fix: keep __nextDataReq query param working

src/run/handlers/server.ts

@@ -83,6 +83,15 @@ export default async (request: Request) => {
       },
     })
 
+    if (new URL(request.url).searchParams.get('__nextDataReq')) {
+      const NEXT_REQUEST_META = Symbol.for('NextInternalRequestMeta')
+      // @ts-expect-error NEXT_REQUEST_META doesn't exist in IncomingMessage type
+      const meta = req[NEXT_REQUEST_META] ?? {}
+      meta.isNextDataReq = true
+      // @ts-expect-error NEXT_REQUEST_META doesn't exist in IncomingMessage type
+      req[NEXT_REQUEST_META] = meta
+    }
+
     disableFaultyTransferEncodingHandling(res as unknown as ComputeJsOutgoingMessage)
 
     const requestContext = getRequestContext() ?? createRequestContext()

tests/e2e/edge-middleware.test.ts

@@ -52,3 +52,23 @@ test('it should render OpenGraph image meta tag correctly', async ({ page, middl
   const size = await getImageSize(Buffer.from(imageBuffer), 'png')
   expect([size.width, size.height]).toEqual([1200, 630])
 })
+
+test('json data rewrite works', async ({ middlewarePages }) => {
+  const response = await fetch(
+    `${middlewarePages.url}/_next/data/build-id/sha.json?__nextDataReq=1`,
+    {
+      headers: {
+        'x-nextjs-data': '1',
+      },
+    },
+  )
+
+  expect(response.ok).toBe(true)
+  const body = await response.text()
+
+  expect(body).toMatch(/^{"pageProps":/)
+
+  const data = JSON.parse(body)
+
+  expect(data.pageProps.message).toBeDefined()
+})

tests/fixtures/middleware-pages/next-env.d.ts

@@ -2,4 +2,4 @@
 /// <reference types="next/image-types/global" />
 
 // NOTE: This file should not be edited
-// see https://nextjs.org/docs/basic-features/typescript for more information.
+// see https://nextjs.org/docs/pages/api-reference/config/typescript for more information.

tests/fixtures/middleware-pages/next.config.js

@@ -21,6 +21,7 @@ if (platform === 'win32') {
   }
 }
 
+/** @type {import('next').NextConfig} */
 module.exports = {
   trailingSlash: true,
   output: 'standalone',

tests/fixtures/middleware-pages/package.json

@@ -13,6 +13,8 @@
     "react-dom": "18.2.0"
   },
   "devDependencies": {
-    "@types/react": "18.2.47"
+    "@types/node": "^20.10.6",
+    "@types/react": "18.2.47",
+    "typescript": "^5.3.3"
   }
 }

tests/fixtures/middleware-pages/tsconfig.json

@@ -11,7 +11,8 @@
     "moduleResolution": "node",
     "resolveJsonModule": true,
     "isolatedModules": true,
-    "jsx": "preserve"
+    "jsx": "preserve",
+    "target": "ES2017"
   },
   "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx"],
   "exclude": ["node_modules"]

tests/utils/create-e2e-fixture.ts

@@ -325,6 +325,7 @@ export const fixtureFactories = {
   bun: () => createE2EFixture('simple', { packageManger: 'bun' }),
   middleware: () => createE2EFixture('middleware'),
   middlewareOg: () => createE2EFixture('middleware-og'),
+  middlewarePages: () => createE2EFixture('middleware-pages'),
   pageRouter: () => createE2EFixture('page-router'),
   pageRouterBasePathI18n: () => createE2EFixture('page-router-base-path-i18n'),
   turborepo: () =>