testy-params-box provides an aggregator to manage String Varargs.
@ParameterizedTest
@CsvSource({
"1, one, two, three"
})
void should_use_string_aggregator(int index, @AggregateWith(StringVargsAggregator.class) String... aggregated) {
assertThat(index).isEqualTo(1);
assertThat(aggregated).containsExactly("one", "two", "three");
}