from __future__ import division, absolute_import

import unittest

from twisted.internet import defer

# Used in test_tests.TestUnhandledDeferred

class TestBleeding(unittest.TestCase):
"""This test creates an unhandled Deferred and leaves it in a cycle.

The Deferred is left in a cycle so that the garbage collector won't pick it
up immediately. We were having some problems where unhandled Deferreds in
one test were failing random other tests. (See #1507, #1213)
"""
def test_unhandledDeferred(self):
try:
1/0
except ZeroDivisionError:
f = defer.fail()
# these two lines create the cycle. don't remove them
l = [f]
l.append(l)