Listing functions when not enough results are available #580

class OpenMLTaskTest(TestBase):

    def mocked_perform_api_call(call):
        # TODO: JvR: Why is this not a staticmethod?
        url = openml.config.server + '/' + call
        return openml._api_calls._read_url(url)

    @mock.patch('openml._api_calls._perform_api_call', side_effect=mocked_perform_api_call)
    def test_list_all_few_results_available(self, _perform_api_call):
        # we want to make sure that the number of api calls is only 1.
        # Although we have multiple versions of the iris dataset, there is only
        # one with this name/version combination

        datasets = openml.datasets.list_datasets(size=1000,
                                                 data_name='iris',
                                                 data_version=1)
        self.assertEqual(len(datasets), 1)
        self.assertEqual(_perform_api_call.call_count, 1)