bpo-45229: Remove test_main in many tests (GH-28405)

Instead of explicitly enumerate test classes for run_unittest()
use the unittest ability to discover tests. This also makes these
tests discoverable and runnable with unittest.

load_tests() can be used for dynamic generating tests and adding
doctests. setUpModule(), tearDownModule() and addModuleCleanup()
can be used for running code before and after all module tests.

59 files changed, 205 insertions, 475 deletions

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index 04516a5..bc40bba 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -695,9 +695,8 @@ def check_sizeof(test, o, size):
 # Decorator for running a function in a different locale, correctly resetting
 # it afterwards.
 
+@contextlib.contextmanager
 def run_with_locale(catstr, *locales):
-    def decorator(func):
-        def inner(*args, **kwds):
             try:
                 import locale
                 category = getattr(locale, catstr)
@@ -716,16 +715,11 @@ def run_with_locale(catstr, *locales):
                     except:
                         pass
 
-            # now run the function, resetting the locale on exceptions
             try:
-                return func(*args, **kwds)
+                yield
             finally:
                 if locale and orig_locale:
                     locale.setlocale(category, orig_locale)
-        inner.__name__ = func.__name__
-        inner.__doc__ = func.__doc__
-        return inner
-    return decorator
 
 #=======================================================================
 # Decorator for running a function in a specific timezone, correctly
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index 9926910..8babab3 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -12,7 +12,6 @@ import argparse
 
 from io import StringIO
 
-from test import support
 from test.support import os_helper
 from unittest import mock
 class StdIOBuffer(StringIO):
@@ -5416,13 +5415,11 @@ class TestExitOnError(TestCase):
             self.parser.parse_args('--integers a'.split())
 
 
-def test_main():
-    support.run_unittest(__name__)
+def tearDownModule():
     # Remove global references to avoid looking like we have refleaks.
     RFile.seen = {}
     WFile.seen = set()
 
 
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_bdb.py b/Lib/test/test_bdb.py
index 398698c..6ec5953 100644
--- a/Lib/test/test_bdb.py
+++ b/Lib/test/test_bdb.py
@@ -57,7 +57,6 @@ import importlib
 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
 
@@ -1193,13 +1192,6 @@ class IssuesTestCase(BaseTestCase):
             with TracerRun(self) as tracer:
                 tracer.runcall(tfunc_import)
 
-def test_main():
-    test.support.run_unittest(
-        StateTestCase,
-        RunTestCase,
-        BreakpointTestCase,
-        IssuesTestCase,
-    )
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_bigaddrspace.py b/Lib/test/test_bigaddrspace.py
index aa1f8ca..50272e9 100644
--- a/Lib/test/test_bigaddrspace.py
+++ b/Lib/test/test_bigaddrspace.py
@@ -92,10 +92,7 @@ class StrTest(unittest.TestCase):
             x = None
 
 
-def test_main():
-    support.run_unittest(BytesTest, StrTest)
-
 if __name__ == '__main__':
     if len(sys.argv) > 1:
         support.set_memlimit(sys.argv[1])
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_bigmem.py b/Lib/test/test_bigmem.py
index 6a244dd..859f153 100644
--- a/Lib/test/test_bigmem.py
+++ b/Lib/test/test_bigmem.py
@@ -1247,11 +1247,8 @@ class ListTest(unittest.TestCase):
         self.assertEqual(l[:10], [1] * 10)
         self.assertEqual(l[-10:], [5] * 10)
 
-def test_main():
-    support.run_unittest(StrTest, BytesTest, BytearrayTest,
-        TupleTest, ListTest)
 
 if __name__ == '__main__':
     if len(sys.argv) > 1:
         support.set_memlimit(sys.argv[1])
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_bool.py b/Lib/test/test_bool.py
index a3214c9..4b32aad 100644
--- a/Lib/test/test_bool.py
+++ b/Lib/test/test_bool.py
@@ -1,7 +1,6 @@
 # Test properties of bool promised by PEP 285
 
 import unittest
-from test import support
 from test.support import os_helper
 
 import os
@@ -370,8 +369,6 @@ class BoolTest(unittest.TestCase):
         f(x)
         self.assertGreaterEqual(x.count, 1)
 
-def test_main():
-    support.run_unittest(BoolTest)
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 7913beb..9965c1f 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -1005,15 +1005,9 @@ class OpenTest(BaseTest):
             self.assertEqual(f.readlines(), [text])
 
 
-def test_main():
-    support.run_unittest(
-        BZ2FileTest,
-        BZ2CompressorTest,
-        BZ2DecompressorTest,
-        CompressDecompressTest,
-        OpenTest,
-    )
+def tearDownModule():
     support.reap_children()
 
+
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_c_locale_coercion.py b/Lib/test/test_c_locale_coercion.py
index fcc8599..71f9347 100644
--- a/Lib/test/test_c_locale_coercion.py
+++ b/Lib/test/test_c_locale_coercion.py
@@ -427,12 +427,9 @@ class LocaleCoercionTests(_LocaleHandlingTestCase):
         self.assertEqual(cmd.stdout.rstrip(), loc)
 
 
-def test_main():
-    support.run_unittest(
-        LocaleConfigurationTests,
-        LocaleCoercionTests
-    )
+def tearDownModule():
     support.reap_children()
 
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_cmd_line.py b/Lib/test/test_cmd_line.py
index cbf9ff2..d93e98f 100644
--- a/Lib/test/test_cmd_line.py
+++ b/Lib/test/test_cmd_line.py
@@ -864,9 +864,10 @@ class SyntaxErrorTests(unittest.TestCase):
     def test_decoding_error_at_the_end_of_the_line(self):
         self.check_string(br"'\u1f'")
 
-def test_main():
-    support.run_unittest(CmdLineTest, IgnoreEnvironmentTest, SyntaxErrorTests)
+
+def tearDownModule():
     support.reap_children()
 
