bpo-40280: Add requires_fork and subprocess to more tests

Lib/test/lock_tests.py

@@ -15,7 +15,7 @@
 from test.support import threading_helper
 
 
-requires_fork = unittest.skipUnless(hasattr(os, 'fork'),
+requires_fork = unittest.skipUnless(support.has_fork_support,
                                     "platform doesn't support fork "
                                      "(no _at_fork_reinit method)")
 

Lib/test/test_json/test_tool.py

@@ -10,6 +10,7 @@
 from test.support.script_helper import assert_python_ok
 
 
+@support.requires_subprocess()
 class TestTool(unittest.TestCase):
     data = """
 

Lib/test/test_mailbox.py

@@ -1061,7 +1061,7 @@ def test_add_and_close(self):
             self.assertEqual(contents, f.read())
         self._box = self._factory(self._path)
 
-    @unittest.skipUnless(hasattr(os, 'fork'), "Test needs fork().")
+    @support.requires_fork()
     @unittest.skipUnless(hasattr(socket, 'socketpair'), "Test needs socketpair().")
     def test_lock_conflict(self):
         # Fork off a child process that will lock the mailbox temporarily,

Lib/test/test_pdb.py

@@ -13,6 +13,7 @@
 
 from contextlib import ExitStack, redirect_stdout
 from io import StringIO
+from test import support
 from test.support import os_helper
 # This little helper class is essential for testing pdb under doctest.
 from test.test_doctest import _FakeInput
@@ -1363,6 +1364,7 @@ def test_pdb_issue_43318():
     """
 
 
+@support.requires_subprocess()
 class PdbTestCase(unittest.TestCase):
     def tearDown(self):
         os_helper.unlink(os_helper.TESTFN)

Lib/test/test_peg_generator/test_c_parser.py

@@ -70,6 +70,7 @@ def test_parse(self):
 """
 
 
+@support.requires_subprocess()
 class TestCParser(unittest.TestCase):
     def setUp(self):
         self._backup_config_vars = dict(sysconfig._CONFIG_VARS)

Lib/test/test_socketserver.py

@@ -28,7 +28,7 @@
 HAVE_UNIX_SOCKETS = hasattr(socket, "AF_UNIX")
 requires_unix_sockets = unittest.skipUnless(HAVE_UNIX_SOCKETS,
                                             'requires Unix sockets')
-HAVE_FORKING = hasattr(os, "fork")
+HAVE_FORKING = test.support.has_fork_support
 requires_forking = unittest.skipUnless(HAVE_FORKING, 'requires forking')
 
 def signal_alarm(n):

Lib/test/test_tools/__init__.py

@@ -13,6 +13,10 @@
     raise unittest.SkipTest("test too slow on ASAN/MSAN build")
 
 
+if not support.has_subprocess_support:
+    raise unittest.SkipTest("test module requires subprocess")
+
+
 basepath = os.path.normpath(
         os.path.dirname(                 # <src/install dir>
             os.path.dirname(                # Lib

Lib/test/test_wait3.py

@@ -9,8 +9,8 @@
 from test.fork_wait import ForkWait
 from test import support
 
-if not hasattr(os, 'fork'):
-    raise unittest.SkipTest("os.fork not defined")
+if not support.has_fork_support:
+    raise unittest.SkipTest("requires working os.fork()")
 
 if not hasattr(os, 'wait3'):
     raise unittest.SkipTest("os.wait3 not defined")

Lib/test/test_wait4.py

@@ -9,7 +9,9 @@
 from test import support
 
 # If either of these do not exist, skip this test.
-support.get_attribute(os, 'fork')
+if not support.has_fork_support:
+    raise unittest.SkipTest("requires working os.fork()")
+
 support.get_attribute(os, 'wait4')