Publish Stable

- @vercel/frameworks@0.0.15
 - @vercel/build-utils@2.4.0
 - @vercel/cgi@1.0.6
 - vercel@19.1.0
 - @vercel/client@8.1.0
 - @vercel/go@1.1.2
 - @vercel/next@2.6.6
 - @vercel/node-bridge@1.3.1
 - @vercel/node@1.7.0
 - @vercel/python@1.2.2
 - @vercel/routing-utils@1.8.3
 - @vercel/ruby@1.2.2
 - @vercel/static-build@0.17.2

.github/CODEOWNERS

@@ -1,27 +1,27 @@
 # Documentation
 # https://help.github.com/en/articles/about-code-owners
 
-*                                        @tootallnate
+*                                        @TooTallNate
 /.github/workflows                       @AndyBitz @styfle
 /packages/frameworks                     @AndyBitz
-/packages/now-cli/src/commands/dev/      @tootallnate @styfle @AndyBitz
-/packages/now-cli/src/util/dev/          @tootallnate @styfle @AndyBitz
-/packages/now-cli/src/commands/domains/  @javivelasco @mglagola @anatrajkovska
-/packages/now-cli/src/commands/certs/    @javivelasco @mglagola @anatrajkovska
+/packages/now-cli/src/commands/dev       @TooTallNate @styfle @AndyBitz
+/packages/now-cli/src/util/dev           @TooTallNate @styfle @AndyBitz
+/packages/now-cli/src/commands/domains   @javivelasco @mglagola @anatrajkovska
+/packages/now-cli/src/commands/certs     @javivelasco @mglagola @anatrajkovska
 /packages/now-cli/src/commands/env       @styfle @lucleray
-/packages/now-client                     @rdev
-/packages/now-build-utils                @styfle @AndyBitz
-/packages/now-node                       @styfle @tootallnate @lucleray
-/packages/now-node-bridge                @styfle @tootallnate @lucleray
+/packages/now-client                     @rdev @styfle @TooTallNate
+/packages/now-build-utils                @styfle @AndyBitz @TooTallNate
+/packages/now-node                       @styfle @TooTallNate @lucleray
+/packages/now-node-bridge                @styfle @TooTallNate @lucleray
 /packages/now-next                       @Timer @ijjk
-/packages/now-go                         @styfle @sophearak
-/packages/now-python                     @styfle @sophearak
-/packages/now-ruby                       @styfle @coetry @nathancahill
+/packages/now-go                         @styfle @TooTallNate
+/packages/now-python                     @styfle @TooTallNate
+/packages/now-ruby                       @styfle @coetry @TooTallNate
 /packages/now-static-build               @styfle @AndyBitz
 /packages/now-routing-utils              @styfle @dav-is @ijjk
 /examples                                @mcsdevv @timothyis
 /examples/create-react-app               @Timer
-/examples/nextjs                         @timneutkens
+/examples/nextjs                         @timneutkens @Timer
 /examples/hugo                           @mcsdevv @timothyis @styfle
-/examples/jekyll                         @mcsdevv @timothyis @sarupbanskota
+/examples/jekyll                         @mcsdevv @timothyis @styfle
 /examples/zola                           @mcsdevv @timothyis @styfle

errors/next-functions-config-optimized-lambdas.md

@@ -0,0 +1,14 @@
+# `@vercel/next` Functions Config Optimized Lambdas Opt-out
+
+#### Why This Warning Occurred
+
+`@vercel/next` by default now bundles pages into optimized functions, minimizing bootup time and increasing overall application throughput.
+When the `functions` config is added in `now.json` or `vercel.json`, it causes conflicts with this optimization, so it is opted-out.
+
+#### Possible Ways to Fix It
+
+Remove the `functions` config from your `now.json` or `vercel.json` to take advantage of this optimization.
+
+### Useful Links
+
+- [Functions Config Documentation](https://vercel.com/docs/configuration?query=functions#project/functions)

errors/next-legacy-routes-optimized-lambdas.md

@@ -0,0 +1,16 @@
+# `@vercel/next` Legacy Routes Optimized Lambdas Opt-out
+
+#### Why This Warning Occurred
+
+`@vercel/next` by default now bundles pages into optimized functions, minimizing bootup time and increasing overall application throughput.
+When legacy `routes` are added in `now.json` or `vercel.json`, they cause conflicts with this optimization, so it is opted-out.
+
+#### Possible Ways to Fix It
+
+Migrate from using legacy `routes` to the new `rewrites`, `redirects`, and `headers` configurations in your `now.json` or `vercel.json` file or leverage them directly in your `next.config.js` with the built-in [custom routes support](https://github.com/zeit/next.js/issues/9081)
+
+### Useful Links
+
+- [Rewrites Documentation](https://vercel.com/docs/configuration?query=rewrites#project/rewrites)
+- [Redirects Documentation](https://vercel.com/docs/configuration?query=rewrites#project/redirects)
+- [Headers Documentation](https://vercel.com/docs/configuration?query=rewrites#project/headers)

packages/frameworks/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/frameworks",
-  "version": "0.0.15-canary.3",
+  "version": "0.0.15",
   "main": "frameworks.json",
   "license": "UNLICENSED",
   "scripts": {
@@ -9,9 +9,9 @@
   "devDependencies": {
     "@types/jest": "24.0.22",
     "@types/node": "12.0.4",
-    "ajv": "6.10.2",
+    "ajv": "6.12.2",
     "jest": "24.9.0",
     "ts-jest": "24.1.0",
-    "typescript": "3.5.2"
+    "typescript": "3.9.3"
   }
 }

packages/now-build-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/build-utils",
-  "version": "2.3.2-canary.2",
+  "version": "2.4.0",
   "license": "MIT",
   "main": "./dist/index.js",
   "types": "./dist/index.d.js",
@@ -45,7 +45,7 @@
     "node-fetch": "2.2.0",
     "semver": "6.1.1",
     "ts-jest": "24.1.0",
-    "typescript": "3.5.2",
+    "typescript": "3.9.3",
     "yazl": "2.4.3"
   }
 }

packages/now-build-utils/src/detect-builders.ts

@@ -82,6 +82,7 @@ export async function detectBuilders(
   defaultRoutes: Route[] | null;
   redirectRoutes: Route[] | null;
   rewriteRoutes: Route[] | null;
+  errorRoutes: Route[] | null;
 }> {
   const errors: ErrorResponse[] = [];
   const warnings: ErrorResponse[] = [];
@@ -99,6 +100,7 @@ export async function detectBuilders(
       defaultRoutes: null,
       redirectRoutes: null,
       rewriteRoutes: null,
+      errorRoutes: null,
     };
   }
 
@@ -154,6 +156,7 @@ export async function detectBuilders(
           defaultRoutes: null,
           redirectRoutes: null,
           rewriteRoutes: null,
+          errorRoutes: null,
         };
       }
 
@@ -231,6 +234,7 @@ export async function detectBuilders(
         redirectRoutes: null,
         defaultRoutes: null,
         rewriteRoutes: null,
+        errorRoutes: null,
       };
     }
 
@@ -272,6 +276,7 @@ export async function detectBuilders(
       redirectRoutes: null,
       defaultRoutes: null,
       rewriteRoutes: null,
+      errorRoutes: null,
     };
   }
 
@@ -309,6 +314,7 @@ export async function detectBuilders(
     redirectRoutes: routesResult.redirectRoutes,
     defaultRoutes: routesResult.defaultRoutes,
     rewriteRoutes: routesResult.rewriteRoutes,
+    errorRoutes: routesResult.errorRoutes,
   };
 }
 
@@ -898,10 +904,17 @@ function getRouteResult(
   defaultRoutes: Route[];
   redirectRoutes: Route[];
   rewriteRoutes: Route[];
+  errorRoutes: Route[];
 } {
   const defaultRoutes: Route[] = [];
   const redirectRoutes: Route[] = [];
   const rewriteRoutes: Route[] = [];
+  const errorRoutes: Route[] = [];
+  const isNextjs =
+    frontendBuilder &&
+    ((frontendBuilder.use && frontendBuilder.use.startsWith('@vercel/next')) ||
+      (frontendBuilder.config &&
+        frontendBuilder.config.framework === 'nextjs'));
 
   if (apiRoutes && apiRoutes.length > 0) {
     if (options.featHandleMiss) {
@@ -968,10 +981,21 @@ function getRouteResult(
     });
   }
 
+  if (options.featHandleMiss && !isNextjs) {
+    // Exclude Next.js to avoid overriding custom error page
+    // https://nextjs.org/docs/advanced-features/custom-error-page
+    errorRoutes.push({
+      status: 404,
+      src: '^/(?!.*api).*$',
+      dest: options.cleanUrls ? '/404' : '/404.html',
+    });
+  }
+
   return {
     defaultRoutes,
     redirectRoutes,
     rewriteRoutes,
+    errorRoutes,
   };
 }
 

packages/now-build-utils/src/errors.ts

@@ -7,11 +7,13 @@ export class NowBuildError extends Error {
   public hideStackTrace = true;
   public code: string;
   public link?: string;
+  public action?: string;
 
-  constructor({ message, code, link }: Props) {
+  constructor({ message, code, link, action }: Props) {
     super(message);
     this.code = code;
     this.link = link;
+    this.action = action;
   }
 }
 
@@ -31,4 +33,8 @@ interface Props {
    * link to more information about this error.
    */
   link?: string;
+  /**
+   * Optional "action" to display before the `link`, such as "More details".
+   */
+  action?: string;
 }

packages/now-build-utils/src/index.ts

@@ -27,6 +27,7 @@ import {
   getLatestNodeVersion,
   getDiscontinuedNodeVersions,
 } from './fs/node-version';
+import { NowBuildError } from './errors';
 import streamToBuffer from './fs/stream-to-buffer';
 import shouldServe from './should-serve';
 import debug from './debug';
@@ -111,9 +112,11 @@ export const getPlatformEnv = (name: string): string | undefined => {
   const n = process.env[nName];
   if (typeof v === 'string') {
     if (typeof n === 'string') {
-      throw new Error(
-        `Both "${vName}" and "${nName}" env vars are defined. Please only define the "${vName}" env var`
-      );
+      throw new NowBuildError({
+        code: 'CONFLICTING_ENV_VAR_NAMES',
+        message: `Both "${vName}" and "${nName}" env vars are defined. Please only define the "${vName}" env var.`,
+        link: 'https://vercel.link/combining-old-and-new-config',
+      });
     }
     return v;
   }

packages/now-build-utils/test/unit.builds-and-routes-detector.test.ts

@@ -531,6 +531,7 @@ describe('Test `detectBuilders`', () => {
     const files = ['api/user.php'];
     // @ts-ignore
     const { errors } = await detectBuilders(files, null, {
+      // @ts-ignore
       functions,
     });
 
