(f))
 
     @requires_keylog
     @unittest.skipIf(Py_DEBUG_WIN32, "Avoid mixing debug/release CRT on Windows")
     def test_keylog_defaults(self):
-        self.addCleanup(support.unlink, support.TESTFN)
+        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
         ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
         self.assertEqual(ctx.keylog_filename, None)
 
-        self.assertFalse(os.path.isfile(support.TESTFN))
-        ctx.keylog_filename = support.TESTFN
-        self.assertEqual(ctx.keylog_filename, support.TESTFN)
-        self.assertTrue(os.path.isfile(support.TESTFN))
+        self.assertFalse(os.path.isfile(os_helper.TESTFN))
+        ctx.keylog_filename = os_helper.TESTFN
+        self.assertEqual(ctx.keylog_filename, os_helper.TESTFN)
+        self.assertTrue(os.path.isfile(os_helper.TESTFN))
         self.assertEqual(self.keylog_lines(), 1)
 
         ctx.keylog_filename = None
@@ -4626,7 +4629,7 @@ class TestSSLDebug(unittest.TestCase):
         with self.assertRaises((IsADirectoryError, PermissionError)):
             # Windows raises PermissionError
             ctx.keylog_filename = os.path.dirname(
-                os.path.abspath(support.TESTFN))
+                os.path.abspath(os_helper.TESTFN))
 
         with self.assertRaises(TypeError):
             ctx.keylog_filename = 1
@@ -4634,10 +4637,10 @@ class TestSSLDebug(unittest.TestCase):
     @requires_keylog
     @unittest.skipIf(Py_DEBUG_WIN32, "Avoid mixing debug/release CRT on Windows")
     def test_keylog_filename(self):
-        self.addCleanup(support.unlink, support.TESTFN)
+        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
         client_context, server_context, hostname = testing_context()
 
-        client_context.keylog_filename = support.TESTFN
+        client_context.keylog_filename = os_helper.TESTFN
         server = ThreadedEchoServer(context=server_context, chatty=False)
         with server:
             with client_context.wrap_socket(socket.socket(),
@@ -4647,7 +4650,7 @@ class TestSSLDebug(unittest.TestCase):
         self.assertEqual(self.keylog_lines(), 6)
 
         client_context.keylog_filename = None
-        server_context.keylog_filename = support.TESTFN
+        server_context.keylog_filename = os_helper.TESTFN
         server = ThreadedEchoServer(context=server_context, chatty=False)
         with server:
             with client_context.wrap_socket(socket.socket(),
@@ -4655,8 +4658,8 @@ class TestSSLDebug(unittest.TestCase):
                 s.connect((HOST, server.port))
         self.assertGreaterEqual(self.keylog_lines(), 11)
 
-        client_context.keylog_filename = support.TESTFN
-        server_context.keylog_filename = support.TESTFN
+        client_context.keylog_filename = os_helper.TESTFN
+        server_context.keylog_filename = os_helper.TESTFN
         server = ThreadedEchoServer(context=server_context, chatty=False)
         with server:
             with client_context.wrap_socket(socket.socket(),
@@ -4672,19 +4675,19 @@ class TestSSLDebug(unittest.TestCase):
                      "test is not compatible with ignore_environment")
     @unittest.skipIf(Py_DEBUG_WIN32, "Avoid mixing debug/release CRT on Windows")
     def test_keylog_env(self):
-        self.addCleanup(support.unlink, support.TESTFN)
+        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
         with unittest.mock.patch.dict(os.environ):
-            os.environ['SSLKEYLOGFILE'] = support.TESTFN
-            self.assertEqual(os.environ['SSLKEYLOGFILE'], support.TESTFN)
+            os.environ['SSLKEYLOGFILE'] = os_helper.TESTFN
+            self.assertEqual(os.environ['SSLKEYLOGFILE'], os_helper.TESTFN)
 
             ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
             self.assertEqual(ctx.keylog_filename, None)
 
             ctx = ssl.create_default_context()
-            self.assertEqual(ctx.keylog_filename, support.TESTFN)
+            self.assertEqual(ctx.keylog_filename, os_helper.TESTFN)
 
             ctx = ssl._create_stdlib_context()
-            self.assertEqual(ctx.keylog_filename, support.TESTFN)
+            self.assertEqual(ctx.keylog_filename, os_helper.TESTFN)
 
     def test_msg_callback(self):
         client_context, server_context, hostname = testing_context()
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index 3ddeb97..4bf7248 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -11,6 +11,7 @@ import unittest.mock
 import tarfile
 
 from test import support
+from test.support import os_helper
 from test.support import script_helper
 