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_cmd_line_script.py b/Lib/test/test_cmd_line_script.py
index 874f4db..9fe748c 100644
--- a/Lib/test/test_cmd_line_script.py
+++ b/Lib/test/test_cmd_line_script.py
@@ -738,9 +738,9 @@ class CmdLineTest(unittest.TestCase):
         self.assertNotEqual(proc.returncode, 0)
 
 
-def test_main():
-    support.run_unittest(CmdLineTest)
+def tearDownModule():
     support.reap_children()
 
+
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py
index 1cd025e..e046577 100644
--- a/Lib/test/test_complex.py
+++ b/Lib/test/test_complex.py
@@ -789,8 +789,6 @@ class ComplexTest(unittest.TestCase):
         self.assertEqual(format(complex(INF, 1), 'F'), 'INF+1.000000j')
         self.assertEqual(format(complex(INF, -1), 'F'), 'INF-1.000000j')
 
-def test_main():
-    support.run_unittest(ComplexTest)
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
index eae98d6..b0df12c 100644
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -1515,16 +1515,10 @@ class FutureTests(BaseTestCase):
         self.assertEqual(f.exception(), e)
 
 
-_threads_key = None
-
 def setUpModule():
-    global _threads_key
-    _threads_key = threading_helper.threading_setup()
-
-
-def tearDownModule():
-    threading_helper.threading_cleanup(*_threads_key)
-    multiprocessing.util._cleanup_tests()
+    unittest.addModuleCleanup(multiprocessing.util._cleanup_tests)
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
 
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 71b6954..9b919e7 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -4996,8 +4996,11 @@ class DictProxyTests(unittest.TestCase):
             self.assertIn('{!r}: {!r}'.format(k, v), r)
 
 
-class PTypesLongInitTest(unittest.TestCase):
+class AAAPTypesLongInitTest(unittest.TestCase):
     # This is in its own TestCase so that it can be run before any other tests.
+    # (Hence the 'AAA' in the test class name: to make it the first
+    # item in a list sorted by name, like
+    # unittest.TestLoader.getTestCaseNames() does.)
     def test_pytype_long_ready(self):
         # Testing SF bug 551412 ...
 
@@ -5735,12 +5738,5 @@ class MroTest(unittest.TestCase):
             pass
 
 
-def test_main():
-    # Run all local test cases, with PTypesLongInitTest first.
-    support.run_unittest(PTypesLongInitTest, OperatorsTest,
-                         ClassPropertiesAndMethods, DictProxyTests,
-                         MiscTests, PicklingTests, SharedKeyTests,
-                         MroTest)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_devpoll.py b/Lib/test/test_devpoll.py
index 110c006..85e0acc 100644
--- a/Lib/test/test_devpoll.py
+++ b/Lib/test/test_devpoll.py
@@ -6,7 +6,7 @@ import os
 import random
 import select
 import unittest
-from test.support import run_unittest, cpython_only
+from test.support import cpython_only
 
 if not hasattr(select, 'devpoll') :
     raise unittest.SkipTest('test works only on Solaris OS family')
@@ -138,8 +138,5 @@ class DevPollTests(unittest.TestCase):
         self.assertRaises(OverflowError, pollster.modify, 1, USHRT_MAX + 1)
 
 
-def test_main():
-    run_unittest(DevPollTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_difflib.py b/Lib/test/test_difflib.py
index 9a24e00..6afd90a 100644
--- a/Lib/test/test_difflib.py
+++ b/Lib/test/test_difflib.py
@@ -1,5 +1,5 @@
 import difflib
-from test.support import run_unittest, findfile
+from test.support import findfile
 import unittest
 import doctest
 import sys
@@ -547,12 +547,14 @@ class TestFindLongest(unittest.TestCase):
         self.assertFalse(self.longer_match_exists(a, b, match.size))
 
 
-def test_main():
+def setUpModule():
     difflib.HtmlDiff._default_prefix = 0
-    Doctests = doctest.DocTestSuite(difflib)
-    run_unittest(
-        TestWithAscii, TestAutojunk, TestSFpatches, TestSFbugs,
-        TestOutputFormat, TestBytes, TestJunkAPIs, TestFindLongest, Doctests)
+
+
+def load_tests(loader, tests, pattern):
+    tests.addTest(doctest.DocTestSuite(difflib))
+    return tests
+
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_distutils.py b/Lib/test/test_distutils.py
index 90bfc70..4b40af0 100644
--- a/Lib/test/test_distutils.py
+++ b/Lib/test/test_distutils.py
@@ -15,16 +15,14 @@ with warnings_helper.check_warnings(
     import distutils.tests
 
 
-def test_main():
-    # used by regrtest
-    support.run_unittest(distutils.tests.test_suite())
-    support.reap_children()
-
-
 def load_tests(*_):
     # used by unittest
     return distutils.tests.test_suite()
 
 
+def tearDownModule():
+    support.reap_children()
+
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_dtrace.py b/Lib/test/test_dtrace.py
index 8612e27..1db73cc 100644
--- a/Lib/test/test_dtrace.py
+++ b/Lib/test/test_dtrace.py
@@ -6,7 +6,7 @@ import sys
 import types
 import unittest
 
-from test.support import findfile, run_unittest
+from test.support import findfile
 
 
 def abspath(filename):
@@ -97,7 +97,7 @@ class SystemTapBackend(TraceBackend):
     COMMAND = ["stap", "-g"]
 
 
-class TraceTests(unittest.TestCase):
+class TraceTests:
     # unittest.TestCase options
     maxDiff = None
 
@@ -149,30 +149,25 @@ class TraceTests(unittest.TestCase):
         self.run_case("line")
 
 
-class DTraceNormalTests(TraceTests):
+class DTraceNormalTests(TraceTests, unittest.TestCase):
     backend = DTraceBackend()
     optimize_python = 0
 
 
-class DTraceOptimizedTests(TraceTests):
+class DTraceOptimizedTests(TraceTests, unittest.TestCase):
     backend = DTraceBackend()
     optimize_python = 2
 
 
-class SystemTapNormalTests(TraceTests):
+class SystemTapNormalTests(TraceTests, unittest.TestCase):
     backend = SystemTapBackend()
     optimize_python = 0
 
