Publish Stable

- vercel@28.4.15
 - @vercel/client@12.2.16
 - @vercel/error-utils@1.0.3
 - @vercel/frameworks@1.1.11
 - @vercel/fs-detectors@3.4.8
 - @vercel/hydrogen@0.0.29
 - @vercel/next@3.2.9
 - @vercel/node-bridge@3.1.2
 - @vercel/node@2.6.2
 - @vercel/redwood@1.0.34
 - @vercel/remix@1.0.35
 - @vercel/routing-utils@2.1.2
 - @vercel/static-build@1.0.35
 - @vercel/static-config@2.0.6

.github/workflows/required-pr-label.yml

@@ -10,13 +10,17 @@ jobs:
         uses: actions/github-script@v6
         with:
           script: |
+            let missing = false;
             const labels = context.payload.pull_request.labels.map(l => l.name);
             if (labels.filter(l => l.startsWith('area:')).length === 0) {
-              console.error('\u001b[31mMissing label: Please add at least one "area" label.');
-              process.exit(1);
+              console.error('::error::Missing label: Please add at least one "area" label.');
+              missing = true;
             }
             if (labels.filter(l => l.startsWith('semver:')).length !== 1) {
-              console.error('\u001b[31mMissing label: Please add exactly one "semver" label.');
+              console.error('::error::Missing label: Please add exactly one "semver" label.');
+              missing = true;
+            }
+            if (missing) {
               process.exit(1);
             }
-            console.log('\u001b[32mSuccess: This pull request has correct labels, thanks!');
+            console.log('::notice::Success: This pull request has correct labels, thanks!');

.github/workflows/test.yml

@@ -82,11 +82,11 @@ jobs:
       - run: yarn install --network-timeout 1000000
 
       - name: Build ${{matrix.packageName}} and all its dependencies
-        run: node_modules/.bin/turbo run build --cache-dir=".turbo" --scope=${{matrix.packageName}} --include-dependencies --no-deps
+        run: node utils/gen.js && node_modules/.bin/turbo run build --cache-dir=".turbo" --scope=${{matrix.packageName}} --include-dependencies --no-deps
         env:
           FORCE_COLOR: '1'
       - name: Test ${{matrix.packageName}}
-        run: node_modules/.bin/turbo run test --cache-dir=".turbo" --scope=${{matrix.packageName}} --no-deps -- ${{ join(matrix.testPaths, ' ') }}
+        run: node utils/gen.js && node_modules/.bin/turbo run test --cache-dir=".turbo" --scope=${{matrix.packageName}} --no-deps -- ${{ join(matrix.testPaths, ' ') }}
         shell: bash
         env:
           VERCEL_CLI_VERSION: ${{ needs.setup.outputs.dplUrl }}/tarballs/vercel.tgz

.gitignore

@@ -28,3 +28,4 @@ test/lib/deployment/failed-page.txt
 __pycache__
 .vercel
 .turbo
+turbo-cache-key.json

README.md

@@ -35,4 +35,4 @@ For details on how to use Vercel, check out our [documentation](https://vercel.c
 
 - [Code of Conduct](./.github/CODE_OF_CONDUCT.md)
 - [Contributing Guidelines](./.github/CONTRIBUTING.md)
-- [MIT License](./LICENSE)
+- [Apache 2.0 License](./LICENSE)

api/package.json

@@ -16,7 +16,7 @@
     "unzip-stream": "0.3.0"
   },
   "devDependencies": {
-    "@types/node": "13.1.4",
+    "@types/node": "14.18.33",
     "@types/node-fetch": "2.5.4",
     "@vercel/node": "1.9.0",
     "typescript": "3.9.6"

examples/nextjs/next.config.js

@@ -1,7 +1,6 @@
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   reactStrictMode: true,
-  swcMinify: true,
 }
 
 module.exports = nextConfig

examples/nextjs/package.json

@@ -9,12 +9,10 @@
     "lint": "next lint"
   },
   "dependencies": {
-    "next": "12.3.1",
+    "eslint": "8.26.0",
+    "eslint-config-next": "13.0.2",
+    "next": "13.0.2",
     "react": "18.2.0",
     "react-dom": "18.2.0"
-  },
-  "devDependencies": {
-    "eslint": "8.23.1",
-    "eslint-config-next": "12.3.1"
   }
 }

examples/nextjs/pages/index.js

@@ -42,6 +42,8 @@ export default function Home() {
 
           <a
             href="https://vercel.com/new?utm_source=create-next-app&utm_medium=default-template&utm_campaign=create-next-app"
+            target="_blank"
+            rel="noopener noreferrer"
             className={styles.card}
           >
             <h2>Deploy &rarr;</h2>

package.json

@@ -44,14 +44,14 @@
     "publish-canary": "git checkout main && git pull && lerna version prerelease --preid canary --message \"Publish Canary\" --exact",
     "publish-from-github": "./utils/publish.sh",
     "changelog": "node utils/changelog.js",
-    "build": "turbo run build",
+    "build": "node utils/gen.js && turbo run build",
     "vercel-build": "yarn build && yarn run pack && cd api && node -r ts-eager/register ./_lib/script/build.ts",
     "pre-commit": "lint-staged",
     "test": "jest --rootDir=\"test\" --testPathPattern=\"\\.test.js\"",
-    "test-unit": "yarn test && turbo run test-unit",
-    "test-integration-cli": "turbo run test-integration-cli",
-    "test-integration-once": "turbo run test-integration-once",
-    "test-integration-dev": "turbo run test-integration-dev",
+    "test-unit": "yarn test && node utils/gen.js && turbo run test-unit",
+    "test-integration-cli": "node utils/gen.js && turbo run test-integration-cli",
+    "test-integration-once": "node utils/gen.js && turbo run test-integration-once",
+    "test-integration-dev": "node utils/gen.js && turbo run test-integration-dev",
     "lint": "eslint . --ext .ts,.js",
     "prepare": "husky install",
     "pack": "cd utils && node -r ts-eager/register ./pack.ts"

packages/build-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/build-utils",
-  "version": "5.5.5",
+  "version": "5.5.7",
   "license": "MIT",
   "main": "./dist/index.js",
   "types": "./dist/index.d.js",

packages/build-utils/src/edge-function.ts

@@ -39,7 +39,7 @@ export class EdgeFunction {
   assets?: { name: string; path: string }[];
 
   /** The regions where the edge function will be executed on */
-  regions?: 'auto' | string[] | 'all' | 'default';
+  regions?: string | string[];
 
   constructor(params: Omit<EdgeFunction, 'type'>) {
     this.type = 'EdgeFunction';

packages/build-utils/src/fs/node-version.ts

@@ -3,28 +3,37 @@ import { NodeVersion } from '../types';
 import { NowBuildError } from '../errors';
 import debug from '../debug';
 
-const allOptions = [
-  { major: 16, range: '16.x', runtime: 'nodejs16.x' },
-  { major: 14, range: '14.x', runtime: 'nodejs14.x' },
-  {
-    major: 12,
-    range: '12.x',
-    runtime: 'nodejs12.x',
-    discontinueDate: new Date('2022-10-03'),
-  },
-  {
-    major: 10,
-    range: '10.x',
-    runtime: 'nodejs10.x',
-    discontinueDate: new Date('2021-04-20'),
-  },
-  {
-    major: 8,
-    range: '8.10.x',
-    runtime: 'nodejs8.10',
-    discontinueDate: new Date('2020-01-06'),
-  },
-] as const;
+function getOptions() {
+  const options = [
+    { major: 16, range: '16.x', runtime: 'nodejs16.x' },
+    { major: 14, range: '14.x', runtime: 'nodejs14.x' },
+    {
+      major: 12,
+      range: '12.x',
+      runtime: 'nodejs12.x',
+      discontinueDate: new Date('2022-10-03'),
+    },
+    {
+      major: 10,
+      range: '10.x',
+      runtime: 'nodejs10.x',
+      discontinueDate: new Date('2021-04-20'),
+    },
+    {
+      major: 8,
+      range: '8.10.x',
+      runtime: 'nodejs8.10',
+      discontinueDate: new Date('2020-01-06'),
+    },
+  ] as const;
+  if (process.env.VERCEL_ALLOW_NODEJS18 === '1') {
+    return [
+      { major: 18, range: '18.x', runtime: 'nodejs18.x' },
+      ...options,
+    ] as const;
+  }
+  return options;
+}
 
 function getHint(isAuto = false) {
   const { major, range } = getLatestNodeVersion();
@@ -34,11 +43,11 @@ function getHint(isAuto = false) {
 }
 
 export function getLatestNodeVersion() {
-  return allOptions[0];
+  return getOptions()[0];
 }
 
 export function getDiscontinuedNodeVersions(): NodeVersion[] {
-  return allOptions.filter(isDiscontinued);
+  return getOptions().filter(isDiscontinued);
 }
 
 export async function getSupportedNodeVersion(
@@ -50,7 +59,7 @@ export async function getSupportedNodeVersion(
   if (engineRange) {
     const found =
       validRange(engineRange) &&
-      allOptions.some(o => {
+      getOptions().some(o => {
         // the array is already in order so return the first
         // match which will be the newest version of node
         selection = o;

packages/build-utils/src/lambda.ts

@@ -23,6 +23,7 @@ export interface LambdaOptionsBase {
   regions?: string[];
   supportsMultiPayloads?: boolean;
   supportsWrapper?: boolean;
+  experimentalResponseStreaming?: boolean;
 }
 
 export interface LambdaOptionsWithFiles extends LambdaOptionsBase {
@@ -60,6 +61,7 @@ export class Lambda {
   zipBuffer?: Buffer;
   supportsMultiPayloads?: boolean;
   supportsWrapper?: boolean;
+  experimentalResponseStreaming?: boolean;
 
   constructor(opts: LambdaOptions) {
     const {
@@ -72,6 +74,7 @@ export class Lambda {
       regions,
       supportsMultiPayloads,
       supportsWrapper,
+      experimentalResponseStreaming,
     } = opts;
     if ('files' in opts) {
       assert(typeof opts.files === 'object', '"files" must be an object');
@@ -132,6 +135,7 @@ export class Lambda {
     this.zipBuffer = 'zipBuffer' in opts ? opts.zipBuffer : undefined;
     this.supportsMultiPayloads = supportsMultiPayloads;
     this.supportsWrapper = supportsWrapper;
+    this.experimentalResponseStreaming = experimentalResponseStreaming;
   }
 
   async createZip(): Promise<Buffer> {

packages/build-utils/src/prerender.ts

@@ -8,6 +8,8 @@ interface PrerenderOptions {
   group?: number;
   bypassToken?: string | null /* optional to be non-breaking change */;
   allowQuery?: string[];
+  initialHeaders?: Record<string, string>;
+  initialStatus?: number;
 }
 
 export class Prerender {
@@ -18,6 +20,8 @@ export class Prerender {
   public group?: number;
   public bypassToken: string | null;
   public allowQuery?: string[];
+  public initialHeaders?: Record<string, string>;
+  public initialStatus?: number;
 
   constructor({
     expiration,
@@ -26,6 +30,8 @@ export class Prerender {
     group,
     bypassToken,
     allowQuery,
+    initialHeaders,
+    initialStatus,
   }: PrerenderOptions) {
     this.type = 'Prerender';
     this.expiration = expiration;
@@ -64,6 +70,30 @@ export class Prerender {
     }
     this.fallback = fallback;
 
+    if (initialHeaders !== undefined) {
+      if (
+        !initialHeaders ||
+        typeof initialHeaders !== 'object' ||
+        Object.entries(initialHeaders).some(
+          ([key, value]) => typeof key !== 'string' || typeof value !== 'string'
+        )
+      ) {
+        throw new Error(
+          `The \`initialHeaders\` argument for \`Prerender\` must be an object with string key/values`
+        );
+      }
+      this.initialHeaders = initialHeaders;
+    }
+
+    if (initialStatus !== undefined) {
+      if (initialStatus <= 0 || !Number.isInteger(initialStatus)) {
+        throw new Error(
+          `The \`initialStatus\` argument for \`Prerender\` must be a natural number.`
+        );
+      }
+      this.initialStatus = initialStatus;
+    }
+
     if (allowQuery !== undefined) {
       if (!Array.isArray(allowQuery)) {
         throw new Error(

packages/build-utils/test/unit.test.ts

@@ -285,6 +285,23 @@ it('should match all semver ranges', async () => {
   );
 });
 
+it('should only allow nodejs18.x when env var is set', async () => {
+  try {
+    expect(getLatestNodeVersion()).toHaveProperty('major', 16);
+    expect(getSupportedNodeVersion('18.x')).rejects.toThrow();
+
+    process.env.VERCEL_ALLOW_NODEJS18 = '1';
+
+    expect(getLatestNodeVersion()).toHaveProperty('major', 18);
+    expect(await getSupportedNodeVersion('18.x')).toHaveProperty('major', 18);
+    expect(await getSupportedNodeVersion('18')).toHaveProperty('major', 18);
+    expect(await getSupportedNodeVersion('18.1.0')).toHaveProperty('major', 18);
+    expect(await getSupportedNodeVersion('>=16')).toHaveProperty('major', 18);
+  } finally {
+    delete process.env.VERCEL_ALLOW_NODEJS18;
+  }
+});
+
 it('should ignore node version in vercel dev getNodeVersion()', async () => {
   expect(
     await getNodeVersion(
@@ -433,6 +450,38 @@ it('should warn for deprecated versions, soon to be discontinued', async () => {
   global.Date.now = realDateNow;
 });
 
+it('should support initialHeaders and initialStatus correctly', async () => {
+  const { Prerender } = require('@vercel/build-utils/dist/prerender.js');
+  new Prerender({
+    expiration: 1,
+    fallback: null,
+    group: 1,
+    bypassToken: 'some-long-bypass-token-to-make-it-work',
+    initialHeaders: {
+      'content-type': 'application/json',
+      'x-initial': 'true',
+    },
+    initialStatus: 308,
+  });
+  new Prerender({
+    expiration: 1,
+    fallback: null,
+    group: 1,
+    bypassToken: 'some-long-bypass-token-to-make-it-work',
+    initialStatus: 308,
+  });
+  new Prerender({
+    expiration: 1,
+    fallback: null,
+    group: 1,
+    bypassToken: 'some-long-bypass-token-to-make-it-work',
+    initialHeaders: {
+      'content-type': 'application/json',
+      'x-initial': 'true',
+    },
+  });
+});
+
 it('should support require by path for legacy builders', () => {
   const index = require('@vercel/build-utils');
 

