Re-simpify AsyncTestCase setUp & tearDown

diff --git a/tornado/test/asyncio_test.py b/tornado/test/asyncio_test.py
index c33d7256b5ad56e692b9e6ed78cc2853fd1c5193..6ad1dcfbbe93971acd0ef1d708bff35e48ace0b0 100644 (file)
--- a/tornado/test/asyncio_test.py
+++ b/tornado/test/asyncio_test.py
@@ -30,6 +30,10 @@ class AsyncIOLoopTest(AsyncTestCase):
         io_loop = AsyncIOLoop(make_current=False)
         return io_loop
 
+    @property
+    def asyncio_loop(self):
+        return self.io_loop.asyncio_loop
+
     def test_asyncio_callback(self):
         # Basic test that the asyncio loop is set up correctly.
         async def add_callback():

diff --git a/tornado/testing.py b/tornado/testing.py
index 0232b219c7621d15a3f098ba8dab9f7745d7929e..508b1273f6b23dce3c3970fcf4ec054e87596f7f 100644 (file)
--- a/tornado/testing.py
+++ b/tornado/testing.py
@@ -182,49 +182,9 @@ class AsyncTestCase(unittest.TestCase):
         self._test_generator = None  # type: Optional[Union[Generator, Coroutine]]
 
     def setUp(self) -> None:
-        setup_with_context_manager(self, warnings.catch_warnings())
-        warnings.filterwarnings(
-            "ignore",
-            message="There is no current event loop",
-            category=DeprecationWarning,
-            module=r"tornado\..*",
-        )
         super().setUp()
-        # NOTE: this code attempts to navigate deprecation warnings introduced
-        # in Python 3.10. The idea of an implicit current event loop is
-        # deprecated in that version, with the intention that tests like this
-        # explicitly create a new event loop and run on it. However, other
-        # packages such as pytest-asyncio (as of version 0.16.0) still rely on
-        # the implicit current event loop and we want to be compatible with them
-        # (even when run on 3.10, but not, of course, on the future version of
-        # python that removes the get/set_event_loop methods completely).
-        #
-        # Deprecation warnings were introduced inconsistently:
-        # asyncio.get_event_loop warns, but
-        # asyncio.get_event_loop_policy().get_event_loop does not. Similarly,
-        # none of the set_event_loop methods warn, although comments on
-        # https://bugs.python.org/issue39529 indicate that they are also
-        # intended for future removal.
-        #
-        # Therefore, we first attempt to access the event loop with the
-        # (non-warning) policy method, and if it fails, fall back to creating a
-        # new event loop. We do not have effective test coverage of the
-        # new event loop case; this will have to be watched when/if
-        # get_event_loop is actually removed.
-        self.should_close_asyncio_loop = False
-        try:
-            self.asyncio_loop = asyncio.get_event_loop_policy().get_event_loop()
-        except Exception:
-            self.asyncio_loop = asyncio.new_event_loop()
-            self.should_close_asyncio_loop = True
-
-        async def get_loop() -> IOLoop:
-            return self.get_new_ioloop()
-
-        self.io_loop = self.asyncio_loop.run_until_complete(get_loop())
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            self.io_loop.make_current()
+        self.io_loop = self.get_new_ioloop()
+        self.io_loop.make_current()
 
     def tearDown(self) -> None:
         # Native coroutines tend to produce warnings if they're not
@@ -259,17 +219,13 @@ class AsyncTestCase(unittest.TestCase):
 
         # Clean up Subprocess, so it can be used again with a new ioloop.
         Subprocess.uninitialize()
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            self.io_loop.clear_current()
+        self.io_loop.clear_current()
         if not isinstance(self.io_loop, _NON_OWNED_IOLOOPS):
             # Try to clean up any file descriptors left open in the ioloop.
             # This avoids leaks, especially when tests are run repeatedly
             # in the same process with autoreload (because curl does not
             # set FD_CLOEXEC on its file descriptors)
             self.io_loop.close(all_fds=True)
-        if self.should_close_asyncio_loop:
-            self.asyncio_loop.close()
         super().tearDown()
         # In case an exception escaped or the StackContext caught an exception
         # when there wasn't a wait() to re-raise it, do so here.