Publish Stable

- @vercel/build-utils@4.2.1
 - vercel@25.2.3
 - @vercel/client@12.0.3
 - @vercel/go@2.0.3
 - @vercel/next@3.1.2
 - @vercel/node@2.3.3
 - @vercel/python@3.0.3
 - @vercel/redwood@1.0.4
 - @vercel/remix@1.0.4
 - @vercel/ruby@1.3.11
 - @vercel/static-build@1.0.3

.prettierignore

@@ -0,0 +1,4 @@
+# https://prettier.io/docs/en/ignore.html
+
+# ignore this file with an intentional syntax error
+packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-syntax.js

package.json

@@ -31,7 +31,7 @@
     "prettier": "2.6.2",
     "ts-eager": "2.0.2",
     "ts-jest": "28.0.5",
-    "turbo": "1.2.14"
+    "turbo": "1.3.1"
   },
   "scripts": {
     "lerna": "lerna",

packages/build-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/build-utils",
-  "version": "4.1.1-canary.1",
+  "version": "4.2.1",
   "license": "MIT",
   "main": "./dist/index.js",
   "types": "./dist/index.d.js",
@@ -31,7 +31,7 @@
     "@types/node-fetch": "^2.1.6",
     "@types/semver": "6.0.0",
     "@types/yazl": "2.4.2",
-    "@vercel/frameworks": "1.0.2-canary.0",
+    "@vercel/frameworks": "1.0.2",
     "@vercel/ncc": "0.24.0",
     "aggregate-error": "3.0.1",
     "async-retry": "1.2.3",

packages/build-utils/src/fs/run-user-scripts.ts

@@ -61,6 +61,13 @@ export interface SpawnOptionsExtended extends SpawnOptions {
    * Pretty formatted command that is being spawned for logging purposes.
    */
   prettyCommand?: string;
+
+  /**
+   * Returns instead of throwing an error when the process exits with a
+   * non-0 exit code. When relevant, the returned object will include
+   * the error code, stdout and stderr.
+   */
+  ignoreNon0Exit?: boolean;
 }
 
 export function spawnAsync(
@@ -79,7 +86,7 @@ export function spawnAsync(
 
     child.on('error', reject);
     child.on('close', (code, signal) => {
-      if (code === 0) {
+      if (code === 0 || opts.ignoreNon0Exit) {
         return resolve();
       }
 
@@ -123,24 +130,24 @@ export function execAsync(
 
       child.on('error', reject);
       child.on('close', (code, signal) => {
-        if (code !== 0) {
-          const cmd = opts.prettyCommand
-            ? `Command "${opts.prettyCommand}"`
-            : 'Command';
-
-          return reject(
-            new NowBuildError({
-              code: `BUILD_UTILS_EXEC_${code || signal}`,
-              message: `${cmd} exited with ${code || signal}`,
-            })
-          );
+        if (code === 0 || opts.ignoreNon0Exit) {
+          return resolve({
+            code,
+            stdout: Buffer.concat(stdoutList).toString(),
+            stderr: Buffer.concat(stderrList).toString(),
+          });
         }
 
-        return resolve({
-          code,
-          stdout: Buffer.concat(stdoutList).toString(),
-          stderr: Buffer.concat(stderrList).toString(),
-        });
+        const cmd = opts.prettyCommand
+          ? `Command "${opts.prettyCommand}"`
+          : 'Command';
+
+        return reject(
+          new NowBuildError({
+            code: `BUILD_UTILS_EXEC_${code || signal}`,
+            message: `${cmd} exited with ${code || signal}`,
+          })
+        );
       });
     }
   );
@@ -166,9 +173,30 @@ export async function execCommand(command: string, options: SpawnOptions = {}) {
   return true;
 }
 
-export async function getNodeBinPath({ cwd }: { cwd: string }) {
-  const { stdout } = await execAsync('npm', ['bin'], { cwd });
-  return stdout.trim();
+export async function getNodeBinPath({
+  cwd,
+}: {
+  cwd: string;
+}): Promise<string | undefined> {
+  const { code, stdout, stderr } = await execAsync('npm', ['bin'], {
+    cwd,
+    prettyCommand: 'npm bin',
+
+    // in some rare cases, we saw `npm bin` exit with a non-0 code, but still
+    // output the right bin path, so we ignore the exit code
+    ignoreNon0Exit: true,
+  });
+
+  const nodeBinPath = stdout.trim();
+
+  if (path.isAbsolute(nodeBinPath)) {
+    return nodeBinPath;
+  }
+
+  throw new NowBuildError({
+    code: `BUILD_UTILS_GET_NODE_BIN_PATH`,
+    message: `Running \`npm bin\` failed to return a valid bin path (code=${code}, stdout=${stdout}, stderr=${stderr})`,
+  });
 }
 
 async function chmodPlusX(fsPath: string) {

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

@@ -0,0 +1,29 @@
+import { execAsync, NowBuildError } from '../src';
+
+it('should execute a command', async () => {
+  const { code, stdout, stderr } = await execAsync('echo', ['hello']);
+
+  expect(code).toBe(0);
+  expect(stdout).toContain('hello');
+  expect(stderr).toBe('');
+});
+
+it('should throw if the command exits with non-0 code', async () => {
+  await expect(execAsync('find', ['unknown-file'])).rejects.toBeInstanceOf(
+    NowBuildError
+  );
+});
+
+it('should return if the command exits with non-0 code and ignoreNon0Exit=true', async () => {
+  const { code, stdout, stderr } = await execAsync('find', ['unknown-file'], {
+    ignoreNon0Exit: true,
+  });
+
+  expect(code).toBe(process.platform === 'win32' ? 2 : 1);
+  expect(stdout).toBe('');
+  expect(stderr).toContain(
+    process.platform === 'win32'
+      ? 'Parameter format not correct'
+      : 'No such file or directory'
+  );
+});

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

@@ -0,0 +1,21 @@
+import { spawnAsync, NowBuildError } from '../src';
+
+it('should execute a command', async () => {
+  // should resolve (it doesn't return anything, so it resolves with "undefined")
+  await expect(spawnAsync('echo', ['hello'])).resolves.toBeUndefined();
+});
+
+it('should throw if the command exits with non-0 code', async () => {
+  await expect(spawnAsync('find', ['unknown-file'])).rejects.toBeInstanceOf(
+    NowBuildError
+  );
+});
+
+it('should return if the command exits with non-0 code and ignoreNon0Exit=true', async () => {
+  // should resolve (it doesn't return anything, so it resolves with "undefined")
+  await expect(
+    spawnAsync('find', ['unknown-file'], {
+      ignoreNon0Exit: true,
+    })
+  ).resolves.toBeUndefined();
+});

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "vercel",
-  "version": "25.1.1-canary.9",
+  "version": "25.2.3",
   "preferGlobal": true,
   "license": "Apache-2.0",
   "description": "The command-line interface for Vercel",
@@ -42,15 +42,15 @@
     "node": ">= 14"
   },
   "dependencies": {
-    "@vercel/build-utils": "4.1.1-canary.1",
-    "@vercel/go": "2.0.2-canary.1",
-    "@vercel/next": "3.0.4",
-    "@vercel/node": "2.2.1-canary.1",
-    "@vercel/python": "3.0.2-canary.1",
-    "@vercel/redwood": "1.0.2-canary.1",
-    "@vercel/remix": "1.0.2-canary.1",
-    "@vercel/ruby": "1.3.10-canary.1",
-    "@vercel/static-build": "1.0.2-canary.1",
+    "@vercel/build-utils": "4.2.1",
+    "@vercel/go": "2.0.3",
+    "@vercel/next": "3.1.2",
+    "@vercel/node": "2.3.3",
+    "@vercel/python": "3.0.3",
+    "@vercel/redwood": "1.0.4",
+    "@vercel/remix": "1.0.4",
+    "@vercel/ruby": "1.3.11",
+    "@vercel/static-build": "1.0.3",
     "update-notifier": "5.1.0"
   },
   "devDependencies": {
@@ -95,8 +95,8 @@
     "@types/which": "1.3.2",
     "@types/write-json-file": "2.2.1",
     "@types/yauzl-promise": "2.1.0",
-    "@vercel/client": "12.0.2-canary.1",
-    "@vercel/frameworks": "1.0.2-canary.0",
+    "@vercel/client": "12.0.3",
+    "@vercel/frameworks": "1.0.2",
     "@vercel/ncc": "0.24.0",
     "@zeit/fun": "0.11.2",
     "@zeit/source-map-support": "0.6.2",

packages/cli/src/commands/alias/rm.ts

@@ -10,7 +10,6 @@ import confirm from '../../util/input/confirm';
 import findAliasByAliasOrId from '../../util/alias/find-alias-by-alias-or-id';
 
 import { Alias } from '../../types';
-import { Output } from '../../util/output';
 import { isValidName } from '../../util/is-valid-name';
 import { getCommandName } from '../../util/pkg-name';
 
@@ -71,7 +70,7 @@ export default async function rm(
   }
 
   const removeStamp = stamp();
-  if (!opts['--yes'] && !(await confirmAliasRemove(output, alias))) {
+  if (!opts['--yes'] && !(await confirmAliasRemove(client, alias))) {
     output.log('Aborted');
     return 0;
   }
@@ -85,7 +84,7 @@ export default async function rm(
   return 0;
 }
 
-async function confirmAliasRemove(output: Output, alias: Alias) {
+async function confirmAliasRemove(client: Client, alias: Alias) {
   const srcUrl = alias.deployment
     ? chalk.underline(alias.deployment.url)
     : null;
@@ -104,7 +103,7 @@ async function confirmAliasRemove(output: Output, alias: Alias) {
     }
   );
 
-  output.log(`The following alias will be removed permanently`);
-  output.print(`  ${tbl}\n`);
-  return confirm(chalk.red('Are you sure?'), false);
+  client.output.log(`The following alias will be removed permanently`);
+  client.output.print(`  ${tbl}\n`);
+  return confirm(client, chalk.red('Are you sure?'), false);
 }

packages/cli/src/commands/billing/index.js

@@ -187,6 +187,7 @@ export default async client => {
       if (cardId) {
         const label = `Are you sure that you to set this card as the default?`;
         const confirmation = await promptBool(label, {
+          ...client,
           trailing: '\n',
         });
 
@@ -262,7 +263,7 @@ export default async client => {
       // typed `vercel billing rm <some-id>`) is valid
       if (cardId) {
         const label = `Are you sure that you want to remove this card?`;
-        const confirmation = await promptBool(label);
+        const confirmation = await promptBool(label, client);
         if (!confirmation) {
           console.log('Aborted');
           break;

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

@@ -16,6 +16,7 @@ import Client from '../../util/client';
 import { getPkgName } from '../../util/pkg-name';
 import { Output } from '../../util/output';
 import { Deployment, PaginationOptions } from '../../types';
+import { normalizeURL } from '../../util/bisect/normalize-url';
 
 interface DeploymentV6
   extends Pick<
@@ -97,9 +98,7 @@ export default async function main(client: Client): Promise<number> {
     run = resolve(run);
   }
 
-  if (!bad.startsWith('https://')) {
-    bad = `https://${bad}`;
-  }
+  bad = normalizeURL(bad);
   let parsed = parse(bad);
   if (!parsed.hostname) {
     output.error('Invalid input: no hostname provided');
@@ -120,9 +119,7 @@ export default async function main(client: Client): Promise<number> {
 
   const badDeploymentPromise = getDeployment(client, bad).catch(err => err);
 
-  if (!good.startsWith('https://')) {
-    good = `https://${good}`;
-  }
+  good = normalizeURL(good);
   parsed = parse(good);
   if (!parsed.hostname) {
     output.error('Invalid input: no hostname provided');

packages/cli/src/commands/build.ts

@@ -140,6 +140,7 @@ export default async function main(client: Client): Promise<number> {
       }
 
       confirmed = await confirm(
+        client,
         `No Project Settings found locally. Run ${cli.getCommandName(
           'pull'
         )} for retrieving them?`,

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

@@ -165,7 +165,7 @@ export default async (client: Client) => {
   const quiet = !isTTY;
 
   // check paths
-  const pathValidation = await validatePaths(output, paths);
+  const pathValidation = await validatePaths(client, paths);
 
   if (!pathValidation.valid) {
     return pathValidation.exitCode;
@@ -243,6 +243,7 @@ export default async (client: Client) => {
     const shouldStartSetup =
       autoConfirm ||
       (await confirm(
+        client,
         `Set up and deploy ${chalk.cyan(`“${toHumanPath(path)}”`)}?`,
         true
       ));
@@ -287,7 +288,7 @@ export default async (client: Client) => {
 
     if (typeof projectOrNewProjectName === 'string') {
       newProjectName = projectOrNewProjectName;
-      rootDirectory = await inputRootDirectory(path, output, autoConfirm);
+      rootDirectory = await inputRootDirectory(client, path, autoConfirm);
     } else {
       project = projectOrNewProjectName;
       rootDirectory = project.rootDirectory;
@@ -521,7 +522,7 @@ export default async (client: Client) => {
       }
 
       const settings = await editProjectSettings(
-        output,
+        client,
         projectSettings,
         framework,
         false,

