05-prj-data-fetching useRouter Issue

[o-faro]

Hello, nice course, but there seems to be an issue with useRouter on pages/events/[...slug].js

Sometimes router.query.slug is an empty object and not only in pre-rendering phase. Especially wenn hitting enter instead of reloading the page.

To make sure not having any errors in my code I copied source code from your repo and changed the firebase url to my project.
I still get this error

I already did some research on this topic and tried to avoid this error by using 'router' Object in a useEffect without success. Using
useRouter().isReady as dependency did not work also. All in all quite unpredictable behaviour.

Also changed from "swr": "^2.2.1" to "swr": "^2.0.0" without success.
And also installed prj-05-data-fetching from this repository. Hitting enter a few times also leads to the described error.

[o-faro]

In case somebody runs into the same issue, my workaround for this at the moment

 // so poor
  const router = useRouter();
  const filterData = router.query.slug;
  // ...
  const filterDate = !filterData
    ? window.location.pathname
      .replace('/events/', '')
      .split('/')
    : filterData;

  const filteredYear = filterDate[0];
  const filteredMonth = filterDate[1];