class Test_raising_errors:
def setup_class(self):
self.eb = EventBus()
self.deaf = Dummy()
self.hey = Dummy()
self.you = Dummy()
def test_raise_when_event_is_of_wrong_type(self):
with pytest.raises(TypeError):
self.eb.register(EventBus, self.hey.increment)
def test_raise_when_trying_to_unregister_before_registering(self):
with pytest.raises(LookupError):
self.eb.unregister(PingEvent, self.hey.increment)
def test_raise_when_unregistering_wrong_listener(self):
self.eb.register(PingEvent, self.hey.increment)
with pytest.raises(LookupError):
self.eb.unregister(PingEvent, self.you.increment)
def test_raise_when_unregistering_from_wrong_event_type(self):
with pytest.raises(LookupError):
self.eb.unregister(AnotherEvent, self.hey.increment)
def test_raise_when_already_unregistered(self):
self.eb.unregister(PingEvent, self.hey.increment)
with pytest.raises(LookupError):
self.eb.unregister(PingEvent, self.hey.increment)
class Test_multiple_listeners:
def setup_class(self):
self.eb = EventBus()
self.deaf = Dummy()
self.hey = Dummy()
self.you = Dummy()
self.eb.register(PingEvent, self.hey.increment)
self.eb.register(AnotherEvent, self.you.increment)
assert self.deaf.x == 1
assert self.hey.x == 1
assert self.you.x == 1
def test_firing_impacts_only_interested_listener(self):
self.eb.dispatch(PingEvent(1))
assert self.deaf.x == 1
assert self.hey.x == 2 # changed
assert self.you.x == 1
self.eb.dispatch(PingEvent(1))
assert self.deaf.x == 1
assert self.hey.x == 3 # changed
assert self.you.x == 1
self.eb.dispatch(AnotherEvent(1))
assert self.deaf.x == 1
assert self.hey.x == 3
assert self.you.x == 2 # changed
def test_others_work_after_one_is_unregistered(self):
self.eb.unregister(PingEvent, self.hey.increment)
self.eb.dispatch(PingEvent(2))
# all unchanged
assert self.deaf.x == 1
assert self.hey.x == 3
assert self.you.x == 2
self.eb.dispatch(AnotherEvent(2))
assert self.deaf.x == 1
assert self.hey.x == 3
assert self.you.x == 4 # changed
def test_can_unregister_last_listener(self):
self.eb.unregister(AnotherEvent, self.you.increment)
self.eb.dispatch(PingEvent(3))
self.eb.dispatch(AnotherEvent(3))
# all unchanged
assert self.deaf.x == 1
assert self.hey.x == 3
assert self.you.x == 4
class Test_single_listener:
def setup_class(self):
self.eb = EventBus()
self.obj = Dummy()
def test_can_register(self):
self.eb.register(PingEvent, self.obj.increment)
assert self.obj.x == 1 # unchanged
def test_can_fire(self):
self.eb.dispatch(PingEvent(1))
assert self.obj.x == 2
self.eb.dispatch(AnotherEvent(1))
assert self.obj.x == 2 # unchanged
self.eb.dispatch(PingEvent(4))
assert self.obj.x == 6
def test_can_unregister(self):
self.eb.unregister(PingEvent, self.obj.increment)
self.eb.dispatch(PingEvent(2))
assert self.obj.x == 6 # unchanged
