Add init to some NextResponse methods (#38071)

* Add `init` to some `NextResponse` methods

* Add NextResponse.redirect test and fix headers

Co-authored-by: JJ Kasper <jj@jjsweb.site>

packages/next/server/web/spec-extension/response.ts

@@ -37,29 +37,34 @@ export class NextResponse extends Response {
     return new NextResponse(response.body, response)
   }
 
-  static redirect(url: string | NextURL | URL, status = 307) {
+  static redirect(url: string | NextURL | URL, init?: number | ResponseInit) {
+    const status = typeof init === 'number' ? init : init?.status ?? 307
     if (!REDIRECTS.has(status)) {
       throw new RangeError(
         'Failed to execute "redirect" on "response": Invalid status code'
       )
     }
+    const initObj = typeof init === 'object' ? init : {}
+    const headers = new Headers(initObj?.headers)
+    headers.set('Location', validateURL(url))
 
     return new NextResponse(null, {
-      headers: { Location: validateURL(url) },
+      ...initObj,
+      headers,
       status,
     })
   }
 
-  static rewrite(destination: string | NextURL | URL) {
-    return new NextResponse(null, {
-      headers: { 'x-middleware-rewrite': validateURL(destination) },
-    })
+  static rewrite(destination: string | NextURL | URL, init?: ResponseInit) {
+    const headers = new Headers(init?.headers)
+    headers.set('x-middleware-rewrite', validateURL(destination))
+    return new NextResponse(null, { ...init, headers })
   }
 
-  static next() {
-    return new NextResponse(null, {
-      headers: { 'x-middleware-next': '1' },
-    })
+  static next(init?: ResponseInit) {
+    const headers = new Headers(init?.headers)
+    headers.set('x-middleware-next', '1')
+    return new NextResponse(null, { ...init, headers })
   }
 }
 

test/e2e/middleware-general/app/middleware.js

@@ -37,9 +37,9 @@ export async function middleware(request) {
   const url = request.nextUrl
 
   if (request.headers.get('x-prerender-revalidate')) {
-    const res = NextResponse.next()
-    res.headers.set('x-middleware', 'hi')
-    return res
+    return NextResponse.next({
+      headers: { 'x-middleware': 'hi' },
+    })
   }
 
   // this is needed for tests to get the BUILD_ID
@@ -187,6 +187,15 @@ export async function middleware(request) {
     return NextResponse.rewrite(new URL('/about/a', request.url))
   }
 
+  if (url.pathname === '/redirect-to-somewhere') {
+    url.pathname = '/somewhere'
+    return NextResponse.redirect(url, {
+      headers: {
+        'x-redirect-header': 'hi',
+      },
+    })
+  }
+
   if (url.pathname.startsWith('/url')) {
     try {
       if (request.nextUrl.pathname === '/url/relative-url') {
@@ -229,18 +238,18 @@ export async function middleware(request) {
     throw new Error('test error')
   }
 
-  const response = NextResponse.next()
   const original = new URL(request.url)
-  response.headers.set('req-url-path', `${original.pathname}${original.search}`)
-  response.headers.set('req-url-basepath', request.nextUrl.basePath)
-  response.headers.set('req-url-pathname', request.nextUrl.pathname)
-  response.headers.set('req-url-query', request.nextUrl.searchParams.get('foo'))
-  response.headers.set('req-url-locale', request.nextUrl.locale)
-  response.headers.set(
-    'req-url-params',
-    url.pathname !== '/static' ? JSON.stringify(params(request.url)) : '{}'
-  )
-  return response
+  return NextResponse.next({
+    headers: {
+      'req-url-path': `${original.pathname}${original.search}`,
+      'req-url-basepath': request.nextUrl.basePath,
+      'req-url-pathname': request.nextUrl.pathname,
+      'req-url-query': request.nextUrl.searchParams.get('foo'),
+      'req-url-locale': request.nextUrl.locale,
+      'req-url-params':
+        url.pathname !== '/static' ? JSON.stringify(params(request.url)) : '{}',
+    },
+  })
 }
 
 function serializeData(data) {

test/e2e/middleware-general/test/index.test.ts

@@ -149,6 +149,22 @@ describe('Middleware Runtime', () => {
       })
     }
 
+    it('should have init header for NextResponse.redirect', async () => {
+      const res = await fetchViaHTTP(
+        next.url,
+        '/redirect-to-somewhere',
+        undefined,
+        {
+          redirect: 'manual',
+        }
+      )
+      expect(res.status).toBe(307)
+      expect(new URL(res.headers.get('location'), 'http://n').pathname).toBe(
+        '/somewhere'
+      )
+      expect(res.headers.get('x-redirect-header')).toBe('hi')
+    })
+
     it('should have correct query values for rewrite to ssg page', async () => {
       const browser = await webdriver(next.url, '/to-ssg')
       await browser.eval('window.beforeNav = 1')

test/e2e/middleware-rewrites/app/middleware.js

@@ -54,7 +54,9 @@ export async function middleware(request) {
 
   if (url.pathname === '/rewrite-me-to-about') {
     url.pathname = '/about'
-    return NextResponse.rewrite(url)
+    return NextResponse.rewrite(url, {
+      headers: { 'x-rewrite-target': String(url) },
+    })
   }
 
   if (url.pathname === '/rewrite-me-with-a-colon') {
@@ -90,9 +92,9 @@ export async function middleware(request) {
       ? '/about-bypass'
       : '/about'
 
-    const response = NextResponse.rewrite(url)
-    response.headers.set('x-middleware-cache', 'no-cache')
-    return response
+    return NextResponse.rewrite(url, {
+      headers: { 'x-middleware-cache': 'no-cache' },
+    })
   }
 
   if (url.pathname.endsWith('/dynamic-replace')) {