def test_emits_no_warnings_when_unused(self):
func = settings.DeprecatedSetting(FakeSetting(result=None),
message='what to do instead')
func.warn = mock.Mock(spec_set=[])
result = func({})
assert result is None
assert not func.warn.called
def test_emits_warnings_when_child_setting_is_used(self):
func = settings.DeprecatedSetting(FakeSetting(result={'foo': 'bar'}),
message='what to do instead')
func.warn = mock.Mock(spec_set=[])
result = func({})
assert result == {'foo': 'bar'}
func.warn.assert_called_once_with('use of fake setting is '
'deprecated: what to do instead')