Why does renderToHTML with getServerSideProps send response, return null?

[visum]

I would like to get the HTML result of a render of page components that use getServerSideProps, but there is a check in renderToHTMLWithComponnets() (packages/next/next-server/server/next-server.ts, line 996) that forces the response to be sent immediately instead of being returned.

      if (html && isServerProps) {
        sendPayload(res, html, 'html', {
          private: isPreviewMode,
          stateful: true, // GSSP request
        })
        return null
      }

My hope was to cache the result.

Can someone help me figure out why this is desirable as designed? It seems to be on purpose, so it feels like I'm using it wrong.

[superkoh]

got the same problem, should post to issues

[visum]

Link to the issue: #11665