Minor - P4 test_find_is_async relies on a server-side Javascript delay, and it fails once every few thousand runs:
====================================================================== FAIL [0.519s]: test_find_is_async (tornado_tests.test_motor_collection.MotorCollectionTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/.tox/tornado4-py36/lib/python3.6/site-packages/tornado/testing.py", line 136, in __call__ result = self.orig_method(*args, **kwargs) File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/.tox/tornado4-py36/lib/python3.6/site-packages/tornado/testing.py", line 529, in post_coroutine timeout=timeout) File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/.tox/tornado4-py36/lib/python3.6/site-packages/tornado/ioloop.py", line 457, in run_sync return future_cell[0].result() File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/.tox/tornado4-py36/lib/python3.6/site-packages/tornado/concurrent.py", line 237, in result raise_exc_info(self._exc_info) File "<string>", line 3, in raise_exc_info File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/.tox/tornado4-py36/lib/python3.6/site-packages/tornado/gen.py", line 1024, in run yielded = self.gen.send(value) File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/.tox/tornado4-py36/lib/python3.6/types.py", line 182, in send return self.__wrapped.send(val) File "/data/mci/68b835babf09eff1eb41d81cd929496a/src/test/tornado_tests/test_motor_collection.py", line 121, in test_find_is_async self.assertEqual([{'_id': 2}, {'_id': 1}], results) AssertionError: Lists differ: [{'_id': 2}, {'_id': 1}] != [{'_id': 1}, {'_id': 2}] First differing element 0: {'_id': 2} {'_id': 1} - [{'_id': 2}, {'_id': 1}] ? ^ ^ + [{'_id': 1}, {'_id': 2}] ? ^ ^