 
-class SystemTapOptimizedTests(TraceTests):
+class SystemTapOptimizedTests(TraceTests, unittest.TestCase):
     backend = SystemTapBackend()
     optimize_python = 2
 
 
-def test_main():
-    run_unittest(DTraceNormalTests, DTraceOptimizedTests, SystemTapNormalTests,
-                 SystemTapOptimizedTests)
-
-
 if __name__ == '__main__':
     test_main()
diff --git a/Lib/test/test_fcntl.py b/Lib/test/test_fcntl.py
index 83ee7a5..fc8c393 100644
--- a/Lib/test/test_fcntl.py
+++ b/Lib/test/test_fcntl.py
@@ -6,7 +6,7 @@ import struct
 import sys
 import unittest
 from multiprocessing import Process
-from test.support import (verbose, run_unittest, cpython_only)
+from test.support import verbose, cpython_only
 from test.support.import_helper import import_module
 from test.support.os_helper import TESTFN, unlink
 
@@ -210,8 +210,5 @@ class TestFcntl(unittest.TestCase):
             os.close(test_pipe_w)
 
 
-def test_main():
-    run_unittest(TestFcntl)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_filecmp.py b/Lib/test/test_filecmp.py
index 64ba5a0..9b5ac12 100644
--- a/Lib/test/test_filecmp.py
+++ b/Lib/test/test_filecmp.py
@@ -246,8 +246,5 @@ class DirCompareTestCase(unittest.TestCase):
             self.assertEqual(report_lines, expected_report_lines)
 
 
-def test_main():
-    support.run_unittest(FileCompareTestCase, DirCompareTestCase)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py
index cdca5a8..4269b0e 100644
--- a/Lib/test/test_fileio.py
+++ b/Lib/test/test_fileio.py
@@ -9,7 +9,7 @@ from array import array
 from weakref import proxy
 from functools import wraps
 
-from test.support import run_unittest, cpython_only, swap_attr, gc_collect
+from test.support import cpython_only, swap_attr, gc_collect
 from test.support.os_helper import (TESTFN, TESTFN_UNICODE, make_bad_fd)
 from test.support.warnings_helper import check_warnings
 from collections import UserList
@@ -606,15 +606,12 @@ class PyOtherFileTests(OtherFileTests, unittest.TestCase):
             self.assertNotEqual(w.warnings, [])
 
 
-def test_main():
+def tearDownModule():
     # Historically, these tests have been sloppy about removing TESTFN.
     # So get rid of it no matter what.
-    try:
-        run_unittest(CAutoFileTests, PyAutoFileTests,
-                     COtherFileTests, PyOtherFileTests)
-    finally:
-        if os.path.exists(TESTFN):
-            os.unlink(TESTFN)
+    if os.path.exists(TESTFN):
+        os.unlink(TESTFN)
+
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index 3492ba4..56e3d8a 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -10,6 +10,7 @@ import errno
 import os
 import threading
 import time
+import unittest
 try:
     import ssl
 except ImportError:
@@ -1144,18 +1145,10 @@ class MiscTestCase(TestCase):
         support.check__all__(self, ftplib, not_exported=not_exported)
 
 
-def test_main():
-    tests = [TestFTPClass, TestTimeouts,
-             TestIPv6Environment,
-             TestTLS_FTPClassMixin, TestTLS_FTPClass,
-             MiscTestCase]
-
+def setUpModule():
     thread_info = threading_helper.threading_setup()
-    try:
-        support.run_unittest(*tests)
-    finally:
-        threading_helper.threading_cleanup(*thread_info)
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
 
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index 1528cf6..6c28b2b 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -1,6 +1,6 @@
 import unittest
 import unittest.mock
-from test.support import (verbose, refcount_test, run_unittest,
+from test.support import (verbose, refcount_test,
                           cpython_only)
 from test.support.import_helper import import_module
 from test.support.os_helper import temp_dir, TESTFN, unlink
@@ -1389,30 +1389,27 @@ class PythonFinalizationTests(unittest.TestCase):
         assert_python_ok("-c", code)
 
 
-def test_main():
+def setUpModule():
+    global enabled, debug
     enabled = gc.isenabled()
     gc.disable()
     assert not gc.isenabled()
     debug = gc.get_debug()
     gc.set_debug(debug & ~gc.DEBUG_LEAK) # this test is supposed to leak
+    gc.collect() # Delete 2nd generation garbage
+
+
+def tearDownModule():
+    gc.set_debug(debug)
+    # test gc.enable() even if GC is disabled by default
+    if verbose:
+        print("restoring automatic collection")
+    # make sure to always test gc.enable()
+    gc.enable()
+    assert gc.isenabled()
+    if not enabled:
+        gc.disable()
 
-    try:
-        gc.collect() # Delete 2nd generation garbage
-        run_unittest(
-            GCTests,
-            GCCallbackTests,
-            GCTogglingTests,
-            PythonFinalizationTests)
-    finally:
-        gc.set_debug(debug)
-        # test gc.enable() even if GC is disabled by default
-        if verbose:
-            print("restoring automatic collection")
-        # make sure to always test gc.enable()
-        gc.enable()
-        assert gc.isenabled()
-        if not enabled:
-            gc.disable()
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_global.py b/Lib/test/test_global.py
index c71d055..d0bde3f 100644
--- a/Lib/test/test_global.py
+++ b/Lib/test/test_global.py
@@ -1,6 +1,6 @@
 """Verify that warnings are issued for global statements following use."""
 