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

@@ -46,7 +46,7 @@ export default async function add(
 
   const addStamp = stamp();
   const { domain, data: argData } = parsedParams;
-  const data = await getDNSData(output, argData);
+  const data = await getDNSData(client, argData);
   if (!data) {
     output.log(`Aborted`);
     return 1;

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

@@ -87,7 +87,8 @@ export default async function buy(
     !(await promptBool(
       `Buy now for ${chalk.bold(`$${price}`)} (${`${period}yr${
         period > 1 ? 's' : ''
-      }`})?`
+      }`})?`,
+      client
     ))
   ) {
     return 0;
@@ -99,7 +100,7 @@ export default async function buy(
       : `Auto renew every ${renewalPrice.period} years for ${chalk.bold(
           `$${price}`
         )}?`,
-    { defaultValue: true }
+    { ...client, defaultValue: true }
   );
 
   let buyResult;

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

@@ -77,7 +77,8 @@ export default async function move(
       !(await promptBool(
         `Are you sure you want to move ${param(domainName)} to ${param(
           destination
-        )}?`
+        )}?`,
+        client
       ))
     ) {
       output.log('Aborted');
@@ -95,7 +96,8 @@ export default async function move(
       );
       if (
         !(await promptBool(
-          `Are you sure you want to move ${param(domainName)}?`
+          `Are you sure you want to move ${param(domainName)}?`,
+          client
         ))
       ) {
         output.log('Aborted');

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

@@ -92,7 +92,10 @@ export default async function rm(
   const skipConfirmation = opts['--yes'] || false;
   if (
     !skipConfirmation &&
-    !(await promptBool(`Are you sure you want to remove ${param(domainName)}?`))
+    !(await promptBool(
+      `Are you sure you want to remove ${param(domainName)}?`,
+      client
+    ))
   ) {
     output.log('Aborted');
     return 0;
@@ -230,7 +233,7 @@ async function removeDomain(
 
     if (
       !skipConfirmation &&
-      !(await promptBool(`Remove conflicts associated with domain?`))
+      !(await promptBool(`Remove conflicts associated with domain?`, client))
     ) {
       output.log('Aborted');
       return 0;

packages/cli/src/commands/domains/transfer-in.ts

@@ -81,7 +81,8 @@ export default async function transferIn(
   const shouldTransfer = await promptBool(
     transferPolicy === 'no-change'
       ? `Transfer now for ${chalk.bold(`$${price}`)}?`
-      : `Transfer now with 1yr renewal for ${chalk.bold(`$${price}`)}?`
+      : `Transfer now with 1yr renewal for ${chalk.bold(`$${price}`)}?`,
+    client
   );
   if (!shouldTransfer) {
     return 0;

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

@@ -31,7 +31,7 @@ export default async function add(
   // improve the way we show inquirer prompts
   require('../../util/input/patch-inquirer');
 
-  const stdInput = await readStandardInput();
+  const stdInput = await readStandardInput(client.stdin);
   let [envName, envTargetArg, envGitBranch] = args;
 
   if (args.length > 3) {

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

@@ -74,6 +74,7 @@ export default async function pull(
     exists &&
     !skipConfirmation &&
     !(await confirm(
+      client,
       `Found existing file ${param(filename)}. Do you want to overwrite?`,
       false
     ))

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

@@ -104,6 +104,7 @@ export default async function rm(
   if (
     !skipConfirmation &&
     !(await confirm(
+      client,
       `Removing Environment Variable ${param(env.key)} from ${formatEnvTarget(
         env
       )} in Project ${chalk.bold(project.name)}. Are you sure?`,

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

@@ -65,7 +65,7 @@ export default async function init(
     return extractExample(client, name, dir, force, 'v1');
   }
 
-  const found = await guess(exampleList, name);
+  const found = await guess(client, exampleList, name);
 
   if (typeof found === 'string') {
     return extractExample(client, found, dir, force);
@@ -194,7 +194,7 @@ function prepareFolder(cwd: string, folder: string, force?: boolean) {
 /**
  * Guess which example user try to init
  */
-async function guess(exampleList: string[], name: string) {
+async function guess(client: Client, exampleList: string[], name: string) {
   const GuessError = new Error(
     `No example found for ${chalk.bold(name)}, run ${getCommandName(
       `init`
@@ -208,7 +208,7 @@ async function guess(exampleList: string[], name: string) {
   const found = didYouMean(name, exampleList, 0.7);
 
   if (typeof found === 'string') {
-    if (await promptBool(`Did you mean ${chalk.bold(found)}?`)) {
+    if (await promptBool(`Did you mean ${chalk.bold(found)}?`, client)) {
       return found;
     }
   } else {

packages/cli/src/index.ts

@@ -387,6 +387,8 @@ const main = async () => {
   // Shared API `Client` instance for all sub-commands to utilize
   client = new Client({
     apiUrl,
+    stdin: process.stdin,
+    stdout: process.stdout,
     output,
     config,
     authConfig,

packages/cli/src/util/bisect/normalize-url.ts

@@ -0,0 +1,7 @@
+function hasScheme(url: string): Boolean {
+  return url.startsWith('http://') || url.startsWith('https://');
+}
+
+export function normalizeURL(url: string): string {
+  return hasScheme(url) ? url : `https://${url}`;
+}

packages/cli/src/util/build/write-build-result.ts

@@ -385,8 +385,14 @@ export async function* findDirs(
   }
   for (const path of paths) {
     const abs = join(dir, path);
-    const s = await fs.stat(abs);
-    if (s.isDirectory()) {
+    let stat: fs.Stats;
+    try {
+      stat = await fs.lstat(abs);
+    } catch (err: any) {
+      if (err.code === 'ENOENT') continue;
+      throw err;
+    }
+    if (stat.isDirectory()) {
       if (path === name) {
         yield relative(root, abs);
       } else {

packages/cli/src/util/client.ts

@@ -32,6 +32,8 @@ export interface ClientOptions {
   argv: string[];
   apiUrl: string;
   authConfig: AuthConfig;
+  stdin: NodeJS.ReadStream;
+  stdout: NodeJS.WriteStream;
   output: Output;
   config: GlobalConfig;
   localConfig?: VercelConfig;
@@ -45,6 +47,8 @@ export default class Client extends EventEmitter {
   argv: string[];
   apiUrl: string;
   authConfig: AuthConfig;
+  stdin: NodeJS.ReadStream;
+  stdout: NodeJS.WriteStream;
   output: Output;
   config: GlobalConfig;
   localConfig?: VercelConfig;
@@ -55,6 +59,8 @@ export default class Client extends EventEmitter {
     this.argv = opts.argv;
     this.apiUrl = opts.apiUrl;
     this.authConfig = opts.authConfig;
+    this.stdin = opts.stdin;
+    this.stdout = opts.stdout;
     this.output = opts.output;
     this.config = opts.config;
     this.localConfig = opts.localConfig;

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

@@ -425,10 +425,6 @@ export async function getBuildMatches(
       src = extensionless;
     }
 
-    // We need to escape brackets since `glob` will
-    // try to find a group otherwise
-    src = src.replace(/(\[|\])/g, '[$1]');
-
     const files = fileList
       .filter(name => name === src || minimatch(name, src, { dot: true }))
       .map(name => join(cwd, name));

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

@@ -0,0 +1,18 @@
+import { Headers } from 'node-fetch';
+import { IncomingHttpHeaders, OutgoingHttpHeaders } from 'http';
+
+export function nodeHeadersToFetchHeaders(
+  nodeHeaders: IncomingHttpHeaders | OutgoingHttpHeaders
+): Headers {
+  const headers = new Headers();
+  for (const [name, value] of Object.entries(nodeHeaders)) {
+    if (Array.isArray(value)) {
+      for (const val of value) {
+        headers.append(name, val);
+      }
+    } else if (typeof value !== 'undefined') {
+      headers.set(name, String(value));
+    }
+  }
+  return headers;
+}

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

@@ -1,12 +1,13 @@
+import ms from 'ms';
 import url, { URL } from 'url';
 import http from 'http';
 import fs from 'fs-extra';
 import chalk from 'chalk';
+import fetch from 'node-fetch';
 import plural from 'pluralize';
 import rawBody from 'raw-body';
 import listen from 'async-listen';
 import minimatch from 'minimatch';
-import ms from 'ms';
 import httpProxy from 'http-proxy';
 import { randomBytes } from 'crypto';
 import serveHandler from 'serve-handler';
@@ -16,11 +17,11 @@ import path, { isAbsolute, basename, dirname, extname, join } from 'path';
 import once from '@tootallnate/once';
 import directoryTemplate from 'serve-handler/src/directory';
 import getPort from 'get-port';
-import { ChildProcess } from 'child_process';
 import isPortReachable from 'is-port-reachable';
 import deepEqual from 'fast-deep-equal';
 import which from 'which';
 import npa from 'npm-package-arg';
+import type { ChildProcess } from 'child_process';
 
 import { getVercelIgnore, fileNameSymbol } from '@vercel/client';
 import {
@@ -90,6 +91,7 @@ import {
 import { ProjectEnvVariable, ProjectSettings } from '../../types';
 import exposeSystemEnvs from './expose-system-envs';
 import { treeKill } from '../tree-kill';
+import { nodeHeadersToFetchHeaders } from './headers';
 
 const frontendRuntimeSet = new Set(
   frameworkList.map(f => f.useRuntime?.use || '@vercel/static-build')
@@ -327,6 +329,8 @@ export default class DevServer {
   ): Promise<void> {
     const name = relative(this.cwd, fsPath);
     try {
+      await this.getVercelConfig();
+
       this.files[name] = await FileFsRef.fromFsPath({ fsPath });
       const extensionless = this.getExtensionlessFile(name);
       if (extensionless) {
@@ -593,7 +597,7 @@ export default class DevServer {
         await this.exit();
       }
 
-      if (warnings && warnings.length > 0) {
+      if (warnings?.length > 0) {
         warnings.forEach(warning =>
           this.output.warn(warning.message, null, warning.link, warning.action)
         );
@@ -1106,6 +1110,7 @@ export default class DevServer {
         view = errorTemplate({
           http_status_code: statusCode,
           http_status_description,
+          error_code,
           request_id: requestId,
         });
       }
@@ -1337,32 +1342,6 @@ export default class DevServer {
     return false;
   };
 
-  /*
-  runDevMiddleware = async (
-    req: http.IncomingMessage,
-    res: http.ServerResponse
-  ) => {
-    const { devMiddlewarePlugins } = await loadCliPlugins(
-      this.cwd,
-      this.output
-    );
-    try {
-      for (let plugin of devMiddlewarePlugins) {
-        const result = await plugin.plugin.runDevMiddleware(req, res, this.cwd);
-        if (result.finished) {
-          return result;
-        }
-      }
-      return { finished: false };
-    } catch (e) {
-      return {
-        finished: true,
-        error: e,
-      };
-    }
-  };
-  */
-
   /**
    * Serve project directory as a v2 deployment.
    */
@@ -1429,13 +1408,143 @@ export default class DevServer {
     let statusCode: number | undefined;
     let prevUrl = req.url;
     let prevHeaders: HttpHeadersConfig = {};
+    let middlewarePid: number | undefined;
 
-    /*
-    const middlewareResult = await this.runDevMiddleware(req, res);
+    // Run the middleware file, if present, and apply any
+    // mutations to the incoming request based on the
+    // result of the middleware invocation.
+    const middleware = [...this.buildMatches.values()].find(
+      m => m.config?.middleware === true
+    );
+    if (middleware) {
+      let startMiddlewareResult: StartDevServerResult | undefined;
+      // TODO: can we add some caching to prevent (re-)starting
+      // the middleware server for every HTTP request?
+      const { envConfigs, files, devCacheDir, cwd: workPath } = this;
+      try {
+        startMiddlewareResult =
+          await middleware.builderWithPkg.builder.startDevServer?.({
+            files,
+            entrypoint: middleware.entrypoint,
+            workPath,
+            repoRootPath: this.cwd,
+            config: middleware.config || {},
+            meta: {
+              isDev: true,
+              devCacheDir,
+              requestUrl: req.url,
+              env: { ...envConfigs.runEnv },
+              buildEnv: { ...envConfigs.buildEnv },
+            },
+          });
 
