Test trigger for Odoo stock issues

trigger.sql

CREATE OR REPLACE FUNCTION check_quants_equal_moves()
RETURNS TRIGGER AS
$BODY$
DECLARE
  quants_amount int;
  moves_from int;
  moves_to int;
BEGIN
  quants_amount := (
    select sum(quantity) qty
    from stock_quant q
    where location_id = OLD.location_id
    and product_id = OLD.product_id
  );
  moves_from := (
    select coalesce(sum(qty_done), 0) qty
    from stock_move_line l
    where l.state = 'done'
    and location_id = OLD.location_id
    and product_id = OLD.product_id
  );
  moves_to := (
    select coalesce(sum(qty_done), 0) qty
    from stock_move_line l
    where l.state = 'done'
    and location_dest_id = OLD.location_id
    and product_id = OLD.product_id
  );
  IF quants_amount != moves_to - moves_from THEN
    raise exception '% is not % - %', quants_amount, moves_to, moves_from;
  END IF;
  RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql;

CREATE CONSTRAINT TRIGGER quants_equal_moves
AFTER INSERT OR UPDATE ON stock_quant
DEFERRABLE
INITIALLY DEFERRED
FOR EACH ROW EXECUTE PROCEDURE check_quants_equal_moves();

-- testing
begin;
update stock_move_line set qty_done = 5 where id = 1;
update stock_quant set quantity = 5 where id = 1;
update stock_quant set quantity = -5 where id = 2;
commit;
select id, location_id, location_dest_id, qty_done, state from stock_move_line where product_id = 1;
select id, location_id, quantity from stock_quant where product_id = 1;