[next] Ensure we resolve _next/data dynamic routes correctly with i18n

packages/next/src/server-build.ts

@@ -1401,8 +1401,16 @@ export async function serverBuild({
               );
 
               const { pathname } = new URL(route.dest || '/', 'http://n');
+              let prerenderPathname = pathname;
 
-              if (prerenders[path.join('./', pathname)]) {
+              if (routesManifest.i18n) {
+                prerenderPathname = pathname.replace(
+                  /^\/\$nextLocale/,
+                  `/${routesManifest.i18n.defaultLocale}`
+                );
+              }
+
+              if (prerenders[path.join('./', prerenderPathname)]) {
                 route.dest = `/_next/data/${buildId}${pathname}.json`;
               }
               return route;

packages/next/test/fixtures/00-middleware-i18n/index.test.js

@@ -0,0 +1,8 @@
+const path = require('path');
+const { deployAndTest } = require('../../utils');
+
+describe(`${__dirname.split(path.sep).pop()}`, () => {
+  it('should deploy and pass probe checks', async () => {
+    await deployAndTest(__dirname);
+  });
+});

packages/next/test/fixtures/00-middleware-i18n/middleware.js

@@ -0,0 +1,248 @@
+import { NextResponse } from 'next/server';
+
+const ALLOWED = ['allowed'];
+
+export const config = {
+  matcher: [
+    '/dynamic/:path*',
+    '/_sites/:path*',
+    '/:teamId/:slug',
+    '/:path*',
+    '/',
+  ],
+};
+
+export function middleware(request) {
+  const url = request.nextUrl;
+  const pathname = url.pathname;
+
+  if (process.env.FOO) {
+    console.log(`Includes env variable ${process.env.FOO}`);
+  }
+
+  if (url.pathname === '/redirect-me') {
+    url.pathname = '/from-middleware';
+    return NextResponse.redirect(url, 307);
+  }
+
+  if (url.pathname === '/next') {
+    return NextResponse.next();
+  }
+
+  if (url.pathname === '/version') {
+    return NextResponse.json({
+      enumerable: Object.keys(self).includes('VercelRuntime'),
+      version: self.VercelRuntime.version,
+    });
+  }
+
+  if (url.pathname === '/globals') {
+    const globalThisKeys = Object.keys(globalThis);
+    const globalKeys = globalThisKeys.reduce((acc, globalName) => {
+      const key = globalName.toString();
+      if (global[key]) acc.push(key);
+      return acc;
+    }, []);
+
+    const res = NextResponse.next();
+    res.headers.set(
+      'data',
+      JSON.stringify({ globals: globalKeys, globalThis: globalThisKeys })
+    );
+    return res;
+  }
+
+  if (url.pathname === '/log') {
+    console.log('hi there');
+    return;
+  }
+
+  if (url.pathname === '/somewhere') {
+    url.pathname = '/from-middleware';
+    return NextResponse.redirect(url);
+  }
+
+  if (url.pathname === '/logs') {
+    console.clear();
+    for (let i = 0; i < 3; i++) console.count();
+    console.count('test');
+    console.count('test');
+    console.dir({ hello: 'world' });
+    console.log('hello');
+    console.log('world');
+    return;
+  }
+
+  if (url.pathname === '/greetings') {
+    const data = { message: 'hello world!' };
+    const res = NextResponse.next();
+    res.headers.set('x-example', 'edge');
+    res.headers.set('data', JSON.stringify(data));
+    return res;
+  }
+
+  if (url.pathname === '/rewrite-me-to-about') {
+    url.pathname = '/about';
+    url.searchParams.set('middleware', 'foo');
+    return NextResponse.rewrite(url);
+  }
+
+  if (url.pathname === '/rewrite-to-site') {
+    const customUrl = new URL(url);
+    customUrl.pathname = '/_sites/subdomain-1/';
+    console.log('rewriting to', customUrl.pathname, customUrl.href);
+    return NextResponse.rewrite(customUrl);
+  }
+
+  if (url.pathname === '/redirect-me-to-about') {
+    url.pathname = '/about';
+    url.searchParams.set('middleware', 'foo');
+    return Response.redirect(url);
+  }
+
+  if (url.pathname === '/rewrite-absolute') {
+    return NextResponse.rewrite('https://example.vercel.sh/foo?foo=bar');
