def test_trait_method_optional_true(self):
# Test the instance method calls the top-level function correctly.
expr = expression.trait("name").trait("attr", optional=True)
expected = [
create_graph(
NamedTraitObserver(name="name", notify=True, optional=False),
NamedTraitObserver(name="attr", notify=True, optional=True),
),
]
actual = expr._as_graphs()
self.assertEqual(actual, expected)
def test_not_equal_type(self):
observer = NamedTraitObserver(name="foo", notify=True, optional=True)
imposter = mock.Mock()
imposter.name = "foo"
imposter.notify = True
imposter.optional = True
self.assertNotEqual(observer, imposter)
def trait(name, notify=True, optional=False):
""" Create a new expression for observing a trait with the exact
name given.
Events emitted (if any) will be instances of
:class:`~traits.observation.events.TraitChangeEvent`.
Parameters
----------
name : str
Name of the trait to match.
notify : bool, optional
Whether to notify for changes. Default is to notify.
optional : bool, optional
If true, skip this observer if the requested trait is not found.
Default is false, and an error will be raised if the requested
trait is not found.
Returns
-------
new_expression : ObserverExpression
"""
observer = NamedTraitObserver(
name=name, notify=notify, optional=optional)
return SingleObserverExpression(observer)
def test_trait_name_optional_true(self):
# Test the top-level function
expr = expression.trait("name", optional=True)
expected = [
create_graph(
NamedTraitObserver(name="name", notify=True, optional=True)),
]
actual = expr._as_graphs()
self.assertEqual(actual, expected)
def create_observer(**kwargs):
""" Convenient function for creating an instance of NamedTraitObserver.
"""
values = dict(
name="name",
notify=True,
optional=False,
)
values.update(kwargs)
return NamedTraitObserver(**values)
def test_equal_observers(self):
observer1 = NamedTraitObserver(name="foo", notify=True, optional=True)
observer2 = NamedTraitObserver(name="foo", notify=True, optional=True)
self.assertEqual(observer1, observer2)
self.assertEqual(hash(observer1), hash(observer2))
def test_not_equal_optional(self):
observer1 = NamedTraitObserver(name="foo", notify=True, optional=False)
observer2 = NamedTraitObserver(name="foo", notify=True, optional=True)
self.assertNotEqual(observer1, observer2)
