I wanted to use this linter, but they don't support many things that are used in real production code. By example, a simple postgres function like this one can't be parsed:

  CREATE OR REPLACE FUNCTION public.setof_test()
   RETURNS SETOF text
   LANGUAGE sql
   STABLE STRICT
  AS $function$
    select unnest(array['hi', 'test'])
  $function$
  ;