 # Check for our compression modules.
@@ -30,7 +31,7 @@ except ImportError:
 def sha256sum(data):
     return sha256(data).hexdigest()
 
-TEMPDIR = os.path.abspath(support.TESTFN) + "-tardir"
+TEMPDIR = os.path.abspath(os_helper.TESTFN) + "-tardir"
 tarextdir = TEMPDIR + '-extract-test'
 tarname = support.findfile("testtar.tar")
 gzipname = os.path.join(TEMPDIR, "testtar.tar.gz")
@@ -575,21 +576,21 @@ class MiscReadTestBase(CommonReadTest):
 
     @unittest.skipUnless(hasattr(os, "link"),
                          "Missing hardlink implementation")
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_extract_hardlink(self):
         # Test hardlink extraction (e.g. bug #857297).
         with tarfile.open(tarname, errorlevel=1, encoding="iso8859-1") as tar:
             tar.extract("ustar/regtype", TEMPDIR)
-            self.addCleanup(support.unlink, os.path.join(TEMPDIR, "ustar/regtype"))
+            self.addCleanup(os_helper.unlink, os.path.join(TEMPDIR, "ustar/regtype"))
 
             tar.extract("ustar/lnktype", TEMPDIR)
-            self.addCleanup(support.unlink, os.path.join(TEMPDIR, "ustar/lnktype"))
+            self.addCleanup(os_helper.unlink, os.path.join(TEMPDIR, "ustar/lnktype"))
             with open(os.path.join(TEMPDIR, "ustar/lnktype"), "rb") as f:
                 data = f.read()
             self.assertEqual(sha256sum(data), sha256_regtype)
 
             tar.extract("ustar/symtype", TEMPDIR)
-            self.addCleanup(support.unlink, os.path.join(TEMPDIR, "ustar/symtype"))
+            self.addCleanup(os_helper.unlink, os.path.join(TEMPDIR, "ustar/symtype"))
             with open(os.path.join(TEMPDIR, "ustar/symtype"), "rb") as f:
                 data = f.read()
             self.assertEqual(sha256sum(data), sha256_regtype)
@@ -622,7 +623,7 @@ class MiscReadTestBase(CommonReadTest):
                 self.assertEqual(tarinfo.mtime, file_mtime, errmsg)
         finally:
             tar.close()
-            support.rmtree(DIR)
+            os_helper.rmtree(DIR)
 
     def test_extract_directory(self):
         dirtype = "ustar/dirtype"
@@ -637,11 +638,11 @@ class MiscReadTestBase(CommonReadTest):
                 if sys.platform != "win32":
                     self.assertEqual(os.stat(extracted).st_mode & 0o777, 0o755)
         finally:
-            support.rmtree(DIR)
+            os_helper.rmtree(DIR)
 
     def test_extractall_pathlike_name(self):
         DIR = pathlib.Path(TEMPDIR) / "extractall"
-        with support.temp_dir(DIR), \
+        with os_helper.temp_dir(DIR), \
              tarfile.open(tarname, encoding="iso8859-1") as tar:
             directories = [t for t in tar if t.isdir()]
             tar.extractall(DIR, directories)
@@ -652,7 +653,7 @@ class MiscReadTestBase(CommonReadTest):
     def test_extract_pathlike_name(self):
         dirtype = "ustar/dirtype"
         DIR = pathlib.Path(TEMPDIR) / "extractall"
-        with support.temp_dir(DIR), \
+        with os_helper.temp_dir(DIR), \
              tarfile.open(tarname, encoding="iso8859-1") as tar:
             tarinfo = tar.getmember(dirtype)
             tar.extract(tarinfo, path=DIR)
@@ -676,7 +677,7 @@ class MiscReadTestBase(CommonReadTest):
             else:
                 self.fail("ReadError not raised")
         finally:
-            support.unlink(empty)
+            os_helper.unlink(empty)
 
     def test_parallel_iteration(self):
         # Issue #16601: Restarting iteration over tarfile continued
@@ -1026,7 +1027,7 @@ class GNUReadTest(LongnameTest, ReadTest, unittest.TestCase):
                 fobj.write(b'x' * 4096)
                 fobj.truncate()
             s = os.stat(name)
-            support.unlink(name)
+            os_helper.unlink(name)
             return (s.st_blocks * 512 < s.st_size)
         else:
             return False
@@ -1171,7 +1172,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             finally:
                 tar.close()
         finally:
-            support.rmdir(path)
+            os_helper.rmdir(path)
 
