[3.9] bpo-45229: Remove test_main in many tests (GH-28405) (GH-28456)

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..
(cherry picked from commit 40348ac)

Author: serhiy-storchaka

Lib/lib2to3/tests/data/py2_test_grammar.py

@@ -8,7 +8,7 @@
 # regression test, the filterwarnings() call has been added to
 # regrtest.py.
 
-from test.test_support import run_unittest, check_syntax_error
+from test.test_support import check_syntax_error
 import unittest
 import sys
 # testing import *
@@ -967,8 +967,5 @@ def _checkeval(msg, ret):
         self.assertEqual((6 < 4 if 0 else 2), 2)
 
 
-def test_main():
-    run_unittest(TokenTests, GrammarTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()

Lib/lib2to3/tests/data/py3_test_grammar.py

@@ -8,7 +8,7 @@
 # regression test, the filterwarnings() call has been added to
 # regrtest.py.
 
-from test.support import run_unittest, check_syntax_error
+from test.support import check_syntax_error
 import unittest
 import sys
 # testing import *
@@ -952,8 +952,5 @@ def _checkeval(msg, ret):
         self.assertEqual((6 < 4 if 0 else 2), 2)
 
 
-def test_main():
-    run_unittest(TokenTests, GrammarTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()

Lib/test/support/__init__.py

@@ -1525,9 +1525,8 @@ 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)
@@ -1546,16 +1545,11 @@ def inner(*args, **kwds):
                     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

Lib/test/test_argparse.py

@@ -5394,13 +5394,11 @@ def test_exit_on_error_with_bad_args(self):
             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()

Lib/test/test_bdb.py

@@ -1149,13 +1149,6 @@ def main():
             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()

Lib/test/test_bigaddrspace.py

@@ -92,10 +92,7 @@ def test_repeat(self):
             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()

Lib/test/test_bigmem.py

@@ -1247,11 +1247,8 @@ def test_sort(self, size):
         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()

Lib/test/test_bool.py

@@ -362,8 +362,6 @@ def test_real_and_imag(self):
         self.assertIs(type(False.real), int)
         self.assertIs(type(False.imag), int)
 
-def test_main():
-    support.run_unittest(BoolTest)
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()

Lib/test/test_bz2.py

@@ -1002,15 +1002,9 @@ def test_newline(self):
             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()

Lib/test/test_c_locale_coercion.py

@@ -427,12 +427,9 @@ def test_PYTHONCOERCECLOCALE_set_to_one(self):
         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()

Lib/test/test_cmd_line.py

@@ -841,9 +841,9 @@ def test_sys_flags_not_set(self):
         )
 
 
-def test_main():
-    support.run_unittest(CmdLineTest, IgnoreEnvironmentTest)
+def tearDownModule():
     support.reap_children()
 
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()

Lib/test/test_cmd_line_script.py

@@ -737,9 +737,9 @@ def test_nonexisting_script(self):
         self.assertNotEqual(proc.returncode, 0)
 
 
-def test_main():
-    support.run_unittest(CmdLineTest)
+def tearDownModule():
     support.reap_children()
 
+
 if __name__ == '__main__':
-    test_main()
+    unittest.main()

Lib/test/test_complex.py

@@ -751,8 +751,6 @@ def test_format(self):
         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()

Lib/test/test_concurrent_futures.py

@@ -1500,16 +1500,10 @@ def test_multiple_set_exception(self):
         self.assertEqual(f.exception(), e)
 
 
-_threads_key = None
-
 def setUpModule():
-    global _threads_key
-    _threads_key = support.threading_setup()
-
-
-def tearDownModule():
-    support.threading_cleanup(*_threads_key)
-    multiprocessing.util._cleanup_tests()
+    unittest.addModuleCleanup(multiprocessing.util._cleanup_tests)
+    thread_info = support.threading_setup()
+    unittest.addModuleCleanup(support.threading_cleanup, *thread_info)
 
 
 if __name__ == "__main__":

Lib/test/test_descr.py

@@ -4945,8 +4945,11 @@ def test_repr(self):
             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 ...
 
@@ -5684,12 +5687,5 @@ class A(metaclass=M):
             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()

Lib/test/test_devpoll.py

@@ -6,7 +6,7 @@
 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 @@ def test_events_mask_overflow_c_limits(self):
         self.assertRaises(OverflowError, pollster.modify, 1, USHRT_MAX + 1)
 
 
-def test_main():
-    run_unittest(DevPollTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()

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 @@ def test_longest_match_with_popular_chars(self):
         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()

Lib/test/test_distutils.py

@@ -9,16 +9,14 @@
 import test.support
 
 
-def test_main():
-    # used by regrtest
-    test.support.run_unittest(distutils.tests.test_suite())
-    test.support.reap_children()
-
-
 def load_tests(*_):
     # used by unittest
     return distutils.tests.test_suite()
 
 
+def tearDownModule():
+    test.support.reap_children()
+
+
 if __name__ == "__main__":
-    test_main()
+    unittest.main()

Lib/test/test_dtrace.py

@@ -6,7 +6,7 @@
 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 @@ def test_line(self):
         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()

Lib/test/test_fcntl.py

@@ -6,7 +6,7 @@
 import sys
 import unittest
 from multiprocessing import Process
-from test.support import (verbose, TESTFN, unlink, run_unittest, import_module,
+from test.support import (verbose, TESTFN, unlink, import_module,
                           cpython_only)
 
 # Skip test if no fcntl module.
@@ -188,8 +188,6 @@ def test_fcntl_f_getpath(self):
         res = fcntl.fcntl(self.f.fileno(), fcntl.F_GETPATH, bytes(len(expected)))
         self.assertEqual(expected, res)
 
-def test_main():
-    run_unittest(TestFcntl)
 
 if __name__ == '__main__':
-    test_main()
+    unittest.main()