def test_weakref_event_emitter_cb(disconnect_and_should_be_none):
"""
Note that as above but with pure callback, We keep a reference to it, the
reason is that unlike with bound method, the callback may be a closure and
may not stick around.
We thus expect the wekref to be None only if explicitely disconnected
"""
e = EventEmitter(type='test_weak')
def cb(self):
pass
ref_cb = weakref.ref(cb)
e.connect(cb)
with e.blocker(cb):
e()
if disconnect_and_should_be_none:
e.disconnect(cb)
del cb
assert ref_cb() is None
else:
del cb
assert ref_cb() is not None
def test_weakref_event_emitter():
"""
We are testing that an event blocker does not keep hard reference to
the object we are blocking, especially if it's a bound method.
The reason it used to keep references is to get the count of how many time
a callback was blocked, but if the object does not exists, then the bound method
does not and thus there is no way to ask for it's count.
so we can keep only weak refs.
"""
e = EventEmitter(type='test_weak')
class Obj:
def cb(self):
pass
o = Obj()
ref_o = weakref.ref(o)
e.connect(o.cb)
#
with e.blocker(o.cb):
e()
del o
assert ref_o() is None
def test_event_blocker_count():
"""Test event emitter block counter with emission."""
e = EventEmitter(type="test")
with e.blocker() as block:
e()
e()
e()
assert block.count == 3