     # mock the following:
     #  os.listdir: so we know that files are in the wrong order
@@ -1193,9 +1194,9 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             finally:
                 tar.close()
         finally:
-            support.unlink(os.path.join(path, "1"))
-            support.unlink(os.path.join(path, "2"))
-            support.rmdir(path)
+            os_helper.unlink(os.path.join(path, "1"))
+            os_helper.unlink(os.path.join(path, "2"))
+            os_helper.rmdir(path)
 
     def test_gettarinfo_pathlike_name(self):
         with tarfile.open(tmpname, self.mode) as tar:
@@ -1229,10 +1230,10 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             finally:
                 tar.close()
         finally:
-            support.unlink(target)
-            support.unlink(link)
+            os_helper.unlink(target)
+            os_helper.unlink(link)
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_symlink_size(self):
         path = os.path.join(TEMPDIR, "symlink")
         os.symlink("link_target", path)
@@ -1244,7 +1245,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             finally:
                 tar.close()
         finally:
-            support.unlink(path)
+            os_helper.unlink(path)
 
     def test_add_self(self):
         # Test for #1257255.
@@ -1257,7 +1258,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             self.assertEqual(tar.getnames(), [],
                     "added the archive to itself")
 
-            with support.change_cwd(TEMPDIR):
+            with os_helper.change_cwd(TEMPDIR):
                 tar.add(dstname)
             self.assertEqual(tar.getnames(), [],
                     "added the archive to itself")
@@ -1270,7 +1271,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
         try:
             for name in ("foo", "bar", "baz"):
                 name = os.path.join(tempdir, name)
-                support.create_empty_file(name)
+                os_helper.create_empty_file(name)
 
             def filter(tarinfo):
                 if os.path.basename(tarinfo.name) == "bar":
@@ -1298,7 +1299,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             finally:
                 tar.close()
         finally:
-            support.rmtree(tempdir)
+            os_helper.rmtree(tempdir)
 
     # Guarantee that stored pathnames are not modified. Don't
     # remove ./ or ../ or double slashes. Still make absolute
@@ -1309,7 +1310,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
         # and compare the stored name with the original.
         foo = os.path.join(TEMPDIR, "foo")
         if not dir:
-            support.create_empty_file(foo)
+            os_helper.create_empty_file(foo)
         else:
             os.mkdir(foo)
 
@@ -1326,14 +1327,14 @@ class WriteTest(WriteTestBase, unittest.TestCase):
             tar.close()
 
         if not dir:
-            support.unlink(foo)
+            os_helper.unlink(foo)
         else:
-            support.rmdir(foo)
+            os_helper.rmdir(foo)
 
         self.assertEqual(t.name, cmp_path or path.replace(os.sep, "/"))
 
 
-    @support.skip_unless_symlink
+    @os_helper.skip_unless_symlink
     def test_extractall_symlinks(self):
         # Test if extractall works properly when tarfile contains symlinks
         tempdir = os.path.join(TEMPDIR, "testsymlinks")
@@ -1356,8 +1357,8 @@ class WriteTest(WriteTestBase, unittest.TestCase):
                 except OSError:
                     self.fail("extractall failed with symlinked files")
         finally:
-            support.unlink(temparchive)
-            support.rmtree(tempdir)
+            os_helper.unlink(temparchive)
+            os_helper.rmtree(tempdir)
 
     def test_pathnames(self):
         self._test_pathname("foo")
@@ -1385,7 +1386,7 @@ class WriteTest(WriteTestBase, unittest.TestCase):
 
     def test_cwd(self):
         # Test adding the current working directory.
-        with support.change_cwd(TEMPDIR):
+        with os_helper.change_cwd(TEMPDIR):
             tar = tarfile.open(tmpname, self.mode)
             try:
                 tar.add(".")
@@ -1453,7 +1454,7 @@ class StreamWriteTest(WriteTestBase, unittest.TestCase):
         # Test for issue #8464: Create files with correct
         # permissions.
         if os.path.exists(tmpname):
-            support.unlink(tmpname)
+            os_helper.unlink(tmpname)
 
