dynamic=auto doesn't generate static files/use Next.js cache

[pmi]

Summary

Next.js 14.1.0

I have a page with generateStaticParams that produces html+meta+rsc files for every content item in .next/server/app/... folder at build time when dynamic=force-static or dynamic=error.

But whenever I set dynamic=auto it doesn't generate static files and I can see in logs that each request is processed at runtime:

• dynamic=auto
  • Build logs say pages are SSG
  • No html + meta + rsc files created in .next/server/app/... folder
  • Next.js cache header is absent
• dynamic=force-static
  • Build logs say pages are SSG
  • Files created in .next/server/app/... folder
  • Next.js cache HIT header is present

I don't use any dynamic functions that could bail out static generation.
I use fetch with POST request to graphql endpoint without any custom cache settings.
I use middleware with rewrite invocation if that makes any difference.

Looking at the docs I would assume that Next.js would cache the data + views and create static pages in dynamic=auto mode as well ?
Also, is there is a way to tell if the data fetch results were cached ?

Thanks in advance !

Additional information

Page.tsx

export type PageProps = {
    locale: string,
    contentPath: string[],
}

export default async function Page({params}: { params: PageProps }) {

    console.info(`Accessing page`, params);

    const start = Date.now();
    const data: FetchContentResult = await fetchContent(params);
    const duration = Date.now() - start;

    console.info(`Page fetch took ${duration} ms`);

    validateData(data);

    return (
        <MainView {...data}/>
    )
};

export async function generateMetadata({params}: { params: PageProps }): Promise<Metadata> {
    const {common} = await fetchContent(params);
    return {
        title: common?.get?.displayName || 'Not found',
    };
}

export async function generateStaticParams(props: { params: PageProps }): Promise<any[]> {
    return await fetchContentPathsForAllLocales('\${site}/');
}

where fetchContent is a complex function posting to graphql endpoint with fetch:

    const opts = {
        method: options?.method || 'POST',
        body: options?.body ? JSON.stringify(options?.body) : null,
        headers: mergeHeaders(projectConfig, options?.headers),
        next: options?.next,
        cache: options?.cache,
    };

    try {
        const res = await fetch(apiUrl, opts);
    }

and validateData basically throws notFound if there is no content.

Example

No response

[Rishab49]

can you share the page code?

[pmi]

Hi @Rishab49 !

I have now added page source to the description !

[kurtrank]

I ran into this myself recently, and I think there is a bug and/or the docs are incorrect about auto. I found an existing issue about it here #65799

Also, is there is a way to tell if the data fetch results were cached ?

With 16.3.0 it looks like they are stored in .next/cache/fetch-cache, though maybe that has changed in the last 2 years since you posted this haha.