SELECT
    sum(multiIf(id IS NULL, 1, 0)) -- same for case/if
FROM test
SETTINGS allow_experimental_analyzer = 1, optimize_functions_to_subcolumns = 1;

Received exception from server (version 23.12.2):
Code: 43. DB::Exception: Received from localhost:9000. DB::Exception: Illegal type Int64 of first argument (condition) of function if. Must be UInt8.. (ILLEGAL_TYPE_OF_ARGUMENT)
(query: SELECT
    sum(multiIf(id IS NULL, 1, 0))
FROM test
SETTINGS allow_experimental_analyzer = 1, optimize_functions_to_subcolumns = 1;)

SELECT sum(If(id IS NULL, 1, 0))
FROM test,
(
    SELECT number
    FROM numbers(100)
) AS e
SETTINGS allow_experimental_analyzer = 1, optimize_functions_to_subcolumns = 1

Elapsed: 0.004 sec.

Received exception:
Code: 43. DB::Exception: Illegal type Int64 of last argument for aggregate function with If suffix. (ILLEGAL_TYPE_OF_ARGUMENT)

 SELECT sum(case when id IS NULL then 1 else 0 end)
FROM test,
(
    SELECT number
    FROM numbers(100)
) AS e
SETTINGS allow_experimental_analyzer = 1, optimize_functions_to_subcolumns = 1;

Elapsed: 0.001 sec.

Received exception:
Code: 43. DB::Exception: Illegal type Int64 of first argument (condition) of function if. Must be UInt8. (ILLEGAL_TYPE_OF_ARGUMENT)

Received exception from server (version 24.1.1):
Code: 43. DB::Exception: Received from localhost:9000. DB::Exception: Illegal type Int64 of first argument (condition) of function if. Must be UInt8.. (ILLEGAL_TYPE_OF_ARGUMENT)
(query: select  i_item_desc
      ,w_warehouse_name
      ,d1.d_week_seq d_week_seq
      ,sum(case when p_promo_sk is null then 1 else 0 end) no_promo
      ,sum(case when p_promo_sk is not null then 1 else 0 end) promo
      ,count(*) total_cnt
from catalog_sales
join inventory on (cs_item_sk = inv_item_sk)
join warehouse on (w_warehouse_sk=inv_warehouse_sk)
join item on (i_item_sk = cs_item_sk)
join customer_demographics on (cs_bill_cdemo_sk = cd_demo_sk)
join household_demographics on (cs_bill_hdemo_sk = hd_demo_sk)
join date_dim d1 on (cs_sold_date_sk = d1.d_date_sk)
join date_dim d2 on (inv_date_sk = d2.d_date_sk)
join date_dim d3 on (cs_ship_date_sk = d3.d_date_sk)
left outer join promotion on (cs_promo_sk=p_promo_sk)
left outer join catalog_returns on (cr_item_sk = cs_item_sk and cr_order_number = cs_order_number)
where d1.d_week_seq = d2.d_week_seq
  and inv_quantity_on_hand < cs_quantity 
  and d3.d_date > d1.d_date + 5
  and hd_buy_potential = '1001-5000'
  and d1.d_year = 2001
  and cd_marital_status = 'M'
group by i_item_desc,w_warehouse_name,d1.d_week_seq
order by total_cnt desc, i_item_desc, w_warehouse_name, d_week_seq
LIMIT 100;)