-    if (middlewareResult) {
-      if (middlewareResult.error) {
-        this.sendError(
+        if (startMiddlewareResult) {
+          const { port, pid } = startMiddlewareResult;
+          middlewarePid = pid;
+          this.devServerPids.add(pid);
+
+          const middlewareReqHeaders = nodeHeadersToFetchHeaders(req.headers);
+
+          // Add the Vercel platform proxy request headers
+          const proxyHeaders = this.getProxyHeaders(req, requestId, true);
+          for (const [name, value] of nodeHeadersToFetchHeaders(proxyHeaders)) {
+            middlewareReqHeaders.set(name, value);
+          }
+
+          const middlewareRes = await fetch(
+            `http://127.0.0.1:${port}${parsed.path}`,
+            {
+              headers: middlewareReqHeaders,
+              method: req.method,
+              redirect: 'manual',
+            }
+          );
+
+          if (middlewareRes.status === 500) {
+            await this.sendError(
+              req,
+              res,
+              requestId,
+              'EDGE_FUNCTION_INVOCATION_FAILED',
+              500
+            );
+            return;
+          }
+
+          // Apply status code from middleware invocation,
+          // for i.e. redirects or a custom 404 page
+          res.statusCode = middlewareRes.status;
+
+          let rewritePath = '';
+          let contentType = '';
+          let shouldContinue = false;
+          const skipMiddlewareHeaders = new Set([
+            'date',
+            'connection',
+            'content-length',
+            'transfer-encoding',
+          ]);
+          for (const [name, value] of middlewareRes.headers) {
+            if (name === 'x-middleware-next') {
+              shouldContinue = value === '1';
+            } else if (name === 'x-middleware-rewrite') {
+              rewritePath = value;
+              shouldContinue = true;
+            } else if (name === 'content-type') {
+              contentType = value;
+            } else if (!skipMiddlewareHeaders.has(name)) {
+              // Any other kind of response header should be included
+              // on both the incoming HTTP request (for when proxying
+              // to another function) and the outgoing HTTP response.
+              res.setHeader(name, value);
+              req.headers[name] = value;
+            }
+          }
+
+          if (!shouldContinue) {
+            const middlewareBody = await middlewareRes.buffer();
+            this.setResponseHeaders(res, requestId);
+            if (middlewareBody.length > 0) {
+              res.setHeader('content-length', middlewareBody.length);
+              if (contentType) {
+                res.setHeader('content-type', contentType);
+              }
+              res.end(middlewareBody);
+            } else {
+              res.end();
+            }
+            return;
+          }
+
+          if (rewritePath) {
+            // TODO: add validation?
+            debug(`Detected rewrite path from middleware: "${rewritePath}"`);
+            prevUrl = rewritePath;
+
+            // Retain orginal pathname, but override query parameters from the rewrite
+            const beforeRewriteUrl = req.url || '/';
+            const rewriteUrlParsed = url.parse(beforeRewriteUrl, true);
+            delete rewriteUrlParsed.search;
+            rewriteUrlParsed.query = url.parse(rewritePath, true).query;
+            req.url = url.format(rewriteUrlParsed);
+            debug(
+              `Rewrote incoming HTTP URL from "${beforeRewriteUrl}" to "${req.url}"`
+            );
+          }
+        }
+      } catch (err) {
+        // `startDevServer()` threw an error. Most likely this means the dev
+        // server process exited before sending the port information message
+        // (missing dependency at runtime, for example).
+        if (err.code === 'ENOENT') {
+          err.message = `Command not found: ${chalk.cyan(
+            err.path,
+            ...err.spawnargs
+          )}\nPlease ensure that ${cmd(err.path)} is properly installed`;
+          err.link = 'https://vercel.link/command-not-found';
+        }
+
+        await this.sendError(
           req,
           res,
           requestId,
@@ -1443,24 +1552,12 @@ export default class DevServer {
           500
         );
         return;
-      }
-      if (middlewareResult.finished) {
-        return;
-      }
-
-      if (middlewareResult.pathname) {
-        const origUrl = url.parse(req.url || '/', true);
-        origUrl.pathname = middlewareResult.pathname;
-        prevUrl = url.format(origUrl);
-      }
-      if (middlewareResult.query && prevUrl) {
-        const origUrl = url.parse(req.url || '/', true);
-        delete origUrl.search;
-        Object.assign(origUrl.query, middlewareResult.query);
-        prevUrl = url.format(origUrl);
+      } finally {
+        if (middlewarePid) {
+          this.killBuilderDevServer(middlewarePid);
+        }
       }
     }
-    */
 
     for (const phase of phases) {
       statusCode = undefined;
@@ -1740,7 +1837,10 @@ export default class DevServer {
             isDev: true,
             requestPath,
             devCacheDir,
-            env: { ...envConfigs.runEnv },
+            env: {
+              ...envConfigs.runEnv,
+              VERCEL_BUILDER_DEBUG: this.output.debugEnabled ? '1' : undefined,
+            },
             buildEnv: { ...envConfigs.buildEnv },
           },
         });
@@ -2185,13 +2285,7 @@ function proxyPass(
         `Failed to complete request to ${req.url}: ${error}`
       );
       if (!res.headersSent) {
-        devServer.sendError(
-          req,
-          res,
-          requestId,
-          'NO_RESPONSE_FROM_FUNCTION',
-          502
-        );
+        devServer.sendError(req, res, requestId, 'FUNCTION_INVOCATION_FAILED');
       }
     }
   );
@@ -2269,11 +2363,12 @@ async function findBuildMatch(
       if (!isIndex(match.src)) {
         return match;
       } else {
-        // if isIndex === true and ends in .html, we're done. Otherwise, keep searching
-        bestIndexMatch = match;
+        // If isIndex === true and ends in `.html`, we're done.
+        // Otherwise, keep searching.
         if (extname(match.src) === '.html') {
-          return bestIndexMatch;
+          return match;
         }
+        bestIndexMatch = match;
       }
     }
   }
@@ -2295,6 +2390,13 @@ async function shouldServe(
     config,
     builderWithPkg: { builder },
   } = match;
+
+  // "middleware" file is not served as a regular asset,
+  // instead it gets invoked as part of the routing logic.
+  if (config?.middleware === true) {
+    return false;
+  }
+
   const cleanSrc = src.endsWith('.html') ? src.slice(0, -5) : src;
   const trimmedPath = requestPath.endsWith('/')
     ? requestPath.slice(0, -1)

packages/cli/src/util/dns/get-dns-data.ts

@@ -2,26 +2,29 @@ import chalk from 'chalk';
 import { DNSRecordData } from '../../types';
 import textInput from '../input/text';
 import promptBool from '../input/prompt-bool';
-import { Output } from '../output';
+import Client from '../client';
 
 const RECORD_TYPES = ['A', 'AAAA', 'ALIAS', 'CAA', 'CNAME', 'MX', 'SRV', 'TXT'];
 
 export default async function getDNSData(
-  output: Output,
+  client: Client,
   data: null | DNSRecordData
 ): Promise<DNSRecordData | null> {
   if (data) {
     return data;
   }
+  const { output } = client;
 
   try {
     // first ask for type, branch from there
     const possibleTypes = new Set(RECORD_TYPES);
-    const type = (await textInput({
-      label: `- Record type (${RECORD_TYPES.join(', ')}): `,
-      validateValue: (v: string) =>
-        Boolean(v && possibleTypes.has(v.trim().toUpperCase()))
-    }))
+    const type = (
+      await textInput({
+        label: `- Record type (${RECORD_TYPES.join(', ')}): `,
+        validateValue: (v: string) =>
+          Boolean(v && possibleTypes.has(v.trim().toUpperCase())),
+      })
+    )
       .trim()
       .toUpperCase();
 
@@ -39,7 +42,7 @@ export default async function getDNSData(
           target
         )}.`
       );
-      return (await verifyData())
+      return (await verifyData(client))
         ? {
             name,
             type,
@@ -47,8 +50,8 @@ export default async function getDNSData(
               priority,
               weight,
               port,
-              target
-            }
+              target,
+            },
           }
         : null;
     }
@@ -61,23 +64,23 @@ export default async function getDNSData(
           `${mxPriority}`
         )} ${chalk.cyan(value)}`
       );
-      return (await verifyData())
+      return (await verifyData(client))
         ? {
             name,
             type,
             value,
-            mxPriority
+            mxPriority,
           }
         : null;
     }
 
     const value = await getTrimmedString(`- ${type} value: `);
     output.log(`${chalk.cyan(name)} ${chalk.bold(type)} ${chalk.cyan(value)}`);
-    return (await verifyData())
+    return (await verifyData(client))
       ? {
           name,
           type,
-          value
+          value,
         }
       : null;
   } catch (error) {
@@ -85,13 +88,13 @@ export default async function getDNSData(
   }
 }
 
-async function verifyData() {
-  return promptBool('Is this correct?');
+async function verifyData(client: Client) {
+  return promptBool('Is this correct?', client);
 }
 
 async function getRecordName(type: string) {
   const input = await textInput({
-    label: `- ${type} name: `
+    label: `- ${type} name: `,
   });
   return input === '@' ? '' : input;
 }
@@ -100,14 +103,14 @@ async function getNumber(label: string) {
   return Number(
     await textInput({
       label,
-      validateValue: v => Boolean(v && Number(v))
+      validateValue: v => Boolean(v && Number(v)),
     })
   );
 }
 async function getTrimmedString(label: string) {
   const res = await textInput({
     label,
-    validateValue: v => Boolean(v && v.trim().length > 0)
+    validateValue: v => Boolean(v && v.trim().length > 0),
   });
   return res.trim();
 }

packages/cli/src/util/domains/purchase-domain-if-available.ts

@@ -54,7 +54,8 @@ export default async function purchaseDomainIfAvailable(
       !(await promptBool(
         `Buy ${chalk.underline(domain)} for ${chalk.bold(
           `$${price}`
-        )} (${plural('yr', period, true)})?`
+        )} (${plural('yr', period, true)})?`,
+        client
       ))
     ) {
       output.print(eraseLines(1));

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

@@ -1,12 +1,19 @@
 import inquirer from 'inquirer';
+import Client from '../client';
 
 export default async function confirm(
+  client: Client,
   message: string,
   preferred: boolean
 ): Promise<boolean> {
   require('./patch-inquirer');
 
-  const answers = await inquirer.prompt({
+  const prompt = inquirer.createPromptModule({
+    input: client.stdin,
+    output: client.stdout,
+  });
+
+  const answers = await prompt({
     type: 'confirm',
     name: 'value',
     message,

packages/cli/src/util/input/edit-project-settings.ts

@@ -1,8 +1,8 @@
 import inquirer from 'inquirer';
 import confirm from './confirm';
 import chalk from 'chalk';
-import { Output } from '../output';
 import frameworkList, { Framework } from '@vercel/frameworks';
+import Client from '../client';
 import { isSettingValue } from '../is-setting-value';
 import { ProjectSettings } from '../../types';
 
@@ -22,12 +22,14 @@ const settingKeys = Object.keys(settingMap).sort() as unknown as readonly [
 export type PartialProjectSettings = Pick<ProjectSettings, ConfigKeys>;
 
 export default async function editProjectSettings(
-  output: Output,
+  client: Client,
   projectSettings: PartialProjectSettings | null,
   framework: Framework | null,
   autoConfirm: boolean,
   localConfigurationOverrides: PartialProjectSettings | null
 ): Promise<ProjectSettings> {
+  const { output } = client;
+
   // Create initial settings object defaulting everything to `null` and assigning what may exist in `projectSettings`
   const settings: ProjectSettings = Object.assign(
     {
@@ -118,7 +120,7 @@ export default async function editProjectSettings(
   // Prompt the user if they want to modify any settings not defined by local configuration.
   if (
     autoConfirm ||
-    !(await confirm('Want to modify these settings?', false))
+    !(await confirm(client, 'Want to modify these settings?', false))
   ) {
     return settings;
   }

packages/cli/src/util/input/input-project.ts

@@ -47,11 +47,16 @@ export default async function inputProject(
 
   if (!detectedProject) {
     // did not auto-detect a project to link
-    shouldLinkProject = await confirm(`Link to existing project?`, false);
+    shouldLinkProject = await confirm(
+      client,
+      `Link to existing project?`,
+      false
+    );
   } else {
     // auto-detected a project to link
     if (
       await confirm(
+        client,
         `Found project ${chalk.cyan(
           `“${org.slug}/${detectedProject.name}”`
         )}. Link to it?`,
@@ -63,6 +68,7 @@ export default async function inputProject(
 
     // user doesn't want to link the auto-detected project
     shouldLinkProject = await confirm(
+      client,
       `Link to different existing project?`,
       true
     );
@@ -73,7 +79,11 @@ export default async function inputProject(
     let project: Project | ProjectNotFound | null = null;
 
     while (!project || project instanceof ProjectNotFound) {
-      const answers = await inquirer.prompt({
+      const prompt = inquirer.createPromptModule({
+        input: client.stdin,
+        output: client.stdout,
+      });
+      const answers = await prompt({
         type: 'input',
         name: 'existingProjectName',
         message: `What’s the name of your existing project?`,

packages/cli/src/util/input/input-root-directory.ts

@@ -1,12 +1,12 @@
 import path from 'path';
 import chalk from 'chalk';
 import inquirer from 'inquirer';
-import { Output } from '../output';
 import { validateRootDirectory } from '../validate-paths';
+import Client from '../client';
 
 export async function inputRootDirectory(
+  client: Client,
   cwd: string,
-  output: Output,
   autoConfirm = false
 ) {
   if (autoConfirm) {
@@ -15,7 +15,11 @@ export async function inputRootDirectory(
 
   // eslint-disable-next-line no-constant-condition
   while (true) {
-    const { rootDirectory } = await inquirer.prompt({
+    const prompt = inquirer.createPromptModule({
+      input: client.stdin,
+      output: client.stdout,
+    });
+    const { rootDirectory } = await prompt({
       type: 'input',
       name: 'rootDirectory',
       message: `In which directory is your code located?`,
@@ -38,7 +42,7 @@ export async function inputRootDirectory(
 
     if (
       (await validateRootDirectory(
-        output,
+        client.output,
         cwd,
         fullPath,
         'Please choose a different one.'