@@ -867,12 +868,14 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, pkg, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/next');
     expect(errors).toBe(null);
     expect(defaultRoutes).toStrictEqual([]);
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes).toStrictEqual([]);
+    expect(errorRoutes).toStrictEqual([]);
   });
 
   it('package.json + no build + next', async () => {
@@ -887,12 +890,14 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, pkg, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/next');
     expect(errors).toBe(null);
     expect(defaultRoutes).toStrictEqual([]);
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes).toStrictEqual([]);
+    expect(errorRoutes).toStrictEqual([]);
   });
 
   it('package.json + no build', async () => {
@@ -913,12 +918,15 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, { featHandleMiss });
     expect(builders).toBe(null);
     expect(errors).toBe(null);
     expect(defaultRoutes).toStrictEqual([]);
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes).toStrictEqual([]);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('no package.json + public', async () => {
@@ -929,6 +937,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, { featHandleMiss });
     expect(builders![1].use).toBe('@vercel/static');
     expect(errors).toBe(null);
@@ -939,6 +948,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('no package.json + no build + raw static + api', async () => {
@@ -949,6 +960,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/users.js');
@@ -963,6 +975,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('package.json + no build + root + api', async () => {
@@ -990,6 +1004,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, undefined, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/[endpoint]/[id].js');
@@ -1002,6 +1017,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(rewriteRoutes!.length).toBe(2);
     expect((rewriteRoutes![0] as Source).src).toBe('^/api/([^/]+)/([^/]+)$');
     expect((rewriteRoutes![1] as Source).status).toBe(404);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('api + next + public', async () => {
@@ -1016,6 +1033,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, pkg, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/endpoint.js');
@@ -1029,6 +1047,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes).toStrictEqual([]);
   });
 
   it('api + next + raw static', async () => {
@@ -1043,6 +1062,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, pkg, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/endpoint.js');
@@ -1056,6 +1076,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes).toStrictEqual([]);
   });
 
   it('api + raw static', async () => {
@@ -1066,6 +1087,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/endpoint.js');
@@ -1079,6 +1101,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('api + raw static + package.json no build script', async () => {
@@ -1093,6 +1117,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, pkg, { featHandleMiss });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/version.js');
@@ -1106,6 +1131,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('api + public', async () => {
@@ -1116,7 +1143,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       'README.md',
     ];
 
-    const { builders } = await detectBuilders(files, undefined, {
+    const { builders, errorRoutes } = await detectBuilders(files, undefined, {
       featHandleMiss,
     });
     expect(builders![0].use).toBe('@vercel/node');
@@ -1124,6 +1151,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(builders![1].use).toBe('@vercel/static');
     expect(builders![1].src).toBe('public/**/*');
     expect(builders!.length).toBe(2);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('api go with test files', async () => {
@@ -1142,21 +1171,26 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       'api/src/controllers/user.module_test.go',
     ];
 
-    const { builders } = await detectBuilders(files, undefined, {
+    const { builders, errorRoutes } = await detectBuilders(files, undefined, {
       featHandleMiss,
     });
     expect(builders!.length).toBe(7);
     expect(builders!.some(b => b.src.endsWith('_test.go'))).toBe(false);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('just public', async () => {
     const files = ['public/index.html', 'public/favicon.ico', 'README.md'];
 
-    const { builders } = await detectBuilders(files, undefined, {
+    const { builders, errorRoutes } = await detectBuilders(files, undefined, {
       featHandleMiss,
     });
     expect(builders![0].src).toBe('public/**/*');
+    expect(builders![0].use).toBe('@vercel/static');
     expect(builders!.length).toBe(1);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('next + public', async () => {
@@ -1166,10 +1200,13 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     };
     const files = ['package.json', 'public/index.html', 'README.md'];
 
-    const { builders } = await detectBuilders(files, pkg, { featHandleMiss });
+    const { builders, errorRoutes } = await detectBuilders(files, pkg, {
+      featHandleMiss,
+    });
     expect(builders![0].use).toBe('@vercel/next');
     expect(builders![0].src).toBe('package.json');
     expect(builders!.length).toBe(1);
+    expect(errorRoutes!.length).toBe(0);
   });
 
   it('nuxt', async () => {
@@ -1179,10 +1216,14 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     };
     const files = ['package.json', 'pages/index.js'];
 
-    const { builders } = await detectBuilders(files, pkg, { featHandleMiss });
+    const { builders, errorRoutes } = await detectBuilders(files, pkg, {
+      featHandleMiss,
+    });
     expect(builders![0].use).toBe('@vercel/static-build');
     expect(builders![0].src).toBe('package.json');
     expect(builders!.length).toBe(1);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('nuxt + tag canary', async () => {
@@ -1192,23 +1233,29 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     };
     const files = ['package.json', 'pages/index.js'];
 
-    const { builders } = await detectBuilders(files, pkg, {
+    const { builders, errorRoutes } = await detectBuilders(files, pkg, {
       tag: 'canary',
       featHandleMiss,
     });
     expect(builders![0].use).toBe('@vercel/static-build@canary');
     expect(builders![0].src).toBe('package.json');
     expect(builders!.length).toBe(1);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('package.json with no build + api', async () => {
     const pkg = { dependencies: { next: '9.0.0' } };
     const files = ['package.json', 'api/[endpoint].js'];
 
-    const { builders } = await detectBuilders(files, pkg, { featHandleMiss });
+    const { builders, errorRoutes } = await detectBuilders(files, pkg, {
+      featHandleMiss,
+    });
     expect(builders![0].use).toBe('@vercel/node');
     expect(builders![0].src).toBe('api/[endpoint].js');
     expect(builders!.length).toBe(1);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('package.json with no build + public directory', async () => {
@@ -1327,7 +1374,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
   it('many static files + one api file', async () => {
     const files = Array.from({ length: 5000 }).map((_, i) => `file${i}.html`);
     files.push('api/index.ts');
-    const { builders } = await detectBuilders(files, undefined, {
+    const { builders, errorRoutes } = await detectBuilders(files, undefined, {
       featHandleMiss,
     });
 
@@ -1336,6 +1383,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(builders![0].src).toBe('api/index.ts');
     expect(builders![1].use).toBe('@vercel/static');
     expect(builders![1].src).toBe('!{api/**,package.json}');
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('functions with nextjs', async () => {
@@ -1530,6 +1579,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     const files = ['api/user.php'];
     // @ts-ignore
     const { errors } = await detectBuilders(files, null, {
+      // @ts-ignore
       functions,
       featHandleMiss,
     });
@@ -1630,6 +1680,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
 
     // @ts-ignore
     const { errors } = await detectBuilders(files, null, {
+      // @ts-ignore
       functions,
       featHandleMiss,
     });
@@ -1646,6 +1697,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
 
     // @ts-ignore: Since we test an invalid type
     const { errors } = await detectBuilders(files, null, {
+      // @ts-ignore
       functions,
       featHandleMiss,
     });
@@ -1681,6 +1733,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, {
       projectSettings,
       featHandleMiss,
@@ -1693,6 +1746,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(defaultRoutes).toStrictEqual([]);
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes).toStrictEqual([]);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('Custom static output directory with api', async () => {
@@ -1707,6 +1762,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, {
       projectSettings,
       featHandleMiss,
@@ -1722,6 +1778,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
     expect(redirectRoutes).toStrictEqual([]);
     expect(rewriteRoutes!.length).toBe(1);
     expect((rewriteRoutes![0] as Source).status).toBe(404);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('Framework with non-package.json entrypoint', async () => {
@@ -1730,7 +1788,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       framework: 'hugo',
     };
 
-    const { builders } = await detectBuilders(files, null, {
+    const { builders, errorRoutes } = await detectBuilders(files, null, {
       projectSettings,
       featHandleMiss,
     });
@@ -1745,6 +1803,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
         },
       },
     ]);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('No framework, only package.json', async () => {
@@ -1755,7 +1815,9 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
       },
     };
 
-    const { builders } = await detectBuilders(files, pkg, { featHandleMiss });
+    const { builders, errorRoutes } = await detectBuilders(files, pkg, {
+      featHandleMiss,
+    });
 
     expect(builders).toEqual([
       {
@@ -1766,13 +1828,15 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
         },
       },
     ]);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('Framework with an API', async () => {
     const files = ['config.rb', 'api/date.rb'];
     const projectSettings = { framework: 'middleman' };
 
-    const { builders } = await detectBuilders(files, null, {
+    const { builders, errorRoutes } = await detectBuilders(files, null, {
       projectSettings,
       featHandleMiss,
     });
@@ -1794,6 +1858,8 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
         },
       },
     ]);
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('Error for non-api functions', async () => {
@@ -1843,13 +1909,19 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
   it('All static if `buildCommand` is an empty string with an `outputDirectory`', async () => {
     const files = ['out/index.html'];
     const projectSettings = { buildCommand: '', outputDirectory: 'out' };
-    const { builders, errors } = await detectBuilders(files, null, {
-      projectSettings,
-      featHandleMiss,
-    });
+    const { builders, errors, errorRoutes } = await detectBuilders(
+      files,
+      null,
+      {
+        projectSettings,
+        featHandleMiss,
+      }
+    );
     expect(errors).toBe(null);
     expect(builders![0]!.use).toBe('@vercel/static');
     expect(builders![0]!.src).toBe('out/**/*');
+    expect(errorRoutes!.length).toBe(1);
+    expect((errorRoutes![0] as Source).status).toBe(404);
   });
 
   it('do not require build script when `buildCommand` is an empty string', async () => {
@@ -2025,9 +2097,13 @@ it('Test `detectRoutes` with `featHandleMiss=true`', async () => {
   {
     const files = ['api/user.go', 'api/team.js', 'api/package.json'];
 
-    const { defaultRoutes, rewriteRoutes } = await detectBuilders(files, null, {
-      featHandleMiss,
-    });
+    const { defaultRoutes, rewriteRoutes, errorRoutes } = await detectBuilders(
+      files,
+      null,
+      {
+        featHandleMiss,
+      }
+    );
     expect(defaultRoutes).toStrictEqual([
       { handle: 'miss' },
       {
@@ -2043,6 +2119,44 @@ it('Test `detectRoutes` with `featHandleMiss=true`', async () => {
         continue: true,
       },
     ]);
+    expect(errorRoutes).toStrictEqual([
+      {
+        status: 404,
+        src: '^/(?!.*api).*$',
+        dest: '/404.html',
+      },
+    ]);
+
+    const pattern = new RegExp(errorRoutes![0].src!);
+
+    [
+      '/',
+      '/index.html',
+      '/page.html',
+      '/page',
+      '/another/index.html',
+      '/another/page.html',
+      '/another/page',
+      '/another/sub/index.html',
+      '/another/sub/page.html',
+      '/another/sub/page',
+    ].forEach(file => {
+      expect(file).toMatch(pattern);
+    });
+
+    [
+      '/api',
+      '/api/',
+      '/api/index.html',
+      '/api/page.html',
+      '/api/page',
+      '/api/sub',
+      '/api/sub/index.html',
+      '/api/sub/page.html',
+      '/api/sub/page',
+    ].forEach(file => {
+      expect(file).not.toMatch(pattern);
+    });
   }
 
