NextResponse error after upgrading to version 13.5.2

[Revaycolizer]

Link to the code that reproduces this issue

https://github.com/Revaycolizer/minimal-repo/tree/main/app/api

To Reproduce

1. Clone repo
2. next build
3. See type error on GET route handler

Current vs. Expected behavior

Expected to return data but instead it throws an error stating that Promise<NextResponse | undefined>" is not a valid GET return type:

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
      Platform: win32
      Arch: x64
      Version: Windows 10 Pro
    Binaries:
      Node: 16.17.0
      npm: N/A
      Yarn: N/A
      pnpm: N/A
    Relevant Packages:
      next: 13.5.2
      eslint-config-next: 13.5.2
      react: 18.2.0
      react-dom: 18.2.0
      typescript: 5.1.6
    Next.js Config:
      output: N/A

Which area(s) are affected? (Select all that apply)

App Router

Additional context

I am deploying my application in vercel

[hipdev]

Hello, in the last Next.js version apparently new rules were added, and you can no longer return undefined, the route API expects you to return "Response | Promise"
As the error mentions, you have an undefined in your GET route.
Just add a response in this last catch and that's it 👍

export async function GET(req: Request, res: Response) {
  try {
    const cookieStore = cookies()
    const token = cookieStore.get(SEARCHED)
    const posts = JSON.parse(token!.value)

    return NextResponse.json(posts)
  } catch (error) {
    return NextResponse.json(
      { error: 'Ouch, GET is not working my friend' },
      { status: 500 },
    )
  }
}

[gavhuang]

@hipdev thank you!

Adding a return in the catch block fixed it for me.

[Revaycolizer]

It works @hipdev thanks

[nextjs-bot]

This issue has been automatically marked as stale due to two years of inactivity. It will be closed in 7 days unless there’s further input. If you believe this issue is still relevant, please leave a comment or provide updated details. Thank you.