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "vercel",
-  "version": "28.4.11",
+  "version": "28.4.15",
   "preferGlobal": true,
   "license": "Apache-2.0",
   "description": "The command-line interface for Vercel",
@@ -41,16 +41,16 @@
     "node": ">= 14"
   },
   "dependencies": {
-    "@vercel/build-utils": "5.5.5",
-    "@vercel/go": "2.2.13",
-    "@vercel/hydrogen": "0.0.26",
-    "@vercel/next": "3.2.5",
-    "@vercel/node": "2.5.25",
-    "@vercel/python": "3.1.22",
-    "@vercel/redwood": "1.0.31",
-    "@vercel/remix": "1.0.32",
-    "@vercel/ruby": "1.3.39",
-    "@vercel/static-build": "1.0.32",
+    "@vercel/build-utils": "5.5.7",
+    "@vercel/go": "2.2.15",
+    "@vercel/hydrogen": "0.0.29",
+    "@vercel/next": "3.2.9",
+    "@vercel/node": "2.6.2",
+    "@vercel/python": "3.1.24",
+    "@vercel/redwood": "1.0.34",
+    "@vercel/remix": "1.0.35",
+    "@vercel/ruby": "1.3.41",
+    "@vercel/static-build": "1.0.35",
     "update-notifier": "5.1.0"
   },
   "devDependencies": {
@@ -81,7 +81,7 @@
     "@types/minimatch": "3.0.3",
     "@types/mri": "1.1.0",
     "@types/ms": "0.7.30",
-    "@types/node": "11.11.0",
+    "@types/node": "14.18.33",
     "@types/node-fetch": "2.5.10",
     "@types/npm-package-arg": "6.1.0",
     "@types/pluralize": "0.0.29",
@@ -95,9 +95,10 @@
     "@types/which": "1.3.2",
     "@types/write-json-file": "2.2.1",
     "@types/yauzl-promise": "2.1.0",
-    "@vercel/client": "12.2.13",
-    "@vercel/frameworks": "1.1.8",
-    "@vercel/fs-detectors": "3.4.5",
+    "@vercel/client": "12.2.16",
+    "@vercel/error-utils": "1.0.3",
+    "@vercel/frameworks": "1.1.11",
+    "@vercel/fs-detectors": "3.4.8",
     "@vercel/fun": "1.0.4",
     "@vercel/ncc": "0.24.0",
     "@zeit/source-map-support": "0.6.2",

packages/cli/src/commands/deploy/index.ts

@@ -70,7 +70,7 @@ import getPrebuiltJson from '../../util/deploy/get-prebuilt-json';
 import { createGitMeta } from '../../util/create-git-meta';
 import { isValidArchive } from '../../util/deploy/validate-archive-format';
 import { parseEnv } from '../../util/parse-env';
-import { errorToString, isErrnoException, isError } from '../../util/is-error';
+import { errorToString, isErrnoException, isError } from '@vercel/error-utils';
 import { pickOverrides } from '../../util/projects/project-settings';
 
 export default async (client: Client): Promise<number> => {

packages/cli/src/commands/dev/dev.ts

@@ -3,16 +3,14 @@ import fs from 'fs-extra';
 
 import DevServer from '../../util/dev/server';
 import { parseListen } from '../../util/dev/parse-listen';
-import { ProjectEnvVariable } from '../../types';
 import Client from '../../util/client';
 import { getLinkedProject } from '../../util/projects/link';
 import { ProjectSettings } from '../../types';
-import getDecryptedEnvRecords from '../../util/get-decrypted-env-records';
 import setupAndLink from '../../util/link/setup-and-link';
-import getSystemEnvValues from '../../util/env/get-system-env-values';
 import { getCommandName } from '../../util/pkg-name';
 import param from '../../util/output/param';
 import { OUTPUT_DIR } from '../../util/build/write-build-result';
+import { pullEnvRecords } from '../../util/env/get-env-records';
 
 type Options = {
   '--listen': string;
@@ -57,8 +55,7 @@ export default async function dev(
   }
 
   let projectSettings: ProjectSettings | undefined;
-  let projectEnvs: ProjectEnvVariable[] = [];
-  let systemEnvValues: string[] = [];
+  let envValues: Record<string, string> = {};
   if (link.status === 'linked') {
     const { project, org } = link;
     client.config.currentTeam = org.type === 'team' ? org.id : undefined;
@@ -69,19 +66,15 @@ export default async function dev(
       cwd = join(cwd, project.rootDirectory);
     }
 
-    [{ envs: projectEnvs }, { systemEnvValues }] = await Promise.all([
-      getDecryptedEnvRecords(output, client, project.id, 'vercel-cli:dev'),
-      project.autoExposeSystemEnvs
-        ? getSystemEnvValues(output, client, project.id)
-        : { systemEnvValues: [] },
-    ]);
+    envValues = (
+      await pullEnvRecords(output, client, project.id, 'vercel-cli:dev')
+    ).env;
   }
 
   const devServer = new DevServer(cwd, {
     output,
     projectSettings,
-    projectEnvs,
-    systemEnvValues,
+    envValues,
   });
 
   // If there is no Development Command, we must delete the

packages/cli/src/commands/dev/index.ts

@@ -15,7 +15,7 @@ import readConfig from '../../util/config/read-config';
 import readJSONFile from '../../util/read-json-file';
 import { getPkgName, getCommandName } from '../../util/pkg-name';
 import { CantParseJSONFile } from '../../util/errors-ts';
-import { isErrnoException } from '../../util/is-error';
+import { isErrnoException } from '@vercel/error-utils';
 
 const COMMAND_CONFIG = {
   dev: ['dev'],

packages/cli/src/commands/domains/buy.ts

@@ -11,7 +11,7 @@ import promptBool from '../../util/input/prompt-bool';
 import purchaseDomain from '../../util/domains/purchase-domain';
 import stamp from '../../util/output/stamp';
 import { getCommandName } from '../../util/pkg-name';
-import { errorToString } from '../../util/is-error';
+import { errorToString } from '@vercel/error-utils';
 
 type Options = {};
 

packages/cli/src/commands/env/pull.ts

@@ -4,21 +4,21 @@ import { closeSync, openSync, readSync } from 'fs';
 import { resolve } from 'path';
 import { Project, ProjectEnvTarget } from '../../types';
 import Client from '../../util/client';
-import exposeSystemEnvs from '../../util/dev/expose-system-envs';
 import { emoji, prependEmoji } from '../../util/emoji';
-import getSystemEnvValues from '../../util/env/get-system-env-values';
-import getDecryptedEnvRecords from '../../util/get-decrypted-env-records';
 import confirm from '../../util/input/confirm';
 import { Output } from '../../util/output';
 import param from '../../util/output/param';
 import stamp from '../../util/output/stamp';
 import { getCommandName } from '../../util/pkg-name';
-import { EnvRecordsSource } from '../../util/env/get-env-records';
+import {
+  EnvRecordsSource,
+  pullEnvRecords,
+} from '../../util/env/get-env-records';
 import {
   buildDeltaString,
   createEnvObject,
 } from '../../util/env/diff-env-files';
-import { isErrnoException } from '../../util/is-error';
+import { isErrnoException } from '@vercel/error-utils';
 
 const CONTENTS_PREFIX = '# Created by Vercel CLI\n';
 
@@ -97,20 +97,11 @@ export default async function pull(
   const pullStamp = stamp();
   output.spinner('Downloading');
 
-  const [{ envs: projectEnvs }, { systemEnvValues }] = await Promise.all([
-    getDecryptedEnvRecords(output, client, project.id, source, environment),
-    project.autoExposeSystemEnvs
-      ? getSystemEnvValues(output, client, project.id)
-      : { systemEnvValues: [] },
-  ]);
-
-  const records = exposeSystemEnvs(
-    projectEnvs,
-    systemEnvValues,
-    project.autoExposeSystemEnvs,
-    undefined,
-    environment
-  );
+  const records = (
+    await pullEnvRecords(output, client, project.id, source, {
+      target: environment || ProjectEnvTarget.Development,
+    })
+  ).env;
 
   let deltaString = '';
   let oldEnv;

packages/cli/src/commands/git/index.ts

@@ -1,6 +1,6 @@
 import chalk from 'chalk';
 import Client from '../../util/client';
-import { ensureLink } from '../../util/ensure-link';
+import { ensureLink } from '../../util/link/ensure-link';
 import getArgs from '../../util/get-args';
 import getInvalidSubcommand from '../../util/get-invalid-subcommand';
 import handleError from '../../util/handle-error';
@@ -80,7 +80,7 @@ export default async function main(client: Client) {
   argv._ = argv._.slice(1);
   subcommand = argv._[0];
   const args = argv._.slice(1);
-  const confirm = Boolean(argv['--yes']);
+  const autoConfirm = Boolean(argv['--yes']);
   const { output } = client;
 
   let paths = [process.cwd()];
@@ -90,7 +90,7 @@ export default async function main(client: Client) {
   }
   const { path } = pathValidation;
 
-  const linkedProject = await ensureLink('git', client, path, confirm);
+  const linkedProject = await ensureLink('git', client, path, { autoConfirm });
   if (typeof linkedProject === 'number') {
     return linkedProject;
   }

packages/cli/src/commands/init/index.ts

@@ -7,7 +7,7 @@ import handleError from '../../util/handle-error';
 import logo from '../../util/output/logo';
 import init from './init';
 import { getPkgName } from '../../util/pkg-name';
-import { isError } from '../../util/is-error';
+import { isError } from '@vercel/error-utils';
 
 const COMMAND_CONFIG = {
   init: ['init'],

packages/cli/src/commands/inspect.ts

@@ -13,7 +13,7 @@ import { getDeployment } from '../util/get-deployment';
 import { Deployment } from '@vercel/client';
 import { Build } from '../types';
 import title from 'title';
-import { isErrnoException } from '../util/is-error';
+import { isErrnoException } from '@vercel/error-utils';
 import { isAPIError } from '../util/errors-ts';
 import { URL } from 'url';
 

packages/cli/src/commands/link/index.ts

@@ -3,9 +3,7 @@ import Client from '../../util/client';
 import getArgs from '../../util/get-args';
 import logo from '../../util/output/logo';
 import { getPkgName } from '../../util/pkg-name';
-import setupAndLink from '../../util/link/setup-and-link';
-import { getCommandName } from '../../util/pkg-name';
-import param from '../../util/output/param';
+import { ensureLink } from '../../util/link/ensure-link';
 
 const help = () => {
   console.log(`
@@ -70,31 +68,16 @@ export default async function main(client: Client) {
   }
 
   const cwd = argv._[1] || process.cwd();
-  const link = await setupAndLink(client, cwd, {
+
+  const link = await ensureLink('link', client, cwd, {
+    autoConfirm: !!argv['--yes'],
     forceDelete: true,
-    autoConfirm: argv['--yes'],
     projectName: argv['--project'],
     successEmoji: 'success',
-    setupMsg: 'Set up',
   });
 
-  if (link.status === 'error') {
-    if (link.reason === 'HEADLESS') {
-      client.output.error(
-        `Command ${getCommandName(
-          'link'
-        )} requires confirmation. Use option ${param('--yes')} to confirm.`
-      );
-    }
-    return link.exitCode;
-  } else if (link.status === 'not_linked') {
-    // User aborted project linking questions
-    return 0;
-  } else if (link.status === 'linked') {
-    // Successfully linked
-    return 0;
-  } else {
-    const err: never = link;
-    throw new Error('Unknown link status: ' + err);
+  if (typeof link === 'number') {
+    return link;
   }
+  return 0;
 }

packages/cli/src/commands/list.ts

@@ -17,10 +17,10 @@ import Client from '../util/client';
 import { Deployment } from '@vercel/client';
 import validatePaths from '../util/validate-paths';
 import { getLinkedProject } from '../util/projects/link';
-import { ensureLink } from '../util/ensure-link';
+import { ensureLink } from '../util/link/ensure-link';
 import getScope from '../util/get-scope';
 import { isAPIError } from '../util/errors-ts';
-import { isErrnoException } from '../util/is-error';
+import { isErrnoException } from '@vercel/error-utils';
 
 const help = () => {
   console.log(`
@@ -56,7 +56,7 @@ const help = () => {
   ${chalk.gray('–')} List all deployments for the project ${chalk.dim(
     '`my-app`'
   )} in the team of the currently linked project
-  
+
     ${chalk.cyan(`$ ${getPkgName()} ls my-app`)}
 
   ${chalk.gray('–')} Filter deployments by metadata
@@ -112,7 +112,7 @@ export default async function main(client: Client) {
     return 2;
   }
 
-  const yes = !!argv['--yes'];
+  const autoConfirm = !!argv['--yes'];
   const prod = argv['--prod'] || false;
 
   const meta = parseMeta(argv['--meta']);
@@ -145,7 +145,9 @@ export default async function main(client: Client) {
   // If there's no linked project and user doesn't pass `app` arg,
   // prompt to link their current directory.
   if (status === 'not_linked' && !app) {
-    const linkedProject = await ensureLink('list', client, path, yes);
+    const linkedProject = await ensureLink('list', client, path, {
+      autoConfirm,
+    });
     if (typeof linkedProject === 'number') {
       return linkedProject;
     }

packages/cli/src/commands/logout.ts

@@ -6,7 +6,7 @@ import getArgs from '../util/get-args';
 import Client from '../util/client';
 import { getCommandName, getPkgName } from '../util/pkg-name';
 import { isAPIError } from '../util/errors-ts';
-import { errorToString } from '../util/is-error';
+import { errorToString } from '@vercel/error-utils';
 
 const help = () => {
   console.log(`

packages/cli/src/commands/pull.ts

@@ -4,24 +4,18 @@ import Client from '../util/client';
 import { ProjectEnvTarget } from '../types';
 import { emoji, prependEmoji } from '../util/emoji';
 import getArgs from '../util/get-args';
-import setupAndLink from '../util/link/setup-and-link';
 import logo from '../util/output/logo';
 import stamp from '../util/output/stamp';
 import { getPkgName } from '../util/pkg-name';
-import {
-  getLinkedProject,
-  VERCEL_DIR,
-  VERCEL_DIR_PROJECT,
-} from '../util/projects/link';
+import { VERCEL_DIR, VERCEL_DIR_PROJECT } from '../util/projects/link';
 import { writeProjectSettings } from '../util/projects/project-settings';
 import envPull from './env/pull';
-import { getCommandName } from '../util/pkg-name';
-import param from '../util/output/param';
-import type { Project, Org } from '../types';
+import type { Project } from '../types';
 import {
   isValidEnvTarget,
   getEnvTargetPlaceholder,
 } from '../util/env/env-target';
+import { ensureLink } from '../util/link/ensure-link';
 
 const help = () => {
   return console.log(`
@@ -83,43 +77,6 @@ function parseArgs(client: Client) {
   return argv;
 }
 
-type LinkResult = {
-  org: Org;
-  project: Project;
-};
-async function ensureLink(
-  client: Client,
-  cwd: string,
-  yes: boolean
-): Promise<LinkResult | number> {
-  let link = await getLinkedProject(client, cwd);
-  if (link.status === 'not_linked') {
-    link = await setupAndLink(client, cwd, {
-      autoConfirm: yes,
-      successEmoji: 'link',
-      setupMsg: 'Set up',
-    });
-
-    if (link.status === 'not_linked') {
-      // User aborted project linking questions
-      return 0;
-    }
-  }
-
-  if (link.status === 'error') {
-    if (link.reason === 'HEADLESS') {
-      client.output.error(
-        `Command ${getCommandName(
-          'pull'
-        )} requires confirmation. Use option ${param('--yes')} to confirm.`
-      );
-    }
-    return link.exitCode;
-  }
-
-  return { org: link.org, project: link.project };
-}
-
 async function pullAllEnvFiles(
   environment: ProjectEnvTarget,
   client: Client,
@@ -140,7 +97,9 @@ async function pullAllEnvFiles(
   );
 }
 
-function parseEnvironment(environment = 'development'): ProjectEnvTarget {
+export function parseEnvironment(
+  environment = 'development'
+): ProjectEnvTarget {
   if (!isValidEnvTarget(environment)) {
     throw new Error(
       `environment "${environment}" not supported; must be one of ${getEnvTargetPlaceholder()}`
@@ -156,10 +115,10 @@ export default async function main(client: Client) {
   }
 
   const cwd = argv._[1] || process.cwd();
-  const yes = Boolean(argv['--yes']);
+  const autoConfirm = Boolean(argv['--yes']);
   const environment = parseEnvironment(argv['--environment'] || undefined);
 
