def test_conn_missing_cluster(self):
        db.merge_conn(
            Connection(
                conn_id=ADX_TEST_CONN_ID,
                conn_type='azure_data_explorer',
                login='client_id',
                password='client secret',
                extra=json.dumps({}),
            )
        )
        with pytest.raises(AirflowException) as ctx:
            AzureDataExplorerHook(azure_data_explorer_conn_id=ADX_TEST_CONN_ID)
        assert 'Host connection option is required' in str(ctx.value)