-from test.support import run_unittest, check_syntax_error
+from test.support import check_syntax_error
 from test.support.warnings_helper import check_warnings
 import unittest
 import warnings
@@ -53,10 +53,12 @@ x = 2
         compile(prog_text_4, "<test string>", "exec")
 
 
-def test_main():
-    with warnings.catch_warnings():
-        warnings.filterwarnings("error", module="<test string>")
-        run_unittest(GlobalTests)
+def setUpModule():
+    cm = warnings.catch_warnings()
+    cm.__enter__()
+    unittest.addModuleCleanup(cm.__exit__, None, None, None)
+    warnings.filterwarnings("error", module="<test string>")
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py
index 7b51e45..f86e767 100644
--- a/Lib/test/test_gzip.py
+++ b/Lib/test/test_gzip.py
@@ -10,7 +10,6 @@ import struct
 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
@@ -842,9 +841,5 @@ class TestCommandLine(unittest.TestCase):
         self.assertEqual(out, b'')
 
 
-def test_main(verbose=None):
-    support.run_unittest(TestGzip, TestOpen, TestCommandLine)
-
-
 if __name__ == "__main__":
-    test_main(verbose=True)
+    unittest.main()
diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 69790ec..1cc020f 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -1302,21 +1302,9 @@ class ScriptTestCase(unittest.TestCase):
             self.assertEqual(mock_server.address_family, socket.AF_INET)
 
 
-def test_main(verbose=None):
-    cwd = os.getcwd()
-    try:
-        support.run_unittest(
-            RequestHandlerLoggingTestCase,
-            BaseHTTPRequestHandlerTestCase,
-            BaseHTTPServerTestCase,
-            SimpleHTTPServerTestCase,
-            CGIHTTPServerTestCase,
-            SimpleHTTPRequestHandlerTestCase,
-            MiscTestCase,
-            ScriptTestCase
-        )
-    finally:
-        os.chdir(cwd)
+def setUpModule():
+    unittest.addModuleCleanup(os.chdir, os.getcwd())
+
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_importlib/test_locks.py b/Lib/test/test_importlib/test_locks.py
index 0e94ce9..9290bac 100644
--- a/Lib/test/test_importlib/test_locks.py
+++ b/Lib/test/test_importlib/test_locks.py
@@ -4,6 +4,7 @@ init = test_util.import_importlib('importlib')
 
 import sys
 import threading
+import unittest
 import weakref
 
 from test import support
@@ -139,15 +140,10 @@ class LifetimeTests:
  ) = test_util.test_both(LifetimeTests, init=init)
 
 
-@threading_helper.reap_threads
-def test_main():
-    support.run_unittest(Frozen_ModuleLockAsRLockTests,
-                         Source_ModuleLockAsRLockTests,
-                         Frozen_DeadlockAvoidanceTests,
-                         Source_DeadlockAvoidanceTests,
-                         Frozen_LifetimeTests,
-                         Source_LifetimeTests)
+def setUpModule():
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
 
 
 if __name__ == '__main__':
-    test_main()
+    unittets.main()
diff --git a/Lib/test/test_importlib/test_threaded_import.py b/Lib/test/test_importlib/test_threaded_import.py
index 03bde96..76b028e 100644
--- a/Lib/test/test_importlib/test_threaded_import.py
+++ b/Lib/test/test_importlib/test_threaded_import.py
@@ -14,7 +14,7 @@ import shutil
 import threading
 import unittest
 from unittest import mock
-from test.support import (verbose, run_unittest)
+from test.support import verbose
 from test.support.import_helper import forget
 from test.support.os_helper import (TESTFN, unlink, rmtree)
 from test.support import script_helper, threading_helper
@@ -258,19 +258,16 @@ class ThreadedImportTests(unittest.TestCase):
         script_helper.assert_python_ok(fn)
 
 
-@threading_helper.reap_threads
-def test_main():
-    old_switchinterval = None
+def setUpModule():
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
     try:
         old_switchinterval = sys.getswitchinterval()
+        unittest.addModuleCleanup(sys.setswitchinterval, old_switchinterval)
         sys.setswitchinterval(1e-5)
     except AttributeError:
         pass
-    try:
-        run_unittest(ThreadedImportTests)
-    finally:
-        if old_switchinterval is not None:
-            sys.setswitchinterval(old_switchinterval)
+
 
 if __name__ == "__main__":
-    test_main()
+    unittets.main()
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index e87311a..0e9191e 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -24,7 +24,7 @@ try:
 except ImportError:
     ThreadPoolExecutor = None
 
-from test.support import run_unittest, cpython_only
+from test.support import cpython_only
 from test.support import MISSING_C_DOCSTRINGS, ALWAYS_EQ
 from test.support.import_helper import DirsOnSysPath
 from test.support.os_helper import TESTFN
@@ -4343,19 +4343,5 @@ def foo():
             self.assertInspectEqual(path, module)
 
 
-def test_main():
-    run_unittest(
-        TestDecorators, TestRetrievingSourceCode, TestOneliners, TestBlockComments,
-        TestBuggyCases, TestInterpreterStack, TestClassesAndFunctions, TestPredicates,
-        TestGetcallargsFunctions, TestGetcallargsMethods,
-        TestGetcallargsUnboundMethods, TestGetattrStatic, TestGetGeneratorState,
-        TestNoEOL, TestSignatureObject, TestSignatureBind, TestParameterObject,
-        TestBoundArguments, TestSignaturePrivateHelpers,
-        TestSignatureDefinitions, TestIsDataDescriptor,
-        TestGetClosureVars, TestUnwrap, TestMain, TestReload,
-        TestGetCoroutineState, TestGettingSourceOfToplevelFrames,
-        TestGetsourceInteractive,
-    )
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py
index 20cb9c0..554f602 100644
--- a/Lib/test/test_iter.py
+++ b/Lib/test/test_iter.py
@@ -2,7 +2,7 @@
 
 import sys
 import unittest
-from test.support import run_unittest, cpython_only
+from test.support import cpython_only
 from test.support.os_helper import TESTFN, unlink
 from test.support import check_free_after_iterating, ALWAYS_EQ, NEVER_EQ
 import pickle
@@ -1037,9 +1037,5 @@ class TestCase(unittest.TestCase):
         self.assertRaises(ZeroDivisionError, iter, BadIterableClass())
 