   {
@@ -2326,6 +2440,7 @@ it('Test `detectRoutes` with `featHandleMiss=true`, `cleanUrls=true`', async ()
       defaultRoutes,
       redirectRoutes,
       rewriteRoutes,
+      errorRoutes,
     } = await detectBuilders(files, null, options);
     testHeaders(redirectRoutes);
     expect(defaultRoutes).toStrictEqual([]);
@@ -2336,6 +2451,13 @@ it('Test `detectRoutes` with `featHandleMiss=true`, `cleanUrls=true`', async ()
         continue: true,
       },
     ]);
+    expect(errorRoutes).toStrictEqual([
+      {
+        status: 404,
+        src: '^/(?!.*api).*$',
+        dest: '/404',
+      },
+    ]);
 
     // expected redirect should match inputs
     const getLocation = createReplaceLocation(redirectRoutes);

packages/now-build-utils/test/unit.get-platform-env.test.ts

@@ -39,7 +39,7 @@ describe('Test `getPlatformEnv()`', () => {
     assert(err);
     assert.equal(
       err!.message,
-      'Both "VERCEL_FOO" and "NOW_FOO" env vars are defined. Please only define the "VERCEL_FOO" env var'
+      'Both "VERCEL_FOO" and "NOW_FOO" env vars are defined. Please only define the "VERCEL_FOO" env var.'
     );
   });
 });

packages/now-cgi/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/cgi",
-  "version": "1.0.6-canary.0",
+  "version": "1.0.6",
   "license": "MIT",
   "repository": {
     "type": "git",

packages/now-cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "vercel",
-  "version": "19.0.2-canary.8",
+  "version": "19.1.0",
   "preferGlobal": true,
   "license": "Apache-2.0",
   "description": "The command-line interface for Now",
@@ -62,13 +62,13 @@
     "node": ">= 10"
   },
   "dependencies": {
-    "@vercel/build-utils": "2.3.2-canary.2",
-    "@vercel/go": "1.1.2-canary.0",
-    "@vercel/next": "2.6.3-canary.4",
-    "@vercel/node": "1.6.2-canary.4",
-    "@vercel/python": "1.2.2-canary.1",
-    "@vercel/ruby": "1.2.2-canary.0",
-    "@vercel/static-build": "0.17.2-canary.0"
+    "@vercel/build-utils": "2.4.0",
+    "@vercel/go": "1.1.2",
+    "@vercel/next": "2.6.6",
+    "@vercel/node": "1.7.0",
+    "@vercel/python": "1.2.2",
+    "@vercel/ruby": "1.2.2",
+    "@vercel/static-build": "0.17.2"
   },
   "devDependencies": {
     "@sentry/node": "5.5.0",
@@ -106,7 +106,7 @@
     "@zeit/fun": "0.11.2",
     "@zeit/ncc": "0.18.5",
     "@zeit/source-map-support": "0.6.2",
-    "ajv": "6.10.2",
+    "ajv": "6.12.2",
     "alpha-sort": "2.0.1",
     "ansi-escapes": "3.0.0",
     "ansi-regex": "3.0.0",
@@ -136,6 +136,7 @@
     "escape-html": "1.0.3",
     "esm": "3.1.4",
     "execa": "3.2.0",
+    "fast-deep-equal": "3.1.3",
     "fs-extra": "7.0.1",
     "get-port": "5.1.1",
     "glob": "7.1.2",
@@ -182,7 +183,7 @@
     "tmp-promise": "1.0.3",
     "tree-kill": "1.2.1",
     "ts-node": "8.3.0",
-    "typescript": "3.6.4",
+    "typescript": "3.9.3",
     "universal-analytics": "0.4.20",
     "update-check": "1.5.3",
     "utility-types": "2.1.0",

packages/now-cli/scripts/build.ts

@@ -75,6 +75,17 @@ async function main() {
   const dest = join(dirRoot, 'dist/runtimes');
   await cpy('**/*', dest, { parents: true, cwd: runtimes });
 
+  // Band-aid to delete stuff that `ncc` bundles, but it shouldn't:
+
+  // TypeScript definition files from `@vercel/build-utils`
+  await remove(join(dirRoot, 'dist', 'dist'));
+
+  // The Readme and `package.json` from "config-chain" module
+  await remove(join(dirRoot, 'dist', 'config-chain'));
+
+  // A bunch of source `.ts` files from CLI's `util` directory
+  await remove(join(dirRoot, 'dist', 'util'));
+
   console.log('Finished building `now-cli`');
 }
 

packages/now-cli/src/commands/deploy/latest.js

@@ -39,7 +39,6 @@ import {
 } from '../../util/errors-ts';
 import { SchemaValidationFailed } from '../../util/errors';
 import purchaseDomainIfAvailable from '../../util/domains/purchase-domain-if-available';
-import isWildcardAlias from '../../util/alias/is-wildcard-alias';
 import confirm from '../../util/input/confirm';
 import editProjectSettings from '../../util/input/edit-project-settings';
 import {
@@ -56,6 +55,7 @@ import validatePaths, {
 } from '../../util/validate-paths';
 import { readLocalConfig } from '../../util/config/files';
 import { getCommandName } from '../../util/pkg-name.ts';
+import { getPreferredPreviewURL } from '../../util/deploy/get-preferred-preview-url.ts';
 
 const addProcessEnv = async (log, env) => {
   let val;
@@ -87,6 +87,7 @@ const addProcessEnv = async (log, env) => {
 
 const printDeploymentStatus = async (
   output,
+  client,
   {
     readyState,
     alias: aliasList,
@@ -119,18 +120,14 @@ const printDeploymentStatus = async (
     let previewUrl;
     let isWildcard;
     if (!isFile && Array.isArray(aliasList) && aliasList.length > 0) {
-      // search for a non now.sh/non wildcard domain
-      // but fallback to the first alias in the list
-      const mainAlias =
-        aliasList.find(
-          alias =>
-            !alias.endsWith('.now.sh') &&
-            !alias.endsWith('.vercel.app') &&
-            !isWildcardAlias(alias)
-        ) || aliasList[0];
-
-      isWildcard = isWildcardAlias(mainAlias);
-      previewUrl = isWildcard ? mainAlias : `https://${mainAlias}`;
+      const previewUrlInfo = await getPreferredPreviewURL(client, aliasList);
+      if (previewUrlInfo) {
+        isWildcard = previewUrlInfo.isWildcard;
+        previewUrl = previewUrlInfo.previewUrl;
+      } else {
+        isWildcard = false;
+        previewUrl = `https://${deploymentUrl}`;
+      }
     } else {
       // fallback to deployment url
       isWildcard = false;
@@ -251,7 +248,9 @@ export default async function main(
   if (argv['--name']) {
     output.print(
       `${prependEmoji(
-        `The ${param('--name')} flag is deprecated (https://zeit.ink/1B)`,
+        `The ${param(
+          '--name'
+        )} option is deprecated (https://vercel.link/name-flag)`,
         emoji('warning')
       )}\n`
     );
@@ -389,7 +388,7 @@ export default async function main(
       `${prependEmoji(
         `The ${code('name')} property in ${highlight(
           localConfig[fileNameSymbol]
-        )} is deprecated (https://zeit.ink/5F)`,
+        )} is deprecated (https://vercel.link/name-prop)`,
         emoji('warning')
       )}\n`
     );
@@ -573,8 +572,11 @@ export default async function main(
 
     if (deployment instanceof Error) {
       output.error(
-        `${deployment.message ||
-          'An unexpected error occurred while deploying your project'} (http://zeit.ink/P4)`
+        deployment.message ||
+          'An unexpected error occurred while deploying your project',
+        null,
+        'https://vercel.link/help',
+        'Contact Support'
       );
       return 1;
     }
@@ -701,6 +703,12 @@ export default async function main(
 
   return printDeploymentStatus(
     output,
+    new Client({
+      apiUrl: ctx.apiUrl,
+      token: ctx.authConfig.token,
+      currentTeam: org.type === 'team' ? org.id : null,
+      debug: debugEnabled,
+    }),
     deployment,
     deployStamp,
     !argv['--no-clipboard'],

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

@@ -119,7 +119,7 @@ export default async function main(ctx: NowContext) {
   try {
     return await dev(ctx, argv, args, output);
   } catch (err) {
-    output.error(err.message);
+    output.prettyError(err);
     output.debug(stringifyError(err));
     return 1;
   }

packages/now-cli/src/commands/login.js

@@ -257,7 +257,7 @@ const login = async ctx => {
 
   output.print(
     `${prependEmoji(
-      `Connect your Git Repositories to deploy every branch push automatically (https://zeit.ink/1X).`,
+      `Connect your Git Repositories to deploy every branch push automatically (https://vercel.link/git).`,
       emoji('tip')
     )}\n`
   );

packages/now-cli/src/commands/projects.js

@@ -1,8 +1,8 @@
 import chalk from 'chalk';
 import table from 'text-table';
-import mri from 'mri';
 import ms from 'ms';
 import strlen from '../util/strlen';
+import getArgs from '../util/get-args';
 import { handleError, error } from '../util/error';
 import exit from '../util/exit';
 import Client from '../util/client.ts';
@@ -11,7 +11,6 @@ import getScope from '../util/get-scope';
 import createOutput from '../util/output';
 import getCommandFlags from '../util/get-command-flags';
 import wait from '../util/output/wait';
-import getPrefixedFlags from '../util/get-prefixed-flags';
 import { getPkgName, getCommandName } from '../util/pkg-name.ts';
 
 const e = encodeURIComponent;
@@ -56,23 +55,25 @@ let apiUrl;
 let subcommand;
 
 const main = async ctx => {
-  argv = mri(ctx.argv.slice(2), {
-    boolean: ['help'],
-    alias: {
-      help: 'h',
-      next: 'N',
-    },
-  });
+  try {
+    argv = getArgs(ctx.argv.slice(2), {
+      '--next': Number,
+      '-N': '--next',
+    });
+  } catch (error) {
+    handleError(error);
+    return exit(1);
+  }
 
   argv._ = argv._.slice(1);
 
-  debug = argv.debug;
+  debug = argv['--debug'];
   apiUrl = ctx.apiUrl;
-  subcommand = argv._[0];
+  subcommand = argv._[0] || 'list';
 
-  if (argv.help || !subcommand) {
+  if (argv['--help']) {
     help();
-    await exit(0);
+    return exit(2);
   }
 
   const output = createOutput({ debug });
@@ -126,15 +127,16 @@ async function run({ client, contextName }) {
           )}`
         )
       );
-      return exit(1);
+      return exit(2);
     }
 
     const stopSpinner = wait(`Fetching projects in ${chalk.bold(contextName)}`);
 
     let projectsUrl = '/v4/projects/?limit=20';
 
