withUser redirect to login page takes much longer on Vercel than on localhost

[azhong-git]

Hi I am using withUser on a page /ssr-required following the official example. It will redirect to a static login page /auth if user is not authenticated. However I found that the redirection itself takes quite long (as long as 4 seconds) when deployed on Vercel. It almost felt that the page is unresponsive for 4 seconds.

I believe "this long pause" is contributed by redirection (not Firebase init on the auth page). My reasoning:

• When page is redirected to /auth, in my case I expect to observe a brief moment of no content because I set whenUnauthedBeforeInit: AuthAction.RETURN_NULL on /auth.tsx. I did observed this brief moment of no content, right after the long pause. This suggests the long pause is caused by redirection.
• I tried to go directly to /auth and did not observe the long pause.

Other findings:

• In a short period, the long pause is no longer happening after the first time accessing ssr-required.
• This long pause seems to only happen on Vercel and not localhost.

Any help would be appreciated!

ssr-required/index.tsx that uses withUser to redirect to auth:

export const getServerSideProps = withUserTokenSSR({
  whenUnauthed: AuthAction.REDIRECT_TO_LOGIN,
})(async ({ user, req }: any) => {
    // Call some api using user token and return data in props 
  };
});

export default withUser({
  whenUnauthedAfterInit: AuthAction.REDIRECT_TO_LOGIN,
  whenUnauthedBeforeInit: AuthAction.REDIRECT_TO_LOGIN,
})(UserConsole as any);

auth.tsx static page

const Auth = () => (
  <div>
      <FirebaseAuth />
  </div>
);

export default withUser({
  whenAuthed: AuthAction.REDIRECT_TO_APP,
  whenUnauthedAfterInit: AuthAction.RENDER,
  whenUnauthedBeforeInit: AuthAction.RETURN_NULL,
})(Auth);