bpo-33562: Check the global asyncio event loop policy isn't set after any tests (GH-7328)

Author: brettcannon

Lib/test/libregrtest/save_env.py

@@ -1,3 +1,4 @@
+import asyncio
 import builtins
 import locale
 import logging
@@ -65,8 +66,14 @@ def __init__(self, testname, verbose=0, quiet=False, *, pgo=False):
                  'sysconfig._CONFIG_VARS', 'sysconfig._INSTALL_SCHEMES',
                  'files', 'locale', 'warnings.showwarning',
                  'shutil_archive_formats', 'shutil_unpack_formats',
+                 'asyncio.events._event_loop_policy',
                 )
 
+    def get_asyncio_events__event_loop_policy(self):
+        return support.maybe_get_event_loop_policy()
+    def restore_asyncio_events__event_loop_policy(self, policy):
+        asyncio.set_event_loop_policy(policy)
+
     def get_sys_argv(self):
         return id(sys.argv), sys.argv, sys.argv[:]
     def restore_sys_argv(self, saved_argv):

Lib/test/support/__init__.py

@@ -3,6 +3,7 @@
 if __name__ != 'test.support':
     raise ImportError('support must be imported from the test package')
 
+import asyncio.events
 import collections.abc
 import contextlib
 import errno
@@ -2878,3 +2879,8 @@ def __fspath__(self):
             raise self.path
         else:
             return self.path
+
+
+def maybe_get_event_loop_policy():
+    """Return the global event loop policy if one is set, else return None."""
+    return asyncio.events._event_loop_policy

Lib/test/test_asyncgen.py

@@ -328,6 +328,7 @@ def setUp(self):
     def tearDown(self):
         self.loop.close()
         self.loop = None
+        asyncio.set_event_loop_policy(None)
 
     async def to_list(self, gen):
         res = []

Lib/test/test_asyncio/test_base_events.py

@@ -24,6 +24,10 @@
 PY34 = sys.version_info >= (3, 4)
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 def mock_socket_module():
     m_socket = mock.MagicMock(spec=socket)
     for name in (

Lib/test/test_asyncio/test_buffered_proto.py

@@ -4,6 +4,10 @@
 from test.test_asyncio import functional as func_tests
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 class ReceiveStuffProto(asyncio.BufferedProtocol):
     def __init__(self, cb, con_lost_fut):
         self.cb = cb

Lib/test/test_asyncio/test_context.py

@@ -3,6 +3,10 @@
 import unittest
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 class DecimalContextTest(unittest.TestCase):
 
     def test_asyncio_task_decimal_context(self):

Lib/test/test_asyncio/test_events.py

@@ -37,6 +37,10 @@
 from test import support
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 def osx_tiger():
     """Return True if the platform is Mac OS 10.4 or older."""
     if sys.platform != 'darwin':

Lib/test/test_asyncio/test_futures.py

@@ -14,6 +14,10 @@
 from test import support
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 def _fakefunc(f):
     return f
 

Lib/test/test_asyncio/test_locks.py

@@ -16,6 +16,10 @@
 RGX_REPR = re.compile(STR_RGX_REPR)
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 class LockTests(test_utils.TestCase):
 
     def setUp(self):

Lib/test/test_asyncio/test_pep492.py

@@ -11,6 +11,10 @@
 from test.test_asyncio import utils as test_utils
 
 
+def tearDownModule():
+    asyncio.set_event_loop_policy(None)
+
+
 # Test that asyncio.iscoroutine() uses collections.abc.Coroutine
 class FakeCoro:
     def send(self, value):