Reducing code repetition with guards

[Indeedornot]

Hi!
I am using routing guards to ensure the given parameters are of a correct type - however it causes a lot of unnecessary code repetition - due to beforeEnter being a macro and cannot share any code

const path = '/[occasionId]/artists/new/';
const router = useRouter();
const route = useRoute(path);

definePage({
	beforeEnter: (to, from, next) => {
		const params = to.params;
		const occasionId = Guards.Numbers.toNumber(params?.occasionId);

		if (occasionId === null) {
			next(Redirects.errorLocation('Invalid Parameters: ', params));
			return;
		}

		next();
	}
});
onBeforeRouteUpdate((to, from, next) => {
	const params = to.params as RouteParams<typeof path>;
	const occasionId = Guards.Numbers.toNumber(params?.occasionId);

	if (occasionId === null) {
		next(Redirects.errorLocation('Invalid Parameters: ', params) satisfies RouteLocationRaw);
		return;
	}

	next();
});

type Params = {
	occasionId: number;
};

another thing is that i cannot use any casts or satisfies inside of beforeEnter due to it throwing an error