 
-def test_main():
-    run_unittest(TestCase)
-
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 9998f1a..211fe4b 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -5514,25 +5514,11 @@ class MiscTestCase(unittest.TestCase):
 # Set the locale to the platform-dependent default.  I have no idea
 # why the test does this, but in any case we save the current locale
 # first and restore it at the end.
-@support.run_with_locale('LC_ALL', '')
-def test_main():
-    tests = [
-        BuiltinLevelsTest, BasicFilterTest, CustomLevelsAndFiltersTest,
-        HandlerTest, MemoryHandlerTest, ConfigFileTest, SocketHandlerTest,
-        DatagramHandlerTest, MemoryTest, EncodingTest, WarningsTest,
-        ConfigDictTest, ManagerTest, FormatterTest, BufferingFormatterTest,
-        StreamHandlerTest, LogRecordFactoryTest, ChildLoggerTest,
-        QueueHandlerTest, ShutdownTest, ModuleLevelMiscTest, BasicConfigTest,
-        LoggerAdapterTest, LoggerTest, SMTPHandlerTest, FileHandlerTest,
-        RotatingFileHandlerTest,  LastResortTest, LogRecordTest,
-        ExceptionTest, SysLogHandlerTest, IPv6SysLogHandlerTest, HTTPHandlerTest,
-        NTEventLogHandlerTest, TimedRotatingFileHandlerTest,
-        UnixSocketHandlerTest, UnixDatagramHandlerTest, UnixSysLogHandlerTest,
-        MiscTestCase
-    ]
-    if hasattr(logging.handlers, 'QueueListener'):
-        tests.append(QueueListenerTest)
-    support.run_unittest(*tests)
+def setUpModule():
+    cm = support.run_with_locale('LC_ALL', '')
+    cm.__enter__()
+    unittest.addModuleCleanup(cm.__exit__, None, None, None)
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_lzma.py b/Lib/test/test_lzma.py
index 1e2066b..145c8cf 100644
--- a/Lib/test/test_lzma.py
+++ b/Lib/test/test_lzma.py
@@ -9,9 +9,7 @@ import sys
 from test import support
 import unittest
 
-from test.support import (
-    _4G, bigmemtest, run_unittest
-)
+from test.support import _4G, bigmemtest
 from test.support.import_helper import import_module
 from test.support.os_helper import (
     TESTFN, unlink
@@ -1941,14 +1939,5 @@ ISSUE_21872_DAT = (
 )
 
 
-def test_main():
-    run_unittest(
-        CompressorDecompressorTestCase,
-        CompressDecompressFunctionTestCase,
-        FileTestCase,
-        OpenTestCase,
-        MiscellaneousTestCase,
-    )
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index 8a5d692..604fc45 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -2300,15 +2300,9 @@ class MiscTestCase(unittest.TestCase):
                              not_exported={"linesep", "fcntl"})
 
 
-def test_main():
-    tests = (TestMailboxSuperclass, TestMaildir, TestMbox, TestMMDF, TestMH,
-             TestBabyl, TestMessage, TestMaildirMessage, TestMboxMessage,
-             TestMHMessage, TestBabylMessage, TestMMDFMessage,
-             TestMessageConversion, TestProxyFile, TestPartialFile,
-             MaildirTestCase, TestFakeMailBox, MiscTestCase)
-    support.run_unittest(*tests)
+def tearDownModule():
     support.reap_children()
 
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_multibytecodec.py b/Lib/test/test_multibytecodec.py
index 3efa150..cf8bb5e 100644
--- a/Lib/test/test_multibytecodec.py
+++ b/Lib/test/test_multibytecodec.py
@@ -403,8 +403,6 @@ class TestHZStateful(TestStateful):
     reset = b'~}'
     expected_reset = expected + reset
 
-def test_main():
-    support.run_unittest(__name__)
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_optparse.py b/Lib/test/test_optparse.py
index 1ed6bf9..28b2744 100644
--- a/Lib/test/test_optparse.py
+++ b/Lib/test/test_optparse.py
@@ -1656,8 +1656,5 @@ class MiscTestCase(unittest.TestCase):
         support.check__all__(self, optparse, not_exported=not_exported)
 
 
-def test_main():
-    support.run_unittest(__name__)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_ossaudiodev.py b/Lib/test/test_ossaudiodev.py
index d3766e5..ebce3e9 100644
--- a/Lib/test/test_ossaudiodev.py
+++ b/Lib/test/test_ossaudiodev.py
@@ -188,7 +188,7 @@ class OSSAudioDevTests(unittest.TestCase):
         mixer.close()
         self.assertRaises(ValueError, mixer.fileno)
 
-def test_main():
+def setUpModule():
     try:
         dsp = ossaudiodev.open('w')
     except (ossaudiodev.error, OSError) as msg:
@@ -197,7 +197,6 @@ def test_main():
             raise unittest.SkipTest(msg)
         raise
     dsp.close()
-    support.run_unittest(__name__)
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_pipes.py b/Lib/test/test_pipes.py
index 6a13b36..6335e7c 100644
--- a/Lib/test/test_pipes.py
+++ b/Lib/test/test_pipes.py
@@ -3,7 +3,7 @@ import os
 import string
 import unittest
 import shutil
-from test.support import run_unittest, reap_children, unix_shell
+from test.support import reap_children, unix_shell
 from test.support.os_helper import TESTFN, unlink
 
 
@@ -199,9 +199,10 @@ class SimplePipeTests(unittest.TestCase):
         self.assertNotEqual(id(t.steps), id(u.steps))
         self.assertEqual(t.debugging, u.debugging)
 
-def test_main():
-    run_unittest(SimplePipeTests)
+
+def tearDownModule():
     reap_children()
 
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_pkgutil.py b/Lib/test/test_pkgutil.py
index 3c29080..0cc99e0 100644
--- a/Lib/test/test_pkgutil.py
+++ b/Lib/test/test_pkgutil.py
@@ -1,5 +1,4 @@
 from pathlib import Path
-from test.support import run_unittest
 from test.support.import_helper import unload, CleanImport
 from test.support.warnings_helper import check_warnings
 import unittest
@@ -626,9 +625,7 @@ class ImportlibMigrationTests(unittest.TestCase):
             self.assertEqual(len(w.warnings), 0)
 
