[BUG] Location header uses absolute url instead of relative url

[ericmatthys]

Describe the bug

When using middleware to redirect to a different URL (https://nextjs.org/docs/app/guides/redirecting#nextresponseredirect-in-middleware), the Location header is always absolute. When deployed to Vercel or running dev locally, the Location header can be relative.

Cloudflare or opennextjs-cloudflare preview: location: https://example.workers.dev/foo
Vercel or next dev: location: /foo

This has a couple effects:

• Automated tests that are asserting on the location header are not consistent between local and deployment.
• When using a worker to proxy requests from preview urls with custom domains to workers.dev urls, the location header is using the workers.dev url causing a redirect away from the custom domain.

Steps to reproduce

In middleware, perform a redirect like so:

middleware.ts

export function middleware(request: NextRequest) {
  const url = request.nextUrl.clone();

  if (url.pathname.startsWith('/foo') {
    return NextResponse.next();
  }

  url.pathname = '/foo';
  return NextResponse.redirect(url);
}

Request the site and inspect the location header of the 307 redirect response.

Expected behavior

The location header should match local dev and Vercel behavior, using a relative url when possible.

@opennextjs/cloudflare version

1.5.1

Wrangler version

4.24.1

next info output

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 23.6.0: Mon Jul 29 21:14:30 PDT 2024; root:xnu-10063.141.2~1/RELEASE_ARM64_T6000
  Available memory (MB): 65536
  Available CPU cores: 10
Binaries:
  Node: 22.17.0
  npm: 10.9.2
  Yarn: N/A
  pnpm: 8.15.9
Relevant Packages:
  next: 14.2.30 // An outdated version detected (latest is 15.4.3), upgrade is highly recommended!
  eslint-config-next: 14.2.29
  react: 18.3.1
  react-dom: 18.3.1
  typescript: 5.8.3
Next.js Config:
  output: N/A
 ⚠ An outdated version detected (latest is 15.4.3), upgrade is highly recommended!
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.

Additional context

No response

[sommeeeer]

Should be fixed on latest release.