Describe the feature you'd like to request

I'm a library author of a lib that does server-side rendering using getInitialProps and would like to access pages' getServerSideProps

The way it works right now in my library:

1. Wrap _app default export with a HOC
2. Makes a prepass of the whole app tree to fetch underlying queries
3. Puts those queries in a cache once they're done
4. Renders page with a hydrated cache

When using getInitialProps in my _app.tsx I'd like to be able to resolve the page component's getServerSideProps in order to do combine a getInitialProps-call which does a prepass and renders the tree but that could also get the data that the specific page component has requested.

Related issues that this would resolve:

• @trpc/next with ssr: true breaks getServerSideProps trpc/trpc#596 (my project)
• [next-urql] Using SSR with both withUrqlClient and getServerSideProps urql-graphql/urql#1091

Describe the solution you'd like

It would be nice if

type AppContextType<R extends NextRouter = NextRouter> = {
    Component: NextComponentType<NextPageContext>;
    AppTree: AppTreeType;
    ctx: NextPageContext;
    router: R;
};

Was extended to something that contained the component's GetServerSidePropsContext-function, example:

type AppContextType<R extends NextRouter = NextRouter, Q extends ParsedUrlQuery = ParsedUrlQuery> = {
    Component: NextComponentType<NextPageContext>;
    ComponentGetServerSideProps: GetServerSidePropsContext<Q>;
    AppTree: AppTreeType;
    ctx: NextPageContext;
    router: R;
};

Describe alternatives you've considered

There might be a way of explicitly loading a component's getServerSideProps function in my library's root HOC that I add to the _app - maybe using something like loadComponents. Is there perhaps a way of doing that?

Extra notes

This all currently works with stale-while-revalidate edge-caching on Vercel - to see a reference project have a look at https://typescript.careers (source is in the footer)