 
-def test_main():
-    run_unittest(PkgutilTests, PkgutilPEP302Tests, ExtendPathTests,
-                 NestedNamespacePackageTest, ImportlibMigrationTests)
+def tearDownModule():
     # this is necessary if test is run repeated (like when finding leaks)
     import zipimport
     import importlib
@@ -637,4 +634,4 @@ def test_main():
 
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_poll.py b/Lib/test/test_poll.py
index de62350..82bbb3a 100644
--- a/Lib/test/test_poll.py
+++ b/Lib/test/test_poll.py
@@ -7,7 +7,7 @@ import select
 import threading
 import time
 import unittest
-from test.support import run_unittest, cpython_only
+from test.support import cpython_only
 from test.support import threading_helper
 from test.support.os_helper import TESTFN
 
@@ -229,8 +229,5 @@ class PollTests(unittest.TestCase):
             os.close(w)
 
 
-def test_main():
-    run_unittest(PollTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py
index 8dd6ea6..44cf523 100644
--- a/Lib/test/test_poplib.py
+++ b/Lib/test/test_poplib.py
@@ -9,6 +9,7 @@ import os
 import errno
 import threading
 
+import unittest
 from unittest import TestCase, skipUnless
 from test import support as test_support
 from test.support import hashlib_helper
@@ -538,15 +539,10 @@ class TestTimeouts(TestCase):
             poplib.POP3(HOST, self.port, timeout=0)
 
 
-def test_main():
-    tests = [TestPOP3Class, TestTimeouts,
-             TestPOP3_SSLClass, TestPOP3_TLSClass]
+def setUpModule():
     thread_info = threading_helper.threading_setup()
-    try:
-        test_support.run_unittest(*tests)
-    finally:
-        threading_helper.threading_cleanup(*thread_info)
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
 
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index e466688..56b72f4 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -2171,17 +2171,9 @@ class TestPosixWeaklinking(unittest.TestCase):
                 os.utime("path", dir_fd=0)
 
 
-def test_main():
-    try:
-        support.run_unittest(
-            PosixTester,
-            PosixGroupsTester,
-            TestPosixSpawn,
-            TestPosixSpawnP,
-            TestPosixWeaklinking
-        )
-    finally:
-        support.reap_children()
+def tearDownModule():
+    support.reap_children()
+
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_profile.py b/Lib/test/test_profile.py
index 7de7d52..d97fe44 100644
--- a/Lib/test/test_profile.py
+++ b/Lib/test/test_profile.py
@@ -6,7 +6,6 @@ import unittest
 import os
 from difflib import unified_diff
 from io import StringIO
-from test.support import run_unittest
 from test.support.os_helper import TESTFN, unlink, temp_dir, change_cwd
 from contextlib import contextmanager
 
@@ -156,12 +155,10 @@ def silent():
     finally:
         sys.stdout = stdout
 
-def test_main():
-    run_unittest(ProfileTest)
 
 def main():
     if '-r' not in sys.argv:
-        test_main()
+        unittest.main()
     else:
         regenerate_expected_output(__file__, ProfileTest)
 
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index a952ab9..25ac1fb 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -1581,20 +1581,11 @@ class TestInternalUtilities(unittest.TestCase):
                 self.assertIsNone(self._get_revised_path(trailing_argv0dir))
 
 
-@threading_helper.reap_threads
-def test_main():
-    try:
-        test.support.run_unittest(PydocDocTest,
-                                  PydocImportTest,
-                                  TestDescriptions,
-                                  PydocServerTest,
-                                  PydocUrlHandlerTest,
-                                  TestHelper,
-                                  PydocWithMetaClasses,
-                                  TestInternalUtilities,
-                                  )
-    finally:
-        reap_children()
+def setUpModule():
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
+    unittest.addModuleCleanup(reap_children)
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_resource.py b/Lib/test/test_resource.py
index d909e31..f2642c6 100644
--- a/Lib/test/test_resource.py
+++ b/Lib/test/test_resource.py
@@ -174,8 +174,5 @@ class ResourceTest(unittest.TestCase):
                          limits)
 
 
-def test_main(verbose=None):
-    support.run_unittest(ResourceTest)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_sax.py b/Lib/test/test_sax.py
index 801143f..eda4e6a 100644
--- a/Lib/test/test_sax.py
+++ b/Lib/test/test_sax.py
@@ -24,7 +24,7 @@ import sys
 from urllib.error import URLError
 import urllib.request
 from test.support import os_helper
-from test.support import findfile, run_unittest
+from test.support import findfile
 from test.support.os_helper import FakePath, TESTFN
 
 
@@ -1506,22 +1506,5 @@ class CDATAHandlerTest(unittest.TestCase):
         self.assertEqual(self.char_index, 2)
 
 
-def test_main():
-    run_unittest(MakeParserTest,
-                 ParseTest,
-                 SaxutilsTest,
-                 PrepareInputSourceTest,
-                 StringXmlgenTest,
-                 BytesXmlgenTest,
-                 WriterXmlgenTest,
-                 StreamWriterXmlgenTest,
-                 StreamReaderWriterXmlgenTest,
-                 ExpatReaderTest,
-                 ErrorReportingTest,
-                 XmlReaderTest,
-                 LexicalHandlerTest,
-                 CDATAHandlerTest)
-
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py
index 851b1fc..fe6b725 100644
--- a/Lib/test/test_selectors.py
+++ b/Lib/test/test_selectors.py
@@ -49,7 +49,7 @@ def find_ready_matching(ready, flag):
     return match
 
 
-class BaseSelectorTestCase(unittest.TestCase):
+class BaseSelectorTestCase:
 
     def make_socketpair(self):
         rd, wr = socketpair()
@@ -493,26 +493,28 @@ class ScalableSelectorMixIn:
         self.assertEqual(NUM_FDS // 2, len(fds))
 
 
-class DefaultSelectorTestCase(BaseSelectorTestCase):
+class DefaultSelectorTestCase(BaseSelectorTestCase, unittest.TestCase):
 
