Function groups_with_nulls

datafusion/functions-aggregate/src/string_agg.rs:829–852

()

    #[test]
    fn groups_with_nulls() -> Result<()> {
        let mut acc = make_groups_acc("|");

        // Group 0: "a", NULL, "c" → "a|c"
        // Group 1: NULL, "b"     → "b"
        // Group 2: NULL only     → NULL
        let values: ArrayRef = Arc::new(LargeStringArray::from(vec![
            Some("a"),
            None,
            Some("c"),
            None,
            Some("b"),
            None,
        ]));
        let group_indices = vec![0, 1, 0, 2, 1, 2];
        acc.update_batch(&[values], &group_indices, None, 3)?;

        let result = evaluate_groups(&mut acc, EmitTo::All);
        assert_eq!(
            result,
            vec![Some("a|c".to_string()), Some("b".to_string()), None,]
        );
        Ok(())
    }

    #[test]
    fn groups_with_filter() -> Result<()> {