fix: add missing data to middleware request object

README.md

@@ -48,6 +48,12 @@ Next.js Middleware works out of the box on Netlify. By default, middleware runs
 support for running Middleware at the origin, set the environment variable `NEXT_DISABLE_NETLIFY_EDGE` to `true`. Be
 aware that this will result in slower performance, as all pages that match middleware must use SSR.
 
+### Limitations
+
+Due to how the site configuration is handled when it's run using Netlify Edge Functions, data such as `locale` and `defaultLocale` will be missing on the `req.nextUrl` object when running `netlify dev`. 
+
+However, this data is available on `req.nextUrl` in a production environment.
+
 ## Monorepos
 
 If you are using a monorepo you will need to change `publish` to point to the full path to the built `.next` directory,

packages/next/src/middleware/request.ts

@@ -83,7 +83,7 @@ export class MiddlewareRequest extends Request {
   }
 
   get nextUrl() {
-    return this.nextRequest.url
+    return this.nextRequest.nextUrl
   }
 
   get url() {

packages/runtime/src/helpers/edge.ts

@@ -7,6 +7,8 @@ import { copy, copyFile, emptyDir, ensureDir, readJSON, readJson, writeJSON, wri
 import type { MiddlewareManifest } from 'next/dist/build/webpack/plugins/middleware-plugin'
 import type { RouteHas } from 'next/dist/lib/load-custom-routes'
 
+import { getRequiredServerFiles } from './config'
+
 // This is the format as of [email protected]
 interface EdgeFunctionDefinitionV1 {
   env: string[]
@@ -198,6 +200,11 @@ export const writeEdgeFunctions = async (netlifyConfig: NetlifyConfig) => {
 
   await copy(getEdgeTemplatePath('../edge-shared'), join(edgeFunctionRoot, 'edge-shared'))
 
+  const { publish } = netlifyConfig.build
+  const nextConfigFile = await getRequiredServerFiles(publish)
+  const nextConfig = nextConfigFile.config
+  await writeJSON(join(edgeFunctionRoot, 'edge-shared', 'nextConfig.json'), nextConfig)
+
   if (!process.env.NEXT_DISABLE_EDGE_IMAGES) {
     console.log(
       'Using Netlify Edge Functions for image format detection. Set env var "NEXT_DISABLE_EDGE_IMAGES=true" to disable.',

packages/runtime/src/templates/edge/runtime.ts

@@ -1,6 +1,7 @@
 import type { Context } from 'https://edge.netlify.com'
 // Available at build time
 import matchers from './matchers.json' assert { type: 'json' }
+import nextConfig from '../edge-shared/nextConfig.json' assert { type: 'json' }
 import edgeFunction from './bundle.js'
 import { buildResponse } from '../edge-shared/utils.ts'
 import { getMiddlewareRouteMatcher, MiddlewareRouteMatch, searchParamsToUrlQuery } from '../edge-shared/next-utils.ts'
@@ -32,7 +33,7 @@ export interface RequestData {
     name?: string
     params?: { [key: string]: string }
   }
-  url: string
+  url: URL
   body?: ReadableStream<Uint8Array>
 }
 
@@ -81,10 +82,11 @@ const handler = async (req: Request, context: Context) => {
   const request: RequestData = {
     headers: Object.fromEntries(req.headers.entries()),
     geo,
-    url: url.toString(),
+    url,
     method: req.method,
     ip: context.ip,
     body: req.body ?? undefined,
+    nextConfig,
   }
 
   try {