-    if (argv.next) {
-      projectsUrl += `&until=${argv.next}`;
+    const next = argv['--next'];
+    if (next) {
+      projectsUrl += `&until=${next}`;
     }
 
     const { projects: list, pagination } = await client.fetch(projectsUrl, {
@@ -175,14 +177,7 @@ async function run({ client, contextName }) {
       }
 
       if (pagination && pagination.count === 20) {
-        const prefixedArgs = getPrefixedFlags(argv);
-        const flags = getCommandFlags(prefixedArgs, [
-          '_',
-          '--next',
-          '-N',
-          '-d',
-          '-y',
-        ]);
+        const flags = getCommandFlags(argv, ['_', '--next', '-N', '-d', '-y']);
         const nextCmd = `projects ls${flags} --next ${pagination.next}`;
         console.log(`To display the next page run ${getCommandName(nextCmd)}`);
       }
@@ -271,7 +266,7 @@ async function run({ client, contextName }) {
 
   console.error(error('Please specify a valid subcommand: ls | add | rm'));
   help();
-  exit(1);
+  exit(2);
 }
 
 process.on('uncaughtException', err => {

packages/now-cli/src/index.js

@@ -24,6 +24,7 @@ import checkForUpdate from 'update-check';
 import ms from 'ms';
 import { URL } from 'url';
 import * as Sentry from '@sentry/node';
+import { NowBuildError } from '@vercel/build-utils';
 import getGlobalPathConfig from './util/config/global-path';
 import {
   getDefaultConfig,
@@ -114,10 +115,10 @@ const main = async argv_ => {
   }
 
   if (
-    localConfig instanceof NowError &&
+    (localConfig instanceof NowError || localConfig instanceof NowBuildError) &&
     !(localConfig instanceof ERRORS.CantFindConfig)
   ) {
-    output.error(`Failed to load local config file: ${localConfig.message}`);
+    output.prettyError(localConfig);
     return 1;
   }
 
@@ -529,7 +530,7 @@ const main = async argv_ => {
 
   if (argv['--team']) {
     output.warn(
-      `The ${param('--team')} flag is deprecated. Please use ${param(
+      `The ${param('--team')} option is deprecated. Please use ${param(
         '--scope'
       )} instead.`
     );
@@ -644,27 +645,6 @@ const main = async argv_ => {
         )} could not be resolved. Please verify your internet connectivity and DNS configuration.`
       );
       output.debug(err.stack);
-
-      return 1;
-    }
-
-    await reportError(Sentry, err, apiUrl, configFiles);
-
-    // If there is a code we should not consider the error unexpected
-    // but instead show the message. Any error that is handled by this should
-    // actually be handled in the sub command instead. Please make sure
-    // that happens for anything that lands here. It should NOT bubble up to here.
-    if (err.code) {
-      output.debug(err.stack);
-      output.error(err.message);
-
-      if (shouldCollectMetrics) {
-        metric
-          .event(eventCategory, '1', pkg.version)
-          .exception(err.message)
-          .send();
-      }
-
       return 1;
     }
 
@@ -675,9 +655,23 @@ const main = async argv_ => {
         .send();
     }
 
-    // Otherwise it is an unexpected error and we should show the trace
-    // and an unexpected error message
-    output.error(`An unexpected error occurred in ${subcommand}: ${err.stack}`);
+    // If there is a code we should not consider the error unexpected
+    // but instead show the message. Any error that is handled by this should
+    // actually be handled in the sub command instead. Please make sure
+    // that happens for anything that lands here. It should NOT bubble up to here.
+    if (err.code) {
+      output.debug(err.stack);
+      output.prettyError(err);
+    } else {
+      await reportError(Sentry, err, apiUrl, configFiles);
+
+      // Otherwise it is an unexpected error and we should show the trace
+      // and an unexpected error message
+      output.error(
+        `An unexpected error occurred in ${subcommand}: ${err.stack}`
+      );
+    }
+
     return 1;
   }
 
@@ -688,8 +682,6 @@ const main = async argv_ => {
   return exitCode;
 };
 
-debug('start');
-
 const handleRejection = async err => {
   debug('handling rejection');
 

packages/now-cli/src/util/certs/get-certs-for-cn.ts

@@ -0,0 +1,17 @@
+import { stringify } from 'querystring';
+import { Cert } from '../../types';
+import Client from '../client';
+
+/**
+ * Returns certs that contain @param cn.
+ */
+export async function getCertsForCn(
+  client: Client,
+  cn: string,
+  { limit }: { limit?: number } = {}
+) {
+  const { certs } = await client.fetch<{
+    certs: Cert[];
+  }>(`/v4/now/certs?${stringify({ cn, ...(limit ? { limit } : {}) })}`);
+  return certs;
+}

packages/now-cli/src/util/client.ts

@@ -24,7 +24,7 @@ export default class Client extends EventEmitter {
   _withCache: boolean;
   _output: Output;
   _token: string;
-  currentTeam?: string;
+  currentTeam?: string | null;
 
   constructor({
     apiUrl,
@@ -36,7 +36,7 @@ export default class Client extends EventEmitter {
   }: {
     apiUrl: string;
     token: string;
-    currentTeam?: string;
+    currentTeam?: string | null;
     forceNew?: boolean;
     withCache?: boolean;
     debug?: boolean;

packages/now-cli/src/util/config/local-path.ts

@@ -1,6 +1,7 @@
 import path from 'path';
 import mri from 'mri';
 import { InvalidLocalConfig } from '../errors';
+import { ConflictingConfigFiles } from '../errors-ts';
 import { existsSync } from 'fs';
 
 export default function getLocalPathConfig(prefix: string) {
@@ -11,20 +12,30 @@ export default function getLocalPathConfig(prefix: string) {
     },
   });
 
+  // If `--local-config` flag was specified, then that takes priority
   const customPath = args['local-config'];
-
-  if (customPath && typeof customPath !== 'string') {
-    throw new InvalidLocalConfig(customPath);
+  if (customPath) {
+    if (typeof customPath !== 'string') {
+      throw new InvalidLocalConfig(customPath);
+    }
+    return path.resolve(prefix, customPath);
   }
 
-  const possibleConfigFiles = [
-    path.join(prefix, 'vercel.json'),
-    path.join(prefix, 'now.json'),
-  ];
+  // Otherwise check for either `vercel.json` or `now.json`.
+  // Throw an error if both exist.
+  const vercelConfigPath = path.join(prefix, 'vercel.json');
+  const nowConfigPath = path.join(prefix, 'now.json');
 
-  return (
-    (customPath && path.resolve(prefix, customPath)) ||
-    possibleConfigFiles.find(configFile => existsSync(configFile)) ||
-    possibleConfigFiles[0]
-  );
+  const vercelConfigExists = existsSync(vercelConfigPath);
+  const nowConfigExists = existsSync(nowConfigPath);
+
+  if (nowConfigExists && vercelConfigExists) {
+    throw new ConflictingConfigFiles([vercelConfigPath, nowConfigPath]);
+  }
+
+  if (nowConfigExists) {
+    return nowConfigPath;
+  }
+
+  return vercelConfigPath;
 }

packages/now-cli/src/util/deploy/get-preferred-preview-url.ts

@@ -0,0 +1,48 @@
+import isWildcardAlias from '../alias/is-wildcard-alias';
+import { getCertsForCn } from '../certs/get-certs-for-cn';
+import Client from '../client';
+
+/**
+ * Tries to find the "best" alias url.
+ * @param aliasList
+ */
+export async function getPreferredPreviewURL(
+  client: Client,
+  aliasList: string[]
+) {
+  if (aliasList.length === 0) {
+    return null;
+  }
+
+  /**
+   * First checks for non public aliases and non wildcard domains.
+   */
+  const preferredAliases = aliasList.filter(
+    alias =>
+      !alias.endsWith('.now.sh') &&
+      !alias.endsWith('.vercel.app') &&
+      !isWildcardAlias(alias)
+  );
+  for (const alias of preferredAliases) {
+    const certs = await getCertsForCn(client, alias, { limit: 1 }).catch(() => {
+      return null;
+    });
+    if (certs && certs.length > 0) {
+      return { previewUrl: `https://${alias}`, isWildcard: false };
+    }
+  }
+
+  /**
+   * Fallback to first alias
+   */
+  const [firstAlias] = aliasList;
+  if (isWildcardAlias(firstAlias)) {
+    return { previewUrl: firstAlias, isWildcard: true };
+  }
+
+  if (firstAlias.endsWith('.vercel.app') || firstAlias.endsWith('.now.sh')) {
+    return { previewUrl: `https://${firstAlias}`, isWildcard: false };
+  }
+
+  return { previewUrl: `http://${firstAlias}`, isWildcard: false };
+}

packages/now-cli/src/util/dev/builder-cache.ts

@@ -3,9 +3,9 @@ import semver from 'semver';
 import npa from 'npm-package-arg';
 import pluralize from 'pluralize';
 import { basename, join } from 'path';
-import { PackageJson } from '@vercel/build-utils';
 import XDGAppPaths from 'xdg-app-paths';
 import { mkdirp, readJSON, writeJSON } from 'fs-extra';
+import { NowBuildError, PackageJson } from '@vercel/build-utils';
 import cliPkg from '../pkg';
 
 import { NoBuilderCacheError } from '../errors-ts';
@@ -232,21 +232,41 @@ async function npmInstall(
   output.debug(`Running npm install in ${cwd}`);
 
   try {
-    await execa(
-      'npm',
-      [
-        'install',
-        '--save-exact',
-        '--no-package-lock',
-        '--no-audit',
-        '--no-progress',
-        ...sortedPackages,
-      ],
-      {
-        cwd,
-        stdio: output.isDebugEnabled() ? 'inherit' : undefined,
+    const args = [
+      'install',
+      '--save-exact',
+      '--no-package-lock',
+      '--no-audit',
+      '--no-progress',
+    ];
+    if (process.stderr.isTTY) {
+      // Force colors in the npm child process
+      // https://docs.npmjs.com/misc/config#color
+      args.push('--color=always');
+    }
+    args.push(...sortedPackages);
+    const result = await execa('npm', args, {
+      cwd,
+      reject: false,
+      stdio: output.isDebugEnabled() ? 'inherit' : 'pipe',
+    });
+    if (result.failed) {
+      stopSpinner();
+      if (result.stdout) {
+        console.log(result.stdout);
       }
-    );
+      if (result.stderr) {
+        console.error(result.stderr);
+      }
+      throw new NowBuildError({
+        message:
+          (result as any).code === 'ENOENT'
+            ? '`npm` is not installed'
+            : 'Failed to install `vercel dev` dependencies',
+        code: 'NPM_INSTALL_ERROR',
+        link: 'https://vercel.link/npm-install-failed-dev',
+      });
+    }
   } finally {
     stopSpinner();
   }

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

@@ -18,6 +18,7 @@ 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 { getVercelIgnore, fileNameSymbol } from '@vercel/client';
@@ -114,6 +115,7 @@ export default class DevServer {
   public cwd: string;
   public debug: boolean;
   public output: Output;
+  public proxy: httpProxy;
   public envConfigs: EnvConfigs;
   public frameworkSlug: string | null;
   public files: BuilderInputs;
@@ -124,7 +126,6 @@ export default class DevServer {
   private caseSensitive: boolean;
   private apiDir: string | null;
   private apiExtensions: Set<string>;
-  private proxy: httpProxy;
   private server: http.Server;
   private stopping: boolean;
   private buildMatches: Map<string, BuildMatch>;
@@ -234,8 +235,18 @@ export default class DevServer {
       }
     }
 
