await req.json() in edge middleware returns undefined

[switz]

What version of Next.js are you using?

12.0.7

What version of Node.js are you using?

14 LTS

What browser are you using?

Firefox

What operating system are you using?

Mac 12.1

How are you deploying your application?

locally

Describe the Bug

I have a _middleware.ts file:

export async function middleware(req: NextRequest) {
  if (req.method !== 'POST') {
    return error('POST only...');
  }

  const body = await req.json().catch((err) => {
    console.log('token json', err);
  });
  console.log({ body });


  // etc...

}

This logs out:

token json TypeError: invalid json body reason: Unexpected end of JSON input
    at NextRequestHint.json (evalmachine.<anonymous>:172:19)
    at async Object.middleware [as handler] (webpack-internal:///./src/pages/api/token/_middleware.ts:50:16)
    at async adapter (webpack-internal:///../../node_modules/next/dist/server/web/adapter.js:30:22)
    at async DevServer.runMiddleware (/Users/me/app/node_modules/next/dist/server/next-server.js:448:26)
    at async DevServer.runMiddleware (/Users/me/app/node_modules/next/dist/server/dev/next-dev-server.js:400:28)
    at async Object.fn (/Users/me/app/node_modules/next/dist/server/next-server.js:827:34)
    at async Router.execute (/Users/me/app/node_modules/next/dist/server/router.js:222:32)
    at async DevServer.run (/Users/me/app/node_modules/next/dist/server/next-server.js:1135:29)
    at async DevServer.run (/Users/me/app/node_modules/next/dist/server/dev/next-dev-server.js:445:20)
    at async DevServer.handleRequest (/Users/me/app/node_modules/next/dist/server/next-server.js:325:20)
{ body: undefined }

By calling:

curl 'http://localhost:3000/api/token' -X POST  -H 'Accept: application/json' -H 'Content-Type: application/json' --data-raw '{"test":1}'

Expected Behavior

{ test: 1 } should be returned from await req.json()

To Reproduce

Create a basic middleware as outlined above and call it with the basic curl command.

[javivelasco]

Closing this in favour of #30953

[github-actions]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.