         original_umask = os.umask(0o022)
         try:
@@ -1599,7 +1600,7 @@ class DeviceHeaderTest(WriteTestBase, unittest.TestCase):
             self.assertEqual(buf_blk[device_headers], b"0000000\0" * 2)
             self.assertEqual(buf_reg[device_headers], b"\0" * 16)
         finally:
-            support.rmtree(tempdir)
+            os_helper.rmtree(tempdir)
 
 
 class CreateTest(WriteTestBase, unittest.TestCase):
@@ -1609,7 +1610,7 @@ class CreateTest(WriteTestBase, unittest.TestCase):
     file_path = os.path.join(TEMPDIR, "spameggs42")
 
     def setUp(self):
-        support.unlink(tmpname)
+        os_helper.unlink(tmpname)
 
     @classmethod
     def setUpClass(cls):
@@ -1618,7 +1619,7 @@ class CreateTest(WriteTestBase, unittest.TestCase):
 
     @classmethod
     def tearDownClass(cls):
-        support.unlink(cls.file_path)
+        os_helper.unlink(cls.file_path)
 
     def test_create(self):
         with tarfile.open(tmpname, self.mode) as tobj:
@@ -1733,8 +1734,8 @@ class HardlinkTest(unittest.TestCase):
 
     def tearDown(self):
         self.tar.close()
-        support.unlink(self.foo)
-        support.unlink(self.bar)
+        os_helper.unlink(self.foo)
+        os_helper.unlink(self.bar)
 
     def test_add_twice(self):
         # The same name will be added as a REGTYPE every
@@ -2043,7 +2044,7 @@ class AppendTestBase:
     def setUp(self):
         self.tarname = tmpname
         if os.path.exists(self.tarname):
-            support.unlink(self.tarname)
+            os_helper.unlink(self.tarname)
 
     def _create_testtar(self, mode="w:"):
         with tarfile.open(tarname, encoding="iso8859-1") as src:
@@ -2288,7 +2289,7 @@ class CommandLineTest(unittest.TestCase):
         files = [support.findfile('tokenize_tests.txt'),
                  support.findfile('tokenize_tests-no-coding-cookie-'
                                   'and-utf8-bom-sig-only.txt')]
-        self.addCleanup(support.unlink, tar_name)
+        self.addCleanup(os_helper.unlink, tar_name)
         with tarfile.open(tar_name, 'w') as tf:
             for tardata in files:
                 tf.add(tardata, arcname=os.path.basename(tardata))
@@ -2334,7 +2335,7 @@ class CommandLineTest(unittest.TestCase):
                     self.assertEqual(out, b'')
                     self.assertEqual(rc, 1)
                 finally:
-                    support.unlink(tmpname)
+                    os_helper.unlink(tmpname)
 
     def test_list_command(self):
         for tar_name in testtarnames:
@@ -2376,7 +2377,7 @@ class CommandLineTest(unittest.TestCase):
                 with tarfile.open(tmpname) as tar:
                     tar.getmembers()
             finally:
-                support.unlink(tmpname)
+                os_helper.unlink(tmpname)
 
     def test_create_command_verbose(self):
         files = [support.findfile('tokenize_tests.txt'),
@@ -2390,7 +2391,7 @@ class CommandLineTest(unittest.TestCase):
                 with tarfile.open(tmpname) as tar:
                     tar.getmembers()
             finally:
-                support.unlink(tmpname)
+                os_helper.unlink(tmpname)
 
     def test_create_command_dotless_filename(self):
         files = [support.findfile('tokenize_tests.txt')]
@@ -2400,7 +2401,7 @@ class CommandLineTest(unittest.TestCase):
             with tarfile.open(dotlessname) as tar:
                 tar.getmembers()
         finally:
-            support.unlink(dotlessname)
+            os_helper.unlink(dotlessname)
 
     def test_create_command_dot_started_filename(self):
         tar_name = os.path.join(TEMPDIR, ".testtar")
@@ -2411,7 +2412,7 @@ class CommandLineTest(unittest.TestCase):
             with tarfile.open(tar_name) as tar:
                 tar.getmembers()
         finally:
-            support.unlink(tar_name)
+            os_helper.unlink(tar_name)
 