-  const link = await ensureLink(client, cwd, yes);
+  const link = await ensureLink('pull', client, cwd, { autoConfirm });
   if (typeof link === 'number') {
     return link;
   }

packages/cli/src/commands/teams/add.ts

@@ -11,7 +11,7 @@ import { getPkgName, getCommandName } from '../../util/pkg-name';
 import Client from '../../util/client';
 import createTeam from '../../util/teams/create-team';
 import patchTeam from '../../util/teams/patch-team';
-import { errorToString, isError } from '../../util/is-error';
+import { errorToString, isError } from '@vercel/error-utils';
 
 const validateSlugKeypress = (data: string, value: string) =>
   // TODO: the `value` here should contain the current value + the keypress

packages/cli/src/commands/teams/invite.ts

@@ -12,7 +12,7 @@ import { email as regexEmail } from '../../util/input/regexes';
 import getTeams from '../../util/teams/get-teams';
 import inviteUserToTeam from '../../util/teams/invite-user-to-team';
 import { isAPIError } from '../../util/errors-ts';
-import { errorToString, isError } from '../../util/is-error';
+import { errorToString, isError } from '@vercel/error-utils';
 
 const validateEmail = (data: string) =>
   regexEmail.test(data.trim()) || data.length === 0;

packages/cli/src/index.ts

@@ -1,5 +1,5 @@
 #!/usr/bin/env node
-import { isErrnoException, isError, errorToString } from './util/is-error';
+import { isErrnoException, isError, errorToString } from '@vercel/error-utils';
 
 try {
   // Test to see if cwd has been deleted before
@@ -610,6 +610,21 @@ const main = async () => {
       return 1;
     }
 
+    if (isErrnoException(err) && err.code === 'ECONNRESET') {
+      // Error message will look like the following:
+      // request to https://api.vercel.com/v2/user failed, reason: socket hang up
+      const matches = /request to https:\/\/(.*?)\//.exec(err.message || '');
+      const hostname = matches?.[1];
+      if (hostname) {
+        output.error(
+          `Connection to ${highlight(
+            hostname
+          )} interrupted. Please verify your internet connectivity and DNS configuration.`
+        );
+      }
+      return 1;
+    }
+
     if (
       isErrnoException(err) &&
       (err.code === 'NOT_AUTHORIZED' || err.code === 'TEAM_DELETED')

packages/cli/src/util/build/import-builders.ts

@@ -16,7 +16,7 @@ import { VERCEL_DIR } from '../projects/link';
 import { Output } from '../output';
 import readJSONFile from '../read-json-file';
 import { CantParseJSONFile } from '../errors-ts';
-import { errorToString, isErrnoException, isError } from '../is-error';
+import { errorToString, isErrnoException, isError } from '@vercel/error-utils';
 import cmd from '../output/cmd';
 import code from '../output/code';
 

packages/cli/src/util/certs/create-cert-from-file.ts

@@ -2,7 +2,7 @@ import { readFileSync } from 'fs';
 import { resolve } from 'path';
 import Client from '../client';
 import { Cert } from '../../types';
-import { isErrnoException } from '../is-error';
+import { isErrnoException } from '@vercel/error-utils';
 import { isAPIError } from '../errors-ts';
 
 export default async function createCertFromFile(

packages/cli/src/util/certs/issue-cert.ts

@@ -2,7 +2,7 @@ import retry from 'async-retry';
 import { Cert } from '../../types';
 import Client from '../client';
 import { isAPIError } from '../errors-ts';
-import { isError } from '../is-error';
+import { isError } from '@vercel/error-utils';
 
 // When it's a configuration error we should retry because of the DNS propagation
 // otherwise we bail to handle the error in the upper level

packages/cli/src/util/client.ts

@@ -1,8 +1,7 @@
 import { bold } from 'chalk';
 import inquirer from 'inquirer';
 import { EventEmitter } from 'events';
-import { URLSearchParams } from 'url';
-import { parse as parseUrl } from 'url';
+import { URL } from 'url';
 import { VercelConfig } from '@vercel/client';
 import retry, { RetryFunction, Options as RetryOptions } from 'async-retry';
 import fetch, { BodyInit, Headers, RequestInit, Response } from 'node-fetch';
@@ -23,7 +22,7 @@ import type {
 } from '../types';
 import { sharedPromise } from './promise';
 import { APIError } from './errors-ts';
-import { normalizeError } from './is-error';
+import { normalizeError } from '@vercel/error-utils';
 
 const isSAMLError = (v: any): v is SAMLError => {
   return v && v.saml;
@@ -87,25 +86,18 @@ export default class Client extends EventEmitter implements Stdio {
   }
 
   private _fetch(_url: string, opts: FetchOptions = {}) {
-    const parsedUrl = parseUrl(_url, true);
-    const apiUrl = parsedUrl.host
-      ? `${parsedUrl.protocol}//${parsedUrl.host}`
-      : '';
+    const url = new URL(_url, this.apiUrl);
 
     if (opts.accountId || opts.useCurrentTeam !== false) {
-      const query = new URLSearchParams(parsedUrl.query);
-
       if (opts.accountId) {
         if (opts.accountId.startsWith('team_')) {
-          query.set('teamId', opts.accountId);
+          url.searchParams.set('teamId', opts.accountId);
         } else {
-          query.delete('teamId');
+          url.searchParams.delete('teamId');
         }
       } else if (opts.useCurrentTeam !== false && this.config.currentTeam) {
-        query.set('teamId', this.config.currentTeam);
+        url.searchParams.set('teamId', this.config.currentTeam);
       }
-
-      _url = `${apiUrl}${parsedUrl.pathname}?${query}`;
     }
 
     const headers = new Headers(opts.headers);
@@ -122,7 +114,6 @@ export default class Client extends EventEmitter implements Stdio {
       body = opts.body;
     }
 
-    const url = `${apiUrl ? '' : this.apiUrl}${_url}`;
     const requestId = this.requestIdCounter++;
     return this.output.time(res => {
       if (res) {
@@ -130,7 +121,7 @@ export default class Client extends EventEmitter implements Stdio {
           res.statusText
         }: ${res.headers.get('x-vercel-id')}`;
       } else {
-        return `#${requestId} → ${opts.method || 'GET'} ${url}`;
+        return `#${requestId} → ${opts.method || 'GET'} ${url.href}`;
       }
     }, fetch(url, { ...opts, headers, body }));
   }

packages/cli/src/util/config/files.ts

@@ -10,7 +10,7 @@ import error from '../output/error';
 import highlight from '../output/highlight';
 import { VercelConfig } from '../dev/types';
 import { AuthConfig, GlobalConfig } from '../../types';
-import { isErrnoException, isError } from '../is-error';
+import { isErrnoException, isError } from '@vercel/error-utils';
 
 const VERCEL_DIR = getGlobalPathConfig();
 const CONFIG_FILE_PATH = join(VERCEL_DIR, 'config.json');

packages/cli/src/util/create-git-meta.ts

@@ -5,7 +5,7 @@ import git from 'git-last-commit';
 import { exec } from 'child_process';
 import { GitMetadata, Project } from '../types';
 import { Output } from './output';
-import { errorToString } from './is-error';
+import { errorToString } from '@vercel/error-utils';
 
 export async function createGitMeta(
   directory: string,

packages/cli/src/util/dev/builder.ts

@@ -87,8 +87,12 @@ async function createBuildProcess(
 
   return new Promise((resolve, reject) => {
     // The first message that the builder process sends is the `ready` event
-    buildProcess.once('message', ({ type }) => {
-      if (type !== 'ready') {
+    buildProcess.once('message', data => {
+      if (
+        data !== null &&
+        typeof data === 'object' &&
+        (data as { type: string }).type !== 'ready'
+      ) {
         reject(new Error('Did not get "ready" event from builder'));
       } else {
         resolve(buildProcess);

packages/cli/src/util/dev/expose-system-envs.ts

@@ -1,46 +0,0 @@
-import {
-  ProjectEnvType,
-  ProjectEnvVariable,
-  ProjectEnvTarget,
-} from '../../types';
-import { Env } from '@vercel/build-utils';
-
-function getSystemEnvValue(
-  systemEnvRef: string,
-  { vercelUrl }: { vercelUrl?: string }
-) {
-  if (systemEnvRef === 'VERCEL_URL') {
-    return vercelUrl || '';
-  }
-
-  return '';
-}
-
-export default function exposeSystemEnvs(
-  projectEnvs: ProjectEnvVariable[],
-  systemEnvValues: string[],
-  autoExposeSystemEnvs: boolean | undefined,
-  vercelUrl?: string,
-  target?: ProjectEnvTarget
-) {
-  const envs: Env = {};
-
-  if (autoExposeSystemEnvs) {
-    envs['VERCEL'] = '1';
-    envs['VERCEL_ENV'] = target || 'development';
-
-    for (const key of systemEnvValues) {
-      envs[key] = getSystemEnvValue(key, { vercelUrl });
-    }
-  }
-
-  for (let env of projectEnvs) {
-    if (env.type === ProjectEnvType.System) {
-      envs[env.key] = getSystemEnvValue(env.value, { vercelUrl });
-    } else {
-      envs[env.key] = env.value;
-    }
-  }
-
-  return envs;
-}

packages/cli/src/util/dev/headers.ts

@@ -16,3 +16,75 @@ export function nodeHeadersToFetchHeaders(
   }
   return headers;
 }
+
+/**
+ * Request headers that are not allowed to be overridden by a middleware.
+ */
+const NONOVERRIDABLE_HEADERS: Set<string> = new Set([
+  'host',
+  'connection',
+  'content-length',
+  'transfer-encoding',
+  'keep-alive',
+  'transfer-encoding',
+  'te',
+  'upgrade',
+  'trailer',
+]);
+
+/**
+ * Adds/Updates/Deletes headers in `reqHeaders` based on the response headers
+ * from a middleware (`respHeaders`).
+ *
+ * `x-middleware-override-headers` is a comma-separated list of *all* header
+ * names that should appear in new request headers. Names not in this list
+ * will be deleted.
+ *
+ * `x-middleware-request-*` is the new value for each header. This can't be
+ * omitted, even if the header is not being modified.
+ *
+ */
+export function applyOverriddenHeaders(
+  reqHeaders: { [k: string]: string | string[] | undefined },
+  respHeaders: Headers
+) {
+  const overriddenHeaders = respHeaders.get('x-middleware-override-headers');
+  if (!overriddenHeaders) {
+    return;
+  }
+
+  const overriddenKeys: Set<string> = new Set();
+  for (const key of overriddenHeaders.split(',')) {
+    overriddenKeys.add(key.trim());
+  }
+
+  respHeaders.delete('x-middleware-override-headers');
+
+  // Delete headers.
+  for (const key of Object.keys(reqHeaders)) {
+    if (!NONOVERRIDABLE_HEADERS.has(key) && !overriddenKeys.has(key)) {
+      delete reqHeaders[key];
+    }
+  }
+
+  // Update or add headers.
+  for (const key of overriddenKeys.keys()) {
+    if (NONOVERRIDABLE_HEADERS.has(key)) {
+      continue;
+    }
+
+    const valueKey = 'x-middleware-request-' + key;
+    const newValue = respHeaders.get(valueKey);
+    const oldValue = reqHeaders[key];
+
+    if (oldValue !== newValue) {
+      if (newValue) {
+        reqHeaders[key] = newValue;
+      } else {
+        delete reqHeaders[key];
+      }
+    }
+
+    respHeaders.delete(valueKey);
+  }
+}

packages/cli/src/util/dev/parse-listen.ts

@@ -31,11 +31,11 @@ export function parseListen(str: string, defaultPort = 3000): ListenSpec {
       return [url.pathname];
     case 'tcp:':
       url.port = url.port || String(defaultPort);
-      return [parseInt(url.port, 10), url.hostname];
+      return [parseInt(url.port, 10), url.hostname ?? undefined];
     default:
       if (!url.slashes) {
         if (url.protocol === null) {
-          return [defaultPort, url.pathname];
+          return [defaultPort, url.pathname ?? undefined];
         }
         port = Number(url.hostname);
         if (url.protocol && !isNaN(port)) {

packages/cli/src/util/dev/parse-query-string.ts

@@ -4,7 +4,7 @@
  * @param querystring - The querystring to parse, also known as the "search" string.
  */
 export function parseQueryString(
-  querystring?: string
+  querystring?: string | null
 ): Record<string, string[]> {
   const query: Record<string, string[]> = Object.create(null);
   if (!querystring || !querystring.startsWith('?') || querystring === '?') {
@@ -38,9 +38,9 @@ export function parseQueryString(
  */
 export function formatQueryString(
   query: Record<string, string[]> | undefined
-): string | undefined {
+): string | null {
   if (!query) {
-    return undefined;
+    return null;
   }
   let s = '';
   let prefix = '?';
@@ -55,5 +55,5 @@ export function formatQueryString(
       prefix = '&';
     }
   }
-  return s || undefined;
+  return s || null;
 }

packages/cli/src/util/dev/router.ts

@@ -57,7 +57,8 @@ export async function devRouter(
   phase?: HandleValue | null
 ): Promise<RouteResult> {
   let result: RouteResult | undefined;
-  let { pathname: reqPathname = '/', search: reqSearch } = url.parse(reqUrl);
+  let { pathname: reqPathname, search: reqSearch } = url.parse(reqUrl);
+  reqPathname ??= '/';
   const reqQuery = parseQueryString(reqSearch);
   const combinedHeaders: HttpHeadersConfig = { ...previousHeaders };
   let status: number | undefined;
@@ -130,7 +131,8 @@ export async function devRouter(
           phase !== 'hit' &&
           !isDestUrl
         ) {
-          const { pathname = '/' } = url.parse(destPath);
+          let { pathname } = url.parse(destPath);
+          pathname ??= '/';
           const hasDestFile = await devServer.hasFilesystem(
             pathname,
             vercelConfig
@@ -186,8 +188,9 @@ export async function devRouter(
           if (!destPath.startsWith('/')) {
             destPath = `/${destPath}`;
           }
-          const { pathname: destPathname = '/', search: destSearch } =
+          let { pathname: destPathname, search: destSearch } =
             url.parse(destPath);
+          destPathname ??= '/';
           const destQuery = parseQueryString(destSearch);
           Object.assign(destQuery, reqQuery);
           result = {

packages/cli/src/util/dev/server.ts

@@ -85,17 +85,16 @@ import {
   HttpHeadersConfig,
   EnvConfigs,
 } from './types';
-import { ProjectEnvVariable, ProjectSettings } from '../../types';
-import exposeSystemEnvs from './expose-system-envs';
+import { ProjectSettings } from '../../types';
 import { treeKill } from '../tree-kill';
-import { nodeHeadersToFetchHeaders } from './headers';
+import { applyOverriddenHeaders, nodeHeadersToFetchHeaders } from './headers';
 import { formatQueryString, parseQueryString } from './parse-query-string';
 import {
   errorToString,
   isErrnoException,
   isError,
   isSpawnError,
-} from '../is-error';
+} from '@vercel/error-utils';
 import isURL from './is-url';
 import { pickOverrides } from '../projects/project-settings';
 import { replaceLocalhost } from './parse-listen';
@@ -168,15 +167,13 @@ export default class DevServer {
   private blockingBuildsPromise: Promise<void> | null;
   private startPromise: Promise<void> | null;
 
-  private systemEnvValues: string[];
-  private projectEnvs: ProjectEnvVariable[];
+  private envValues: Record<string, string>;
 
   constructor(cwd: string, options: DevServerOptions) {
     this.cwd = cwd;
     this.output = options.output;
     this.envConfigs = { buildEnv: {}, runEnv: {}, allEnv: {} };
-    this.systemEnvValues = options.systemEnvValues || [];
-    this.projectEnvs = options.projectEnvs || [];
+    this.envValues = options.envValues || {};
     this.files = {};
     this.originalProjectSettings = options.projectSettings;
     this.projectSettings = options.projectSettings;
@@ -684,16 +681,13 @@ export default class DevServer {
 