packages/cli/src/util/input/prompt-bool.ts

@@ -5,21 +5,21 @@ type Options = {
   defaultValue?: boolean;
   noChar?: string;
   resolveChars?: Set<string>;
-  stdin?: NodeJS.ReadStream;
-  stdout?: NodeJS.WriteStream;
+  stdin: NodeJS.ReadStream;
+  stdout: NodeJS.WriteStream;
   trailing?: string;
   yesChar?: string;
 };
 
-export default async function promptBool(label: string, options: Options = {}) {
+export default async function promptBool(label: string, options: Options) {
   const {
+    stdin,
+    stdout,
     defaultValue = false,
     abortSequences = new Set(['\u0003']),
     resolveChars = new Set(['\r']),
     yesChar = 'y',
     noChar = 'n',
-    stdin = process.stdin,
-    stdout = process.stdout,
     trailing = '',
   } = options;
 

packages/cli/src/util/input/read-standard-input.ts

@@ -1,13 +1,15 @@
-export default async function readStandardInput(): Promise<string> {
+export default async function readStandardInput(
+  stdin: NodeJS.ReadStream
+): Promise<string> {
   return new Promise<string>(resolve => {
     setTimeout(() => resolve(''), 500);
 
-    if (process.stdin.isTTY) {
+    if (stdin.isTTY) {
       // found tty so we know there is nothing piped to stdin
       resolve('');
     } else {
-      process.stdin.setEncoding('utf8');
-      process.stdin.once('data', resolve);
+      stdin.setEncoding('utf8');
+      stdin.once('data', resolve);
     }
   });
 }

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

@@ -80,6 +80,7 @@ export default async function setupAndLink(
   const shouldStartSetup =
     autoConfirm ||
     (await confirm(
+      client,
       `${setupMsg} ${chalk.cyan(`“${toHumanPath(path)}”`)}?`,
       true
     ));
@@ -120,7 +121,7 @@ export default async function setupAndLink(
 
   if (typeof projectOrNewProjectName === 'string') {
     newProjectName = projectOrNewProjectName;
-    rootDirectory = await inputRootDirectory(path, output, autoConfirm);
+    rootDirectory = await inputRootDirectory(client, path, autoConfirm);
   } else {
     const project = projectOrNewProjectName;
 
@@ -224,7 +225,7 @@ export default async function setupAndLink(
       const { projectSettings, framework } = deployment;
 
       settings = await editProjectSettings(
-        output,
+        client,
         projectSettings,
         framework,
         autoConfirm,

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

@@ -14,7 +14,7 @@ export default async function reauthenticate(
     client.output.log(
       `You must re-authenticate with SAML to use ${bold(error.scope)} scope.`
     );
-    if (await confirm(`Log in with SAML?`, true)) {
+    if (await confirm(client, `Log in with SAML?`, true)) {
       return doSamlLogin(client, error.teamId);
     }
   } else {

packages/cli/src/util/validate-paths.ts

@@ -5,6 +5,7 @@ import chalk from 'chalk';
 import { homedir } from 'os';
 import confirm from './input/confirm';
 import toHumanPath from './humanize-path';
+import Client from './client';
 
 const stat = promisify(lstatRaw);
 
@@ -51,9 +52,11 @@ export async function validateRootDirectory(
 }
 
 export default async function validatePaths(
-  output: Output,
+  client: Client,
   paths: string[]
 ): Promise<{ valid: true; path: string } | { valid: false; exitCode: number }> {
+  const { output } = client;
+
   // can't deploy more than 1 path
   if (paths.length > 1) {
     output.print(`${chalk.red('Error!')} Can't deploy more than one path.\n`);
@@ -85,6 +88,7 @@ export default async function validatePaths(
   // ask confirmation if the directory is home
   if (path === homedir()) {
     const shouldDeployHomeDirectory = await confirm(
+      client,
       `You are deploying your home directory. Do you want to continue?`,
       false
     );

packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-config.js

@@ -0,0 +1,7 @@
+export const config = {
+  runtime: 'invalid-runtime-value',
+};
+
+export default async function edge(request, event) {
+  throw new Error('intentional runtime error');
+}

packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-no-handler.js

@@ -0,0 +1,8 @@
+export const config = {
+  runtime: 'experimental-edge',
+};
+
+export async function notTheDefaultExport(request, event) {
+  // this will never be run
+  return new Response('some response body');
+}

packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-runtime.js

@@ -0,0 +1,7 @@
+export const config = {
+  runtime: 'experimental-edge',
+};
+
+export default async function edge(request, event) {
+  throw new Error('intentional runtime error');
+}

packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-startup.js

@@ -0,0 +1,10 @@
+export const config = {
+  runtime: 'experimental-edge',
+};
+
+export default async function edge(request, event) {
+  // this should never be executed
+  return new Response('some response body');
+}
+
+throw new Error('intentional startup error');

packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-syntax.js

@@ -0,0 +1,9 @@
+export const config = {
+  runtime: 'experimental-edge'
+}
+
+export default async function edge(request, event) {
+  return new Response('some response body');
+
+// intentional missing closing bracket to produce syntax error
+// }

packages/cli/test/dev/fixtures/edge-function-error/api/edge-error-unknown-import.js

@@ -0,0 +1,9 @@
+import unknownModule from 'unknown-module-893427589372458934795843';
+
+export const config = {
+  runtime: 'experimental-edge',
+};
+
+export default async function edge(request, event) {
+  return new Response(unknownModule('some response body'));
+}

packages/cli/test/dev/fixtures/edge-function/api/edge-500-response.js

@@ -0,0 +1,9 @@
+export const config = {
+  runtime: 'experimental-edge',
+};
+
+export default async function edge(request, event) {
+  return new Response('responding with intentional 500 from user code', {
+    status: 500,
+  });
+}

packages/cli/test/dev/fixtures/edge-function/yarn.lock

@@ -0,0 +1,8 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+decamelize@6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-6.0.0.tgz#8cad4d916fde5c41a264a43d0ecc56fe3d31749e"
+  integrity sha512-Fv96DCsdOgB6mdGl67MT5JaTNKRzrzill5OH5s8bjYJXVlcXyPYGyPsUkWyGV5p1TXI5esYIYMMeDJL0hEIwaA==

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

@@ -0,0 +1 @@
+export default () => new Response(null, { status: 500 });

packages/cli/test/dev/fixtures/middleware-error-at-init/middleware.js

@@ -0,0 +1 @@
+throw new Error('Middleware init error');

packages/cli/test/dev/fixtures/middleware-error-in-handler/middleware.js

@@ -0,0 +1,3 @@
+export default () => {
+  throw new Error('Middleware handler error');
+};

packages/cli/test/dev/fixtures/middleware-matchers/middleware.js

@@ -0,0 +1,13 @@
+// Supports both a single string value or an array of matchers
+export const config = {
+  matcher: ['/about/:path*', '/dashboard/:path*'],
+};
+
+export default function middleware(request, _event) {
+  const response = new Response('middleware response');
+
+  // Set custom header
+  response.headers.set('x-modified-edge', 'true');
+
+  return response;
+}

packages/cli/test/dev/fixtures/middleware-redirect/middleware.js

@@ -0,0 +1,9 @@
+export default req => {
+  const url = new URL(req.url);
+  return new Response(null, {
+    status: 302,
+    headers: {
+      location: `https://vercel.com${url.pathname}${url.search}`,
+    },
+  });
+};

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

@@ -0,0 +1 @@
+export default () => new Response('hi from middleware');

packages/cli/test/dev/fixtures/middleware-rewrite-query/api/fn.js

@@ -0,0 +1,5 @@
+export default (req, res) => {
+  res.json({
+    url: req.url,
+  });
+};

packages/cli/test/dev/fixtures/middleware-rewrite-query/middleware.js

@@ -0,0 +1,6 @@
+export default () =>
+  new Response(null, {
+    headers: {
+      'x-middleware-rewrite': '/api/fn?from-middleware=true',
+    },
+  });

packages/cli/test/dev/fixtures/middleware-rewrite/another.html

@@ -0,0 +1 @@
+<h1>Another</h1>

packages/cli/test/dev/fixtures/middleware-rewrite/index.html

@@ -0,0 +1 @@
+<h1>Index</h1>

packages/cli/test/dev/fixtures/middleware-rewrite/middleware.js

@@ -0,0 +1,19 @@
+export default req => {
+  const url = new URL(req.url);
+
+  if (url.pathname === '/') {
+    // Pass-through "index.html" page
+    return new Response(null, {
+      headers: {
+        'x-middleware-next': '1',
+      },
+    });
+  }
+
+  // Everything else goes to "another.html"
+  return new Response(null, {
+    headers: {
+      'x-middleware-rewrite': '/another.html',
+    },
+  });
+};

packages/cli/test/dev/fixtures/no-api/vercel.json

@@ -0,0 +1,3 @@
+{
+  "version": 2
+}

packages/cli/test/dev/integration-1.test.ts

@@ -23,7 +23,7 @@ test('[vercel dev] should support edge functions', async () => {
 
     const body = { hello: 'world' };
 
-    let res = await fetch(`http://localhost:${port}/api/edge-function`, {
+    let res = await fetch(`http://localhost:${port}/api/edge-success`, {
       method: 'POST',
       headers: {
         'content-type': 'application/json',
@@ -36,7 +36,7 @@ test('[vercel dev] should support edge functions', async () => {
     // are set up; so, we test that they are all passed through properly
     expect(await res.json()).toMatchObject({
       headerContentType: 'application/json',
-      url: `http://localhost:${port}/api/edge-function`,
+      url: `http://localhost:${port}/api/edge-success`,
       method: 'POST',
       body: '{"hello":"world"}',
       decamelized: 'some_camel_case_thing',
@@ -48,6 +48,235 @@ test('[vercel dev] should support edge functions', async () => {
   }
 });
 
+test(
+  '[vercel dev] edge functions respond properly the same as production',
+  testFixtureStdio('edge-function', async (testPath: any) => {
+    await testPath(500, '/api/edge-500-response');
+    await testPath(200, '/api/edge-success');
+  })
+);
+
+test('[vercel dev] should support edge functions returning intentional 500 responses', async () => {
+  const dir = fixture('edge-function');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    const body = { hello: 'world' };
+
+    let res = await fetch(`http://localhost:${port}/api/edge-500-response`, {
+      method: 'POST',
+      headers: {
+        'content-type': 'application/json',
+      },
+      body: JSON.stringify(body),
+    });
+    validateResponseHeaders(res);
+
+    expect(await res.status).toBe(500);
+    expect(await res.text()).toBe(
+      'responding with intentional 500 from user code'
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
+test('[vercel dev] should handle runtime errors thrown in edge functions', async () => {
+  const dir = fixture('edge-function-error');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    let res = await fetch(`http://localhost:${port}/api/edge-error-runtime`, {
+      method: 'GET',
+      headers: {
+        Accept:
+          'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+      },
+    });
+    validateResponseHeaders(res);
+
+    const { stdout, stderr } = await dev.kill('SIGTERM');
+
+    expect(await res.text()).toMatch(
+      /<strong>500<\/strong>: INTERNAL_SERVER_ERROR/g
+    );
+    expect(stdout).toMatch(/Unhandled rejection: intentional runtime error/g);
+    expect(stderr).toMatch(
+      /Failed to complete request to \/api\/edge-error-runtime: Error: socket hang up/g
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
+test('[vercel dev] should handle config errors thrown in edge functions', async () => {
+  const dir = fixture('edge-function-error');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    let res = await fetch(`http://localhost:${port}/api/edge-error-config`, {
+      method: 'GET',
+      headers: {
+        Accept:
+          'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+      },
+    });
+    validateResponseHeaders(res);
+
+    const { stderr } = await dev.kill('SIGTERM');
+
+    expect(await res.text()).toMatch(
+      /<strong>500<\/strong>: INTERNAL_SERVER_ERROR/g
+    );
+    expect(stderr).toMatch(
+      /Invalid function runtime "invalid-runtime-value" for "api\/edge-error-config.js". Valid runtimes are: \["experimental-edge"\]/g
+    );
+    expect(stderr).toMatch(
+      /Failed to complete request to \/api\/edge-error-config: Error: socket hang up/g
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
+test('[vercel dev] should handle startup errors thrown in edge functions', async () => {
+  const dir = fixture('edge-function-error');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    let res = await fetch(`http://localhost:${port}/api/edge-error-startup`, {
+      method: 'GET',
+      headers: {
+        Accept:
+          'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+      },
+    });
+    validateResponseHeaders(res);
+
+    const { stderr } = await dev.kill('SIGTERM');
+
+    expect(await res.text()).toMatch(
+      /<strong>500<\/strong>: INTERNAL_SERVER_ERROR/g
+    );
+    expect(stderr).toMatch(/Failed to instantiate edge runtime./g);
+    expect(stderr).toMatch(/intentional startup error/g);
+    expect(stderr).toMatch(
+      /Failed to complete request to \/api\/edge-error-startup: Error: socket hang up/g
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
+test('[vercel dev] should handle syntax errors thrown in edge functions', async () => {
+  const dir = fixture('edge-function-error');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    let res = await fetch(`http://localhost:${port}/api/edge-error-syntax`, {
+      method: 'GET',
+      headers: {
+        Accept:
+          'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+      },
+    });
+    validateResponseHeaders(res);
+
+    const { stderr } = await dev.kill('SIGTERM');
+
+    expect(await res.text()).toMatch(
+      /<strong>500<\/strong>: INTERNAL_SERVER_ERROR/g
+    );
+    expect(stderr).toMatch(/Failed to instantiate edge runtime./g);
+    expect(stderr).toMatch(/Unexpected end of file/g);
+    expect(stderr).toMatch(
+      /Failed to complete request to \/api\/edge-error-syntax: Error: socket hang up/g
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
+test('[vercel dev] should handle import errors thrown in edge functions', async () => {
+  const dir = fixture('edge-function-error');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    let res = await fetch(
+      `http://localhost:${port}/api/edge-error-unknown-import`,
+      {
+        method: 'GET',
+        headers: {
+          Accept:
+            'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+        },
+      }
+    );
+    validateResponseHeaders(res);
+
+    const { stderr } = await dev.kill('SIGTERM');
+
+    expect(await res.text()).toMatch(
+      /<strong>500<\/strong>: INTERNAL_SERVER_ERROR/g
+    );
+    expect(stderr).toMatch(
+      /Could not resolve "unknown-module-893427589372458934795843"/g
+    );
+    expect(stderr).toMatch(
+      /Failed to complete request to \/api\/edge-error-unknown-import: Error: socket hang up/g
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
+test('[vercel dev] should handle missing handler errors thrown in edge functions', async () => {
+  const dir = fixture('edge-function-error');
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    let res = await fetch(
+      `http://localhost:${port}/api/edge-error-no-handler`,
+      {
+        method: 'GET',
+        headers: {
+          Accept:
+            'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
+        },
+      }
+    );
+    validateResponseHeaders(res);
+
+    const { stdout, stderr } = await dev.kill('SIGTERM');
+
+    expect(await res.text()).toMatch(
+      /<strong>500<\/strong>: INTERNAL_SERVER_ERROR/g
+    );
+    expect(stdout).toMatch(
+      /No default export was found. Add a default export to handle requests./g
+    );
+    expect(stderr).toMatch(
+      /Failed to complete request to \/api\/edge-error-no-handler: Error: socket hang up/g
+    );
+  } finally {
+    await dev.kill('SIGTERM');
+  }
+});
+
 test('[vercel dev] should support request body', async () => {
   const dir = fixture('node-request-body');
   const { dev, port, readyResolver } = await testFixture(dir);