     def test_create_command_compressed(self):
         files = [support.findfile('tokenize_tests.txt'),
@@ -2426,41 +2427,41 @@ class CommandLineTest(unittest.TestCase):
                 with filetype.taropen(tar_name) as tar:
                     tar.getmembers()
             finally:
-                support.unlink(tar_name)
+                os_helper.unlink(tar_name)
 
     def test_extract_command(self):
         self.make_simple_tarfile(tmpname)
         for opt in '-e', '--extract':
             try:
-                with support.temp_cwd(tarextdir):
+                with os_helper.temp_cwd(tarextdir):
                     out = self.tarfilecmd(opt, tmpname)
                 self.assertEqual(out, b'')
             finally:
-                support.rmtree(tarextdir)
+                os_helper.rmtree(tarextdir)
 
     def test_extract_command_verbose(self):
         self.make_simple_tarfile(tmpname)
         for opt in '-v', '--verbose':
             try:
-                with support.temp_cwd(tarextdir):
+                with os_helper.temp_cwd(tarextdir):
                     out = self.tarfilecmd(opt, '-e', tmpname,
                                           PYTHONIOENCODING='utf-8')
                 self.assertIn(b' file is extracted.', out)
             finally:
-                support.rmtree(tarextdir)
+                os_helper.rmtree(tarextdir)
 
     def test_extract_command_different_directory(self):
         self.make_simple_tarfile(tmpname)
         try:
-            with support.temp_cwd(tarextdir):
+            with os_helper.temp_cwd(tarextdir):
                 out = self.tarfilecmd('-e', tmpname, 'spamdir')
             self.assertEqual(out, b'')
         finally:
-            support.rmtree(tarextdir)
+            os_helper.rmtree(tarextdir)
 
     def test_extract_command_invalid_file(self):
         zipname = support.findfile('zipdir.zip')
-        with support.temp_cwd(tarextdir):
+        with os_helper.temp_cwd(tarextdir):
             rc, out, err = self.tarfilecmd_failure('-e', zipname)
         self.assertIn(b' is not a tar archive.', err)
         self.assertEqual(out, b'')
@@ -2723,7 +2724,7 @@ class NumericOwnerTest(unittest.TestCase):
 
 
 def setUpModule():
-    support.unlink(TEMPDIR)
+    os_helper.unlink(TEMPDIR)
     os.makedirs(TEMPDIR)
 
     global testtarnames
@@ -2734,14 +2735,14 @@ def setUpModule():
     # Create compressed tarfiles.
     for c in GzipTest, Bz2Test, LzmaTest:
         if c.open:
-            support.unlink(c.tarname)
+            os_helper.unlink(c.tarname)
             testtarnames.append(c.tarname)
             with c.open(c.tarname, "wb") as tar:
                 tar.write(data)
 
 def tearDownModule():
     if os.path.exists(TEMPDIR):
-        support.rmtree(TEMPDIR)
+        os_helper.rmtree(TEMPDIR)
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index ad82e30..47e131a 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -4,7 +4,8 @@ Tests for the threading module.
 
 import test.support
 from test.support import threading_helper
-from test.support import verbose, import_module, cpython_only
+from test.support import verbose, cpython_only
+from test.support.import_helper import import_module
 from test.support.script_helper import assert_python_ok, assert_python_failure
 
 import random
diff --git a/Lib/test/test_trace.py b/Lib/test/test_trace.py
index c03982b..7547855 100644
--- a/Lib/test/test_trace.py
+++ b/Lib/test/test_trace.py
@@ -1,6 +1,7 @@
 import os
 import sys
-from test.support import TESTFN, TESTFN_UNICODE, FS_NONASCII, rmtree, unlink, captured_stdout
+from test.support import captured_stdout
+from test.support.os_helper import (TESTFN, rmtree, unlink)
 from test.support.script_helper import assert_python_ok, assert_python_failure
 import textwrap
 import unittest
diff --git a/Lib/test/test_tracemalloc.py b/Lib/test/test_tracemalloc.py
index c5ae4e6..a0037f8 100644
--- a/Lib/test/test_tracemalloc.py
+++ b/Lib/test/test_tracemalloc.py
@@ -7,6 +7,7 @@ from unittest.mock import patch
 from test.support.script_helper import (assert_python_ok, assert_python_failure,
                                         interpreter_requires_environment)
 from test import support
+from test.support import os_helper
 
 try:
     import _testcapi
@@ -287,11 +288,11 @@ class TestTracemallocEnabled(unittest.TestCase):
         self.assertGreater(snapshot.traces[1].traceback.total_nframe, 10)
 