     // If no .env/.build.env is present, use cloud environment variables
     if (Object.keys(allEnv).length === 0) {
-      const cloudEnv = exposeSystemEnvs(
-        this.projectEnvs || [],
-        this.systemEnvValues || [],
-        this.projectSettings?.autoExposeSystemEnvs,
-        this.address.host
-      );
-
-      allEnv = { ...cloudEnv };
-      runEnv = { ...cloudEnv };
-      buildEnv = { ...cloudEnv };
+      const envValues = { ...this.envValues };
+      if (this.address.host) {
+        envValues['VERCEL_URL'] = this.address.host;
+      }
+      allEnv = { ...envValues };
+      runEnv = { ...envValues };
+      buildEnv = { ...envValues };
     }
 
     // legacy NOW_REGION env variable
@@ -1454,7 +1448,9 @@ export default class DevServer {
             }
           );
 
-          if (middlewareRes.status === 500) {
+          const middlewareBody = await middlewareRes.buffer();
+
+          if (middlewareRes.status === 500 && middlewareBody.byteLength === 0) {
             await this.sendError(
               req,
               res,
@@ -1478,6 +1474,9 @@ export default class DevServer {
             'content-length',
             'transfer-encoding',
           ]);
+
+          applyOverriddenHeaders(req.headers, middlewareRes.headers);
+
           for (const [name, value] of middlewareRes.headers) {
             if (name === 'x-middleware-next') {
               shouldContinue = value === '1';
@@ -1496,7 +1495,6 @@ export default class DevServer {
           }
 
           if (!shouldContinue) {
-            const middlewareBody = await middlewareRes.buffer();
             this.setResponseHeaders(res, requestId);
             if (middlewareBody.length > 0) {
               res.setHeader('content-length', middlewareBody.length);

packages/cli/src/util/dev/types.ts

@@ -16,7 +16,7 @@ import {
 import { VercelConfig } from '@vercel/client';
 import { HandleValue, Route } from '@vercel/routing-utils';
 import { Output } from '../output';
-import { ProjectEnvVariable, ProjectSettings } from '../../types';
+import { ProjectSettings } from '../../types';
 import { BuilderWithPkg } from '../build/import-builders';
 
 export { VercelConfig };
@@ -24,8 +24,7 @@ export { VercelConfig };
 export interface DevServerOptions {
   output: Output;
   projectSettings?: ProjectSettings;
-  systemEnvValues?: string[];
-  projectEnvs?: ProjectEnvVariable[];
+  envValues?: Record<string, string>;
 }
 
 export interface EnvConfigs {

packages/cli/src/util/ensure-link.ts

@@ -1,45 +0,0 @@
-import { Org, Project } from '../types';
-import Client from './client';
-import setupAndLink from './link/setup-and-link';
-import param from './output/param';
-import { getCommandName } from './pkg-name';
-import { getLinkedProject } from './projects/link';
-
-type LinkResult = {
-  org: Org;
-  project: Project;
-};
-
-export async function ensureLink(
-  commandName: string,
-  client: Client,
-  cwd: string,
-  yes: boolean
-): Promise<LinkResult | number> {
-  let link = await getLinkedProject(client, cwd);
-  if (link.status === 'not_linked') {
-    link = await setupAndLink(client, cwd, {
-      autoConfirm: yes,
-      successEmoji: 'link',
-      setupMsg: 'Set up',
-    });
-
-    if (link.status === 'not_linked') {
-      // User aborted project linking questions
-      return 0;
-    }
-  }
-
-  if (link.status === 'error') {
-    if (link.reason === 'HEADLESS') {
-      client.output.error(
-        `Command ${getCommandName(
-          commandName
-        )} requires confirmation. Use option ${param('--yes')} to confirm.`
-      );
-    }
-    return link.exitCode;
-  }
-
-  return { org: link.org, project: link.project };
-}

packages/cli/src/util/env/get-env-records.ts

@@ -2,6 +2,7 @@ import { Output } from '../output';
 import Client from '../client';
 import { ProjectEnvVariable, ProjectEnvTarget } from '../../types';
 import { URLSearchParams } from 'url';
+import * as path from 'path';
 
 /** The CLI command that was used that needs the environment variables. */
 export type EnvRecordsSource =
@@ -49,3 +50,40 @@ export default async function getEnvRecords(
 
   return client.fetch<{ envs: ProjectEnvVariable[] }>(url);
 }
+
+interface PullEnvOptions {
+  target?: ProjectEnvTarget | string;
+  gitBranch?: string;
+}
+
+export async function pullEnvRecords(
+  output: Output,
+  client: Client,
+  projectId: string,
+  source: EnvRecordsSource,
+  { target, gitBranch }: PullEnvOptions = {}
+) {
+  output.debug(
+    `Fetching Environment Variables of project ${projectId} and target ${target}`
+  );
+  const query = new URLSearchParams();
+
+  let url = `/v1/env/pull/${projectId}`;
+
+  if (target) {
+    url = path.join(url, target, gitBranch ?? '');
+  }
+
+  if (source) {
+    query.set('source', source);
+  }
+
+  if (Array.from(query).length > 0) {
+    url += `?${query}`;
+  }
+
+  return client.fetch<{
+    env: Record<string, string>;
+    buildEnv: Record<string, string>;
+  }>(url);
+}

packages/cli/src/util/env/get-system-env-values.ts

@@ -1,12 +0,0 @@
-import { Output } from '../output';
-import Client from '../client';
-
-export default async function getSystemEnvValues(
-  output: Output,
-  client: Client,
-  projectId: string
-) {
-  output.debug(`Fetching System Environment Values of project ${projectId}`);
-  const url = `/v6/projects/${projectId}/system-env-values`;
-  return client.fetch<{ systemEnvValues: string[] }>(url);
-}

packages/cli/src/util/env/known-error.ts

@@ -1,4 +1,4 @@
-import { isErrnoException } from '../is-error';
+import { isErrnoException } from '@vercel/error-utils';
 
 const knownErrorsCodes = new Set([
   'PAYMENT_REQUIRED',

packages/cli/src/util/errors-ts.ts

@@ -5,7 +5,7 @@ import { NowError } from './now-error';
 import code from './output/code';
 import { getCommandName } from './pkg-name';
 import chalk from 'chalk';
-import { isError } from './is-error';
+import { isError } from '@vercel/error-utils';
 
 /**
  * This error is thrown when there is an API error with a payload. The error

packages/cli/src/util/get-config.ts

@@ -10,7 +10,7 @@ import humanizePath from './humanize-path';
 import readJSONFile from './read-json-file';
 import { VercelConfig } from './dev/types';
 import { Output } from './output';
-import { isErrnoException } from './is-error';
+import { isErrnoException } from '@vercel/error-utils';
 
 let config: VercelConfig;
 

packages/cli/src/util/get-decrypted-env-records.ts

@@ -1,66 +0,0 @@
-import Client from './client';
-import { Output } from './output/create-output';
-import {
-  ProjectEnvTarget,
-  ProjectEnvType,
-  ProjectEnvVariable,
-  Secret,
-} from '../types';
-import getEnvRecords, { EnvRecordsSource } from './env/get-env-records';
-import { isAPIError } from './errors-ts';
-
-export default async function getDecryptedEnvRecords(
-  output: Output,
-  client: Client,
-  projectId: string,
-  source: EnvRecordsSource,
-  target?: ProjectEnvTarget
-): Promise<{ envs: ProjectEnvVariable[] }> {
-  const { envs } = await getEnvRecords(output, client, projectId, source, {
-    target: target || ProjectEnvTarget.Development,
-    decrypt: true,
-  });
-
-  const envsWithDecryptedSecrets = await Promise.all(
-    envs.map(async ({ id, type, key, value }) => {
-      // it's not possible to create secret env variables for development
-      // anymore but we keep this because legacy env variables with "decryptable"
-      // secret values still exit in our system
-      if (type === ProjectEnvType.Secret) {
-        try {
-          const secretIdOrName = value;
-
-          if (!secretIdOrName) {
-            return { id, type, key, value: '', found: true };
-          }
-
-          output.debug(`Fetching decrypted secret ${secretIdOrName}`);
-          const secret = await client.fetch<Secret>(
-            `/v2/now/secrets/${secretIdOrName}?decrypt=true`
-          );
-
-          return { id, type, key, value: secret.value, found: true };
-        } catch (err: unknown) {
-          if (isAPIError(err) && err.status === 404) {
-            return { id, type, key, value: '', found: false };
-          }
-
-          throw err;
-        }
-      }
-
-      return { id, type, key, value, found: true };
-    })
-  );
-
-  for (let env of envsWithDecryptedSecrets) {
-    if (!env.found) {
-      output.print('');
-      output.warn(
-        `Unable to download variable ${env.key} because associated secret was deleted`
-      );
-    }
-  }
-
-  return { envs: envsWithDecryptedSecrets };
-}

packages/cli/src/util/input/confirm.ts

@@ -1,4 +1,4 @@
-import Client from '../client';
+import type Client from '../client';
 
 export default async function confirm(
   client: Client,

packages/cli/src/util/link/ensure-link.ts

@@ -0,0 +1,61 @@
+import { Org, Project } from '../../types';
+import Client from '../client';
+import setupAndLink from '../link/setup-and-link';
+import param from '../output/param';
+import { getCommandName } from '../pkg-name';
+import { getLinkedProject } from '../projects/link';
+import type { SetupAndLinkOptions } from '../link/setup-and-link';
+
+type LinkResult = {
+  org: Org;
+  project: Project;
+};
+
+/**
+ * Checks if a project is already linked and if not, links the project and
+ * validates the link response.
+ *
+ * @param commandName - The name of the current command to print in the
+ * event of an error
+ * @param client - The Vercel Node.js client instance
+ * @param cwd - The current working directory
+ * @param opts.forceDelete - When `true`, deletes the project's `.vercel`
+ * directory
+ * @param opts.projectName - The project name to use when linking, otherwise
+ * the current directory
+ * @returns {Promise<LinkResult|number>} Returns a numeric exit code when aborted or
+ * error, otherwise an object containing the org an project
+ */
+export async function ensureLink(
+  commandName: string,
+  client: Client,
+  cwd: string,
+  opts: SetupAndLinkOptions
+): Promise<LinkResult | number> {
+  let link = await getLinkedProject(client, cwd);
+
+  if (
+    (link.status === 'linked' && opts.forceDelete) ||
+    link.status === 'not_linked'
+  ) {
+    link = await setupAndLink(client, cwd, opts);
+
+    if (link.status === 'not_linked') {
+      // User aborted project linking questions
+      return 0;
+    }
+  }
+
+  if (link.status === 'error') {
+    if (link.reason === 'HEADLESS') {
+      client.output.error(
+        `Command ${getCommandName(
+          commandName
+        )} requires confirmation. Use option ${param('--yes')} to confirm.`
+      );
+    }
+    return link.exitCode;
+  }
+
+  return { org: link.org, project: link.project };
+}

packages/cli/src/util/link/setup-and-link.ts

@@ -32,8 +32,8 @@ import { isAPIError } from '../errors-ts';
 export interface SetupAndLinkOptions {
   forceDelete?: boolean;
   autoConfirm?: boolean;
-  successEmoji: EmojiLabel;
-  setupMsg: string;
+  successEmoji?: EmojiLabel;
+  setupMsg?: string;
   projectName?: string;
 }
 
@@ -43,8 +43,8 @@ export default async function setupAndLink(
   {
     forceDelete = false,
     autoConfirm = false,
-    successEmoji,
-    setupMsg,
+    successEmoji = 'link',
+    setupMsg = 'Set up',
     projectName,
   }: SetupAndLinkOptions
 ): Promise<ProjectLinkResult> {

packages/cli/src/util/login/email.ts

@@ -7,7 +7,7 @@ import executeLogin from './login';
 import Client from '../client';
 import { LoginResult } from './types';
 import { isAPIError } from '../errors-ts';
-import { errorToString } from '../is-error';
+import { errorToString } from '@vercel/error-utils';
 
 export default async function doEmailLogin(
   client: Client,

packages/cli/src/util/login/login.ts

@@ -1,6 +1,6 @@
 import Client from '../client';
 import { InvalidEmail, AccountNotFound, isAPIError } from '../errors-ts';
-import { errorToString } from '../is-error';
+import { errorToString } from '@vercel/error-utils';
 import { LoginData } from './types';
 
 export default async function login(

packages/cli/src/util/output/create-output.ts

@@ -2,7 +2,7 @@ import chalk from 'chalk';
 import renderLink from './link';
 import wait, { StopSpinner } from './wait';
 import type { WritableTTY } from '../../types';
-import { errorToString } from '../is-error';
+import { errorToString } from '@vercel/error-utils';
 
 const IS_TEST = process.env.NODE_ENV === 'test';
 

packages/cli/src/util/projects/link.ts

@@ -18,7 +18,7 @@ import { prependEmoji, emoji, EmojiLabel } from '../emoji';
 import { isDirectory } from '../config/global-path';
 import { NowBuildError, getPlatformEnv } from '@vercel/build-utils';
 import outputCode from '../output/code';
-import { isErrnoException, isError } from '../is-error';
+import { isErrnoException, isError } from '@vercel/error-utils';
 
 const readFile = promisify(fs.readFile);
 const writeFile = promisify(fs.writeFile);

packages/cli/src/util/report-error.ts

@@ -1,7 +1,7 @@
 import Client from './client';
 import getScope from './get-scope';
 import getArgs from './get-args';
-import { isError } from './is-error';
+import { isError } from '@vercel/error-utils';
 import type { Team, User } from '../types';
 
 export default async function reportError(

packages/cli/test/dev/fixtures/30-next-image-optimization/package.json

@@ -6,7 +6,7 @@
   },
   "dependencies": {
     "next": "latest",
-    "react": "^17.0.0",
-    "react-dom": "^17.0.0"
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0"
   }
 }

packages/cli/test/dev/fixtures/middleware-500-response/middleware.js

@@ -1 +1 @@
-export default () => new Response(null, { status: 500 });
+export default () => new Response('Example Error', { status: 500 });

packages/cli/test/dev/fixtures/middleware-request-headers-override/api/dump-headers.js

@@ -0,0 +1,3 @@
+export default (req, res) => {
+  res.json(req.headers);
+};

packages/cli/test/dev/fixtures/middleware-request-headers-override/middleware.js

@@ -0,0 +1,18 @@
+export default () => {
+  return new Response(null, {
+    headers: {
+      'x-middleware-next': '1',
+      'x-middleware-override-headers':
+        'x-from-client-a,x-from-client-b,x-from-middleware-a,x-from-middleware-b,transfer-encoding',
+      // Headers to be preserved.
+      'x-middleware-request-x-from-client-a': 'hello from client',
+      // Headers to be modified by the middleware.
+      'x-middleware-request-x-from-client-b': 'hello from middleware',
+      // Headers to be added by the middleware.
+      'x-middleware-request-x-from-middleware-a': 'hello a!',
+      'x-middleware-request-x-from-middleware-b': 'hello b!',
+      // Headers not allowed by the dev server: will be ignored.
+      'transfer-encoding': 'gzip, chunked',
+    },
+  });
+};

packages/cli/test/dev/integration-4.test.ts

@@ -2,6 +2,7 @@ import ms from 'ms';
 import fs from 'fs-extra';
 import { isIP } from 'net';
 import { join } from 'path';
+import { Response } from 'node-fetch';
 
 const {
   fetch,
@@ -550,7 +551,7 @@ test(
 test(
   '[vercel dev] Middleware with an explicit 500 response',
   testFixtureStdio('middleware-500-response', async (testPath: any) => {
-    await testPath(500, '/', /EDGE_FUNCTION_INVOCATION_FAILED/);
+    await testPath(500, '/', 'Example Error');
   })
 );
 
