PRAGMA WindowNewPipeline;

$data = [
    <|a: TzDate("2017-11-25,Europe/Moscow"), b: 1, count: 1|>,
    <|a: TzDate("2017-11-26,Europe/Moscow"), b: 1, count: 2|>,
    <|a: TzDate("2017-11-27,Europe/Moscow"), b: 1, count: 2|>,
    <|a: NULL, b: 1, count: 2|>,
    <|a: NULL, b: 1, count: 2|>,
];

$win_result = (
    SELECT
        COUNT(*) OVER w1 AS actual_count,
        count,
    FROM
        AS_TABLE($data)
    WINDOW
        w1 AS (
            PARTITION COMPACT BY
                b
            ORDER BY
                a ASC
            RANGE BETWEEN Interval("P1D") PRECEDING AND CURRENT ROW
        )
);

$str = ($x) -> {
    return CAST($x as String) ?? "null";
};

SELECT
    Ensure(actual_count, count IS NOT DISTINCT FROM actual_count, $str(actual_count))
FROM
    $win_result
;