         # write on disk
-        snapshot.dump(support.TESTFN)
-        self.addCleanup(support.unlink, support.TESTFN)
+        snapshot.dump(os_helper.TESTFN)
+        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
 
         # load from disk
-        snapshot2 = tracemalloc.Snapshot.load(support.TESTFN)
+        snapshot2 = tracemalloc.Snapshot.load(os_helper.TESTFN)
         self.assertEqual(snapshot2.traces, snapshot.traces)
 
         # tracemalloc must be tracing memory allocations to take a snapshot
@@ -306,11 +307,11 @@ class TestTracemallocEnabled(unittest.TestCase):
         # take a snapshot with a new attribute
         snapshot = tracemalloc.take_snapshot()
         snapshot.test_attr = "new"
-        snapshot.dump(support.TESTFN)
-        self.addCleanup(support.unlink, support.TESTFN)
+        snapshot.dump(os_helper.TESTFN)
+        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
 
         # load() should recreate the attribute
-        snapshot2 = tracemalloc.Snapshot.load(support.TESTFN)
+        snapshot2 = tracemalloc.Snapshot.load(os_helper.TESTFN)
         self.assertEqual(snapshot2.test_attr, "new")
 
     def fork_child(self):
diff --git a/Lib/test/test_xml_etree_c.py b/Lib/test/test_xml_etree_c.py
index e26e171..e68613b 100644
--- a/Lib/test/test_xml_etree_c.py
+++ b/Lib/test/test_xml_etree_c.py
@@ -2,7 +2,7 @@
 import io
 import struct
 from test import support
-from test.support import import_fresh_module
+from test.support.import_helper import import_fresh_module
 import types
 import unittest
 
diff --git a/Lib/unittest/test/test_discovery.py b/Lib/unittest/test/test_discovery.py
index 16e081e..9d502c5 100644
--- a/Lib/unittest/test/test_discovery.py
+++ b/Lib/unittest/test/test_discovery.py
@@ -5,6 +5,7 @@ import sys
 import types
 import pickle
 from test import support
+from test.support import import_helper
 import test.test_importlib.util
 
 import unittest
@@ -848,7 +849,7 @@ class TestDiscovery(unittest.TestCase):
 
         with unittest.mock.patch('builtins.__import__', _import):
             # Since loader.discover() can modify sys.path, restore it when done.
-            with support.DirsOnSysPath():
+            with import_helper.DirsOnSysPath():
                 # Make sure to remove 'package' from sys.modules when done.
                 with test.test_importlib.util.uncache('package'):
                     suite = loader.discover('package')
@@ -865,7 +866,7 @@ class TestDiscovery(unittest.TestCase):
 
         with unittest.mock.patch('builtins.__import__', _import):
             # Since loader.discover() can modify sys.path, restore it when done.
-            with support.DirsOnSysPath():
+            with import_helper.DirsOnSysPath():
                 # Make sure to remove 'package' from sys.modules when done.
                 with test.test_importlib.util.uncache('package'):
                     with self.assertRaises(TypeError) as cm:
diff --git a/Lib/unittest/test/test_result.py b/Lib/unittest/test/test_result.py
index 0ffb87b..a4af67b 100644
--- a/Lib/unittest/test/test_result.py
+++ b/Lib/unittest/test/test_result.py
@@ -2,7 +2,7 @@ import io
 import sys
 import textwrap
 
-from test import support
+from test.support import warnings_helper
 
 import traceback
 import unittest
@@ -458,8 +458,8 @@ OldResult = type('OldResult', (object,), classDict)
 class Test_OldTestResult(unittest.TestCase):
 
     def assertOldResultWarning(self, test, failures):
-        with support.check_warnings(("TestResult has no add.+ method,",
-                                     RuntimeWarning)):
+        with warnings_helper.check_warnings(
+                ("TestResult has no add.+ method,", RuntimeWarning)):
             result = OldResult()
             test.run(result)
             self.assertEqual(len(result.failures), failures)