+  }
+
+  if (url.pathname === '/rewrite-relative') {
+    url.pathname = '/foo';
+    url.searchParams.set('foo', 'bar');
+    return NextResponse.rewrite(url);
+  }
+
+  if (url.pathname === '/redirect-absolute') {
+    return Response.redirect('https://vercel.com');
+  }
+
+  if (url.pathname === '/redirect-301') {
+    url.pathname = '/greetings';
+    return NextResponse.redirect(url, 301);
+  }
+
+  if (url.pathname === '/reflect') {
+    const res = NextResponse.next();
+    res.headers.set(
+      'data',
+      JSON.stringify({
+        geo: request.geo,
+        headers: Object.fromEntries(request.headers),
+        ip: request.ip,
+        method: request.method,
+        nextUrl: {
+          hash: request.nextUrl.hash,
+          hostname: request.nextUrl.hostname,
+          pathname: request.nextUrl.pathname,
+          port: request.nextUrl.port,
+          protocol: request.nextUrl.protocol,
+          search: request.nextUrl.search,
+        },
+        url: request.url,
+      })
+    );
+    return res;
+  }
+
+  if (url.pathname === '/stream-response') {
+    const { readable, writable } = new TransformStream();
+    const waitUntil = (async () => {
+      const enc = new TextEncoder();
+      const writer = writable.getWriter();
+      writer.write(enc.encode('this is a streamed '));
+      writer.write(enc.encode('response '));
+      return writer.close();
+    })();
+
+    return {
+      waitUntil,
+      response: NextResponse.next(),
+    };
+  }
+
+  if (url.pathname === '/throw-error') {
+    const error = new Error('oh no!');
+    console.log('This is not worker.js');
+    console.error(error);
+    return new Promise((_, reject) => reject(error));
+  }
+
+  if (url.pathname === '/throw-error-internal') {
+    function myFunctionName() {
+      throw new Error('Oh no!');
+    }
+
+    function anotherFunction() {
+      return myFunctionName();
+    }
+
+    try {
+      anotherFunction();
+    } catch (err) {
+      console.error(err);
+    }
+
+    return new Promise((_, reject) => reject(new Error('oh no!')));
+  }
+
+  if (url.pathname === '/unhandledrejection') {
+    Promise.reject(new TypeError('captured unhandledrejection error.'));
+    return NextResponse.next();
+  }
+
+  if (pathname.startsWith('/query-params')) {
+    if (pathname.endsWith('/clear')) {
+      const strategy =
+        url.searchParams.get('strategy') === 'rewrite' ? 'rewrite' : 'redirect';
+
+      for (const key of [...url.searchParams.keys()]) {
+        if (!ALLOWED.includes(key)) {
+          url.searchParams.delete(key);
+        }
+      }
+
+      const newPath = url.pathname.replace(/\/clear$/, '');
+      url.pathname = newPath;
+
+      if (strategy === 'redirect') {
+        return NextResponse.redirect(url);
+      } else {
+        return NextResponse.rewrite(url);
+      }
+    }
+
+    const obj = Object.fromEntries([...url.searchParams.entries()]);
+
+    const res = NextResponse.next();
+    res.headers.set('data', JSON.stringify(obj));
+    return res;
+  }
+
+  if (pathname.startsWith('/home')) {
+    if (!request.cookies.get('bucket')) {
+      const bucket = Math.random() >= 0.5 ? 'a' : 'b';
+      url.pathname = `/home/${bucket}`;
+      const response = NextResponse.rewrite(url);
+      response.cookies.set('bucket', bucket);
+      return response;
+    }
+
+    url.pathname = `/home/${request.cookies.get('bucket')}`;
+    return NextResponse.rewrite(url);
+  }
+
+  if (pathname.startsWith('/fetch-subrequest')) {
+    const destinationUrl =
+      url.searchParams.get('url') || 'https://example.vercel.sh';
+    return fetch(destinationUrl, { headers: request.headers });
+  }
+
+  if (url.pathname === '/dynamic/greet') {
+    const res = NextResponse.next();
+    res.headers.set(
+      'data',
+      JSON.stringify({
+        message: url.searchParams.get('greeting') || 'Hi friend',
+      })
+    );
+    return res;
+  }
+}

