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use role sysadmin;
use database ttips;
use schema udfs;

-- creating a javascript function with not null specification
create or replace function not_null_udf()
returns string not null
language javascript
as
$$
    return null
$$;

-- lets see how does it capture
desc function not_null_udf();

-- call the function and observer the behaviour
select not_null_udf();

-- lets fix it
create or replace function not_null_udf()
returns string null
language javascript
as
$$
    return null
$$;

-- rerun the function
select not_null_udf();

-- so this is how it works. This is very similar to strict keyword in stored procedure
-- which we covered in previous chapter (ch-21.1)
-- https://youtu.be/CsH2sB6gwlw

-- lets see if this works in SQL language
create or replace function not_null_sql_udf()
RETURNS string
comment = 'this is simple not null enforcement test for SQL function'
as
$$
    select null
$$;

desc function not_null_sql_udf();
select not_null_sql_udf();

-- now add the paramter and see the behaviour
-- it allows to add the keyword but does not enforce.