     SELECTOR = selectors.DefaultSelector
 
 
-class SelectSelectorTestCase(BaseSelectorTestCase):
+class SelectSelectorTestCase(BaseSelectorTestCase, unittest.TestCase):
 
     SELECTOR = selectors.SelectSelector
 
 
 @unittest.skipUnless(hasattr(selectors, 'PollSelector'),
                      "Test needs selectors.PollSelector")
-class PollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
+class PollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
+                           unittest.TestCase):
 
     SELECTOR = getattr(selectors, 'PollSelector', None)
 
 
 @unittest.skipUnless(hasattr(selectors, 'EpollSelector'),
                      "Test needs selectors.EpollSelector")
-class EpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
+class EpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
+                            unittest.TestCase):
 
     SELECTOR = getattr(selectors, 'EpollSelector', None)
 
@@ -529,7 +531,8 @@ class EpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
 
 @unittest.skipUnless(hasattr(selectors, 'KqueueSelector'),
                      "Test needs selectors.KqueueSelector)")
-class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
+class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
+                             unittest.TestCase):
 
     SELECTOR = getattr(selectors, 'KqueueSelector', None)
 
@@ -561,19 +564,15 @@ class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
 
 @unittest.skipUnless(hasattr(selectors, 'DevpollSelector'),
                      "Test needs selectors.DevpollSelector")
-class DevpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
+class DevpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
+                              unittest.TestCase):
 
     SELECTOR = getattr(selectors, 'DevpollSelector', None)
 
 
-
-def test_main():
-    tests = [DefaultSelectorTestCase, SelectSelectorTestCase,
-             PollSelectorTestCase, EpollSelectorTestCase,
-             KqueueSelectorTestCase, DevpollSelectorTestCase]
-    support.run_unittest(*tests)
+def tearDownModule():
     support.reap_children()
 
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index 556c1cf..db0539b 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -2344,6 +2344,7 @@ class SimpleBackgroundTests(unittest.TestCase):
         self.ssl_io_loop(sock, incoming, outgoing, sslobj.unwrap)
 
 
+@support.requires_resource('network')
 class NetworkedTests(unittest.TestCase):
 
     def test_timeout_connect_ex(self):
@@ -5014,7 +5015,7 @@ class TestEnumerations(unittest.TestCase):
         enum._test_simple_enum(CheckedVerifyMode, ssl.VerifyMode)
 
 
-def test_main(verbose=False):
+def setUpModule():
     if support.verbose:
         plats = {
             'Mac': platform.mac_ver,
@@ -5045,20 +5046,11 @@ def test_main(verbose=False):
         if not os.path.exists(filename):
             raise support.TestFailed("Can't read certificate file %r" % filename)
 
-    tests = [
-        ContextTests, BasicSocketTests, SSLErrorTests, MemoryBIOTests,
-        SSLObjectTests, SimpleBackgroundTests, ThreadedTests,
-        TestPostHandshakeAuth, TestSSLDebug, TestEnumerations,
-    ]
-
-    if support.is_resource_enabled('network'):
-        tests.append(NetworkedTests)
 
+def setUpModule():
     thread_info = threading_helper.threading_setup()
-    try:
-        support.run_unittest(*tests)
-    finally:
-        threading_helper.threading_cleanup(*thread_info)
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 44fe334..8b55352 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -714,9 +714,5 @@ class TestSupport(unittest.TestCase):
     # SuppressCrashReport
 
 
-def test_main():
-    tests = [TestSupport]
-    support.run_unittest(*tests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
index 6970ede..f18baa5 100644
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tcl.py
@@ -751,8 +751,5 @@ def setUpModule():
         print('patchlevel =', tcl.call('info', 'patchlevel'))
 
 
-def test_main():
-    support.run_unittest(TclTest, TkinterTest, BigmemTclTest)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_threadsignals.py b/Lib/test/test_threadsignals.py
index 15e8078..bac82b8 100644
--- a/Lib/test/test_threadsignals.py
+++ b/Lib/test/test_threadsignals.py
@@ -4,7 +4,6 @@ import unittest
 import signal
 import os
 import sys
-from test import support
 from test.support import threading_helper
 import _thread as thread
 import time
@@ -231,7 +230,7 @@ class ThreadSignals(unittest.TestCase):
             signal.signal(signal.SIGUSR1, old_handler)
 
 
-def test_main():
+def setUpModule():
     global signal_blackboard
 
     signal_blackboard = { signal.SIGUSR1 : {'tripped': 0, 'tripped_by': 0 },
@@ -239,10 +238,8 @@ def test_main():
                           signal.SIGALRM : {'tripped': 0, 'tripped_by': 0 } }
 
     oldsigs = registerSignals(handle_signals, handle_signals, handle_signals)
-    try:
-        support.run_unittest(ThreadSignals)
-    finally:
-        registerSignals(*oldsigs)
+    unittest.addModuleCleanup(registerSignals, *oldsigs)
+
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_timeout.py b/Lib/test/test_timeout.py
index 823d5c3..70a0175 100644
--- a/Lib/test/test_timeout.py
+++ b/Lib/test/test_timeout.py
@@ -290,13 +290,9 @@ class UDPTimeoutTestCase(TimeoutTestCase):
         self._sock_operation(1, 1.5, 'recvfrom', 1024)
 
 
-def test_main():
+def setUpModule():
     support.requires('network')
-    support.run_unittest(
-        CreationTestCase,
-        TCPTimeoutTestCase,
-        UDPTimeoutTestCase,
-    )
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_tracemalloc.py b/Lib/test/test_tracemalloc.py
index 5566567..82be98d 100644
--- a/Lib/test/test_tracemalloc.py
+++ b/Lib/test/test_tracemalloc.py
@@ -1082,15 +1082,5 @@ class TestCAPI(unittest.TestCase):
             self.untrack()
 
