Using Spock to test Spring JdbcTemplate - unit-testing

Question

I have the following Java 8 DAO method that uses Spring JdbcTemplate to hit a database:
class MyAppDao {
#Inject
DataSource dataSource
public List<String> getFizzByBuzzIds(List<Integer> buzzIds) {
String sql = "SELECT * from buzzes WHERE buzz_id IN ( :buzzIds )";
NamedParameterJdbcTemplate jdbcTemplate = new NamedParameterJdbcTemplate(dataSource);
Map<String, Object> paramValues = new HashMap<>(1);
paramValues.put("buzzIds", buzzIds);
List<Buzz> buzzes = jdbcTemplate.query(sql,
paramValues, (rs, rowNum) -> {
return new Buzz(rs.getString("buzz_id"), rs.getString("buzz_key"),
rs.getString("buzz_external_id"));
}
);
List<String> fizzes = figureOutSomehow();
return fizzes;
}
}
I cannot change the dependencies injected into this method. The NamedParameterJdbcTemplate instance must be defined inside this method. The only thing I can mock (easily) is the dataSource.
I am trying (and I know, the method isn't written to be conducive to unit tests at all!) to write a Spock unit test for this, and just want to verify that when getFizzByBuzzIds is called, that jdbcTemplate.query is called (with any arguments).
My best attempt:
def 'getFizzByBuzzIds attempts to get case info from the DB'() {
given:
MyAppDao dao = Spy(MyAppDao, constructorArgs: [ dataSource ]) {
getJdbcTemplate() >> Mock(JdbcTemplate) {
1 * query('', null) // ???
}
}
when:
List<Integer> buzzIds = [1, 2, 3, 4]
dao.getFizzByBuzzIds(buzzIds)
then:
1 * dao.jdbcTemplate.query('', null) // ???
}
How can I configure the Spy and the then block label so that executing getFizzByBuzzIds verifies whether the underlying JdbcTemplate.query(...) method is called?