def test_filter_metadata(self):
class Person(HasTraits):
n_jobs = Int(status="public")
n_children = Int() # no metadata
observer = FilteredTraitObserver(
filter=MetadataFilter(metadata_name="status", ),
notify=True,
)
person = Person()
handler = mock.Mock()
call_add_or_remove_notifiers(
object=person,
graph=create_graph(observer),
handler=handler,
)
# when
person.n_jobs += 1
# then
self.assertEqual(handler.call_count, 1)
handler.reset_mock()
# when
person.n_children += 1
# then
self.assertEqual(handler.call_count, 0)
def test_metadata_defined_as_none_is_same_as_undefined(self):
# If a metadata has a None value, it is equivalent to the metadata
# not being defined.
metadata_filter = MetadataFilter(metadata_name="name", )
self.assertFalse(metadata_filter("name",
Int(name=None).as_ctrait()),
"Expected the filter to return false")
def metadata(metadata_name, notify=True):
""" Return a new expression for observing traits where the given metadata
is not None.
Events emitted (if any) will be instances of
:class:`~traits.observation.events.TraitChangeEvent`.
e.g. ``metadata("age")`` matches traits whose 'age' attribute has a
non-None value.
Parameters
----------
metadata_name : str
Name of the metadata to filter traits with.
notify : bool, optional
Whether to notify for changes. Default is to notify.
Returns
-------
new_expression : ObserverExpression
"""
return match(
filter=MetadataFilter(metadata_name=metadata_name),
notify=notify,
)
def test_metadata_method_notify_false(self):
# Test the instance method calls the top-level function correctly.
expr = expression.metadata("bee").metadata("ant", notify=False)
expected = [
create_graph(
FilteredTraitObserver(
filter=MetadataFilter(metadata_name="bee"),
notify=True,
),
FilteredTraitObserver(
filter=MetadataFilter(metadata_name="ant"),
notify=False,
),
),
]
actual = expr._as_graphs()
self.assertEqual(actual, expected)
def test_metadata_defined_vs_undefined(self):
metadata_filter = MetadataFilter(metadata_name="name", )
self.assertTrue(metadata_filter("name",
Int(name=True).as_ctrait()),
"Expected the filter to return true")
self.assertFalse(metadata_filter("name",
Int().as_ctrait()),
"Expected the filter to return false")
def test_metadata_notify_false(self):
# Test the top-level function
expr = expression.metadata("butterfly", notify=False)
expected = [
create_graph(
FilteredTraitObserver(
filter=MetadataFilter(metadata_name="butterfly"),
notify=False,
), ),
]
actual = expr._as_graphs()
self.assertEqual(actual, expected)
def test_repr_value(self):
metadata_filter = MetadataFilter(metadata_name="name", )
actual = repr(metadata_filter)
self.assertEqual(actual, "MetadataFilter(metadata_name='name')")
def test_filter_not_equal_different_type(self):
filter1 = MetadataFilter(metadata_name="name", )
imposter = mock.Mock()
imposter.metadata_name = "name"
self.assertNotEqual(imposter, filter1)
def test_filter_not_equal_name_different(self):
filter1 = MetadataFilter(metadata_name="number", )
filter2 = MetadataFilter(metadata_name="name", )
self.assertNotEqual(filter1, filter2)
def test_filter_equality(self):
filter1 = MetadataFilter(metadata_name="name", )
filter2 = MetadataFilter(metadata_name="name", )
self.assertEqual(filter1, filter2)
self.assertEqual(hash(filter1), hash(filter2))