@@ -613,3 +614,72 @@ test(
     { skipDeploy: true }
   )
 );
+
+test(
+  '[vercel dev] Middleware can override request headers',
+  testFixtureStdio(
+    'middleware-request-headers-override',
+    async (testPath: any) => {
+      await testPath(
+        200,
+        '/api/dump-headers',
+        (actual: string, res: Response) => {
+          // Headers sent to the API route.
+          const headers = JSON.parse(actual);
+
+          // Preserved headers.
+          expect(headers).toHaveProperty(
+            'x-from-client-a',
+            'hello from client'
+          );
+
+          // Headers added/modified by the middleware.
+          expect(headers).toHaveProperty(
+            'x-from-client-b',
+            'hello from middleware'
+          );
+          expect(headers).toHaveProperty('x-from-middleware-a', 'hello a!');
+          expect(headers).toHaveProperty('x-from-middleware-b', 'hello b!');
+
+          // Headers deleted by the middleware.
+          expect(headers).not.toHaveProperty('x-from-client-c');
+
+          // Internal headers should not be visible from API routes.
+          expect(headers).not.toHaveProperty('x-middleware-override-headers');
+          expect(headers).not.toHaveProperty(
+            'x-middleware-request-from-middleware-a'
+          );
+          expect(headers).not.toHaveProperty(
+            'x-middleware-request-from-middleware-b'
+          );
+
+          // Request headers should not be visible from clients.
+          const respHeaders = Object.fromEntries(res.headers.entries());
+          expect(respHeaders).not.toHaveProperty(
+            'x-middleware-override-headers'
+          );
+          expect(respHeaders).not.toHaveProperty(
+            'x-middleware-request-from-middleware-a'
+          );
+          expect(respHeaders).not.toHaveProperty(
+            'x-middleware-request-from-middleware-b'
+          );
+          expect(respHeaders).not.toHaveProperty('from-middleware-a');
+          expect(respHeaders).not.toHaveProperty('from-middleware-b');
+          expect(respHeaders).not.toHaveProperty('x-from-client-a');
+          expect(respHeaders).not.toHaveProperty('x-from-client-b');
+          expect(respHeaders).not.toHaveProperty('x-from-client-c');
+        },
+        /*expectedHeaders=*/ {},
+        {
+          headers: {
+            'x-from-client-a': 'hello from client',
+            'x-from-client-b': 'hello from client',
+            'x-from-client-c': 'hello from client',
+          },
+        }
+      );
+    },
+    { skipDeploy: true }
+  )
+);

packages/cli/test/fixtures/unit/pnpm-pnp-symlink/index.js

@@ -1,4 +1,6 @@
 const { exec } = require('exeggcute');
+const path = require('path');
+const { existsSync, writeFileSync } = require('fs');
 
 const a = require('./a');
 const b = require('./b');
@@ -8,8 +10,14 @@ b();
 
 exec('mkdir public', __dirname)
   .then(() => {
-    exec('echo "Hello, World!" > public/index.html', __dirname).then(() => {
+    const cacheFile = path.join(__dirname, 'node_modules/.was-cached');
+    const cacheExists = existsSync(cacheFile);
+    exec(
+      `echo ${cacheExists ? 'cache exists' : 'no cache'} > public/index.html`,
+      __dirname
+    ).then(() => {
       console.log('Success');
+      writeFileSync(cacheFile, '1');
     });
   })
   .catch(console.error);

packages/cli/test/integration.js

@@ -3446,23 +3446,20 @@ test('deploy pnpm twice using pnp and symlink=false', async t => {
     ]);
   }
 
-  function logs(deploymentUrl) {
-    return execa(binaryPath, ['logs', deploymentUrl, ...defaultArgs]);
-  }
-
   let { exitCode, stderr, stdout } = await deploy();
   t.is(exitCode, 0, formatOutput({ stderr, stdout }));
 
-  let { stdout: logsOutput } = await logs(stdout);
-
-  t.regex(logsOutput, /Build Cache not found/m);
+  let page = await fetch(stdout);
+  let text = await page.text();
+  t.is(text, 'no cache\n');
 
   ({ exitCode, stderr, stdout } = await deploy());
   t.is(exitCode, 0, formatOutput({ stderr, stdout }));
 
-  ({ stdout: logsOutput } = await logs(stdout));
+  page = await fetch(stdout);
+  text = await page.text();
 
-  t.regex(logsOutput, /Build cache downloaded/m);
+  t.is(text, 'cache exists\n');
 });
 
 test('reject deploying with wrong team .vercel config', async t => {

packages/cli/test/mocks/client.ts

@@ -23,7 +23,7 @@ class MockStream extends PassThrough {
     this.isTTY = true;
   }
 
-  // These is for the `ora` module
+  // These are for the `ora` module
   clearLine() {}
   cursorTo() {}
 }

packages/cli/test/mocks/project.ts

@@ -1,37 +1,44 @@
 import { client } from './client';
-import { Project } from '../../src/types';
+import {
+  Project,
+  ProjectEnvTarget,
+  ProjectEnvType,
+  ProjectEnvVariable,
+} from '../../src/types';
 import { formatProvider } from '../../src/util/git/connect-git-provider';
+import { parseEnvironment } from '../../src/commands/pull';
+import { Env } from '@vercel/build-utils/dist';
 
-const envs = [
+const envs: ProjectEnvVariable[] = [
   {
-    type: 'encrypted',
+    type: ProjectEnvType.Encrypted,
     id: '781dt89g8r2h789g',
     key: 'REDIS_CONNECTION_STRING',
     value: 'redis://abc123@redis.example.com:6379',
-    target: ['production', 'preview'],
-    gitBranch: null,
+    target: [ProjectEnvTarget.Production, ProjectEnvTarget.Preview],
+    gitBranch: undefined,
     configurationId: null,
     updatedAt: 1557241361455,
     createdAt: 1557241361455,
   },
   {
-    type: 'encrypted',
+    type: ProjectEnvType.Encrypted,
     id: 'r124t6frtu25df16',
     key: 'SQL_CONNECTION_STRING',
     value: 'Server=sql.example.com;Database=app;Uid=root;Pwd=P455W0RD;',
-    target: ['production'],
-    gitBranch: null,
+    target: [ProjectEnvTarget.Production],
+    gitBranch: undefined,
     configurationId: null,
     updatedAt: 1557241361445,
     createdAt: 1557241361445,
   },
   {
-    type: 'encrypted',
+    type: ProjectEnvType.Encrypted,
     id: 'a235l6frtu25df32',
     key: 'SPECIAL_FLAG',
     value: '1',
-    target: ['development'],
-    gitBranch: null,
+    target: [ProjectEnvTarget.Development],
+    gitBranch: undefined,
     configurationId: null,
     updatedAt: 1557241361445,
     createdAt: 1557241361445,
@@ -206,6 +213,43 @@ export function useProject(project: Partial<Project> = defaultProject) {
     Object.assign(project, req.body);
     res.json(project);
   });
+  client.scenario.get(
+    `/v1/env/pull/${project.id}/:target?/:gitBranch?`,
+    (req, res) => {
+      const target: ProjectEnvTarget | undefined =
+        typeof req.params.target === 'string'
+          ? parseEnvironment(req.params.target)
+          : undefined;
+      let projectEnvs = envs;
+      if (target) {
+        projectEnvs = projectEnvs.filter(env => {
+          if (typeof env.target === 'string') {
+            return env.target === target;
+          }
+          if (Array.isArray(env.target)) {
+            return env.target.includes(target);
+          }
+          return false;
+        });
+      }
+      const allEnvs = Object.entries(
+        exposeSystemEnvs(
+          projectEnvs,
+          systemEnvs.map(env => env.key),
+          project.autoExposeSystemEnvs,
+          undefined,
+          target
+        )
+      );
+
+      const env: Record<string, string> = {};
+
+      allEnvs.forEach(([k, v]) => {
+        env[k] = v ?? '';
+      });
+      res.json({ env: env });
+    }
+  );
   client.scenario.get(
     `/v6/projects/${project.id}/system-env-values`,
     (_req, res) => {
@@ -222,15 +266,26 @@ export function useProject(project: Partial<Project> = defaultProject) {
       });
     }
   );
-  client.scenario.get(`/v8/projects/${project.id}/env`, (_req, res) => {
-    const target = _req.query.target;
-    if (typeof target === 'string') {
-      const targetEnvs = envs.filter(env => env.target.includes(target));
-      res.json({ envs: targetEnvs });
-      return;
+  client.scenario.get(`/v8/projects/${project.id}/env`, (req, res) => {
+    const target: ProjectEnvTarget | undefined =
+      typeof req.query.target === 'string'
+        ? parseEnvironment(req.query.target)
+        : undefined;
+
+    let targetEnvs = envs;
+    if (target) {
+      targetEnvs = targetEnvs.filter(env => {
+        if (typeof env.target === 'string') {
+          return env.target === target;
+        }
+        if (Array.isArray(env.target)) {
+          return env.target.includes(target);
+        }
+        return false;
+      });
     }
 
-    res.json({ envs });
+    res.json({ envs: targetEnvs });
   });
   client.scenario.post(`/v8/projects/${project.id}/env`, (req, res) => {
     const envObj = req.body;
@@ -310,3 +365,43 @@ export function useProject(project: Partial<Project> = defaultProject) {
 
   return { project, envs };
 }
+
+function getSystemEnvValue(
+  systemEnvRef: string,
+  { vercelUrl }: { vercelUrl?: string }
+) {
+  if (systemEnvRef === 'VERCEL_URL') {
+    return vercelUrl || '';
+  }
+
+  return '';
+}
+
+function exposeSystemEnvs(
+  projectEnvs: ProjectEnvVariable[],
+  systemEnvValues: string[],
+  autoExposeSystemEnvs: boolean | undefined,
+  vercelUrl?: string,
+  target?: ProjectEnvTarget
+) {
+  const envs: Env = {};
+
+  if (autoExposeSystemEnvs) {
+    envs['VERCEL'] = '1';
+    envs['VERCEL_ENV'] = target || 'development';
+
+    for (const key of systemEnvValues) {
+      envs[key] = getSystemEnvValue(key, { vercelUrl });
+    }
+  }
+
+  for (let env of projectEnvs) {
+    if (env.type === ProjectEnvType.System) {
+      envs[env.key] = getSystemEnvValue(env.value, { vercelUrl });
+    } else {
+      envs[env.key] = env.value;
+    }
+  }
+
+  return envs;
+}

packages/cli/test/unit/commands/link.test.ts

@@ -0,0 +1,125 @@
+import { basename, join } from 'path';
+import { mkdtemp, readJSON, remove } from 'fs-extra';
+import link from '../../../src/commands/link';
+import { client } from '../../mocks/client';
+import { useUser } from '../../mocks/user';
+import { useTeams } from '../../mocks/team';
+import {
+  defaultProject,
+  useProject,
+  useUnknownProject,
+} from '../../mocks/project';
+import { tmpdir } from 'os';
+
+describe('link', () => {
+  const origCwd = process.cwd();
+
+  it('should prompt for link', async () => {
+    const cwd = await mkdtemp(join(tmpdir(), 'cli-'));
+    try {
+      process.chdir(cwd);
+      const user = useUser();
+      useTeams('team_dummy');
+      const { project } = useProject({
+        ...defaultProject,
+        id: basename(cwd),
+        name: basename(cwd),
+      });
+      useUnknownProject();
+
+      const exitCodePromise = link(client);
+
+      await expect(client.stderr).toOutput('Set up');
+      client.stdin.write('y\n');
+
+      await expect(client.stderr).toOutput(
+        'Which scope should contain your project?'
+      );
+      client.stdin.write('y\n');
+
+      await expect(client.stderr).toOutput('Link to it?');
+      client.stdin.write('y\n');
+
+      await expect(client.stderr).toOutput(
+        `Linked to ${user.username}/${project.name} (created .vercel and added it to .gitignore)`
+      );
+
+      await expect(exitCodePromise).resolves.toEqual(0);
+
+      const projectJson = await readJSON(join(cwd, '.vercel/project.json'));
+      expect(projectJson.orgId).toEqual(user.id);
+      expect(projectJson.projectId).toEqual(project.id);
+    } finally {
+      process.chdir(origCwd);
+      await remove(cwd);
+    }
+  });
+
+  it('should allow specifying `--project` flag', async () => {
+    const cwd = await mkdtemp(join(tmpdir(), 'cli-'));
+    try {
+      process.chdir(cwd);
+      const user = useUser();
+      useTeams('team_dummy');
+      const { project } = useProject({
+        ...defaultProject,
+        id: basename(cwd),
+        name: basename(cwd),
+      });
+      useUnknownProject();
+
+      client.setArgv('--project', project.name!, '--yes');
+      const exitCodePromise = link(client);
+
+      await expect(client.stderr).toOutput(
+        `Linked to ${user.username}/${project.name} (created .vercel and added it to .gitignore)`
+      );
+
+      await expect(exitCodePromise).resolves.toEqual(0);
+
+      const projectJson = await readJSON(join(cwd, '.vercel/project.json'));
+      expect(projectJson.orgId).toEqual(user.id);
+      expect(projectJson.projectId).toEqual(project.id);
+    } finally {
+      process.chdir(origCwd);
+      await remove(cwd);
+    }
+  });
+
+  it('should allow overwriting existing link', async () => {
+    const cwd = await mkdtemp(join(tmpdir(), 'cli-'));
+    try {
+      process.chdir(cwd);
+      const user = useUser();
+      useTeams('team_dummy');
+      const { project: proj1 } = useProject({
+        ...defaultProject,
+        id: 'one',
+        name: 'one',
+      });
+      const { project: proj2 } = useProject({
+        ...defaultProject,
+        id: 'two',
+        name: 'two',
+      });
+      useUnknownProject();
+
+      client.setArgv('--project', proj1.name!, '--yes');
+      await expect(link(client)).resolves.toEqual(0);
+
+      let projectJson = await readJSON(join(cwd, '.vercel/project.json'));
+      expect(projectJson.orgId).toEqual(user.id);
+      expect(projectJson.projectId).toEqual(proj1.id);
+
+      client.setArgv('--project', proj2.name!, '--yes');
+      await expect(link(client)).resolves.toEqual(0);
+
+      projectJson = await readJSON(join(cwd, '.vercel/project.json'));
+      expect(projectJson.orgId).toEqual(user.id);
+      expect(projectJson.projectId).toEqual(proj2.id);
+    } finally {
+      process.chdir(origCwd);
+      await remove(cwd);
+    }
+  });
+});