-    // Update the build matches in case an entrypoint was created or deleted
     const nowConfig = await this.getNowConfig(false);
+
+    // Update the env vars configuration
+    const nowConfigBuild = nowConfig.build || {};
+    const [runEnv, buildEnv] = await Promise.all([
+      this.getLocalEnv('.env', nowConfig.env),
+      this.getLocalEnv('.env.build', nowConfigBuild.env),
+    ]);
+    const allEnv = { ...buildEnv, ...runEnv };
+    this.envConfigs = { buildEnv, runEnv, allEnv };
+
+    // Update the build matches in case an entrypoint was created or deleted
     await this.updateBuildMatches(nowConfig);
 
     const filesChangedArray = [...filesChanged];
@@ -400,7 +411,7 @@ export default class DevServer {
     const blockingBuilds: Promise<void>[] = [];
     for (const match of matches) {
       const currentMatch = this.buildMatches.get(match.src);
-      if (!currentMatch || currentMatch.use !== match.use) {
+      if (!buildMatchEquals(currentMatch, match)) {
         this.output.debug(
           `Adding build match for "${match.src}" with "${match.use}"`
         );
@@ -522,18 +533,11 @@ export default class DevServer {
     // The default empty `vercel.json` is used to serve all files as static
     // when no `vercel.json` is present
     let configPath = 'vercel.json';
-    let config: NowConfig = this.cachedNowConfig || {
+    let config: NowConfig = {
       version: 2,
       [fileNameSymbol]: configPath,
     };
 
-    // We need to delete these properties for zero config to work
-    // with file changes
-    if (this.cachedNowConfig) {
-      delete this.cachedNowConfig.builds;
-      delete this.cachedNowConfig.routes;
-    }
-
     try {
       configPath = getNowConfigPath(this.cwd);
       this.output.debug(`Reading ${configPath}`);
@@ -564,7 +568,7 @@ export default class DevServer {
       nowConfig: config,
     });
     if (routeError) {
-      this.output.error(routeError.message);
+      this.output.prettyError(routeError);
       await this.exit();
     }
     config.routes = maybeRoutes || [];
@@ -581,6 +585,7 @@ export default class DevServer {
         defaultRoutes,
         redirectRoutes,
         rewriteRoutes,
+        errorRoutes,
       } = await detectBuilders(files, pkg, {
         tag: getDistTag(cliPkg.version) === 'canary' ? 'canary' : 'latest',
         functions: config.functions,
@@ -606,20 +611,25 @@ export default class DevServer {
 
         config.builds = config.builds || [];
         config.builds.push(...builders);
-
-        const routes: Route[] = [];
-        const { routes: nowConfigRoutes } = config;
-        routes.push(...(redirectRoutes || []));
-        routes.push(
-          ...appendRoutesToPhase({
-            routes: nowConfigRoutes,
-            newRoutes: rewriteRoutes,
-            phase: 'filesystem',
-          })
-        );
-        routes.push(...(defaultRoutes || []));
-        config.routes = routes;
       }
+
+      let routes: Route[] = [];
+      const { routes: nowConfigRoutes } = config;
+      routes.push(...(redirectRoutes || []));
+      routes.push(
+        ...appendRoutesToPhase({
+          routes: nowConfigRoutes,
+          newRoutes: rewriteRoutes,
+          phase: 'filesystem',
+        })
+      );
+      routes = appendRoutesToPhase({
+        routes,
+        newRoutes: errorRoutes,
+        phase: 'error',
+      });
+      routes.push(...(defaultRoutes || []));
+      config.routes = routes;
     }
 
     if (Array.isArray(config.builds)) {
@@ -767,7 +777,6 @@ export default class DevServer {
       this.getLocalEnv('.env.build', nowConfigBuild.env),
     ]);
     const allEnv = { ...buildEnv, ...runEnv };
-    Object.assign(process.env, allEnv);
     this.envConfigs = { buildEnv, runEnv, allEnv };
 
     const opts = { output: this.output, isBuilds: true };
@@ -1323,8 +1332,7 @@ export default class DevServer {
     const handleMap = getRoutesTypes(routes);
     const missRoutes = handleMap.get('miss') || [];
     const hitRoutes = handleMap.get('hit') || [];
-    handleMap.delete('miss');
-    handleMap.delete('hit');
+    const errorRoutes = handleMap.get('error') || [];
     const phases: (HandleValue | null)[] = [null, 'filesystem'];
 
     let routeResult: RouteResult | null = null;
@@ -1362,7 +1370,7 @@ export default class DevServer {
 
         debug(`ProxyPass: ${destUrl}`);
         this.setResponseHeaders(res, nowRequestId);
-        return proxyPass(req, res, destUrl, this.proxy, this.output);
+        return proxyPass(req, res, destUrl, this, nowRequestId);
       }
 
       match = await findBuildMatch(
@@ -1431,6 +1439,32 @@ export default class DevServer {
         routeResult.status = prevStatus;
       }
 
+      if (!match && errorRoutes.length > 0) {
+        // error phase
+        const routeResultForError = await devRouter(
+          getReqUrl(routeResult),
+          req.method,
+          errorRoutes,
+          this,
+          routeResult.headers,
+          [],
+          'error'
+        );
+
+        const matchForError = await findBuildMatch(
+          this.buildMatches,
+          this.files,
+          routeResultForError.dest,
+          this
+        );
+
+        if (matchForError) {
+          // error phase only applies if the file was found
+          routeResult = routeResultForError;
+          match = matchForError;
+        }
+      }
+
       statusCode = routeResult.status;
 
       if (match) {
@@ -1475,8 +1509,8 @@ export default class DevServer {
           req,
           res,
           `http://localhost:${this.devProcessPort}`,
-          this.proxy,
-          this.output,
+          this,
+          nowRequestId,
           false
         );
       }
@@ -1560,7 +1594,7 @@ export default class DevServer {
           req,
           res,
           nowRequestId,
-          'NO_STATUS_CODE_FROM_DEV_SERVER',
+          'NO_RESPONSE_FROM_FUNCTION',
           502
         );
         return;
@@ -1595,15 +1629,14 @@ export default class DevServer {
           req,
           res,
           `http://localhost:${port}`,
-          this.proxy,
-          this.output,
+          this,
+          nowRequestId,
           false
         );
       } else {
         debug(`Skipping \`startDevServer()\` for ${match.entrypoint}`);
       }
     }
-
     let foundAsset = findAsset(match, requestPath, nowConfig);
 
     if (!foundAsset && callLevel === 0) {
@@ -1626,8 +1659,8 @@ export default class DevServer {
         req,
         res,
         `http://localhost:${this.devProcessPort}`,
-        this.proxy,
-        this.output,
+        this,
+        nowRequestId,
         false
       );
     }
@@ -1721,7 +1754,7 @@ export default class DevServer {
             req,
             res,
             nowRequestId,
-            'NO_STATUS_CODE_FROM_LAMBDA',
+            'NO_RESPONSE_FROM_FUNCTION',
             502
           );
           return;
@@ -1937,24 +1970,27 @@ function proxyPass(
   req: http.IncomingMessage,
   res: http.ServerResponse,
   dest: string,
-  proxy: httpProxy,
-  output: Output,
+  devServer: DevServer,
+  nowRequestId: string,
   ignorePath: boolean = true
 ): void {
-  return proxy.web(
+  return devServer.proxy.web(
     req,
     res,
     { target: dest, ignorePath },
     (error: NodeJS.ErrnoException) => {
-      // If the client hangs up a socket, we do not
-      // want to do anything, as the client just expects
-      // the connection to be closed.
-      if (error.code === 'ECONNRESET') {
-        res.end();
-        return;
+      devServer.output.error(
+        `Failed to complete request to ${req.url}: ${error}`
+      );
+      if (!res.headersSent) {
+        devServer.sendError(
+          req,
+          res,
+          nowRequestId,
+          'NO_RESPONSE_FROM_FUNCTION',
+          502
+        );
       }
-
-      output.error(`Failed to complete request to ${req.url}: ${error}`);
     }
   );
 }
@@ -2014,12 +2050,24 @@ async function findBuildMatch(
   isFilesystem?: boolean
 ): Promise<BuildMatch | null> {
   requestPath = requestPath.replace(/^\//, '');
+
+  let bestIndexMatch: undefined | BuildMatch;
   for (const match of matches.values()) {
     if (await shouldServe(match, files, requestPath, devServer, isFilesystem)) {
-      return match;
+      if (!isIndex(match.src)) {
+        return match;
+      } else {
+        // if isIndex === true and ends in .html, we're done. Otherwise, keep searching
+        bestIndexMatch = match;
+        if (extname(match.src) === '.html') {
+          return bestIndexMatch;
+        }
+      }
     }
   }
-  return null;
+
+  // return a non-.html index file or none are found
+  return bestIndexMatch || null;
 }
 
 async function shouldServe(
@@ -2216,3 +2264,11 @@ function hasNewRoutingProperties(nowConfig: NowConfig) {
     typeof nowConfig.trailingSlash !== undefined
   );
 }
+
+function buildMatchEquals(a?: BuildMatch, b?: BuildMatch): boolean {
+  if (!a || !b) return false;
+  if (a.src !== b.src) return false;
+  if (a.use !== b.use) return false;
+  if (!deepEqual(a.config || {}, b.config || {})) return false;
+  return true;
+}

packages/now-cli/src/util/dev/templates/error_502.jst

@@ -44,22 +44,16 @@
   <p>
     <ul>
       <li>
-        If you are a visitor; contact the website owner or try again later.
-      </li>
-      <li>
-        If you are the owner; <a href="/_logs" target="_blank">check the logs</a> for the application error.
+        Check the logs in your terminal window to see the application error.
       </li>
     </ul>
-    <a target="_blank" href="https://vercel.com/docs/router-status/{{= it.http_status_code }}" class="docs-link" rel="noopener noreferrer">Developer Documentation →</a>
+    <a target="_blank" href="https://vercel.com/docs/error/application/{{= it.error_code }}" class="docs-link" rel="noopener noreferrer">Developer Documentation →</a>
   </p>
   {{??}}
   <p>
     <ul>
       <li>
-        If you are a visitor, please try again later.
-      </li>
-      <li>
-        If you are the owner, no action is needed. Our engineers have been notified.
+        Please open a <a target="_blank" href="https://github.com/vercel/vercel/issues/new/choose">GitHub issue</a> describing the problem you are experiencing with <code>vercel dev</code>.
       </li>
     </ul>
   </p>

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

@@ -1,5 +1,6 @@
 import bytes from 'bytes';
 import { Response } from 'node-fetch';
+import { NowBuildError } from '@vercel/build-utils';
 import { NowError } from './now-error';
 import code from './output/code';
 import { getCommandName } from './pkg-name';
@@ -771,6 +772,20 @@ export class CantParseJSONFile extends NowError<
   }
 }
 
