Postgres outputting an array in PSQL

Question

I have the following function. It is something I am building and want to show the contents of stuff_list so I can prove it is working correctly. I can't however work out what output type I should be using:

CREATE OR REPLACE FUNCTION isf.update_tbl_variadic(VARIADIC _stuff_array stuff[])
  RETURNS SETOF BIGINT[]
  LANGUAGE plpgsql AS
$$
DECLARE
    stuff_list BIGINT[];
BEGIN
    
    stuff_list:= ARRAY (
        SELECT id
    FROM stuff As s
    WHERE s."id"
    IN (
    SELECT t.id
    FROM unnest(_stuff_array) as t(
       id,
       x,
       y,
       created
   )))
 FOR UPDATE;

    RAISE NOTICE '%', stuff_list;
    RETURN stuff_list;
END;
$$;

Is anyone able to help me with this please? I need to generate an array from this to be used in a subsequent query, but for now I just need to see the output.

Answer 1

Since the function is declared as

RETURNS SETOF bigint[]

You need RETURN NEXT:

RETURN NEXT stuff_list;

Alternatively, to return a single array:

RETURNS bigint[]
...
RETURN stuff_list;

Or to return a set of bigint:

RETURNS SETOF bigint
...
RETURN QUERY SELECT unnest(stuff_list);

(Or return IDs directly, instead of aggregating and unnesting back.)