packages/cli/test/unit/util/dev/headers.test.ts

@@ -0,0 +1,77 @@
+import { Headers } from 'node-fetch';
+import { applyOverriddenHeaders } from '../../../../src/util/dev/headers';
+
+describe('applyOverriddenHeaders', () => {
+  it('do nothing if x-middleware-override-headers is not set', async () => {
+    const reqHeaders = { a: '1' };
+    const respHeaders = new Headers();
+
+    applyOverriddenHeaders(reqHeaders, respHeaders);
+    expect(reqHeaders).toStrictEqual({ a: '1' });
+  });
+
+  it('adds a new header', async () => {
+    const reqHeaders = { a: '1' };
+    const respHeaders = new Headers({
+      // Define a new header 'b' and keep the existing header 'a'
+      'x-middleware-override-headers': 'a,b',
+      'x-middleware-request-a': '1',
+      'x-middleware-request-b': '2',
+    });
+
+    applyOverriddenHeaders(reqHeaders, respHeaders);
+    expect(reqHeaders).toStrictEqual({ a: '1', b: '2' });
+  });
+
+  it('delete the header if x-middleware-request-* is undefined', async () => {
+    const reqHeaders = { a: '1', b: '2' };
+    const respHeaders = new Headers({
+      // Deletes a new header 'c' and keep the existing headers `a` and `b`
+      'x-middleware-override-headers': 'a,b,c',
+      'x-middleware-request-a': '1',
+      'x-middleware-request-b': '2',
+    });
+
+    applyOverriddenHeaders(reqHeaders, respHeaders);
+    expect(reqHeaders).toStrictEqual({ a: '1', b: '2' });
+  });
+
+  it('updates an existing header', async () => {
+    const reqHeaders = { a: '1', b: '2' };
+    const respHeaders = new Headers({
+      // Modifies the header 'b' and keep the existing header 'a'
+      'x-middleware-override-headers': 'a,b',
+      'x-middleware-request-a': '1',
+      'x-middleware-request-b': 'modified',
+    });
+
+    applyOverriddenHeaders(reqHeaders, respHeaders);
+    expect(reqHeaders).toStrictEqual({ a: '1', b: 'modified' });
+  });
+
+  it('ignores headers listed in NONOVERRIDABLE_HEADERS', async () => {
+    const reqHeaders = { a: '1', host: 'example.com' };
+    const respHeaders = new Headers({
+      // Define a new header 'b' and 'content-length'
+      'x-middleware-override-headers': 'a,b,content-length',
+      'x-middleware-request-a': '1',
+      'x-middleware-request-b': '2',
+      'x-middleware-request-content-length': '128',
+    });
+
+    applyOverriddenHeaders(reqHeaders, respHeaders);
+    expect(reqHeaders).toStrictEqual({ a: '1', b: '2', host: 'example.com' });
+  });
+
+  it('deletes an existing header', async () => {
+    const reqHeaders = { a: '1', b: '2' };
+    const respHeaders = new Headers({
+      // Deletes the header 'a' and keep the existing header 'b'
+      'x-middleware-override-headers': 'b',
+      'x-middleware-request-b': '2',
+    });
+
+    applyOverriddenHeaders(reqHeaders, respHeaders);
+    expect(reqHeaders).toStrictEqual({ b: '2' });
+  });
+});

packages/cli/test/unit/util/dev/parse-query-string.test.ts

@@ -23,24 +23,24 @@ describe('parseQueryString', () => {
     const parsed = parseQueryString('');
     expect(parsed).toEqual({});
     const format = formatQueryString(parsed);
-    expect(format).toEqual(undefined);
+    expect(format).toEqual(null);
   });
   it('should work with question mark', async () => {
     const parsed = parseQueryString('?');
     expect(parsed).toEqual({});
     const format = formatQueryString(parsed);
-    expect(format).toEqual(undefined);
+    expect(format).toEqual(null);
   });
   it('should work without question mark', async () => {
     const parsed = parseQueryString('blarg');
     expect(parsed).toEqual({});
     const format = formatQueryString(parsed);
-    expect(format).toEqual(undefined);
+    expect(format).toEqual(null);
   });
   it('should work with undefined', async () => {
     const parsed = parseQueryString(undefined);
     expect(parsed).toEqual({});
     const format = formatQueryString(parsed);
-    expect(format).toEqual(undefined);
+    expect(format).toEqual(null);
   });
 });

packages/client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/client",
-  "version": "12.2.13",
+  "version": "12.2.16",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",
   "homepage": "https://vercel.com",
@@ -28,7 +28,7 @@
     "@types/jest": "27.4.1",
     "@types/minimatch": "3.0.5",
     "@types/ms": "0.7.30",
-    "@types/node": "12.0.4",
+    "@types/node": "14.18.33",
     "@types/node-fetch": "2.5.4",
     "@types/recursive-readdir": "2.2.0",
     "@types/tar-fs": "1.16.1",
@@ -43,8 +43,8 @@
     ]
   },
   "dependencies": {
-    "@vercel/build-utils": "5.5.5",
-    "@vercel/routing-utils": "2.0.2",
+    "@vercel/build-utils": "5.5.7",
+    "@vercel/routing-utils": "2.1.2",
     "@zeit/fetch": "5.2.0",
     "async-retry": "1.2.3",
     "async-sema": "3.0.0",

packages/edge/docs/README.md

@@ -6,6 +6,7 @@
 
 - [ExtraResponseInit](interfaces/ExtraResponseInit.md)
 - [Geo](interfaces/Geo.md)
+- [ModifiedRequest](interfaces/ModifiedRequest.md)
 
 ### Variables
 
@@ -15,6 +16,7 @@
 - [LATITUDE_HEADER_NAME](README.md#latitude_header_name)
 - [LONGITUDE_HEADER_NAME](README.md#longitude_header_name)
 - [REGION_HEADER_NAME](README.md#region_header_name)
+- [REQUEST_ID_HEADER_NAME](README.md#request_id_header_name)
 
 ### Functions
 
@@ -89,11 +91,25 @@ Longitude of the original client IP as calculated by Vercel Proxy.
 
 • `Const` **REGION_HEADER_NAME**: `"x-vercel-ip-country-region"`
 
-Region of the original client IP as calculated by Vercel Proxy.
+Country region of the original client IP calculated by Vercel Proxy.
+
+See [docs](https://vercel.com/docs/concepts/edge-network/headers#x-vercel-ip-country-region).
 
 #### Defined in
 
-[src/edge-headers.ts:24](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L24)
+[src/edge-headers.ts:26](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L26)
+
+---
+
+### REQUEST_ID_HEADER_NAME
+
+• `Const` **REQUEST_ID_HEADER_NAME**: `"x-vercel-id"`
+
+The request ID for each request generated by Vercel Proxy.
+
+#### Defined in
+
+[src/edge-headers.ts:30](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L30)
 
 ## Functions
 
@@ -123,7 +139,7 @@ Returns the location information for the incoming request.
 
 #### Defined in
 
-[src/edge-headers.ts:80](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L80)
+[src/edge-headers.ts:106](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L106)
 
 ---
 
@@ -149,7 +165,7 @@ Returns the IP address of the request from the headers.
 
 #### Defined in
 
-[src/edge-headers.ts:66](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L66)
+[src/edge-headers.ts:77](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L77)
 
 ---
 
@@ -197,7 +213,7 @@ export default function middleware(_req: Request) {
 
 #### Defined in
 
-[src/middleware-helpers.ts:94](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L94)
+[src/middleware-helpers.ts:145](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L145)
 
 ---
 
@@ -259,4 +275,4 @@ export const config = { matcher: '/api/users/:path*' };
 
 #### Defined in
 
-[src/middleware-helpers.ts:53](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L53)
+[src/middleware-helpers.ts:101](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L101)

packages/edge/docs/interfaces/ExtraResponseInit.md

@@ -11,6 +11,7 @@
 ### Properties
 
 - [headers](ExtraResponseInit.md#headers)
+- [request](ExtraResponseInit.md#request)
 - [status](ExtraResponseInit.md#status)
 - [statusText](ExtraResponseInit.md#statustext)
 
@@ -25,7 +26,19 @@ along with the response headers from the origin.
 
 #### Defined in
 
-[src/middleware-helpers.ts:6](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L6)
+[src/middleware-helpers.ts:31](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L31)
+
+---
+
+### request
+
+• `Optional` **request**: [`ModifiedRequest`](ModifiedRequest.md)
+
+Fields to rewrite for the upstream request.
+
+#### Defined in
+
+[src/middleware-helpers.ts:35](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L35)
 
 ---
 

packages/edge/docs/interfaces/Geo.md

@@ -8,6 +8,7 @@ The location information of a given request.
 
 - [city](Geo.md#city)
 - [country](Geo.md#country)
+- [countryRegion](Geo.md#countryregion)
 - [latitude](Geo.md#latitude)
 - [longitude](Geo.md#longitude)
 - [region](Geo.md#region)
@@ -22,7 +23,7 @@ The city that the request originated from.
 
 #### Defined in
 
-[src/edge-headers.ts:41](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L41)
+[src/edge-headers.ts:47](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L47)
 
 ---
 
@@ -34,7 +35,20 @@ The country that the request originated from.
 
 #### Defined in
 
-[src/edge-headers.ts:44](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L44)
+[src/edge-headers.ts:50](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L50)
+
+---
+
+### countryRegion
+
+• `Optional` **countryRegion**: `string`
+
+The region part of the ISO 3166-2 code of the client IP.
+See [docs](https://vercel.com/docs/concepts/edge-network/headers#x-vercel-ip-country-region).
+
+#### Defined in
+
+[src/edge-headers.ts:58](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L58)
 
 ---
 
@@ -46,7 +60,7 @@ The latitude of the client.
 
 #### Defined in
 
-[src/edge-headers.ts:50](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L50)
+[src/edge-headers.ts:61](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L61)
 
 ---
 
@@ -58,7 +72,7 @@ The longitude of the client.
 
 #### Defined in
 
-[src/edge-headers.ts:53](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L53)
+[src/edge-headers.ts:64](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L64)
 
 ---
 
@@ -70,4 +84,4 @@ The [Vercel Edge Network region](https://vercel.com/docs/concepts/edge-network/r
 
 #### Defined in
 
-[src/edge-headers.ts:47](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L47)
+[src/edge-headers.ts:53](https://github.com/vercel/vercel/blob/main/packages/edge/src/edge-headers.ts#L53)

packages/edge/docs/interfaces/ModifiedRequest.md

@@ -0,0 +1,38 @@
+# Interface: ModifiedRequest
+
+## Table of contents
+
+### Properties
+
+- [headers](ModifiedRequest.md#headers)
+
+## Properties
+
+### headers
+
+• `Optional` **headers**: `Headers`
+
+If set, overwrites the incoming headers to the origin request.
+
+This is useful when you want to pass data between a Middleware and a
+Serverless or Edge Function.
+
+**`Example`**
+
+<caption>Add a `x-user-id` header and remove the `Authorization` header</caption>
+
+```ts
+import { rewrite } from '@vercel/edge';
+export default async function middleware(request: Request): Promise<Response> {
+  const newHeaders = new Headers(request.headers);
+  newHeaders.set('x-user-id', 'user_123');
+  newHeaders.delete('authorization');
+  return rewrite(request.url, {
+    request: { headers: newHeaders },
+  });
+}
+```
+
+#### Defined in
+
+[src/middleware-helpers.ts:23](https://github.com/vercel/vercel/blob/main/packages/edge/src/middleware-helpers.ts#L23)

packages/edge/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/edge",
-  "version": "0.0.4",
+  "version": "0.1.1",
   "license": "MIT",
   "main": "dist/index.js",
   "module": "dist/index.mjs",
@@ -12,7 +12,7 @@
     "build:docs": "typedoc && prettier --write docs/**/*.md docs/*.md"
   },
   "devDependencies": {
-    "@edge-runtime/jest-environment": "1.1.0-beta.7",
+    "@edge-runtime/jest-environment": "2.0.0",
     "@types/jest": "27.4.1",
     "ts-node": "8.9.1",
     "tsup": "6.1.2",

packages/edge/src/edge-headers.ts

@@ -19,9 +19,15 @@ export const LATITUDE_HEADER_NAME = 'x-vercel-ip-latitude';
  */
 export const LONGITUDE_HEADER_NAME = 'x-vercel-ip-longitude';
 /**
- * Region of the original client IP as calculated by Vercel Proxy.
+ * Country region of the original client IP calculated by Vercel Proxy.
+ *
+ * See [docs](https://vercel.com/docs/concepts/edge-network/headers#x-vercel-ip-country-region).
  */
 export const REGION_HEADER_NAME = 'x-vercel-ip-country-region';
+/**
+ * The request ID for each request generated by Vercel Proxy.
+ */
+export const REQUEST_ID_HEADER_NAME = 'x-vercel-id';
 
 /**
  * We define a new type so this function can be reused with
@@ -46,6 +52,11 @@ export interface Geo {
   /** The [Vercel Edge Network region](https://vercel.com/docs/concepts/edge-network/regions) that received the request. */
   region?: string;
 
+  /** The region part of the ISO 3166-2 code of the client IP.
+   * See [docs](https://vercel.com/docs/concepts/edge-network/headers#x-vercel-ip-country-region).
+   */
+  countryRegion?: string;
+
   /** The latitude of the client. */
   latitude?: string;
 
@@ -67,6 +78,21 @@ export function ipAddress(request: Request): string | undefined {
   return getHeader(request, IP_HEADER_NAME);
 }
 
+/**
+ * Extracts the Vercel Edge Network region name from the request ID.
+ *
+ * @param requestId The request ID (`x-vercel-id`).
+ * @returns The first region received the client request.
+ */
+function getRegionFromRequestId(requestId?: string): string | undefined {
+  if (!requestId) {
+    return 'dev1';
+  }
+
+  // The request ID is in the format of `region::id` or `region1:region2:...::id`.
+  return requestId.split(':')[0];
+}
+
 /**
  * Returns the location information for the incoming request.
  *
@@ -81,7 +107,8 @@ export function geolocation(request: Request): Geo {
   return {
     city: getHeader(request, CITY_HEADER_NAME),
     country: getHeader(request, COUNTRY_HEADER_NAME),
-    region: getHeader(request, REGION_HEADER_NAME),
+    countryRegion: getHeader(request, REGION_HEADER_NAME),
+    region: getRegionFromRequestId(getHeader(request, REQUEST_ID_HEADER_NAME)),
     latitude: getHeader(request, LATITUDE_HEADER_NAME),
     longitude: getHeader(request, LONGITUDE_HEADER_NAME),
   };

packages/edge/src/middleware-helpers.ts

@@ -1,9 +1,57 @@
+export interface ModifiedRequest {
+  /**
+   * If set, overwrites the incoming headers to the origin request.
+   *
+   * This is useful when you want to pass data between a Middleware and a
+   * Serverless or Edge Function.
+   *
+   * @example
+   * <caption>Add a `x-user-id` header and remove the `Authorization` header</caption>
+   *
+   * ```ts
+   * import { rewrite } from '@vercel/edge';
+   * export default async function middleware(request: Request): Promise<Response> {
+   *   const newHeaders = new Headers(request.headers);
+   *   newHeaders.set('x-user-id', 'user_123');
+   *   newHeaders.delete('authorization');
+   *   return rewrite(request.url, {
+   *     request: { headers: newHeaders }
+   *   })
+   * }
+   * ```
+   */
+  headers?: Headers;
+}
+
 export interface ExtraResponseInit extends Omit<ResponseInit, 'headers'> {
   /**
    * These headers will be sent to the user response
    * along with the response headers from the origin.
    */
   headers?: HeadersInit;
+  /**
+   * Fields to rewrite for the upstream request.
+   */
+  request?: ModifiedRequest;
+}
+
+function handleMiddlewareField(
+  init: ExtraResponseInit | undefined,
+  headers: Headers
+) {
+  if (init?.request?.headers) {
+    if (!(init.request.headers instanceof Headers)) {
+      throw new Error('request.headers must be an instance of Headers');
+    }
+
+    const keys = [];
+    for (const [key, value] of init.request.headers) {
+      headers.set('x-middleware-request-' + key, value);
+      keys.push(key);
+    }
+
+    headers.set('x-middleware-override-headers', keys.join(','));
+  }
 }
 