+export class ConflictingConfigFiles extends NowBuildError {
+  files: string[];
+
+  constructor(files: string[]) {
+    super({
+      code: 'CONFLICTING_CONFIG_FILES',
+      message:
+        'Cannot use both a `vercel.json` and `now.json` file. Please delete the `now.json` file.',
+      link: 'https://vercel.link/combining-old-and-new-config',
+    });
+    this.files = files;
+  }
+}
+
 export class CantFindConfig extends NowError<
   'CANT_FIND_CONFIG',
   { paths: string[] }

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

@@ -3,6 +3,7 @@ import { fileNameSymbol } from '@vercel/client';
 import {
   CantParseJSONFile,
   CantFindConfig,
+  ConflictingConfigFiles,
   WorkingDirectoryDoesNotExist,
 } from './errors-ts';
 import humanizePath from './humanize-path';
@@ -49,28 +50,31 @@ export default async function getConfig(
     }
   }
 
-  // Then try with vercel.json in the same directory
+  // Then try with `vercel.json` or `now.json` in the same directory
   const vercelFilePath = path.resolve(localPath, 'vercel.json');
-  const vercelConfig = await readJSONFile(vercelFilePath);
+  const nowFilePath = path.resolve(localPath, 'now.json');
+  const [vercelConfig, nowConfig] = await Promise.all([
+    readJSONFile(vercelFilePath),
+    readJSONFile(nowFilePath),
+  ]);
   if (vercelConfig instanceof CantParseJSONFile) {
     return vercelConfig;
   }
+  if (nowConfig instanceof CantParseJSONFile) {
+    return nowConfig;
+  }
+  if (vercelConfig && nowConfig) {
+    return new ConflictingConfigFiles([vercelFilePath, nowFilePath]);
+  }
   if (vercelConfig !== null) {
-    output.debug(`Found config in file ${vercelFilePath}`);
+    output.debug(`Found config in file "${vercelFilePath}"`);
     config = vercelConfig as NowConfig;
     config[fileNameSymbol] = 'vercel.json';
     return config;
   }
-
-  // Then try with now.json in the same directory
-  const nowFilePath = path.resolve(localPath, 'now.json');
-  const mainConfig = await readJSONFile(nowFilePath);
-  if (mainConfig instanceof CantParseJSONFile) {
-    return mainConfig;
-  }
-  if (mainConfig !== null) {
-    output.debug(`Found config in file ${nowFilePath}`);
-    config = mainConfig as NowConfig;
+  if (nowConfig !== null) {
+    output.debug(`Found config in file "${nowFilePath}"`);
+    config = nowConfig as NowConfig;
     config[fileNameSymbol] = 'now.json';
     return config;
   }

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

@@ -2,6 +2,7 @@ import chalk from 'chalk';
 import boxen from 'boxen';
 import { format } from 'util';
 import { Console } from 'console';
+import renderLink from './link';
 import wait from './wait';
 
 export type Output = ReturnType<typeof createOutput>;
@@ -41,7 +42,7 @@ export default function createOutput({ debug: debugEnabled = false } = {}) {
       boxen(
         chalk.bold.yellow('WARN! ') +
           str +
-          (details ? `\nMore details: ${details}` : ''),
+          (details ? `\nMore details: ${renderLink(details)}` : ''),
         {
           padding: {
             top: 0,
@@ -64,16 +65,21 @@ export default function createOutput({ debug: debugEnabled = false } = {}) {
 
   function error(
     str: string,
-    slug: string | null = null,
-    link: string | null = null
+    slug?: string,
+    link?: string,
+    action = 'More details'
   ) {
     print(`${chalk.red(`Error!`)} ${str}\n`);
     const details = slug ? `https://err.sh/now/${slug}` : link;
     if (details) {
-      print(`More details: ${details}\n`);
+      print(`${chalk.bold(action)}: ${renderLink(details)}\n`);
     }
   }
 
+  function prettyError(err: Error & { link?: string; action?: string }) {
+    return error(err.message, undefined, err.link, err.action);
+  }
+
   function ready(str: string) {
     print(`${chalk.cyan('> Ready!')} ${str}\n`);
   }
@@ -106,8 +112,6 @@ export default function createOutput({ debug: debugEnabled = false } = {}) {
     return wait(message, delay);
   }
 
-  // This is pretty hacky, but since we control the version of Node.js
-  // being used because of `pkg` it's safe to do in this case.
   const c = {
     _times: new Map(),
     log(a: string, ...args: string[]) {
@@ -134,6 +138,7 @@ export default function createOutput({ debug: debugEnabled = false } = {}) {
     log,
     warn,
     error,
+    prettyError,
     ready,
     success,
     debug,

packages/now-cli/src/util/output/error.ts

@@ -1,6 +1,7 @@
 import chalk from 'chalk';
 import { metrics, shouldCollectMetrics } from '../metrics';
 import { APIError } from '../errors-ts';
+import renderLink from './link';
 
 const metric = metrics();
 
@@ -9,10 +10,9 @@ export default function error(...input: string[] | [APIError]) {
   if (typeof input[0] === 'object') {
     const { slug, message, link } = input[0];
     messages = [message];
-    if (slug) {
-      messages.push(`> More details: https://err.sh/now/${slug}`);
-    } else if (link) {
-      messages.push(`> More details: ${link}`);
+    const details = slug ? `https://err.sh/now/${slug}` : link;
+    if (details) {
+      messages.push(`${chalk.bold('More details')}: ${renderLink(details)}`);
     }
   }
 

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

@@ -14,7 +14,7 @@ import chalk from 'chalk';
 import { prependEmoji, emoji } from '../emoji';
 import AJV from 'ajv';
 import { isDirectory } from '../config/global-path';
-import { getPlatformEnv } from '@vercel/build-utils';
+import { NowBuildError, getPlatformEnv } from '@vercel/build-utils';
 
 const readFile = promisify(fs.readFile);
 const writeFile = promisify(fs.writeFile);
@@ -42,10 +42,21 @@ const linkSchema = {
 /**
  * Returns the `<cwd>/.vercel` directory for the current project
  * with a fallback to <cwd>/.now` if it exists.
+ *
+ * Throws an error if *both* `.vercel` and `.now` directories exist.
  */
-export function getVercelDirectory(cwd: string = process.cwd()) {
+export function getVercelDirectory(cwd: string = process.cwd()): string {
   const possibleDirs = [join(cwd, VERCEL_DIR), join(cwd, VERCEL_DIR_FALLBACK)];
-  return possibleDirs.find(d => isDirectory(d)) || possibleDirs[0];
+  const existingDirs = possibleDirs.filter(d => isDirectory(d));
+  if (existingDirs.length > 1) {
+    throw new NowBuildError({
+      code: 'CONFLICTING_CONFIG_DIRECTORIES',
+      message:
+        'Both `.vercel` and `.now` directories exist. Please remove the `.now` directory.',
+      link: 'https://vercel.link/combining-old-and-new-config',
+    });
+  }
+  return existingDirs[0] || possibleDirs[0];
 }
 
 async function getLink(path?: string): Promise<ProjectLink | null> {

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

@@ -82,7 +82,7 @@ export default async function validatePaths(
   if (isFile) {
     output.print(
       `${prependEmoji(
-        'Deploying files with Vercel is deprecated (https://zeit.ink/3Z)',
+        'Deploying files with Vercel is deprecated (https://vercel.link/faq-deploy-file)',
         emoji('warning')
       )}\n`
     );

packages/now-cli/test/dev/fixtures/00-list-directory/.gitignore

@@ -0,0 +1 @@
+.vercel

packages/now-cli/test/dev/fixtures/05-gatsby/src/pages/404.js

@@ -0,0 +1,11 @@
+import React from 'react';
+
+function Custom404() {
+  return (
+    <main>
+      <h1>Custom Gatsby 404</h1>
+    </main>
+  );
+}
+
+export default Custom404;

packages/now-cli/test/dev/fixtures/10-nextjs-node/pages/404.js

@@ -0,0 +1,3 @@
+export default function Custom404() {
+  return <h1>Custom Next 404</h1>;
+}

packages/now-cli/test/dev/fixtures/force-module-commonjs/.gitignore

@@ -0,0 +1 @@
+.vercel

packages/now-cli/test/dev/fixtures/force-module-commonjs/api/index.js

@@ -0,0 +1,3 @@
+export default function(req, res) {
+  res.end('Force "module: commonjs" JavaScript with ES Modules API endpoint');
+}

packages/now-cli/test/dev/fixtures/force-module-commonjs/api/ts.ts

@@ -0,0 +1,5 @@
+import { IncomingMessage, ServerResponse } from 'http';
+
+export default function(req: IncomingMessage, res: ServerResponse) {
+  res.end('Force "module: commonjs" TypeScript API endpoint');
+}

packages/now-cli/test/dev/fixtures/force-module-commonjs/next-env.d.ts

@@ -0,0 +1,2 @@
+/// <reference types="next" />
+/// <reference types="next/types/global" />

packages/now-cli/test/dev/fixtures/force-module-commonjs/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "force-module-commonjs",
+  "private": true,
+  "scripts": {
+    "dev": "next",
+    "build": "next build",
+    "start": "next start"
+  },
+  "dependencies": {
+    "next": "^9.3.4",
+    "react": "^16.13.1",
+    "react-dom": "^16.13.1"
+  },
+  "devDependencies": {
+    "@types/node": "14.0.9",
+    "@types/react": "^16.9.32",
+    "typescript": "^3.8.3"
+  }
+}

packages/now-cli/test/dev/fixtures/force-module-commonjs/pages/index.tsx

@@ -0,0 +1,3 @@
+export default function () {
+  return <div>Force "module: commonjs" test page</div>;
+}

packages/now-cli/test/dev/fixtures/force-module-commonjs/tsconfig.json

@@ -0,0 +1,25 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "target": "esnext",
+    "lib": ["dom", "dom.iterable", "esnext"],
+    "allowJs": true,
+    "skipLibCheck": true,
+    "strict": true,
+    "allowSyntheticDefaultImports": true,
+    "forceConsistentCasingInFileNames": true,
+    "noEmit": true,
+    "esModuleInterop": true,
+    "module": "esnext",
+    "moduleResolution": "node",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "jsx": "preserve",
+    "paths": {
+      "@components/*": ["components/*"],
+      "@lib/*": ["lib/*"]
+    }
+  },
+  "exclude": ["node_modules", "api"],
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx"]
+}

packages/now-cli/test/dev/fixtures/index-html-priority/public/index.css

@@ -0,0 +1 @@
+This is index.css

packages/now-cli/test/dev/fixtures/index-html-priority/public/index.html

@@ -0,0 +1,2 @@
+This is index.html
+

packages/now-cli/test/dev/fixtures/invalidate-vercel-config/api/index.js

@@ -0,0 +1,3 @@
+export default (req, res) => {
+  res.send(process.env);
+};

