def test_get(self):
assert isinstance(NullCollection()[0], NullNode)
def test_first(self):
assert isinstance(NullCollection().first(), NullNode)
def test_slice(self):
assert isinstance(NullCollection()[::2], NullCollection)
def test_collection_to_collection_methods(self, func):
result = getattr(NullCollection(), func)(lambda x: 1)
assert isinstance(result, NullCollection)
def test_dump(self):
with pytest.raises(NullValueError):
return NullCollection().dump().val()
def test_iter_val(self):
with pytest.raises(NullValueError):
return NullCollection().iter_val()
def test_count(self):
assert Collection([]).count().val() == 0
assert Collection([Scalar(1)]).count().val() == 1
assert NullCollection().count().val() == 0