 /**
@@ -56,6 +104,9 @@ export function rewrite(
 ): Response {
   const headers = new Headers(init?.headers ?? {});
   headers.set('x-middleware-rewrite', String(destination));
+
+  handleMiddlewareField(init, headers);
+
   return new Response(null, {
     ...init,
     headers,
@@ -94,6 +145,9 @@ export function rewrite(
 export function next(init?: ExtraResponseInit): Response {
   const headers = new Headers(init?.headers ?? {});
   headers.set('x-middleware-next', '1');
+
+  handleMiddlewareField(init, headers);
+
   return new Response(null, {
     ...init,
     headers,

packages/edge/test/edge-headers.test.ts

@@ -12,6 +12,7 @@ import {
   LATITUDE_HEADER_NAME,
   LONGITUDE_HEADER_NAME,
   REGION_HEADER_NAME,
+  REQUEST_ID_HEADER_NAME,
 } from '../src';
 
 test('`ipAddress` returns the value from the header', () => {
@@ -24,9 +25,16 @@ test('`ipAddress` returns the value from the header', () => {
 });
 
 describe('`geolocation`', () => {
-  test('returns an empty object if headers are not found', () => {
+  test('returns an object with lots of undefined if headers are not found', () => {
     const req = new Request('https://example.vercel.sh');
-    expect(geolocation(req)).toEqual({});
+    expect(geolocation(req)).toEqual({
+      city: undefined,
+      country: undefined,
+      countryRegion: undefined,
+      latitude: undefined,
+      longitude: undefined,
+      region: 'dev1',
+    });
   });
 
   test('reads values from headers', () => {
@@ -36,7 +44,8 @@ describe('`geolocation`', () => {
         [COUNTRY_HEADER_NAME]: 'Israel',
         [LATITUDE_HEADER_NAME]: '32.109333',
         [LONGITUDE_HEADER_NAME]: '34.855499',
-        [REGION_HEADER_NAME]: 'fra1',
+        [REGION_HEADER_NAME]: 'TA', // https://en.wikipedia.org/wiki/ISO_3166-2:IL
+        [REQUEST_ID_HEADER_NAME]: 'fra1::kpwjx-123455678-c0ffee',
       },
     });
     expect(geolocation(req)).toEqual<Geo>({
@@ -45,6 +54,48 @@ describe('`geolocation`', () => {
       latitude: '32.109333',
       longitude: '34.855499',
       region: 'fra1',
+      countryRegion: 'TA',
+    });
+  });
+
+  test('reads values from headers (with a request ID containing two edge regions)', () => {
+    const req = new Request('https://example.vercel.sh', {
+      headers: {
+        [CITY_HEADER_NAME]: 'Tokyo',
+        [COUNTRY_HEADER_NAME]: 'Japan',
+        [LATITUDE_HEADER_NAME]: '37.1233',
+        [LONGITUDE_HEADER_NAME]: '30.733399',
+        [REGION_HEADER_NAME]: '13',
+        [REQUEST_ID_HEADER_NAME]: 'hnd1:iad1::kpwjx-123455678-c0ffee',
+      },
+    });
+    expect(geolocation(req)).toEqual<Geo>({
+      city: 'Tokyo',
+      country: 'Japan',
+      latitude: '37.1233',
+      longitude: '30.733399',
+      region: 'hnd1',
+      countryRegion: '13',
+    });
+  });
+
+  test('reads values from headers (without a request ID)', () => {
+    const req = new Request('https://example.vercel.sh', {
+      headers: {
+        [CITY_HEADER_NAME]: 'Tokyo',
+        [COUNTRY_HEADER_NAME]: 'Japan',
+        [LATITUDE_HEADER_NAME]: '37.1233',
+        [LONGITUDE_HEADER_NAME]: '30.733399',
+        [REGION_HEADER_NAME]: '13',
+      },
+    });
+    expect(geolocation(req)).toEqual<Geo>({
+      city: 'Tokyo',
+      country: 'Japan',
+      latitude: '37.1233',
+      longitude: '30.733399',
+      region: 'dev1',
+      countryRegion: '13',
     });
   });
 });

packages/edge/test/middleware-helpers.test.ts

@@ -22,6 +22,32 @@ describe('rewrite', () => {
       },
     });
   });
+
+  test('receives new request headers', () => {
+    const headers = new Headers();
+    headers.set('x-from-middleware1', 'hello1');
+    headers.set('x-from-middleware2', 'hello2');
+    const resp = rewrite(new URL('https://example.vercel.sh/'), {
+      headers: {
+        'x-custom-header': 'custom-value',
+      },
+      request: { headers },
+    });
+    expect({
+      status: resp.status,
+      headers: Object.fromEntries(resp.headers),
+    }).toMatchObject({
+      status: 200,
+      headers: {
+        'x-middleware-rewrite': 'https://example.vercel.sh/',
+        'x-custom-header': 'custom-value',
+        'x-middleware-override-headers':
+          'x-from-middleware1,x-from-middleware2',
+        'x-middleware-request-x-from-middleware2': 'hello2',
+        'x-middleware-request-x-from-middleware1': 'hello1',
+      },
+    });
+  });
 });
 
 describe('next', () => {
@@ -42,4 +68,30 @@ describe('next', () => {
       },
     });
   });
+
+  test('receives new request headers', () => {
+    const headers = new Headers();
+    headers.set('x-from-middleware1', 'hello1');
+    headers.set('x-from-middleware2', 'hello2');
+    const resp = next({
+      headers: {
+        'x-custom-header': 'custom-value',
+      },
+      request: { headers },
+    });
+    expect({
+      status: resp.status,
+      headers: Object.fromEntries(resp.headers),
+    }).toMatchObject({
+      status: 200,
+      headers: {
+        'x-middleware-next': '1',
+        'x-custom-header': 'custom-value',
+        'x-middleware-override-headers':
+          'x-from-middleware1,x-from-middleware2',
+        'x-middleware-request-x-from-middleware2': 'hello2',
+        'x-middleware-request-x-from-middleware1': 'hello1',
+      },
+    });
+  });
 });

packages/error-utils/jest.config.js

@@ -0,0 +1,13 @@
+/** @type {import('@ts-jest/dist/types').InitialOptionsTsJest} */
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  coverageThreshold: {
+    global: {
+      branches: 100,
+      functions: 100,
+      lines: 100,
+      statements: 100,
+    },
+  },
+};

packages/error-utils/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "@vercel/error-utils",
+  "version": "1.0.3",
+  "description": "A collection of error utilities for vercel/vercel",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/vercel/vercel.git",
+    "directory": "packages/error-utils"
+  },
+  "scripts": {
+    "build": "tsc",
+    "test": "jest --coverage --env node --verbose",
+    "test-unit": "yarn test"
+  },
+  "license": "MIT",
+  "devDependencies": {
+    "@types/jest": "29.2.1",
+    "@types/node": "14.18.33",
+    "jest": "29.2.2",
+    "ts-jest": "29.0.3",
+    "typescript": "^4.8.4"
+  }
+}

packages/error-utils/src/index.ts

@@ -25,7 +25,6 @@ export const isError = (error: unknown): error is Error => {
   // Walk the prototype tree until we find a matching object.
   while (error) {
     if (Object.prototype.toString.call(error) === '[object Error]') return true;
-    // eslint-disable-next-line no-param-reassign -- TODO: Fix eslint error following @vercel/style-guide migration
     error = Object.getPrototypeOf(error);
   }
 

packages/error-utils/test/index.test.ts

@@ -0,0 +1,148 @@
+import fs from 'node:fs';
+import {
+  isObject,
+  isError,
+  isErrnoException,
+  isErrorLike,
+  normalizeError,
+  isSpawnError,
+  errorToString,
+} from '../src';
+
+const ARRAY: any[] = [];
+const BIGINT = 1n;
+const BOOLEAN = true;
+const FUNCTION = () => {};
+const NULL = null;
+const NUMBER = 0;
+const OBJECT = {};
+const STRING = '';
+const SYMBOL = Symbol('');
+const UNDEFINED = undefined;
+
+class CLASS {} // `CLASS` is a function and `new CLASS()` is an Object
+
+test('isObject returns true for objects only', () => {
+  for (const item of [ARRAY, new CLASS(), OBJECT]) {
+    expect(isObject(item)).toBe(true);
+  }
+  for (const item of [
+    BIGINT,
+    BOOLEAN,
+    CLASS,
+    FUNCTION,
+    NULL,
+    NUMBER,
+    STRING,
+    SYMBOL,
+    UNDEFINED,
+  ]) {
+    expect(isObject(item)).toBe(false);
+  }
+});
+
+test('isError returns true for Error instances only', () => {
+  for (const error of [
+    new Error(),
+    new EvalError(),
+    new RangeError(),
+    new ReferenceError(),
+    new SyntaxError(),
+    new TypeError(),
+    new URIError(),
+  ]) {
+    expect(isError(error)).toBe(true);
+  }
+  for (const item of [
+    ARRAY,
+    BIGINT,
+    BOOLEAN,
+    CLASS,
+    new CLASS(),
+    FUNCTION,
+    NULL,
+    NUMBER,
+    OBJECT,
+    STRING,
+    SYMBOL,
+    UNDEFINED,
+  ]) {
+    expect(isError(item)).toBe(false);
+  }
+});
+
+test('isError returns true for objects with a nested Error prototype', () => {
+  class Foo {}
+  const err = new Error();
+  Object.setPrototypeOf(err, Foo.prototype);
+  expect(isError(err)).toBe(true);
+});
+
+test('isErrnoException returns true for NodeJS.ErrnoException only', () => {
+  try {
+    fs.statSync('./i-definitely-do-not-exist');
+    fail();
+  } catch (err) {
+    expect(isErrnoException(err)).toBe(true);
+  }
+});
+
+test('isErrorLike returns true when object is like an error', () => {
+  expect(isErrorLike(new Error())).toBe(true);
+  expect(isErrorLike({ message: '' })).toBe(true);
+  expect(isErrorLike({})).toBe(false);
+});
+
+describe('errorToString', () => {
+  const message = 'message';
+  test('return `message` when first argument is an error', () => {
+    expect(errorToString(new Error(message))).toStrictEqual(message);
+  });
+  test('returns `message` when first argument is error like', () => {
+    expect(errorToString({ message })).toStrictEqual(message);
+  });
+  test('returns first argument when it is a string', () => {
+    expect(errorToString(message)).toStrictEqual(message);
+  });
+  test('returns second argument when first argument is not an error, error like, nor a string', () => {
+    expect(errorToString(null, message)).toStrictEqual(message);
+  });
+  test('returns default fallback message when first argument is not an error, error like, nor a string, and the second argument is not provided', () => {
+    expect(errorToString(null)).toStrictEqual('An unknown error has ocurred.');
+  });
+});
+
+describe('normalizeError', () => {
+  const message = 'message';
+  test('returns first argument if it is an error', () => {
+    expect(normalizeError(new Error(message))).toStrictEqual(
+      new Error(message)
+    );
+  });
+  test('returns a new error if argument is not error like', () => {
+    expect(normalizeError(message)).toStrictEqual(new Error(message));
+  });
+  test('returns a new error if argument is not error like', () => {
+    expect(normalizeError({ message })).toStrictEqual(new Error(message));
+  });
+  test('returns a new error with fallback message if argument is not error like nor a string.', () => {
+    expect(normalizeError(null)).toStrictEqual(
+      new Error('An unknown error has ocurred.')
+    );
+  });
+  test('returns an Error with the input object assigned to it', () => {
+    expect(normalizeError({ message, prop: 'value' })).toStrictEqual(
+      Object.assign(new Error(message), { prop: 'value' })
+    );
+  });
+});
+
+test('isSpawnError', () => {
+  const spawnError = new Error('spawn error');
+  Object.assign(spawnError, {
+    code: 'SPAWN_ERROR',
+    spawnargs: ['a', 'b', 'c'],
+  });
+  expect(isSpawnError(spawnError)).toBe(true);
+  expect(isSpawnError(new Error('not spawn error'))).toBe(false);
+});

packages/error-utils/test/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "types": ["node", "jest"]
+  },
+  "include": ["*.test.ts"]
+}

packages/error-utils/tsconfig.json

@@ -0,0 +1,22 @@
+{
+  "compilerOptions": {
+    "declaration": true,
+    "declarationMap": true,
+    "esModuleInterop": true,
+    "lib": ["ES2020"],
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "noEmitOnError": true,
+    "noFallthroughCasesInSwitch": true,
+    "noImplicitReturns": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "outDir": "./dist",
+    "types": ["node", "jest"],
+    "strict": true,
+    "sourceMap": true,
+    "target": "ES2020"
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules"]
+}

packages/frameworks/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/frameworks",
-  "version": "1.1.8",
+  "version": "1.1.11",
   "main": "./dist/frameworks.js",
   "types": "./dist/frameworks.d.ts",
   "files": [
@@ -19,9 +19,9 @@
   "devDependencies": {
     "@types/jest": "27.4.1",
     "@types/js-yaml": "3.12.1",
-    "@types/node": "12.0.4",
+    "@types/node": "14.18.33",
     "@types/node-fetch": "2.5.8",
-    "@vercel/routing-utils": "2.0.2",
+    "@vercel/routing-utils": "2.1.2",
     "ajv": "6.12.2",
     "typescript": "4.3.4"
   }

packages/fs-detectors/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/fs-detectors",
-  "version": "3.4.5",
+  "version": "3.4.8",
   "description": "Vercel filesystem detectors",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
@@ -19,8 +19,8 @@
     "test-unit": "yarn test"
   },
   "dependencies": {
-    "@vercel/frameworks": "1.1.8",
-    "@vercel/routing-utils": "2.0.2",
+    "@vercel/frameworks": "1.1.11",
+    "@vercel/routing-utils": "2.1.2",
     "glob": "8.0.3",
     "js-yaml": "4.1.0",
     "json5": "2.2.1",
@@ -32,7 +32,7 @@
     "@types/jest": "27.5.1",
     "@types/js-yaml": "4.0.5",
     "@types/minimatch": "3.0.5",
-    "@types/node": "12.12.20",
+    "@types/node": "14.18.33",
     "@types/semver": "7.3.10",
     "@vercel/build-utils": "4.2.0",
     "typescript": "4.3.4"

packages/fs-detectors/src/monorepos/monorepo-managers.ts

@@ -66,7 +66,7 @@ export const monorepoManagers: Array<
         value: null,
       },
       outputDirectory: {
-        placeholder: 'Nx default',
+        value: null,
       },
       installCommand: {
         value: null,
@@ -93,7 +93,7 @@ export const monorepoManagers: Array<
         value: null,
       },
       outputDirectory: {
-        placeholder: 'Rush default',
+        value: null,
       },
       installCommand: {
         placeholder: 'Rush default',

packages/go/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/go",
-  "version": "2.2.13",
+  "version": "2.2.15",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/go",
@@ -35,7 +35,7 @@
     "@types/jest": "28.1.6",
     "@types/node-fetch": "^2.3.0",
     "@types/tar": "^4.0.0",
-    "@vercel/build-utils": "5.5.5",
+    "@vercel/build-utils": "5.5.7",
     "@vercel/ncc": "0.24.0",
     "async-retry": "1.3.1",
     "execa": "^1.0.0",

packages/hydrogen/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/hydrogen",
-  "version": "0.0.26",
+  "version": "0.0.29",
   "license": "MIT",
   "main": "./dist/index.js",
   "homepage": "https://vercel.com/docs",
@@ -20,8 +20,9 @@
   ],
   "devDependencies": {
     "@types/jest": "27.5.1",
-    "@types/node": "*",
-    "@vercel/build-utils": "5.5.5",
+    "@types/node": "14.18.33",
+    "@vercel/build-utils": "5.5.7",
+    "@vercel/static-config": "2.0.6",
     "typescript": "4.6.4"
   }
 }

packages/hydrogen/src/build.ts

@@ -15,6 +15,8 @@ import {
   scanParentDirs,
 } from '@vercel/build-utils';
 import type { BuildV2, PackageJson } from '@vercel/build-utils';
+import { getConfig } from '@vercel/static-config';
+import { Project } from 'ts-morph';
 
 export const build: BuildV2 = async ({
   entrypoint,
@@ -118,6 +120,15 @@ export const build: BuildV2 = async ({
     deploymentTarget: 'v8-worker',
     entrypoint: 'index.js',
     files: edgeFunctionFiles,
+    regions: (() => {
+      try {
+        const project = new Project();
+        const config = getConfig(project, edgeFunctionFiles['index.js'].fsPath);
+        return config?.regions;
+      } catch {
+        return undefined;
+      }
+    })(),
   });
 
