days)->toBe($days) ->and($couponValidity->until)->toBe($until); }); it('rejects invalid coupon validity', function (): void { // GIVEN $days = 0; $until = new DateTime('2026-11-30'); // GIVEN / THEN expect(fn (): CouponValidity => new CouponValidity($days, $until))->toThrow(\DomainException::class); }); });