influxdata/influxdb · error

Expected array value

Error message

Expected array value

What it means

A test panic in the `array_value` test of date_bin_wallclock.rs. The test expects the UDF to return ColumnarValue::Array when given array inputs, downcasts it to a TimestampNanosecondArray, and panics with "Expected array value" if a Scalar is returned instead.

Solutions

1. Reproduce with `cargo test -p query_functions date_bin_wallclock::tests::array_value`.
2. Ensure the implementation returns ColumnarValue::Array whenever any argument is an array, preserving nulls.
3. If the return is intentionally scalar-folded, change the test to build the expected array from the scalar.

Example fix

// before
ColumnarValue::Array(arr) => as_timestamp_nanosecond_array(&arr).unwrap().clone(),
_ => panic!("Expected array value"),
// after
ColumnarValue::Array(arr) => as_timestamp_nanosecond_array(&arr).unwrap().clone(),
ColumnarValue::Scalar(s) => panic!("expected array value, got scalar: {:?}", s),

assert!(matches!(result, ColumnarValue::Array(_)), "array inputs must produce array output");

fn expect_array(v: ColumnarValue) -> ArrayRef {
    match v { ColumnarValue::Array(a) => a, ColumnarValue::Scalar(s) => panic!("expected array, got scalar {:?}", s) }
}

let arr = match result {
    ColumnarValue::Array(a) => a,
    ColumnarValue::Scalar(s) => panic!("expected array value, got scalar {:?}", s),
};

When it happens

Trigger: Calling date_bin_wallclock with array source values (including a null) and matching ColumnarValue::Array; the panic fires when the implementation collapses the result to a scalar or returns the wrong variant.

Common situations: Occurs when an optimization shortcut returns a scalar for uniform array inputs, or when array/null handling is refactored and the array path is bypassed.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Error computing AND
• expected Float64Array
• Expected scalar value
• Expected three arguments
• Expected timestamp data type

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/9b17227e574c97e7. Report an issue: GitHub.

Appendix: source

Thrown at core/query_functions/src/date_bin_wallclock.rs:757

            ))),
            ColumnarValue::Array(arr),
        ];
        let arg_fields = arg_to_fields(&args);
        let result = match udf
            .invoke_with_args(ScalarFunctionArgs {
                args,
                arg_fields,
                number_rows: 3,
                return_field: return_field(DataType::Timestamp(
                    TimeUnit::Nanosecond,
                    Some(Arc::from("Europe/Paris")),
                )),
                config_options: default_config_options(),
            })
            .unwrap()
        {
            ColumnarValue::Array(arr) => as_timestamp_nanosecond_array(&arr).unwrap().clone(),
            _ => panic!("Expected array value"),
        };
        assert_eq!(
            result,
            TimestampNanosecondArray::from(vec![
                Some(MAYDAY - 2 * 60 * 60 * 1_000_000_000),
                None,
                Some(MAYDAY + 22 * 60 * 60 * 1_000_000_000),
            ])
            .with_timezone("Europe/Paris")
        );
    }

    #[test]
    fn array_interval_error() {
        let udf = DateBinWallclockUDF::default();
        let tz = Arc::from("UTC");
        let arr = Arc::new(IntervalMonthDayNanoArray::from(vec![
            Some(IntervalMonthDayNano {

View on GitHub (pinned to 06200ef96b)