   // The `index.html` file is a template, but we want to serve the

packages/next/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/next",
-  "version": "3.2.5",
+  "version": "3.2.9",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/next-js",
@@ -39,14 +39,14 @@
     "@types/fs-extra": "8.0.0",
     "@types/glob": "7.1.3",
     "@types/next-server": "8.0.0",
-    "@types/node": "14.17.27",
+    "@types/node": "14.18.33",
     "@types/resolve-from": "5.0.1",
     "@types/semver": "6.0.0",
     "@types/text-table": "0.2.1",
     "@types/webpack-sources": "3.2.0",
-    "@vercel/build-utils": "5.5.5",
+    "@vercel/build-utils": "5.5.7",
     "@vercel/nft": "0.22.1",
-    "@vercel/routing-utils": "2.0.2",
+    "@vercel/routing-utils": "2.1.2",
     "async-sema": "3.0.1",
     "buffer-crc32": "0.2.13",
     "cheerio": "1.0.0-rc.10",

packages/next/src/server-build.ts

@@ -14,7 +14,7 @@ import {
   Files,
   BuildResultV2Typical as BuildResult,
 } from '@vercel/build-utils';
-import { Route, RouteWithHandle, RouteWithSrc } from '@vercel/routing-utils';
+import { Route, RouteWithHandle } from '@vercel/routing-utils';
 import { MAX_AGE_ONE_YEAR } from '.';
 import {
   NextRequiredServerFilesManifest,
@@ -218,7 +218,8 @@ export async function serverBuild({
       nonLambdaSsgPages,
       route,
       routesManifest.pages404,
-      routesManifest
+      routesManifest,
+      appDir
     );
 
     if (result && result.static404Page) {
@@ -337,6 +338,7 @@ export async function serverBuild({
 
     const apiPages: string[] = [];
     const nonApiPages: string[] = [];
+    const streamingPages: string[] = [];
 
     lambdaPageKeys.forEach(page => {
       if (
@@ -358,6 +360,8 @@ export async function serverBuild({
 
       if (pageMatchesApi(page)) {
         apiPages.push(page);
+      } else if (appDir && lambdaAppPaths[page]) {
+        streamingPages.push(page);
       } else {
         nonApiPages.push(page);
       }
@@ -545,7 +549,12 @@ export async function serverBuild({
     const compressedPages: {
       [page: string]: PseudoFile;
     } = {};
-    const mergedPageKeys = [...nonApiPages, ...apiPages, ...internalPages];
+    const mergedPageKeys = [
+      ...nonApiPages,
+      ...streamingPages,
+      ...apiPages,
+      ...internalPages,
+    ];
     const traceCache = {};
 
     const getOriginalPagePath = (page: string) => {
@@ -703,6 +712,27 @@ export async function serverBuild({
       pageExtensions,
     });
 
+    const streamingPageLambdaGroups = await getPageLambdaGroups({
+      entryPath: requiredServerFilesManifest.appDir || entryPath,
+      config,
+      pages: streamingPages,
+      prerenderRoutes,
+      pageTraces,
+      compressedPages,
+      tracedPseudoLayer: tracedPseudoLayer.pseudoLayer,
+      initialPseudoLayer,
+      lambdaCompressedByteLimit,
+      initialPseudoLayerUncompressed: uncompressedInitialSize,
+      internalPages,
+      pageExtensions,
+    });
+
+    for (const group of streamingPageLambdaGroups) {
+      if (!group.isPrerenders) {
+        group.isStreaming = true;
+      }
+    }
+
     const apiLambdaGroups = await getPageLambdaGroups({
       entryPath: requiredServerFilesManifest.appDir || entryPath,
       config,
@@ -732,13 +762,23 @@ export async function serverBuild({
             pseudoLayerBytes: group.pseudoLayerBytes,
             uncompressedLayerBytes: group.pseudoLayerUncompressedBytes,
           })),
+          streamingPageLambdaGroups: streamingPageLambdaGroups.map(group => ({
+            pages: group.pages,
+            isPrerender: group.isPrerenders,
+            pseudoLayerBytes: group.pseudoLayerBytes,
+            uncompressedLayerBytes: group.pseudoLayerUncompressedBytes,
+          })),
           nextServerLayerSize: initialPseudoLayer.pseudoLayerBytes,
         },
         null,
         2
       )
     );
-    const combinedGroups = [...pageLambdaGroups, ...apiLambdaGroups];
+    const combinedGroups = [
+      ...pageLambdaGroups,
+      ...streamingPageLambdaGroups,
+      ...apiLambdaGroups,
+    ];
 
     await detectLambdaLimitExceeding(
       combinedGroups,
@@ -831,6 +871,7 @@ export async function serverBuild({
         memory: group.memory,
         runtime: nodeVersion.runtime,
         maxDuration: group.maxDuration,
+        isStreaming: group.isStreaming,
       });
 
       for (const page of group.pages) {
@@ -963,61 +1004,6 @@ export async function serverBuild({
   const { staticFiles, publicDirectoryFiles, staticDirectoryFiles } =
     await getStaticFiles(entryPath, entryDirectory, outputDirectory);
 
-  const notFoundPreviewRoutes: RouteWithSrc[] = [];
-
-  if (prerenderManifest.notFoundRoutes?.length > 0 && canUsePreviewMode) {
-    // we combine routes into one src here to reduce the number of needed
-    // routes since only the status is being modified and we don't want
-    // to exceed the routes limit
-    const starterRouteSrc = `^${
-      entryDirectory !== '.'
-        ? `${path.posix.join('/', entryDirectory)}()`
-        : '()'
-    }`;
-    let currentRouteSrc = starterRouteSrc;
-
-    const pushRoute = (src: string) => {
-      notFoundPreviewRoutes.push({
-        src,
-        missing: [
-          {
-            type: 'cookie',
-            key: '__prerender_bypass',
-            value: prerenderManifest.bypassToken || undefined,
-          },
-          {
-            type: 'cookie',
-            key: '__next_preview_data',
-          },
-        ],
-        status: 404,
-      });
-    };
-
-    for (let i = 0; i < prerenderManifest.notFoundRoutes.length; i++) {
-      const route = prerenderManifest.notFoundRoutes[i];
-      const isLastRoute = i === prerenderManifest.notFoundRoutes.length - 1;
-
-      if (prerenderManifest.staticRoutes[route]?.initialRevalidate === false) {
-        if (currentRouteSrc.length + route.length + 1 >= 4000) {
-          pushRoute(currentRouteSrc);
-          currentRouteSrc = starterRouteSrc;
-        }
-        // add to existing route src if src length limit isn't reached
-        currentRouteSrc = `${currentRouteSrc.substring(
-          0,
-          currentRouteSrc.length - 1
-        )}${
-          currentRouteSrc[currentRouteSrc.length - 2] === '(' ? '' : '|'
-        }${route}/?)`;
-
-        if (isLastRoute) {
-          pushRoute(currentRouteSrc);
-        }
-      }
-    }
-  }
-
   const normalizeNextDataRoute = (isOverride = false) => {
     return isNextDataServerResolving
       ? [
@@ -1151,6 +1137,8 @@ export async function serverBuild({
     }
   }
 
+  const rscHeader = routesManifest.rsc?.header || '__rsc__';
+
   return {
     wildcard: wildcardConfig,
     images:
@@ -1329,10 +1317,6 @@ export async function serverBuild({
 
       ...beforeFilesRewrites,
 
-      // ensure prerender's for notFound: true static routes
-      // have 404 status code when not in preview mode
-      ...notFoundPreviewRoutes,
-
       // Make sure to 404 for the /404 path itself
       ...(i18n
         ? [
@@ -1408,7 +1392,7 @@ export async function serverBuild({
               has: [
                 {
                   type: 'header',
-                  key: '__rsc__',
+                  key: rscHeader,
                 },
               ],
               dest: path.posix.join('/', entryDirectory, '/index.rsc'),
@@ -1419,7 +1403,7 @@ export async function serverBuild({
               has: [
                 {
                   type: 'header',
-                  key: '__rsc__',
+                  key: rscHeader,
                 },
               ],
               dest: path.posix.join('/', entryDirectory, '/$1.rsc'),
@@ -1647,18 +1631,6 @@ export async function serverBuild({
         continue: true,
         important: true,
       },
-      ...(appDir
-        ? [
-            {
-              src: path.posix.join('/', entryDirectory, '/(.*).rsc$'),
-              headers: {
-                'content-type': 'application/octet-stream',
-              },
-              continue: true,
-              important: true,
-            },
-          ]
-        : []),
 
       // TODO: remove below workaround when `/` is allowed to be output
       // different than `/index`

packages/next/src/utils.ts

@@ -209,6 +209,10 @@ type RoutesManifestOld = {
       defaultLocale: string;
     }>;
   };
+  rsc?: {
+    header: string;
+    varyHeader: string;
+  };
 };
 
 type RoutesManifestV4 = Omit<RoutesManifestOld, 'dynamicRoutes' | 'version'> & {
@@ -748,6 +752,7 @@ export async function createPseudoLayer(files: {
 
 interface CreateLambdaFromPseudoLayersOptions extends LambdaOptionsWithFiles {
   layers: PseudoLayer[];
+  isStreaming?: boolean;
 }
 
 // measured with 1, 2, 5, 10, and `os.cpus().length || 5`
@@ -757,6 +762,7 @@ const createLambdaSema = new Sema(1);
 export async function createLambdaFromPseudoLayers({
   files: baseFiles,
   layers,
+  isStreaming,
   ...lambdaOptions
 }: CreateLambdaFromPseudoLayersOptions) {
   await createLambdaSema.acquire();
@@ -791,6 +797,11 @@ export async function createLambdaFromPseudoLayers({
 
   return new NodejsLambda({
     ...lambdaOptions,
+    ...(isStreaming
+      ? {
+          experimentalResponseStreaming: true,
+        }
+      : {}),
     files,
     shouldAddHelpers: false,
     shouldAddSourcemapSupport: false,
@@ -1273,6 +1284,7 @@ export type LambdaGroup = {
   pages: string[];
   memory?: number;
   maxDuration?: number;
+  isStreaming?: boolean;
   isPrerenders?: boolean;
   pseudoLayer: PseudoLayer;
   pseudoLayerBytes: number;
@@ -1601,16 +1613,19 @@ export const onPrerenderRouteInitial = (
   nonLambdaSsgPages: Set<string>,
   routeKey: string,
   hasPages404: boolean,
-  routesManifest?: RoutesManifest
+  routesManifest?: RoutesManifest,
+  appDir?: string | null
 ) => {
   let static404Page: string | undefined;
   let static500Page: string | undefined;
 
   // Get the route file as it'd be mounted in the builder output
   const pr = prerenderManifest.staticRoutes[routeKey];
-  const { initialRevalidate, srcRoute } = pr;
+  const { initialRevalidate, srcRoute, dataRoute } = pr;
   const route = srcRoute || routeKey;
 
+  const isAppPathRoute = appDir && dataRoute?.endsWith('.rsc');
+
   const routeNoLocale = routesManifest?.i18n
     ? normalizeLocalePath(routeKey, routesManifest.i18n.locales).pathname
     : routeKey;
@@ -1626,6 +1641,9 @@ export const onPrerenderRouteInitial = (
   }
 
   if (
+    // App paths must be Prerenders to ensure Vary header is
+    // correctly added
+    !isAppPathRoute &&
     initialRevalidate === false &&
     (!canUsePreviewMode || (hasPages404 && routeNoLocale === '/404')) &&
     !prerenderManifest.fallbackRoutes[route] &&
@@ -1836,14 +1854,26 @@ export const onPrerenderRoute =
             ),
           });
 
-    const outputPathPage = normalizeIndexOutput(
-      path.posix.join(entryDirectory, routeFileNoExt),
-      isServerMode
-    );
+    if (isAppPathRoute) {
+      // for literal index routes we need to append an additional /index
+      // due to the proxy's normalizing for /index routes
+      if (routeKey !== '/index' && routeKey.endsWith('/index')) {
+        routeKey = `${routeKey}/index`;
+        routeFileNoExt = routeKey;
+        origRouteFileNoExt = routeKey;
+      }
+    }
+
+    let outputPathPage = path.posix.join(entryDirectory, routeFileNoExt);
+
+    if (!isAppPathRoute) {
+      outputPathPage = normalizeIndexOutput(outputPathPage, isServerMode);
+    }
     const outputPathPageOrig = path.posix.join(
       entryDirectory,
       origRouteFileNoExt
     );
+
     let lambda: undefined | Lambda;
     let outputPathData = path.posix.join(entryDirectory, dataRoute);
 
@@ -1887,7 +1917,7 @@ export const onPrerenderRoute =
       lambda = lambdas[outputSrcPathPage];
     }
 
-    if (!isNotFound && initialRevalidate === false) {
+    if (!isAppPathRoute && !isNotFound && initialRevalidate === false) {
       if (htmlFsRef == null || jsonFsRef == null) {
         throw new NowBuildError({
           code: 'NEXT_HTMLFSREF_JSONFSREF',
@@ -1965,6 +1995,9 @@ export const onPrerenderRoute =
           allowQuery = [];
         }
       }
+      const rscVaryHeader =
+        routesManifest?.rsc?.varyHeader ||
+        '__rsc__, __next_router_state_tree__, __next_router_prefetch__';
 
       prerenders[outputPathPage] = new Prerender({
         expiration: initialRevalidate,
@@ -1973,6 +2006,19 @@ export const onPrerenderRoute =
         fallback: htmlFsRef,
         group: prerenderGroup,
         bypassToken: prerenderManifest.bypassToken,
+        ...(isNotFound
+          ? {
+              initialStatus: 404,
+            }
+          : {}),
+
+        ...(isAppPathRoute
+          ? {
+              initialHeaders: {
+                vary: rscVaryHeader,
+              },
+            }
+          : {}),
       });
       prerenders[outputPathData] = new Prerender({
         expiration: initialRevalidate,
@@ -1981,6 +2027,21 @@ export const onPrerenderRoute =
         fallback: jsonFsRef,
         group: prerenderGroup,
         bypassToken: prerenderManifest.bypassToken,
+
+        ...(isNotFound
+          ? {
+              initialStatus: 404,
+            }
+          : {}),
+
+        ...(isAppPathRoute
+          ? {
+              initialHeaders: {
+                'content-type': 'application/octet-stream',
+                vary: rscVaryHeader,
+              },
+            }
+          : {}),
       });
 
       ++prerenderGroup;
@@ -2391,6 +2452,12 @@ export async function getMiddlewareBundle({
           shortPath.replace(/^app\//, '').replace(/(^|\/)page$/, '') || 'index';
       }
 
+      if (routesManifest?.basePath) {
+        shortPath = path.posix
+          .join(routesManifest.basePath, shortPath)
+          .replace(/^\//, '');
+      }
+
       worker.edgeFunction.name = shortPath;
       source.edgeFunctions[shortPath] = worker.edgeFunction;
 

packages/next/test/fixtures/00-app-dir-static/app/(newroot)/dashboard/another/page.js

@@ -0,0 +1,7 @@
+export default function AnotherPage(props) {
+  return (
+    <>
+      <p>hello from newroot/dashboard/another</p>
+    </>
+  );
+}