packages/now-cli/test/dev/fixtures/invalidate-vercel-config/vercel.json

@@ -0,0 +1 @@
+{ "env": { "FOO": "bar" } }

packages/now-cli/test/dev/fixtures/nested-tsconfig/.gitignore

@@ -0,0 +1 @@
+.vercel

packages/now-cli/test/dev/fixtures/nested-tsconfig/api/index.ts

@@ -0,0 +1,5 @@
+import { IncomingMessage, ServerResponse } from 'http';
+
+export default function(req: IncomingMessage, res: ServerResponse) {
+  res.end('Nested `tsconfig.json` API endpoint');
+}

packages/now-cli/test/dev/fixtures/nested-tsconfig/api/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "api",
+  "devDependencies": {
+    "@types/node": "12"
+  }
+}

packages/now-cli/test/dev/fixtures/nested-tsconfig/api/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "target": "es2015",
+    "lib": ["dom", "dom.iterable", "esnext"],
+    "strict": true,
+    "module": "CommonJS",
+    "esModuleInterop": true
+  },
+  "exclude": ["node_modules"],
+  "include": ["**/*.ts"]
+}

packages/now-cli/test/dev/fixtures/nested-tsconfig/api/yarn.lock

@@ -0,0 +1,8 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+"@types/node@12":
+  version "12.12.43"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-12.12.43.tgz#b60ce047822e526e7a9252e50844eee79d5386ff"
+  integrity sha512-KUyZdkGCnVPuXfsKmDUu2XLui65LZIJ2s0M57noy5e+ixUT2oK33ep7zlvgzI8LElcWqbf8AR+o/3GqAPac2zA==

packages/now-cli/test/dev/fixtures/nested-tsconfig/next-env.d.ts

@@ -0,0 +1,2 @@
+/// <reference types="next" />
+/// <reference types="next/types/global" />

packages/now-cli/test/dev/fixtures/nested-tsconfig/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "nested-tsconfig",
+  "private": true,
+  "scripts": {
+    "dev": "next",
+    "build": "next build",
+    "start": "next start"
+  },
+  "dependencies": {
+    "next": "^9.3.4",
+    "react": "^16.13.1",
+    "react-dom": "^16.13.1"
+  },
+  "devDependencies": {
+    "@types/node": "14.0.9",
+    "@types/react": "^16.9.32",
+    "typescript": "^3.8.3"
+  }
+}

packages/now-cli/test/dev/fixtures/nested-tsconfig/pages/index.tsx

@@ -0,0 +1,3 @@
+export default function () {
+  return <div>Nested tsconfig.json test page</div>;
+}

packages/now-cli/test/dev/fixtures/nested-tsconfig/tsconfig.json

@@ -0,0 +1,25 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "target": "esnext",
+    "lib": ["dom", "dom.iterable", "esnext"],
+    "allowJs": true,
+    "skipLibCheck": true,
+    "strict": true,
+    "allowSyntheticDefaultImports": true,
+    "forceConsistentCasingInFileNames": true,
+    "noEmit": true,
+    "esModuleInterop": true,
+    "module": "esnext",
+    "moduleResolution": "node",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "jsx": "preserve",
+    "paths": {
+      "@components/*": ["components/*"],
+      "@lib/*": ["lib/*"]
+    }
+  },
+  "exclude": ["node_modules", "api"],
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx"]
+}

packages/now-cli/test/dev/fixtures/node-helpers/index.js

@@ -0,0 +1,10 @@
+export default (req, res) => {
+  const hasHelpers = typeof req.query !== 'undefined';
+  res.setHeader('Content-Type', 'application/json');
+  res.end(
+    JSON.stringify({
+      hasHelpers,
+      query: req.query,
+    })
+  );
+};

packages/now-cli/test/dev/fixtures/node-helpers/vercel.json

@@ -0,0 +1 @@
+{ "builds": [{ "src": "index.js", "use": "@vercel/node@canary" }] }

packages/now-cli/test/dev/fixtures/public-and-api/.gitignore

@@ -0,0 +1 @@
+!public

packages/now-cli/test/dev/fixtures/public-and-api/public/404.html

@@ -0,0 +1 @@
+Custom 404 Page

packages/now-cli/test/dev/fixtures/routes-check-true-status/.gitignore

@@ -0,0 +1 @@
+.vercel

packages/now-cli/test/dev/fixtures/routes-custom-404/api/hello.js

@@ -0,0 +1,3 @@
+module.exports = (_req, res) => {
+  res.end('Hello');
+};

packages/now-cli/test/dev/fixtures/routes-custom-404/exact-404.html

@@ -0,0 +1 @@
+Exact Custom 404

packages/now-cli/test/dev/fixtures/routes-custom-404/index.html

@@ -0,0 +1 @@
+Home Page

packages/now-cli/test/dev/fixtures/routes-custom-404/user-404.html

@@ -0,0 +1 @@
+Custom User 404

packages/now-cli/test/dev/fixtures/routes-custom-404/vercel.json

@@ -0,0 +1,8 @@
+{
+  "version": 2,
+  "routes": [
+    { "src": "/exact", "status": 404, "dest": "/exact-404.html" },
+    { "handle": "filesystem" },
+    { "src": "/(.*)", "status": 404, "dest": "/user-404.html" }
+  ]
+}

packages/now-cli/test/dev/fixtures/runtime-not-installed/vercel.json

@@ -0,0 +1,3 @@
+{
+  "builds": [{ "src": "*.js", "use": "@vercel/does-not-exist" }]
+}

packages/now-cli/test/dev/fixtures/test-clean-urls-custom-404/404.html

@@ -0,0 +1 @@
+Custom 404 Page

packages/now-cli/test/dev/fixtures/test-clean-urls-custom-404/about.html

@@ -0,0 +1 @@
+The about page

packages/now-cli/test/dev/fixtures/test-clean-urls-custom-404/contact/me.html

@@ -0,0 +1 @@
+Contact Me Subdirectory

packages/now-cli/test/dev/fixtures/test-clean-urls-custom-404/index.html

@@ -0,0 +1 @@
+This is the home page

packages/now-cli/test/dev/fixtures/test-clean-urls-custom-404/vercel.json

@@ -0,0 +1,3 @@
+{
+  "cleanUrls": true
+}

packages/now-cli/test/dev/fixtures/test-trailing-slash-custom-404/404.html

@@ -0,0 +1 @@
+Custom 404 Page

packages/now-cli/test/dev/fixtures/test-trailing-slash-custom-404/about.html

@@ -0,0 +1 @@
+The about page

packages/now-cli/test/dev/fixtures/test-trailing-slash-custom-404/contact/index.html

@@ -0,0 +1 @@
+Contact Subdirectory

packages/now-cli/test/dev/fixtures/test-trailing-slash-custom-404/index.html

@@ -0,0 +1 @@
+This is the home page

packages/now-cli/test/dev/fixtures/test-trailing-slash-custom-404/vercel.json

@@ -0,0 +1,4 @@
+{
+  "version": 2,
+  "trailingSlash": true
+}

packages/now-cli/test/dev/integration.js

@@ -161,7 +161,7 @@ async function testPath(
     Object.entries(headers).forEach(([key, expectedValue]) => {
       let actualValue = res.headers.get(key);
       if (key.toLowerCase() === 'location' && actualValue === '//') {
-        // HACK: `node-fetch` has strang behavior for location header so fix it
+        // HACK: `node-fetch` has strange behavior for location header so fix it
         // with `manual-dont-change` opt and convert double slash to single.
         // See https://github.com/node-fetch/node-fetch/issues/417#issuecomment-587233352
         actualValue = '/';
@@ -187,20 +187,29 @@ async function testFixture(directory, opts = {}, args = []) {
     }
   );
 
-  const stdoutList = [];
-  const stderrList = [];
-
+  let stdout = '';
+  let stderr = '';
+  const readyResolver = createResolver();
   const exitResolver = createResolver();
 
-  dev.stderr.on('data', data => stderrList.push(Buffer.from(data)));
-  dev.stdout.on('data', data => stdoutList.push(Buffer.from(data)));
+  dev.stdout.setEncoding('utf8');
+  dev.stderr.setEncoding('utf8');
+
+  dev.stdout.on('data', data => {
+    stdout += data;
+  });
+  dev.stderr.on('data', data => {
+    stderr += data;
+
+    if (stderr.includes('Ready! Available at')) {
+      readyResolver.resolve();
+    }
+  });
 
   let printedOutput = false;
 
   dev.on('exit', () => {
     if (!printedOutput) {
-      const stdout = Buffer.concat(stdoutList).toString();
-      const stderr = Buffer.concat(stderrList).toString();
       printOutput(directory, stdout, stderr);
       printedOutput = true;
     }
@@ -209,8 +218,6 @@ async function testFixture(directory, opts = {}, args = []) {
 
   dev.on('error', () => {
     if (!printedOutput) {
-      const stdout = Buffer.concat(stdoutList).toString();
-      const stderr = Buffer.concat(stderrList).toString();
       printOutput(directory, stdout, stderr);
       printedOutput = true;
     }
@@ -226,6 +233,7 @@ async function testFixture(directory, opts = {}, args = []) {
   return {
     dev,
     port,
+    readyResolver,
   };
 }
 
@@ -267,14 +275,12 @@ function testFixtureStdio(
 
     await runNpmInstall(cwd);
 
-    const stdoutList = [];
-    const stderrList = [];
-
+    let stdout = '';
+    let stderr = '';
     const readyResolver = createResolver();
     const exitResolver = createResolver();
 
     try {
-      let stderr = '';
       let printedOutput = false;
 
       const env = skipDeploy
@@ -285,17 +291,19 @@ function testFixtureStdio(
         env,
       });
 
+      dev.stdout.setEncoding('utf8');
+      dev.stderr.setEncoding('utf8');
+
       dev.stdout.pipe(process.stdout);
       dev.stderr.pipe(process.stderr);
 
       dev.stdout.on('data', data => {
-        stdoutList.push(data);
+        stdout += data;
       });
 
       dev.stderr.on('data', data => {
-        stderrList.push(data);
+        stderr += data;
 
-        stderr += data.toString();
         if (stderr.includes('Ready! Available at')) {
           readyResolver.resolve();
         }
@@ -315,8 +323,6 @@ function testFixtureStdio(
 
       dev.on('exit', () => {
         if (!printedOutput) {
-          const stdout = Buffer.concat(stdoutList).toString();
-          const stderr = Buffer.concat(stderrList).toString();
           printOutput(directory, stdout, stderr);
           printedOutput = true;
         }
@@ -325,8 +331,6 @@ function testFixtureStdio(
 
       dev.on('error', () => {
         if (!printedOutput) {
-          const stdout = Buffer.concat(stdoutList).toString();
-          const stderr = Buffer.concat(stderrList).toString();
           printOutput(directory, stdout, stderr);
           printedOutput = true;
         }
@@ -375,6 +379,153 @@ test.afterEach(async () => {
   );
 });
 
