def test_observerlist(self):
ol = observer.ObserverList()
l1 = []
l2 = []
l3 = []
ol.subscribe(l1.append)
ol.notify(1)
ol.subscribe(l2.append)
ol.notify(2)
ol.unsubscribe(l1.append)
ol.notify(3)
def _check(res):
self.failUnlessEqual(l1, [1, 2])
self.failUnlessEqual(l2, [2, 3])
d = nextTurn()
d.addCallback(_check)
def _step2(res):
def _add(a, b, c=None):
l3.append((a, b, c))
ol.unsubscribe(l2.append)
ol.subscribe(_add)
ol.notify(4, 5, c=6)
return nextTurn()
def _check2(res):
self.failUnlessEqual(l3, [(4, 5, 6)])
d.addCallback(_step2)
d.addCallback(_check2)
return d
def test_observer_list_propagate_keyboardinterrupt(self):
"""
``KeyboardInterrupt`` escapes ``ObserverList.notify``.
"""
def observer_one():
raise KeyboardInterrupt()
obs = observer.ObserverList()
obs.subscribe(observer_one)
with self.assertRaises(KeyboardInterrupt):
obs.notify()
def test_observer_list_reentrant(self):
"""
``ObserverList`` is reentrant.
"""
observed = []
def observer_one():
obs.unsubscribe(observer_one)
def observer_two():
observed.append(None)
obs = observer.ObserverList()
obs.subscribe(observer_one)
obs.subscribe(observer_two)
obs.notify()
self.assertEqual([None], observed)
def test_observer_list_observer_errors(self):
"""
An error in an earlier observer does not prevent notification from being
delivered to a later observer.
"""
observed = []
def observer_one():
raise Exception("Some problem here")
def observer_two():
observed.append(None)
obs = observer.ObserverList()
obs.subscribe(observer_one)
obs.subscribe(observer_two)
obs.notify()
self.assertEqual([None], observed)
self.assertEqual(1, len(self.flushLoggedErrors(Exception)))