bug: useIsFirstRender broken with NextJs App router

[technophile-04]

Demo :

It seems that useIsFirstRender always returns false in NextJs App router, here is an example :

Screen.Recording.2023-10-03.at.2.48.58.PM.mov

So localhost:8080 serves the page from app dir and localhost:8080/pagedir serves it from pages dir

As we can see when on localhost:8080 useUpdateEffect runs directly instead on localhost:8080/pagedir it does not since its it first render

here is minimal reproducible repo : https://github.com/technophile-04/useIsFirstRender-mrr

Its just a new create-next-app with usehooks-ts installed and utilizing useDarkMode which internally rely's on useIsFirstRender

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Possible reason :

Maybe it's because Nextjs might be running useIsFirstRender in server before serving it to client, saying this because I came across this vercel/next.js#52566 (comment) which states some hooks can be ran on server like useId etc and useRef might be one of them 🤔 but I maybe completely wrong here !!

Update :

It seems that disabling reactStrictMode in App router solves the issue but its bad idea to do so :(

[juliencrn]

useDarkMode is no longer based on useIsFirstRender, this should be fixed right now