packages/cli/test/dev/integration-2.test.ts

@@ -1,7 +1,17 @@
 // eslint-disable-next-line
-import path from 'path';
+import { join } from 'path';
+import ms from 'ms';
+import fs, { mkdirp } from 'fs-extra';
 
-const { exec, fixture, testFixture, testFixtureStdio } = require('./utils.js');
+const {
+  exec,
+  fetch,
+  fixture,
+  sleep,
+  testFixture,
+  testFixtureStdio,
+  validateResponseHeaders,
+} = require('./utils.js');
 
 test('[vercel dev] validate redirects', async () => {
   const directory = fixture('invalid-redirects');
@@ -334,3 +344,44 @@ test(
     await testPath(200, '/', /A simple deployment with the Vercel API!/m);
   })
 );
+
+test(
+  '[vercel dev] add a `api/fn.ts` when `api` does not exist at startup`',
+  testFixtureStdio('no-api', async (_testPath: any, port: any) => {
+    const directory = fixture('no-api');
+    const apiDir = join(directory, 'api');
+
+    try {
+      {
+        const response = await fetch(`http://localhost:${port}/api/new-file`);
+        validateResponseHeaders(response);
+        expect(response.status).toBe(404);
+      }
+
+      const fileContents = `
+          export const config = {
+            runtime: 'experimental-edge'
+          }
+
+          export default async function edge(request, event) {
+            return new Response('from new file');
+          }
+        `;
+
+      await mkdirp(apiDir);
+      await fs.writeFile(join(apiDir, 'new-file.js'), fileContents);
+
+      // Wait until file events have been processed
+      await sleep(ms('1s'));
+
+      {
+        const response = await fetch(`http://localhost:${port}/api/new-file`);
+        validateResponseHeaders(response);
+        const body = await response.text();
+        expect(body.trim()).toBe('from new file');
+      }
+    } finally {
+      await fs.remove(apiDir);
+    }
+  })
+);

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

@@ -433,3 +433,85 @@ test(
     await testPath(404, '/i-do-not-exist');
   })
 );
+
+test(
+  '[vercel dev] Middleware that returns a 200 response',
+  testFixtureStdio('middleware-response', async (testPath: any) => {
+    await testPath(200, '/', 'hi from middleware');
+    await testPath(200, '/another', 'hi from middleware');
+  })
+);
+
+test(
+  '[vercel dev] Middleware that does basic rewrite',
+  testFixtureStdio('middleware-rewrite', async (testPath: any) => {
+    await testPath(200, '/', '<h1>Index</h1>');
+    await testPath(200, '/index', '<h1>Another</h1>');
+    await testPath(200, '/another', '<h1>Another</h1>');
+    await testPath(200, '/another.html', '<h1>Another</h1>');
+    await testPath(200, '/foo', '<h1>Another</h1>');
+  })
+);
+
+test(
+  '[vercel dev] Middleware that rewrites with custom query params',
+  testFixtureStdio('middleware-rewrite-query', async (testPath: any) => {
+    await testPath(200, '/?foo=bar', '{"url":"/?from-middleware=true"}');
+    await testPath(
+      200,
+      '/another?foo=bar',
+      '{"url":"/another?from-middleware=true"}'
+    );
+    await testPath(
+      200,
+      '/api/fn?foo=bar',
+      '{"url":"/api/fn?from-middleware=true"}'
+    );
+  })
+);
+
+test(
+  '[vercel dev] Middleware that redirects',
+  testFixtureStdio('middleware-redirect', async (testPath: any) => {
+    await testPath(302, '/', null, {
+      location: 'https://vercel.com/',
+    });
+    await testPath(302, '/home', null, {
+      location: 'https://vercel.com/home',
+    });
+    await testPath(302, '/?foo=bar', null, {
+      location: 'https://vercel.com/?foo=bar',
+    });
+  })
+);
+
+test(
+  '[vercel dev] Middleware with error in function handler',
+  testFixtureStdio('middleware-error-in-handler', async (testPath: any) => {
+    await testPath(500, '/', /EDGE_FUNCTION_INVOCATION_FAILED/);
+  })
+);
+
+test(
+  '[vercel dev] Middleware with error at init',
+  testFixtureStdio('middleware-error-at-init', async (testPath: any) => {
+    await testPath(500, '/', /EDGE_FUNCTION_INVOCATION_FAILED/);
+  })
+);
+
+test(
+  '[vercel dev] Middleware with an explicit 500 response',
+  testFixtureStdio('middleware-500-response', async (testPath: any) => {
+    await testPath(500, '/', /EDGE_FUNCTION_INVOCATION_FAILED/);
+  })
+);
+
+test(
+  '[vercel dev] Middleware with `matchers` config',
+  testFixtureStdio('middleware-matchers', async (testPath: any) => {
+    await testPath(404, '/');
+    await testPath(404, '/another');
+    await testPath(200, '/about/page', 'middleware response');
+    await testPath(200, '/dashboard/home', 'middleware response');
+  })
+);

packages/cli/test/dev/utils.js

@@ -257,6 +257,10 @@ async function testFixture(directory, opts = {}, args = []) {
   dev.kill = async (...args) => {
     dev._kill(...args);
     await exitResolver;
+    return {
+      stdout,
+      stderr,
+    };
   };
 
   return {

packages/cli/test/mocks/client.ts

@@ -1,4 +1,5 @@
 import chalk from 'chalk';
+import { PassThrough } from 'stream';
 import { createServer, Server } from 'http';
 import express, { Express, Router } from 'express';
 import listen from 'async-listen';
@@ -23,10 +24,13 @@ export class MockClient extends Client {
       // Gets populated in `startMockServer()`
       apiUrl: '',
       authConfig: {},
+      stdin: new PassThrough(),
+      stdout: new PassThrough(),
       output: new Output(),
       config: {},
       localConfig: {},
     });
+
     this.mockOutput = jest.fn();
 
     this.app = express();
@@ -53,6 +57,12 @@ export class MockClient extends Client {
   }
 
   reset() {
+    this.stdin = new PassThrough();
+    this.stdin.isTTY = true;
+
+    this.stdout = new PassThrough();
+    this.stdout.isTTY = true;
+
     this.output = new Output();
     this.mockOutput = jest.fn();
     this.output.print = s => {

packages/cli/test/unit/mock.test.ts

@@ -0,0 +1,25 @@
+import confirm from '../../src/util/input/confirm';
+import { client } from '../mocks/client';
+
+describe('MockClient', () => {
+  it('should mock `confirm()`', async () => {
+    // true
+    let confirmedPromise = confirm(client, 'Do the thing?', false);
+
+    client.stdin.write('yes\n');
+
+    client.stdout.setEncoding('utf8');
+    client.stdout.on('data', d => console.log({ d }));
+
+    let confirmed = await confirmedPromise;
+    expect(confirmed).toEqual(true);
+
+    // false
+    confirmedPromise = confirm(client, 'Do the thing?', false);
+
+    client.stdin.write('no\n');
+
+    confirmed = await confirmedPromise;
+    expect(confirmed).toEqual(false);
+  });
+});

packages/cli/test/unit/util/bisect/normalize-url.test.ts

@@ -0,0 +1,16 @@
+import { normalizeURL } from '../../../../src/util/bisect/normalize-url';
+
+describe('normalize-url', () => {
+  it('should add https to url without scheme', () => {
+    const normalizedUrl = normalizeURL('vercel.com');
+    expect(normalizedUrl).toEqual('https://vercel.com');
+  });
+  it('should not add anything to a url that starts with https', () => {
+    const normalizedUrl = normalizeURL('https://vercel.com');
+    expect(normalizedUrl).toEqual('https://vercel.com');
+  });
+  it('should not add anything to a url that starts with http', () => {
+    const normalizedUrl = normalizeURL('http://vercel.com');
+    expect(normalizedUrl).toEqual('http://vercel.com');
+  });
+});

packages/cli/test/unit/util/input/edit-project-settings.test.ts

@@ -1,13 +1,6 @@
 import { Framework, frameworks } from '@vercel/frameworks';
 import editProjectSettings from '../../../../src/util/input/edit-project-settings';
-import { Output } from '../../../../src/util/output';
-
-let output: Output;
-
-beforeEach(() => {
-  output = new Output();
-  output.print = jest.fn();
-});
+import { client } from '../../../mocks/client';
 
 const otherFramework = frameworks.find(
   fwk => fwk.name === 'Other'
@@ -20,7 +13,7 @@ describe('editProjectSettings', () => {
   describe('with no settings, "Other" framework, and no overrides provided', () => {
     test('should default all settings to `null` and print user default framework settings', async () => {
       const settings = await editProjectSettings(
-        output,
+        client,
         null,
         otherFramework,
         true,
@@ -34,22 +27,14 @@ describe('editProjectSettings', () => {
         installCommand: null,
         outputDirectory: null,
       });
-      expect((output.print as jest.Mock).mock.calls.length).toBe(5);
-      expect((output.print as jest.Mock).mock.calls[0][0]).toMatch(
+      expect(client.mockOutput.mock.calls.length).toBe(5);
+      expect(client.mockOutput.mock.calls[0][0]).toMatch(
         /No framework detected. Default Project Settings:/
       );
-      expect((output.print as jest.Mock).mock.calls[1][0]).toMatch(
-        /Build Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[2][0]).toMatch(
-        /Development Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[3][0]).toMatch(
-        /Install Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[4][0]).toMatch(
-        /Output Directory/
-      );
+      expect(client.mockOutput.mock.calls[1][0]).toMatch(/Build Command/);
+      expect(client.mockOutput.mock.calls[2][0]).toMatch(/Development Command/);
+      expect(client.mockOutput.mock.calls[3][0]).toMatch(/Install Command/);
+      expect(client.mockOutput.mock.calls[4][0]).toMatch(/Output Directory/);
     });
   });
 
@@ -63,29 +48,21 @@ describe('editProjectSettings', () => {
         outputDirectory: 'OUTPUT_DIRECTORY',
       };
       const settings = await editProjectSettings(
-        output,
+        client,
         projectSettings,
         otherFramework,
         true,
         null
       );
       expect(settings).toStrictEqual({ ...projectSettings, framework: null });
-      expect((output.print as jest.Mock).mock.calls.length).toBe(5);
-      expect((output.print as jest.Mock).mock.calls[0][0]).toMatch(
+      expect(client.mockOutput.mock.calls.length).toBe(5);
+      expect(client.mockOutput.mock.calls[0][0]).toMatch(
         /No framework detected. Default Project Settings:/
       );
-      expect((output.print as jest.Mock).mock.calls[1][0]).toMatch(
-        /Build Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[2][0]).toMatch(
-        /Development Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[3][0]).toMatch(
-        /Install Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[4][0]).toMatch(
-        /Output Directory/
-      );
+      expect(client.mockOutput.mock.calls[1][0]).toMatch(/Build Command/);
+      expect(client.mockOutput.mock.calls[2][0]).toMatch(/Development Command/);
+      expect(client.mockOutput.mock.calls[3][0]).toMatch(/Install Command/);
+      expect(client.mockOutput.mock.calls[4][0]).toMatch(/Output Directory/);
     });
   });
 
