Call rpc void function returns json parsing error

[phamhieu]

Bug report

Describe the bug

My store_sentry_event function used to be defined like this:

create or replace function public.store_sentry_event(json_content jsonb)
  returns void security definer
  language sql
as $$
  insert into private.sentry_event (received, content)
  values(transaction_timestamp(), json_content);
$$;

But I noticed that my code that calls that function directly via SupbaseClient.rpc() started failing with error:

Uncaught (in promise) SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data

supabase/supabase#762

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

1. Create a void function
2. Call void function from supabase client
3. See Json pasing error