def test_list_weakref(self):
# Create one ImmutableList
self.assertEqual(ImmutableList._get_instance_count(), 0)
d = ImmutableList([1, 2])
self.assertEqual(ImmutableList._get_instance_count(), 1)
# Store in a weakref.WeakValueListionary
wvd = weakref.WeakValueDictionary()
wvd[1] = d
self.assertEqual(ImmutableList._get_instance_count(), 1)
self.assertEqual(len(wvd), 1)
self.assertTrue(wvd[1] is d)
# Release the only reference to the ImmutableList
d = None
self.assertEqual(ImmutableList._get_instance_count(), 0)
# Check that it is no longer in wkd
self.assertEqual(len(wvd), 0)
with self.assertRaises(KeyError):
wvd[1]
# Create a new ImmutableList, check that it not magically appears in
# wkd
d = ImmutableList([1, 2])
self.assertEqual(ImmutableList._get_instance_count(), 1)
self.assertEqual(len(wvd), 0)
with self.assertRaises(KeyError):
wvd[1]
def immutables_count():
return (ImmutableDict._get_instance_count() +
ImmutableList._get_instance_count())