@@ -99,28 +76,20 @@ describe('editProjectSettings', () => {
         outputDirectory: 'OUTPUT_DIRECTORY',
       };
       const settings = await editProjectSettings(
-        output,
+        client,
         projectSettings,
         nextJSFramework,
         true,
         null
       );
-      expect((output.print as jest.Mock).mock.calls.length).toBe(5);
-      expect((output.print as jest.Mock).mock.calls[0][0]).toMatch(
+      expect(client.mockOutput.mock.calls.length).toBe(5);
+      expect(client.mockOutput.mock.calls[0][0]).toMatch(
         /Auto-detected Project Settings/
       );
-      expect((output.print as jest.Mock).mock.calls[1][0]).toMatch(
-        /Build Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[2][0]).toMatch(
-        /Development Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[3][0]).toMatch(
-        /Install Command/
-      );
-      expect((output.print as jest.Mock).mock.calls[4][0]).toMatch(
-        /Output Directory/
-      );
+      expect(client.mockOutput.mock.calls[1][0]).toMatch(/Build Command/);
+      expect(client.mockOutput.mock.calls[2][0]).toMatch(/Development Command/);
+      expect(client.mockOutput.mock.calls[3][0]).toMatch(/Install Command/);
+      expect(client.mockOutput.mock.calls[4][0]).toMatch(/Output Directory/);
       expect(settings).toStrictEqual({
         ...projectSettings,
         framework: nextJSFramework.slug,
@@ -146,38 +115,28 @@ describe('editProjectSettings', () => {
         outputDirectory: 'OUTPUT_DIRECTORY',
       };
       const settings = await editProjectSettings(
-        output,
+        client,
         projectSettings,
         nextJSFramework,
         true,
         overrides
       );
-      expect((output.print as jest.Mock).mock.calls.length).toBe(9);
-      expect((output.print as jest.Mock).mock.calls[0][0]).toMatch(
+      expect(client.mockOutput.mock.calls.length).toBe(9);
+      expect(client.mockOutput.mock.calls[0][0]).toMatch(
         /Local settings detected in vercel.json:/
       );
-      expect((output.print as jest.Mock).mock.calls[1][0]).toMatch(
-        /Build Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[2][0]).toMatch(
-        /Ignore Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[3][0]).toMatch(
+      expect(client.mockOutput.mock.calls[1][0]).toMatch(/Build Command:/);
+      expect(client.mockOutput.mock.calls[2][0]).toMatch(/Ignore Command:/);
+      expect(client.mockOutput.mock.calls[3][0]).toMatch(
         /Development Command:/
       );
-      expect((output.print as jest.Mock).mock.calls[4][0]).toMatch(
-        /Framework:/
-      );
-      expect((output.print as jest.Mock).mock.calls[5][0]).toMatch(
-        /Install Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[6][0]).toMatch(
-        /Output Directory:/
-      );
-      expect((output.print as jest.Mock).mock.calls[7][0]).toMatch(
+      expect(client.mockOutput.mock.calls[4][0]).toMatch(/Framework:/);
+      expect(client.mockOutput.mock.calls[5][0]).toMatch(/Install Command:/);
+      expect(client.mockOutput.mock.calls[6][0]).toMatch(/Output Directory:/);
+      expect(client.mockOutput.mock.calls[7][0]).toMatch(
         /Merging default Project Settings for Svelte. Previously listed overrides are prioritized./
       );
-      expect((output.print as jest.Mock).mock.calls[8][0]).toMatch(
+      expect(client.mockOutput.mock.calls[8][0]).toMatch(
         /Auto-detected Project Settings/
       );
 
@@ -196,38 +155,28 @@ describe('editProjectSettings', () => {
         outputDirectory: 'OUTPUT_DIRECTORY',
       };
       const settings = await editProjectSettings(
-        output,
+        client,
         null,
         nextJSFramework,
         true,
         overrides
       );
-      expect((output.print as jest.Mock).mock.calls.length).toBe(9);
-      expect((output.print as jest.Mock).mock.calls[0][0]).toMatch(
+      expect(client.mockOutput.mock.calls.length).toBe(9);
+      expect(client.mockOutput.mock.calls[0][0]).toMatch(
         /Local settings detected in vercel.json:/
       );
-      expect((output.print as jest.Mock).mock.calls[1][0]).toMatch(
-        /Build Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[2][0]).toMatch(
-        /Ignore Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[3][0]).toMatch(
+      expect(client.mockOutput.mock.calls[1][0]).toMatch(/Build Command:/);
+      expect(client.mockOutput.mock.calls[2][0]).toMatch(/Ignore Command:/);
+      expect(client.mockOutput.mock.calls[3][0]).toMatch(
         /Development Command:/
       );
-      expect((output.print as jest.Mock).mock.calls[4][0]).toMatch(
-        /Framework:/
-      );
-      expect((output.print as jest.Mock).mock.calls[5][0]).toMatch(
-        /Install Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[6][0]).toMatch(
-        /Output Directory:/
-      );
-      expect((output.print as jest.Mock).mock.calls[7][0]).toMatch(
+      expect(client.mockOutput.mock.calls[4][0]).toMatch(/Framework:/);
+      expect(client.mockOutput.mock.calls[5][0]).toMatch(/Install Command:/);
+      expect(client.mockOutput.mock.calls[6][0]).toMatch(/Output Directory:/);
+      expect(client.mockOutput.mock.calls[7][0]).toMatch(
         /Merging default Project Settings for Svelte. Previously listed overrides are prioritized./
       );
-      expect((output.print as jest.Mock).mock.calls[8][0]).toMatch(
+      expect(client.mockOutput.mock.calls[8][0]).toMatch(
         /Auto-detected Project Settings/
       );
       expect(settings).toStrictEqual(overrides);
@@ -245,38 +194,28 @@ describe('editProjectSettings', () => {
         outputDirectory: 'OUTPUT_DIRECTORY',
       };
       const settings = await editProjectSettings(
-        output,
+        client,
         null,
         null,
         true,
         overrides
       );
-      expect((output.print as jest.Mock).mock.calls.length).toBe(9);
-      expect((output.print as jest.Mock).mock.calls[0][0]).toMatch(
+      expect(client.mockOutput.mock.calls.length).toBe(9);
+      expect(client.mockOutput.mock.calls[0][0]).toMatch(
         /Local settings detected in vercel.json:/
       );
-      expect((output.print as jest.Mock).mock.calls[1][0]).toMatch(
-        /Build Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[2][0]).toMatch(
-        /Ignore Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[3][0]).toMatch(
+      expect(client.mockOutput.mock.calls[1][0]).toMatch(/Build Command:/);
+      expect(client.mockOutput.mock.calls[2][0]).toMatch(/Ignore Command:/);
+      expect(client.mockOutput.mock.calls[3][0]).toMatch(
         /Development Command:/
       );
-      expect((output.print as jest.Mock).mock.calls[4][0]).toMatch(
-        /Framework:/
-      );
-      expect((output.print as jest.Mock).mock.calls[5][0]).toMatch(
-        /Install Command:/
-      );
-      expect((output.print as jest.Mock).mock.calls[6][0]).toMatch(
-        /Output Directory:/
-      );
-      expect((output.print as jest.Mock).mock.calls[7][0]).toMatch(
+      expect(client.mockOutput.mock.calls[4][0]).toMatch(/Framework:/);
+      expect(client.mockOutput.mock.calls[5][0]).toMatch(/Install Command:/);
+      expect(client.mockOutput.mock.calls[6][0]).toMatch(/Output Directory:/);
+      expect(client.mockOutput.mock.calls[7][0]).toMatch(
         /Merging default Project Settings for Svelte. Previously listed overrides are prioritized./
       );
-      expect((output.print as jest.Mock).mock.calls[8][0]).toMatch(
+      expect(client.mockOutput.mock.calls[8][0]).toMatch(
         /Auto-detected Project Settings/
       );
 

packages/client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/client",
-  "version": "12.0.2-canary.1",
+  "version": "12.0.3",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",
   "homepage": "https://vercel.com",
@@ -42,7 +42,7 @@
     ]
   },
   "dependencies": {
-    "@vercel/build-utils": "4.1.1-canary.1",
+    "@vercel/build-utils": "4.2.1",
     "@zeit/fetch": "5.2.0",
     "async-retry": "1.2.3",
     "async-sema": "3.0.0",

packages/edge/README.md

@@ -0,0 +1,3 @@
+# `@vercel/edge`
+
+A set of utilities to help you deploy your app on the Edge using Vercel.

packages/edge/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@vercel/edge",
+  "version": "0.0.1",
+  "license": "MIT",
+  "main": "dist/index.js",
+  "module": "dist/index.mjs",
+  "types": "dist/index.d.ts",
+  "scripts": {
+    "build": "tsup src/index.ts --dts --format esm,cjs",
+    "test-unit": "jest",
+    "prepublishOnly": "yarn build"
+  },
+  "devDependencies": {
+    "@edge-runtime/jest-environment": "1.1.0-beta.7",
+    "@types/jest": "27.4.1",
+    "ts-node": "8.9.1",
+    "tsup": "6.1.2",
+    "typescript": "4.7.4"
+  },
+  "jest": {
+    "preset": "ts-jest",
+    "testEnvironment": "node",
+    "globals": {
+      "ts-jest": {
+        "diagnostics": true,
+        "isolatedModules": true
+      }
+    }
+  }
+}

packages/edge/src/edge-headers.ts

@@ -0,0 +1,82 @@
+/**
+ * City of the original client IP calculated by Vercel Proxy.
+ */
+export const CITY_HEADER_NAME = 'x-vercel-ip-city';
+/**
+ * Country of the original client IP calculated by Vercel Proxy.
+ */
+export const COUNTRY_HEADER_NAME = 'x-vercel-ip-country';
+/**
+ * Ip from Vercel Proxy. Do not confuse it with the client Ip.
+ */
+export const IP_HEADER_NAME = 'x-real-ip';
+/**
+ * Latitude of the original client IP calculated by Vercel Proxy.
+ */
+export const LATITUDE_HEADER_NAME = 'x-vercel-ip-latitude';
+/**
+ * Longitude of the original client IP calculated by Vercel Proxy.
+ */
+export const LONGITUDE_HEADER_NAME = 'x-vercel-ip-longitude';
+/**
+ * Region of the original client IP calculated by Vercel Proxy.
+ */
+export const REGION_HEADER_NAME = 'x-vercel-ip-country-region';
+
+/**
+ * We define a new type so this function can be reused with
+ * the global `Request`, `node-fetch` and other types.
+ */
+interface Request {
+  headers: {
+    get(name: string): string | null;
+  };
+}
+
+/**
+ * The location information of a given request
+ */
+export interface Geo {
+  /** The city that the request originated from */
+  city?: string;
+  /** The country that the request originated from */
+  country?: string;
+  /** The Vercel Edge Network region that received the request */
+  region?: string;
+  /** The latitude of the client */
+  latitude?: string;
+  /** The longitude of the client */
+  longitude?: string;
+}
+
+function getHeader(request: Request, key: string): string | undefined {
+  return request.headers.get(key) ?? undefined;
+}
+
+/**
+ * Returns the IP address of the request from the headers.
+ *
+ * @see {@link IP_HEADER_NAME}
+ */
+export function ipAddress(request: Request): string | undefined {
+  return getHeader(request, IP_HEADER_NAME);
+}
+
+/**
+ * Returns the location information from for the incoming request
+ *
+ * @see {@link CITY_HEADER_NAME}
+ * @see {@link COUNTRY_HEADER_NAME}
+ * @see {@link REGION_HEADER_NAME}
+ * @see {@link LATITUDE_HEADER_NAME}
+ * @see {@link LONGITUDE_HEADER_NAME}
+ */
+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),
+    latitude: getHeader(request, LATITUDE_HEADER_NAME),
+    longitude: getHeader(request, LONGITUDE_HEADER_NAME),
+  };
+}

packages/edge/src/index.ts

@@ -0,0 +1,5 @@
+export type { ExtraResponseInit } from './middleware-helpers';
+export * from './middleware-helpers';
+
+export type { Geo } from './edge-headers';
+export * from './edge-headers';

packages/edge/src/middleware-helpers.ts

@@ -0,0 +1,34 @@
+export type ExtraResponseInit = Omit<ResponseInit, 'headers'> & {
+  /**
+   * These headers will be sent to the user response
+   * along with the response headers from the origin
+   */
+  headers?: HeadersInit;
+};
+
+/**
+ * Rewrite the request into a different URL.
+ */
+export function rewrite(
+  destination: string | URL,
+  init?: ExtraResponseInit
+): Response {
+  const headers = new Headers(init?.headers ?? {});
+  headers.set('x-middleware-rewrite', String(destination));
+  return new Response(null, {
+    ...init,
+    headers,
+  });
+}
+
+/**
+ * This tells the Middleware to continue with the request.
+ */
+export function next(init?: ExtraResponseInit): Response {
+  const headers = new Headers(init?.headers ?? {});
+  headers.set('x-middleware-next', '1');
+  return new Response(null, {
+    ...init,
+    headers,
+  });
+}

