Question 183101 in Javascript Question posted in
A very good W3school tutorial can be found here.

Javascript – TypeError: Cannot read properties of undefined (reading 'headers') at eval Next js

Hi i am having this error in next js

TypeError: Cannot read properties of undefined (reading 'headers')
at eval (webpack-internal:///(sc_server)/./node_modules/next/dist/server/future/route-modules/app-route/module.js:254:61)

a sample of code snippet

  newUser
    .save()
    .then(() =>
      NextResponse.json({ msg: "Successfuly created new User: " + newUser ,status:200})
    )
    .catch((err: string) =>{
    NextResponse.json({ error: "Error on '/api/register': " + err ,status:400})
    }
    );

tried multiple approach like importing NextApiRequest and NextApiResponse and using it.
it has no status and json properties in it basically it is giving types error property does not exist in NextApiResponse.
so i am using NextResponse directly still getting this error

Tags:

2

Answers


  1. 0

    The error you’re encountering seems to be related to the headers property in the NextResponse object. However, it’s difficult to pinpoint the exact cause without a complete code snippet or more context. Nevertheless, I can provide some general guidance to help you troubleshoot and resolve the issue.

    Make sure you are importing the NextResponse object correctly. In Next.js, the NextApiResponse type provides the structure for the response object, but you need to create an instance of NextResponse to work with the response.
    Ensure that you have the following import statement at the top of your file:

    import { NextApiResponse } from 'next';

    And then create an instance of NextResponse using:

    const NextResponse = response as NextApiResponse;

    Make sure response is the variable that holds the response object you received as a parameter in your API route handler.
    Confirm that the newUser.save() function returns a valid response object. Check if the returned value has the necessary properties, such as headers, before accessing them in your response handling code.
    You might also consider wrapping the entire newUser.save() logic in a try/catch block to catch any potential errors and handle them accordingly. For example:

    try {
  await newUser.save();
  return NextResponse.json({ msg: "Successfully created new User: " + newUser, status: 200 });
} catch (error) {
  return NextResponse.json({ error: "Error on '/api/register': " + error, status: 400 });
}

    Note the use of async/await to handle the promise returned by newUser.save(). Ensure that the surrounding function is marked as async for this approach to work.
    Check the versions of the Next.js packages you are using. It’s possible that the issue is caused by a compatibility problem between different versions. Ensure that all relevant packages (next, react, react-dom, etc.) are up to date and compatible with each other.I hope I could help you

    Login or Signup to reply.
  2. 0

    I think you have to return the NextResponse.json.

    That is what could be causing that error.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search