Function getRouteId

packages/sveltekit/src/common/utils.ts:25–43

(event: EventLike)

 * otherwise falls back to getOwnPropertyDescriptor for SvelteKit 1.x.
 */
export function getRouteId(event: EventLike): string | void {
  if (typeof event.untrack === 'function') {
    return event.untrack(() => event.route?.id ?? undefined);
  }

  const route = event.route;
  if (!route) {
    return;
  }

  const descriptor = Object.getOwnPropertyDescriptor(route, 'id');
  const fromDescriptor = descriptor?.value as string | null | undefined;

  if (fromDescriptor !== undefined && fromDescriptor !== null) {
    return fromDescriptor;
  }

  return;
}

/**
 * Determines if a thrown "error" is a Redirect object which SvelteKit users can throw to redirect to another route