 
-def test_main():
-    support.run_unittest(
-        TestTraceback,
-        TestTracemallocEnabled,
-        TestSnapshot,
-        TestFilters,
-        TestCommandLine,
-        TestCAPI,
-    )
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_unicode_file.py b/Lib/test/test_unicode_file.py
index e397949..80c22c6 100644
--- a/Lib/test/test_unicode_file.py
+++ b/Lib/test/test_unicode_file.py
@@ -6,7 +6,6 @@ import sys
 import unicodedata
 
 import unittest
-from test.support import run_unittest
 from test.support.os_helper import (rmtree, change_cwd, TESTFN_UNICODE,
     TESTFN_UNENCODABLE, create_empty_file)
 
@@ -136,8 +135,6 @@ class TestUnicodeFiles(unittest.TestCase):
             self._do_directory(TESTFN_UNENCODABLE+ext,
                                TESTFN_UNENCODABLE+ext)
 
-def test_main():
-    run_unittest(__name__)
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_unicode_file_functions.py b/Lib/test/test_unicode_file_functions.py
index 7ef11aa..54916dec4 100644
--- a/Lib/test/test_unicode_file_functions.py
+++ b/Lib/test/test_unicode_file_functions.py
@@ -5,7 +5,6 @@ import sys
 import unittest
 import warnings
 from unicodedata import normalize
-from test import support
 from test.support import os_helper
 
 
@@ -185,15 +184,5 @@ class UnicodeNFKDFileTests(UnicodeFileTests):
     normal_form = 'NFKD'
 
 
-def test_main():
-    support.run_unittest(
-        UnicodeFileTests,
-        UnicodeNFCFileTests,
-        UnicodeNFDFileTests,
-        UnicodeNFKCFileTests,
-        UnicodeNFKDFileTests,
-    )
-
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_unittest.py b/Lib/test/test_unittest.py
index bfc3ded..1079c7d 100644
--- a/Lib/test/test_unittest.py
+++ b/Lib/test/test_unittest.py
@@ -3,14 +3,14 @@ import unittest.test
 from test import support
 
 
-def test_main():
-    # used by regrtest
-    support.run_unittest(unittest.test.suite())
-    support.reap_children()
-
 def load_tests(*_):
     # used by unittest
     return unittest.test.suite()
 
+
+def tearDownModule():
+    support.reap_children()
+
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_urllib2_localnet.py b/Lib/test/test_urllib2_localnet.py
index ebb43c3..36fb05d 100644
--- a/Lib/test/test_urllib2_localnet.py
+++ b/Lib/test/test_urllib2_localnet.py
@@ -661,17 +661,10 @@ class TestUrlopen(unittest.TestCase):
         self.assertEqual(index + 1, len(lines))
 
 
-threads_key = None
-
 def setUpModule():
-    # Store the threading_setup in a key and ensure that it is cleaned up
-    # in the tearDown
-    global threads_key
-    threads_key = threading_helper.threading_setup()
-
-def tearDownModule():
-    if threads_key:
-        threading_helper.threading_cleanup(*threads_key)
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_winreg.py b/Lib/test/test_winreg.py
index 487abcd..fedfbe9 100644
--- a/Lib/test/test_winreg.py
+++ b/Lib/test/test_winreg.py
@@ -3,7 +3,6 @@
 
 import os, sys, errno
 import unittest
-from test import support
 from test.support import import_helper
 import threading
 from platform import machine, win32_edition
@@ -490,12 +489,9 @@ class Win64WinregTests(BaseWinregTests):
         with self.assertRaises(FileNotFoundError) as ctx:
             QueryValue(HKEY_CLASSES_ROOT, 'some_value_that_does_not_exist')
 
-def test_main():
-    support.run_unittest(LocalWinregTests, RemoteWinregTests,
-                         Win64WinregTests)
 
 if __name__ == "__main__":
     if not REMOTE_NAME:
         print("Remote registry calls can be tested using",
               "'test_winreg.py --remote \\\\machine_name'")
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py
index a9f6746..85e27ad 100644
--- a/Lib/test/test_xmlrpc.py
+++ b/Lib/test/test_xmlrpc.py
@@ -1504,16 +1504,10 @@ class UseBuiltinTypesTestCase(unittest.TestCase):
         self.assertTrue(server.use_builtin_types)
 
 
-@threading_helper.reap_threads
-def test_main():
-    support.run_unittest(XMLRPCTestCase, HelperTestCase, DateTimeTestCase,
-            BinaryTestCase, FaultTestCase, UseBuiltinTypesTestCase,
-            SimpleServerTestCase, SimpleServerEncodingTestCase,
-            KeepaliveServerTestCase1, KeepaliveServerTestCase2,
-            GzipServerTestCase, GzipUtilTestCase, HeadersServerTestCase,
-            MultiPathServerTestCase, ServerProxyTestCase, FailingServerTestCase,
-            CGIHandlerTestCase, SimpleXMLRPCDispatcherTestCase)
+def setUpModule():
+    thread_info = threading_helper.threading_setup()
+    unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)
 
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_xmlrpc_net.py b/Lib/test/test_xmlrpc_net.py
index f3652b8..51167b2 100644
--- a/Lib/test/test_xmlrpc_net.py
+++ b/Lib/test/test_xmlrpc_net.py
@@ -5,6 +5,9 @@ from test import support
 import xmlrpc.client as xmlrpclib
 
 
+support.requires("network")
+
+
 @unittest.skip('XXX: buildbot.python.org/all/xmlrpc/ is gone')
 class PythonBuildersTest(unittest.TestCase):
 
@@ -24,9 +27,5 @@ class PythonBuildersTest(unittest.TestCase):
         self.assertTrue([x for x in builders if "3.x" in x], builders)
 
 
-def test_main():
-    support.requires("network")
-    support.run_unittest(PythonBuildersTest)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index 486200a..392dcfa 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -861,15 +861,9 @@ class BadFileZipImportTestCase(unittest.TestCase):
             zipimport._zip_directory_cache.clear()
 
 
-def test_main():
-    try:
-        support.run_unittest(
-              UncompressedZipImportTestCase,
-              CompressedZipImportTestCase,
-              BadFileZipImportTestCase,
-            )
-    finally:
-        os_helper.unlink(TESTMOD)
+def tearDownModule():
+    os_helper.unlink(TESTMOD)
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()