Force useSWR return data fetching not to be undefined with config.fallbackData

[tannguyencse19]

Continue from #1764 😄

I want to return static data when useSWR fetch error or data is undefined.

I try this

// <Children />
const { data } = useSWR("/destination", {
  fallbackData: static_data,
});

data type still static_data_type | undefined. Any short way to get around this?

---

Don't know this way will also make useSWR return data not undefined or not?

// <Parent />
export const getStaticProps: GetStaticProps = async (
  context
) => {
  const planet = await fetch("/destination");

  return {
    props: {
      SWRFallback: {
        "/destination": planet ? planet : static_data,
      },
    },
  };
};

[iv-stpn]

+1

It would be great for this behavior to work with SSR as well for dynamic fetching, to have some sort of globally shared variable that could serve as a revalidated cache (e.g. a user object fetched via /api/me in the root layout that is expected to be available throughout the app, and could be mutated once the user updates their profile)