exception when others then 
    return someFuncErrorProc ();

CREATE OR REPLACE FUNCTION public.error_message(
	)
    RETURNS text
    LANGUAGE 'plpgsql'
    COST 100.0
    VOLATILE NOT LEAKPROOF 
AS $function$

declare
	SQLMessage text;
begin
	get stacked diagnostics
    	SQLMessage = MESSAGE_TEXT;
	return SQLMessage;
end

$function$;

CREATE OR REPLACE FUNCTION test.test_er(
	)
    RETURNS text
    LANGUAGE 'plpgsql'
    COST 100.0
    VOLATILE NOT LEAKPROOF 
AS $function$

declare
	em text;
    SQLMessage text;
begin
	insert into test.test_excep values (1, 1, current_date, 'TEST1');
    em = 'TS: '; -- || error_message();
    return em;
exception
	when others then
    	em = 'TE: ' || error_message();
--		get stacked diagnostics
--			SQLMessage = MESSAGE_TEXT;

	return em; -- || '\r\nSQLM: ' || SQLMessage;
end

$function$;