packages/next/test/fixtures/00-middleware-i18n/next.config.js

@@ -0,0 +1,42 @@
+module.exports = {
+  generateBuildId() {
+    return 'testing-build-id';
+  },
+  i18n: {
+    locales: ['en', 'fr'],
+    defaultLocale: 'en',
+  },
+  redirects() {
+    return [
+      {
+        source: '/redirect-me',
+        destination: '/from-next-config',
+        permanent: false,
+      },
+    ];
+  },
+  rewrites() {
+    return {
+      beforeFiles: [
+        {
+          source: '/rewrite-before-files',
+          destination: '/somewhere',
+        },
+      ],
+      afterFiles: [
+        {
+          source: '/after-file-rewrite',
+          destination: '/about',
+        },
+        {
+          source: '/after-file-rewrite-auto-static',
+          destination: '/home/a',
+        },
+        {
+          source: '/after-file-rewrite-auto-static-dynamic',
+          destination: '/dynamic/first',
+        },
+      ],
+    };
+  },
+};

packages/next/test/fixtures/00-middleware-i18n/package.json

@@ -0,0 +1,11 @@
+{
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build"
+  },
+  "dependencies": {
+    "next": "canary",
+    "react": "latest",
+    "react-dom": "latest"
+  }
+}

packages/next/test/fixtures/00-middleware-i18n/pages/[teamId]/[slug].js

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p>/[teamId]/[slug]</p>;
+}

packages/next/test/fixtures/00-middleware-i18n/pages/_sites/[site].js

@@ -0,0 +1,31 @@
+export default function Page(props) {
+  return (
+    <>
+      <p>/_sites/[site]</p>
+      <p>{JSON.stringify(props)}</p>
+    </>
+  );
+}
+
+export function getStaticProps({ params }) {
+  return {
+    props: {
+      params,
+      now: Date.now(),
+    },
+  };
+}
+
+export function getStaticPaths() {
+  return {
+    paths: [
+      {
+        params: { site: 'subdomain-1' },
+      },
+      {
+        params: { site: 'subdomain-2' },
+      },
+    ],
+    fallback: 'blocking',
+  };
+}

packages/next/test/fixtures/00-middleware-i18n/pages/about.js

@@ -0,0 +1,17 @@
+export default function Main({ message, middleware }) {
+  return (
+    <div>
+      <h1 className="title">About Page</h1>
+      <p className={message}>{message}</p>
+      <p className="middleware">{middleware}</p>
+    </div>
+  );
+}
+
+export const getServerSideProps = ({ query }) => ({
+  props: {
+    middleware: query.middleware || '',
+    message: query.message || '',
+    page: 'about',
+  },
+});

packages/next/test/fixtures/00-middleware-i18n/pages/dynamic/[id]/index.js

@@ -0,0 +1,3 @@
+export default function Index() {
+  return <p className="title">Dynamic route</p>;
+}

packages/next/test/fixtures/00-middleware-i18n/pages/dynamic/static.js

@@ -0,0 +1,3 @@
+export default function Index() {
+  return <p className="title">static route</p>;
+}