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

@@ -0,0 +1,50 @@
+/**
+ * @jest-environment @edge-runtime/jest-environment
+ */
+
+import {
+  CITY_HEADER_NAME,
+  COUNTRY_HEADER_NAME,
+  Geo,
+  geolocation,
+  ipAddress,
+  IP_HEADER_NAME,
+  LATITUDE_HEADER_NAME,
+  LONGITUDE_HEADER_NAME,
+  REGION_HEADER_NAME,
+} from '../src';
+
+test('`ipAddress` returns the value from the header', () => {
+  const req = new Request('https://example.vercel.sh', {
+    headers: {
+      [IP_HEADER_NAME]: '127.0.0.1',
+    },
+  });
+  expect(ipAddress(req)).toBe('127.0.0.1');
+});
+
+describe('`geolocation`', () => {
+  test('returns an empty object if headers are not found', () => {
+    const req = new Request('https://example.vercel.sh');
+    expect(geolocation(req)).toEqual({});
+  });
+
+  test('reads values from headers', () => {
+    const req = new Request('https://example.vercel.sh', {
+      headers: {
+        [CITY_HEADER_NAME]: 'Tel Aviv',
+        [COUNTRY_HEADER_NAME]: 'Israel',
+        [LATITUDE_HEADER_NAME]: '32.109333',
+        [LONGITUDE_HEADER_NAME]: '34.855499',
+        [REGION_HEADER_NAME]: 'fra1',
+      },
+    });
+    expect(geolocation(req)).toEqual<Geo>({
+      city: 'Tel Aviv',
+      country: 'Israel',
+      latitude: '32.109333',
+      longitude: '34.855499',
+      region: 'fra1',
+    });
+  });
+});

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

@@ -0,0 +1,45 @@
+/**
+ * @jest-environment @edge-runtime/jest-environment
+ */
+
+import { next, rewrite } from '../src/middleware-helpers';
+
+describe('rewrite', () => {
+  test('receives custom headers', () => {
+    const resp = rewrite(new URL('https://example.vercel.sh/'), {
+      headers: {
+        'x-custom-header': 'custom-value',
+      },
+    });
+    expect({
+      status: resp.status,
+      headers: Object.fromEntries(resp.headers),
+    }).toMatchObject({
+      status: 200,
+      headers: {
+        'x-custom-header': 'custom-value',
+        'x-middleware-rewrite': 'https://example.vercel.sh/',
+      },
+    });
+  });
+});
+
+describe('next', () => {
+  test('receives custom headers', () => {
+    const resp = next({
+      headers: {
+        'x-custom-header': 'custom-value',
+      },
+    });
+    expect({
+      status: resp.status,
+      headers: Object.fromEntries(resp.headers),
+    }).toMatchObject({
+      status: 200,
+      headers: {
+        'x-custom-header': 'custom-value',
+        'x-middleware-next': '1',
+      },
+    });
+  });
+});

packages/edge/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "esModuleInterop": true,
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "target": "ES2020",
+    "module": "commonjs",
+    "outDir": "dist",
+    "sourceMap": false,
+    "declaration": true,
+    "skipLibCheck": true,
+    "moduleResolution": "node",
+    "typeRoots": ["./@types", "./node_modules/@types"]
+  },
+  "include": ["src/**/*", "test/**/*"],
+  "exclude": ["node_modules"]
+}

packages/frameworks/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/frameworks",
-  "version": "1.0.2-canary.0",
+  "version": "1.0.2",
   "main": "./dist/frameworks.js",
   "types": "./dist/frameworks.d.ts",
   "files": [
@@ -21,7 +21,7 @@
     "@types/js-yaml": "3.12.1",
     "@types/node": "12.0.4",
     "@types/node-fetch": "2.5.8",
-    "@vercel/routing-utils": "1.13.5-canary.0",
+    "@vercel/routing-utils": "1.13.5",
     "ajv": "6.12.2",
     "typescript": "4.3.4"
   }

packages/go/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/go",
-  "version": "2.0.2-canary.1",
+  "version": "2.0.3",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/go",
@@ -25,7 +25,7 @@
     "@types/fs-extra": "^5.0.5",
     "@types/node-fetch": "^2.3.0",
     "@types/tar": "^4.0.0",
-    "@vercel/build-utils": "4.1.1-canary.1",
+    "@vercel/build-utils": "4.2.1",
     "@vercel/ncc": "0.24.0",
     "async-retry": "1.3.1",
     "execa": "^1.0.0",

packages/next/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/next",
-  "version": "3.0.4",
+  "version": "3.1.2",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/next-js",
@@ -45,9 +45,9 @@
     "@types/semver": "6.0.0",
     "@types/text-table": "0.2.1",
     "@types/webpack-sources": "3.2.0",
-    "@vercel/build-utils": "4.1.1-canary.1",
-    "@vercel/nft": "0.19.1",
-    "@vercel/routing-utils": "1.13.5-canary.0",
+    "@vercel/build-utils": "4.2.1",
+    "@vercel/nft": "0.20.1",
+    "@vercel/routing-utils": "1.13.5",
     "async-sema": "3.0.1",
     "buffer-crc32": "0.2.13",
     "cheerio": "1.0.0-rc.10",

packages/next/src/index.ts

@@ -78,7 +78,6 @@ import {
   updateRouteSrc,
   validateEntrypoint,
 } from './utils';
-import assert from 'assert';
 
 export const version = 2;
 export const htmlContentType = 'text/html; charset=utf-8';
@@ -1521,35 +1520,35 @@ export const build: BuildV2 = async ({
     const pageLambdaGroups: Array<LambdaGroup> = [];
 
     if (isSharedLambdas) {
-      const initialPageLambdaGroups = await getPageLambdaGroups(
+      const initialPageLambdaGroups = await getPageLambdaGroups({
         entryPath,
         config,
-        nonApiPages,
-        new Set(),
+        pages: nonApiPages,
+        prerenderRoutes: new Set(),
         pageTraces,
         compressedPages,
-        tracedPseudoLayer?.pseudoLayer || {},
-        0,
-        0,
+        tracedPseudoLayer: tracedPseudoLayer?.pseudoLayer || {},
+        initialPseudoLayer: { pseudoLayer: {}, pseudoLayerBytes: 0 },
+        initialPseudoLayerUncompressed: 0,
         lambdaCompressedByteLimit,
         // internal pages are already referenced in traces for serverless
         // like builds
-        []
-      );
+        internalPages: [],
+      });
 
-      const initialApiLambdaGroups = await getPageLambdaGroups(
+      const initialApiLambdaGroups = await getPageLambdaGroups({
         entryPath,
         config,
-        apiPages,
-        new Set(),
+        pages: apiPages,
+        prerenderRoutes: new Set(),
         pageTraces,
         compressedPages,
-        tracedPseudoLayer?.pseudoLayer || {},
-        0,
-        0,
+        tracedPseudoLayer: tracedPseudoLayer?.pseudoLayer || {},
+        initialPseudoLayer: { pseudoLayer: {}, pseudoLayerBytes: 0 },
+        initialPseudoLayerUncompressed: 0,
         lambdaCompressedByteLimit,
-        []
-      );
+        internalPages: [],
+      });
 
       debug(
         JSON.stringify(
@@ -2613,15 +2612,6 @@ async function getServerlessPages(params: {
   for (const edgeFunctionFile of Object.keys(
     middlewareManifest?.functions ?? {}
   )) {
-    // `getStaticProps` are expecting `Prerender` output which is a Serverless function
-    // and not an Edge Function. Therefore we only remove API endpoints for now, as they
-    // don't have `getStaticProps`.
-    //
-    // Context: https://github.com/vercel/vercel/pull/7905#discussion_r890213165
-    assert(
-      edgeFunctionFile.startsWith('/api/'),
-      `Only API endpoints are currently supported for Edge endpoints.`
-    );
     delete pages[edgeFunctionFile.slice(1) + '.js'];
   }
 

packages/next/src/server-build.ts

@@ -425,11 +425,8 @@ export async function serverBuild({
     const uncompressedInitialSize = Object.keys(
       initialPseudoLayer.pseudoLayer
     ).reduce((prev, cur) => {
-      return (
-        prev +
-          (initialPseudoLayer.pseudoLayer[cur] as PseudoFile)
-            .uncompressedSize || 0
-      );
+      const file = initialPseudoLayer.pseudoLayer[cur] as PseudoFile;
+      return prev + file.uncompressedSize || 0;
     }, 0);
 
     debug(
@@ -611,43 +608,36 @@ export async function serverBuild({
       }, {})
     );
 
-    const initialPseudoLayerSize = Object.keys(
-      initialPseudoLayer.pseudoLayer
-    ).reduce((prev, cur) => {
-      const file = initialPseudoLayer.pseudoLayer[cur] as PseudoFile;
-      return prev + file.uncompressedSize || 0;
-    }, 0);
-
     const pageExtensions = requiredServerFilesManifest.config?.pageExtensions;
 
-    const pageLambdaGroups = await getPageLambdaGroups(
-      requiredServerFilesManifest.appDir || entryPath,
+    const pageLambdaGroups = await getPageLambdaGroups({
+      entryPath: requiredServerFilesManifest.appDir || entryPath,
       config,
-      nonApiPages,
+      pages: nonApiPages,
       prerenderRoutes,
       pageTraces,
       compressedPages,
-      tracedPseudoLayer.pseudoLayer,
-      initialPseudoLayer.pseudoLayerBytes,
-      initialPseudoLayerSize,
+      tracedPseudoLayer: tracedPseudoLayer.pseudoLayer,
+      initialPseudoLayer,
+      lambdaCompressedByteLimit,
+      initialPseudoLayerUncompressed: uncompressedInitialSize,
+      internalPages,
+      pageExtensions,
+    });
+
+    const apiLambdaGroups = await getPageLambdaGroups({
+      entryPath: requiredServerFilesManifest.appDir || entryPath,
+      config,
+      pages: apiPages,
+      prerenderRoutes,
+      pageTraces,
+      compressedPages,
+      tracedPseudoLayer: tracedPseudoLayer.pseudoLayer,
+      initialPseudoLayer,
+      initialPseudoLayerUncompressed: uncompressedInitialSize,
       lambdaCompressedByteLimit,
       internalPages,
-      pageExtensions
-    );
-
-    const apiLambdaGroups = await getPageLambdaGroups(
-      requiredServerFilesManifest.appDir || entryPath,
-      config,
-      apiPages,
-      prerenderRoutes,
-      pageTraces,
-      compressedPages,
-      tracedPseudoLayer.pseudoLayer,
-      initialPseudoLayer.pseudoLayerBytes,
-      initialPseudoLayerSize,
-      lambdaCompressedByteLimit,
-      internalPages
-    );
+    });
 
     debug(
       JSON.stringify(
@@ -682,7 +672,6 @@ export async function serverBuild({
       const lambda = await createLambdaFromPseudoLayers({
         files: launcherFiles,
         layers: [
-          initialPseudoLayer.pseudoLayer,
           group.pseudoLayer,
           [...group.pages, ...internalPages].reduce((prev, page) => {
             const pageFileName = path.normalize(
@@ -945,8 +934,13 @@ export async function serverBuild({
             continue: true,
             ...(isOverride ? { override: true } : {}),
           },
+          // handle non-trailing slash
           {
-            src: path.join('^/', entryDirectory, '((?!_next/).*)$'),
+            src: path.join(
+              '^/',
+              entryDirectory,
+              '((?!_next/)(?:.*[^/]|.*))/?$'
+            ),
             has: [
               {
                 type: 'header',

packages/next/src/utils.ts

@@ -1275,26 +1275,39 @@ export const MAX_UNCOMPRESSED_LAMBDA_SIZE = 250 * 1000 * 1000; // 250MB
 const LAMBDA_RESERVED_UNCOMPRESSED_SIZE = 2.5 * 1000 * 1000; // 2.5MB
 const LAMBDA_RESERVED_COMPRESSED_SIZE = 250 * 1000; // 250KB
 
-export async function getPageLambdaGroups(
-  entryPath: string,
-  config: Config,
-  pages: string[],
-  prerenderRoutes: Set<string>,
+export async function getPageLambdaGroups({
+  entryPath,
+  config,
+  pages,
+  prerenderRoutes,
+  pageTraces,
+  compressedPages,
+  tracedPseudoLayer,
+  initialPseudoLayer,
+  initialPseudoLayerUncompressed,
+  lambdaCompressedByteLimit,
+  internalPages,
+  pageExtensions,
+}: {
+  entryPath: string;
+  config: Config;
+  pages: string[];
+  prerenderRoutes: Set<string>;
   pageTraces: {
     [page: string]: {
       [key: string]: FileFsRef;
     };
-  },
+  };
   compressedPages: {
     [page: string]: PseudoFile;
-  },
-  tracedPseudoLayer: PseudoLayer,
-  initialPseudoLayerSize: number,
-  initialPseudoLayerUncompressedSize: number,
-  lambdaCompressedByteLimit: number,
-  internalPages: string[],
-  pageExtensions?: string[]
-) {
+  };
+  tracedPseudoLayer: PseudoLayer;
+  initialPseudoLayer: PseudoLayerResult;
+  initialPseudoLayerUncompressed: number;
+  lambdaCompressedByteLimit: number;
+  internalPages: string[];
+  pageExtensions?: string[];
+}) {
   const groups: Array<LambdaGroup> = [];
 
   for (const page of pages) {
@@ -1341,10 +1354,10 @@ export async function getPageLambdaGroups(
         }
 
         const underUncompressedLimit =
-          newTracedFilesUncompressedSize + initialPseudoLayerUncompressedSize <
+          newTracedFilesUncompressedSize <
           MAX_UNCOMPRESSED_LAMBDA_SIZE - LAMBDA_RESERVED_UNCOMPRESSED_SIZE;
         const underCompressedLimit =
-          newTracedFilesSize + initialPseudoLayerSize <
+          newTracedFilesSize <
           lambdaCompressedByteLimit - LAMBDA_RESERVED_COMPRESSED_SIZE;
 
         return underUncompressedLimit && underCompressedLimit;
@@ -1359,9 +1372,9 @@ export async function getPageLambdaGroups(
         pages: [page],
         ...opts,
         isPrerenders: isPrerenderRoute,
-        pseudoLayerBytes: 0,
-        pseudoLayerUncompressedBytes: 0,
-        pseudoLayer: {},
+        pseudoLayerBytes: initialPseudoLayer.pseudoLayerBytes,
+        pseudoLayerUncompressedBytes: initialPseudoLayerUncompressed,
+        pseudoLayer: Object.assign({}, initialPseudoLayer.pseudoLayer),
       };
       groups.push(newGroup);
       matchingGroup = newGroup;

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

@@ -77,6 +77,13 @@ export function middleware(request) {
     return NextResponse.rewrite(url);
   }
 
+  if (url.pathname === '/rewrite-to-site') {
+    const customUrl = new URL(url);
+    customUrl.pathname = '/_sites/subdomain-1/';
+    console.log('rewriting to', customUrl.pathname, customUrl.href);
+    return NextResponse.rewrite(customUrl);
+  }
+
   if (url.pathname === '/redirect-me-to-about') {
     url.pathname = '/about';
     url.searchParams.set('middleware', 'foo');

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

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

packages/next/test/fixtures/00-middleware/vercel.json

@@ -2,6 +2,15 @@
   "version": 2,
   "builds": [{ "src": "package.json", "use": "@vercel/next" }],
   "probes": [
+    {
+      "path": "/_next/data/testing-build-id/rewrite-to-site.json",
+      "status": 200,
+      "headers": {
+        "x-nextjs-data": 1
+      },
+      "mustContain": "site\":\"subdomain-1\"",
+      "mustNotContain": "<html>"
+    },
     {
       "path": "/redirect-me",
       "status": 307,

packages/next/test/integration/index.test.js

@@ -105,6 +105,21 @@ it('should build using server build', async () => {
       log.includes('WARNING: Unable to find source file for page')
     )
   ).toBeFalsy();
+
+  const lambdas = new Set();
+  let totalLambdas = 0;
+
+  for (const item of Object.values(output)) {
+    if (item.type === 'Lambda') {
+      totalLambdas += 1;
+      lambdas.add(item);
+    } else if (item.type === 'Prerender') {
+      lambdas.add(item.lambda);
+      totalLambdas += 1;
+    }
+  }
+  expect(lambdas.size).toBe(5);
+  expect(lambdas.size).toBeLessThan(totalLambdas);
 });
 
 it('should build custom error lambda correctly', async () => {
@@ -715,7 +730,7 @@ it('Should provide lambda info when limit is hit (server build)', async () => {
   console.log = origLog;
 
   expect(logs).toContain(
-    'Max serverless function size was exceeded for 1 function'
+    'Max serverless function size was exceeded for 2 functions'
   );
   expect(logs).toContain(
     'Max serverless function size of 50 MB compressed or 250 MB uncompressed reached'
@@ -802,3 +817,99 @@ it('Should provide lambda info when limit is hit for internal pages (server buil
   expect(logs).toMatch(/public\/big-image-1\.jpg/);
   expect(logs).toMatch(/public\/big-image-2\.jpg/);
 });
+
+it('Should provide lambda info when limit is hit (uncompressed)', async () => {
+  let logs = '';
+
+  const origLog = console.log;
+
+  console.log = function (...args) {
+    logs += args.join(' ');
+    origLog(...args);
+  };
+
+  try {
+    await runBuildLambda(
+      path.join(__dirname, 'test-limit-exceeded-404-static-files')
+    );
+  } catch (err) {
+    console.error(err);
+  }
+  console.log = origLog;
+
+  expect(logs).toContain(
+    'Max serverless function size was exceeded for 1 function'
+  );
+  expect(logs).toContain(
+    'Max serverless function size of 50 MB compressed or 250 MB uncompressed reached'
+  );
+  expect(logs).toContain(`Serverless Function's page: api/hello.js`);
+  expect(logs).toMatch(
+    /Large Dependencies.*?Uncompressed size.*?Compressed size/
+  );
+  expect(logs).toMatch(/data\.txt/);
+  expect(logs).toMatch(/\.next\/server\/pages/);
+});
+
+it('Should de-dupe correctly when limit is close (uncompressed)', async () => {
+  const origLog = console.log;
+  const origError = console.error;
+  const caughtLogs = [];
+
+  console.log = function (...args) {
+    caughtLogs.push(args.join(' '));
+    origLog.apply(this, args);
+  };
+  console.error = function (...args) {
+    caughtLogs.push(args.join(' '));
+    origError.apply(this, args);
+  };
+
+  const {
+    buildResult: { output },
+  } = await runBuildLambda(
+    path.join(__dirname, 'test-limit-large-uncompressed-files')
+  );
+
+  console.log = origLog;
+  console.error = origError;
+
+  expect(output['index']).toBeDefined();
+  expect(output['another']).toBeDefined();
+  expect(output['api/hello']).toBeDefined();
+  expect(output['api/hello-1']).toBeDefined();
+  expect(output['api/hello-2']).toBeDefined();
+  expect(output['api/hello-3']).toBeDefined();
+  expect(output['api/hello-4']).toBeDefined();
+  expect(output['_app']).not.toBeDefined();
+  expect(output['_error']).not.toBeDefined();
+  expect(output['_document']).not.toBeDefined();
+
+  expect(output['index'] === output['another']).toBe(true);
+  expect(output['index'] !== output['api/hello']).toBe(true);
+  expect(output['api/hello'] === output['api/hello-1']).toBe(true);
+  expect(output['api/hello'] === output['api/hello-2']).toBe(true);
+  expect(output['api/hello'] === output['api/hello-3']).toBe(true);
+  expect(output['api/hello'] === output['api/hello-4']).toBe(true);
+
+  expect(
+    caughtLogs.some(log =>
+      log.includes('WARNING: Unable to find source file for page')
+    )
+  ).toBeFalsy();
+
+  const lambdas = new Set();
+  let totalLambdas = 0;
+
+  for (const item of Object.values(output)) {
+    if (item.type === 'Lambda') {
+      totalLambdas += 1;
+      lambdas.add(item);
+    } else if (item.type === 'Prerender') {
+      lambdas.add(item.lambda);
+      totalLambdas += 1;
+    }
+  }
+  expect(lambdas.size).toBe(2);
+  expect(lambdas.size).toBeLessThan(totalLambdas);
+});

packages/next/test/integration/test-limit-exceeded-404-static-files/next.config.js

@@ -0,0 +1,33 @@
+const fs = require('fs');
+const assert = require('assert');
+
+const locales = ['en'];
+let charStart = 97;
+let charEnd = 105;
+
+// generate 81 random locales under en
+for (let i = charStart; i <= charEnd; i++) {
+  const firstChar = String.fromCharCode(i);
+
+  for (let j = charStart; j <= charEnd; j++) {
+    const secondChar = String.fromCharCode(j);
+    locales.push(`en-${firstChar}${secondChar}`);
+  }
+}
+
+assert(
+  locales.length === 82,
+  `unexpected locale count, expected 82, received ${locales.length}`
+);
+
+// generate 100MB text file which will be traced in `/api/hello`
+// which when combined with the 404 HTML files will push us over the 250MB
+// uncompressed limit
+fs.writeFileSync('data.txt', new Array(100 * 1000 * 1000).fill('a').join());
+
+module.exports = {
+  i18n: {
+    locales,
+    defaultLocale: 'en',
+  },
+};

packages/next/test/integration/test-limit-exceeded-404-static-files/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "test-limit",
+  "version": "1.0.0",
+  "scripts": {
+    "build": "next build"
+  },
+  "dependencies": {
+    "next": "canary",
+    "react": "17.0.2",
+    "react-dom": "17.0.2"
+  }
+}

packages/next/test/integration/test-limit-exceeded-404-static-files/pages/404.js

@@ -0,0 +1,19 @@
+export default function Page(props) {
+  return (
+    <>
+      <p>404 | Page Not Found</p>
+      <p>{JSON.stringify(props)}</p>
+    </>
+  );
+}
+
+export function getStaticProps({ locale }) {
+  return {
+    props: {
+      locale,
+      // 1MB string which is duplicated in HTML totalling 2MB
+      // this will be generated for each locale as well
+      largeData: new Array(1 * 1000 * 1000).fill('a').join(''),
+    },
+  };
+}

packages/next/test/integration/test-limit-exceeded-404-static-files/pages/_app.js

@@ -0,0 +1,16 @@
+/* eslint-disable */
+import React from 'react';
+
+if (typeof window === 'undefined') {
+  try {
+    const fs = require('fs');
+    const path = require('path');
+    fs.readdirSync(path.join(process.cwd(), 'public'));
+    fs.readdirSync(path.join(process.cwd(), 'node_modules/chrome-aws-lambda'));
+    fs.readdirSync(path.join(process.cwd(), 'node_modules/firebase'));
+  } catch (_) {}
+}
+
+export default function MyApp({ Component, pageProps }) {
+  return React.createElement(Component, pageProps);
+}

packages/next/test/integration/test-limit-exceeded-404-static-files/pages/api/hello.js

@@ -0,0 +1,12 @@
+import fs from 'fs';
+import path from 'path';
+
+try {
+  fs.readFileSync(path.join(process.cwd(), 'data.txt'));
+} catch (_) {
+  /**/
+}
+
+export default function handler(req, res) {
+  res.end('hello');
+}

packages/next/test/integration/test-limit-exceeded-404-static-files/pages/index.js

@@ -0,0 +1,3 @@
+export default function Home() {
+  return 'index page';
+}

packages/next/test/integration/test-limit-exceeded-404-static-files/vercel.json

@@ -0,0 +1,9 @@
+{
+  "version": 2,
+  "builds": [
+    {
+      "src": "package.json",
+      "use": "@vercel/next"
+    }
+  ]
+}

packages/next/test/integration/test-limit-large-uncompressed-files/next.config.js

@@ -0,0 +1,6 @@
+const fs = require('fs');
+
+// generate 200MB file which will be traced in `/api/hello`
+fs.writeFileSync('data.txt', Buffer.alloc(200 * 1024 * 1024));
+
+module.exports = {};

packages/next/test/integration/test-limit-large-uncompressed-files/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "test-limit",
+  "version": "1.0.0",
+  "scripts": {
+    "build": "next build"
+  },
+  "dependencies": {
+    "next": "canary",
+    "react": "17.0.2",
+    "react-dom": "17.0.2"
+  }
+}

packages/next/test/integration/test-limit-large-uncompressed-files/pages/_app.js

@@ -0,0 +1,16 @@
+/* eslint-disable */
+import React from 'react';
+
+if (typeof window === 'undefined') {
+  try {
+    const fs = require('fs');
+    const path = require('path');
+    fs.readdirSync(path.join(process.cwd(), 'public'));
+    fs.readdirSync(path.join(process.cwd(), 'node_modules/chrome-aws-lambda'));
+    fs.readdirSync(path.join(process.cwd(), 'node_modules/firebase'));
+  } catch (_) {}
+}
+
+export default function MyApp({ Component, pageProps }) {
+  return React.createElement(Component, pageProps);
+}

packages/next/test/integration/test-limit-large-uncompressed-files/pages/another.js

@@ -0,0 +1,10 @@
+export default function Home() {
+  return 'another page';
+}
+
+export function getServerSideProps() {
+  require('fs').readFileSync(require('path').join(process.cwd(), 'data.txt'));
+  return {
+    props: {},
+  };
+}

packages/next/test/integration/test-limit-large-uncompressed-files/pages/api/hello-1.js

@@ -0,0 +1,12 @@
+import fs from 'fs';
+import path from 'path';
+
+try {
+  fs.readFileSync(path.join(process.cwd(), 'data.txt'));
+} catch (_) {
+  /**/
+}
+
+export default function handler(req, res) {
+  res.end('hello');
+}