+test('[vercel dev] prints `npm install` errors', async t => {
+  const dir = fixture('runtime-not-installed');
+  const result = await exec(dir);
+  t.truthy(result.stderr.includes('npm ERR! 404'));
+  t.truthy(
+    result.stderr.includes('Failed to install `vercel dev` dependencies')
+  );
+  t.truthy(
+    result.stderr.includes('https://vercel.link/npm-install-failed-dev')
+  );
+});
+
+test('[vercel dev] `vercel.json` should be invalidated if deleted', async t => {
+  const dir = fixture('invalidate-vercel-config');
+  const configPath = join(dir, 'vercel.json');
+  const originalConfig = await fs.readJSON(configPath);
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    {
+      // Env var should be set from `vercel.json`
+      const res = await fetch(`http://localhost:${port}/api`);
+      const body = await res.json();
+      t.is(body.FOO, 'bar');
+    }
+
+    {
+      // Env var should not be set after `vercel.json` is deleted
+      await fs.remove(configPath);
+      await sleep(1000);
+
+      const res = await fetch(`http://localhost:${port}/api`);
+      const body = await res.json();
+      t.is(body.FOO, undefined);
+    }
+  } finally {
+    await dev.kill('SIGTERM');
+    await fs.writeJSON(configPath, originalConfig);
+  }
+});
+
+test('[vercel dev] reflects changes to config and env without restart', async t => {
+  const dir = fixture('node-helpers');
+  const configPath = join(dir, 'vercel.json');
+  const originalConfig = await fs.readJSON(configPath);
+  const { dev, port, readyResolver } = await testFixture(dir);
+
+  try {
+    await readyResolver;
+
+    {
+      // Node.js helpers should be available by default
+      const res = await fetch(`http://localhost:${port}/?foo=bar`);
+      const body = await res.json();
+      t.is(body.hasHelpers, true);
+      t.is(body.query.foo, 'bar');
+    }
+
+    {
+      // Disable the helpers via `config.helpers = false`
+      const config = {
+        ...originalConfig,
+        builds: [
+          {
+            ...originalConfig.builds[0],
+            config: {
+              helpers: false,
+            },
+          },
+        ],
+      };
+      await fs.writeJSON(configPath, config);
+      await sleep(1000);
+
+      const res = await fetch(`http://localhost:${port}/?foo=bar`);
+      const body = await res.json();
+      t.is(body.hasHelpers, false);
+      t.is(body.query, undefined);
+    }
+
+    {
+      // Enable the helpers via `config.helpers = true`
+      const config = {
+        ...originalConfig,
+        builds: [
+          {
+            ...originalConfig.builds[0],
+            config: {
+              helpers: true,
+            },
+          },
+        ],
+      };
+      await fs.writeJSON(configPath, config);
+      await sleep(1000);
+
+      const res = await fetch(`http://localhost:${port}/?foo=baz`);
+      const body = await res.json();
+      t.is(body.hasHelpers, true);
+      t.is(body.query.foo, 'baz');
+    }
+
+    {
+      // Disable the helpers via `NODEJS_HELPERS = '0'`
+      const config = {
+        ...originalConfig,
+        build: {
+          env: {
+            NODEJS_HELPERS: '0',
+          },
+        },
+      };
+      await fs.writeJSON(configPath, config);
+      await sleep(1000);
+
+      const res = await fetch(`http://localhost:${port}/?foo=baz`);
+      const body = await res.json();
+      t.is(body.hasHelpers, false);
+      t.is(body.query, undefined);
+    }
+
+    {
+      // Enable the helpers via `NODEJS_HELPERS = '1'`
+      const config = {
+        ...originalConfig,
+        build: {
+          env: {
+            NODEJS_HELPERS: '1',
+          },
+        },
+      };
+      await fs.writeJSON(configPath, config);
+      await sleep(1000);
+
+      const res = await fetch(`http://localhost:${port}/?foo=boo`);
+      const body = await res.json();
+      t.is(body.hasHelpers, true);
+      t.is(body.query.foo, 'boo');
+    }
+  } finally {
+    await dev.kill('SIGTERM');
+    await fs.writeJSON(configPath, originalConfig);
+  }
+});
+
 test(
   '[vercel dev] validate routes that use `check: true`',
   testFixtureStdio('routes-check-true', async testPath => {
@@ -391,6 +542,17 @@ test(
   })
 );
 
+test(
+  '[vercel dev] validate routes that use custom 404 page',
+  testFixtureStdio('routes-custom-404', async testPath => {
+    await testPath(200, '/', 'Home Page');
+    await testPath(404, '/nothing', 'Custom User 404');
+    await testPath(404, '/exact', 'Exact Custom 404');
+    await testPath(200, '/api/hello', 'Hello');
+    await testPath(404, '/api/nothing', 'Custom User 404');
+  })
+);
+
 test(
   '[vercel dev] handles miss after route',
   testFixtureStdio('handle-miss-after-route', async testPath => {
@@ -477,7 +639,8 @@ test(
     await testPath(200, '/api/date', /current date/);
     await testPath(200, '/api/rand', /random number/);
     await testPath(200, '/api/rand.js', /random number/);
-    await testPath(404, '/api/api');
+    await testPath(404, '/api/api', /NOT_FOUND/m);
+    await testPath(404, '/nothing', /Custom 404 Page/);
   })
 );
 
@@ -573,7 +736,11 @@ test('[vercel dev] validate mixed routes and rewrites', async t => {
   const output = await exec(directory);
 
   t.is(output.exitCode, 1, formatOutput(output));
-  t.regex(output.stderr, /Cannot define both `routes` and `rewrites`/m);
+  t.regex(
+    output.stderr,
+    /If `rewrites`, `redirects`, `headers`, `cleanUrls` or `trailingSlash` are used, then `routes` cannot be present./m
+  );
+  t.regex(output.stderr, /vercel\.link\/mix-routing-props/m);
 });
 
 // Test seems unstable: It won't return sometimes.
@@ -672,6 +839,17 @@ test(
   })
 );
 
+test(
+  '[vercel dev] should serve custom 404 when `cleanUrls: true`',
+  testFixtureStdio('test-clean-urls-custom-404', async testPath => {
+    await testPath(200, '/', 'This is the home page');
+    await testPath(200, '/about', 'The about page');
+    await testPath(200, '/contact/me', 'Contact Me Subdirectory');
+    await testPath(404, '/nothing', 'Custom 404 Page');
+    await testPath(404, '/nothing/', 'Custom 404 Page');
+  })
+);
+
 test(
   '[vercel dev] test cleanUrls and trailingSlash serve correct content',
   testFixtureStdio('test-clean-urls-trailing-slash', async testPath => {
@@ -740,6 +918,16 @@ test(
   })
 );
 
+test(
+  '[vercel dev] should serve custom 404 when `trailingSlash: true`',
+  testFixtureStdio('test-trailing-slash-custom-404', async testPath => {
+    await testPath(200, '/', 'This is the home page');
+    await testPath(200, '/about.html', 'The about page');
+    await testPath(200, '/contact/', 'Contact Subdirectory');
+    await testPath(404, '/nothing/', 'Custom 404 Page');
+  })
+);
+
 test(
   '[vercel dev] test trailingSlash false serve correct content',
   testFixtureStdio('test-trailing-slash-false', async testPath => {
@@ -772,7 +960,11 @@ test(
   testFixtureStdio(
     'invalid-builder-routes',
     async testPath => {
-      await testPath(500, '/', /Invalid regular expression/m);
+      await testPath(
+        500,
+        '/',
+        /Route at index 0 has invalid `src` regular expression/m
+      );
     },
     { skipDeploy: true }
   )
@@ -897,6 +1089,8 @@ test(
   '[vercel dev] 10-nextjs-node',
   testFixtureStdio('10-nextjs-node', async testPath => {
     await testPath(200, '/', /Next.js \+ Node.js API/m);
+    await testPath(200, '/api/date', new RegExp(new Date().getFullYear()));
+    await testPath(404, '/nothing', /Custom Next 404/);
   })
 );
 
@@ -1339,3 +1533,36 @@ test(
     await testPath(200, `/api/user.sh`, /Hello, from Bash!/m);
   })
 );
+
+test(
+  '[vercel dev] Should work with nested `tsconfig.json` files',
+  testFixtureStdio('nested-tsconfig', async testPath => {
+    await testPath(200, `/`, /Nested tsconfig.json test page/);
+    await testPath(200, `/api`, 'Nested `tsconfig.json` API endpoint');
+  })
+);
+
+test(
+  '[vercel dev] Should force `tsc` option "module: commonjs" for `startDevServer()`',
+  testFixtureStdio('force-module-commonjs', async testPath => {
+    await testPath(200, `/`, /Force "module: commonjs" test page/);
+    await testPath(
+      200,
+      `/api`,
+      'Force "module: commonjs" JavaScript with ES Modules API endpoint'
+    );
+    await testPath(
+      200,
+      `/api/ts`,
+      'Force "module: commonjs" TypeScript API endpoint'
+    );
+  })
+);
+
+test(
+  '[vercel dev] should prioritize index.html over other file named index.*',
+  testFixtureStdio('index-html-priority', async testPath => {
+    await testPath(200, '/', 'This is index.html');
+    await testPath(200, '/index.css', 'This is index.css');
+  })
+);

packages/now-cli/test/fixtures/unit/get-vercel-directory-error/.gitignore

@@ -0,0 +1,2 @@
+!.vercel
+!.now

packages/now-cli/test/fixtures/unit/get-vercel-directory-legacy/.gitignore

@@ -0,0 +1 @@
+!.now

packages/now-cli/test/fixtures/unit/get-vercel-directory/.gitignore

@@ -0,0 +1 @@
+!.vercel

packages/now-cli/test/helpers/prepare.js

@@ -514,6 +514,11 @@ CMD ["node", "index.js"]`,
         ],
       }),
     },
+    'conflicting-now-json-vercel-json': {
+      'index.html': '<h1>I am a website.</h1>',
+      'vercel.json': getConfigFile(true),
+      'now.json': getConfigFile(true),
+    },
   };
 
   for (const typeName of Object.keys(spec)) {

packages/now-cli/test/integration-v1.js

@@ -1703,7 +1703,7 @@ test('ensure we are getting a warning for the old team flag', async t => {
   // Ensure the warning is printed
   t.true(
     stderr.includes(
-      'WARN! The "--team" flag is deprecated. Please use "--scope" instead.'
+      'WARN! The "--team" option is deprecated. Please use "--scope" instead.'
     )
   );
 

packages/now-cli/test/integration.js

@@ -1589,7 +1589,7 @@ test('create a staging deployment', async t => {
     /Setting target to staging/gm,
     formatOutput(targetCall)
   );
-
+  t.regex(targetCall.stdout, /https:\/\//gm);
   t.is(targetCall.exitCode, 0, formatOutput(targetCall));
 
   const { host } = new URL(targetCall.stdout);
@@ -1625,6 +1625,7 @@ test('create a production deployment', async t => {
     /Setting target to production/gm,
     formatOutput(targetCall)
   );
+  t.regex(targetCall.stdout, /https:\/\//gm);
 
   const { host: targetHost } = new URL(targetCall.stdout);
   const targetDeployment = await apiFetch(
@@ -1648,6 +1649,7 @@ test('create a production deployment', async t => {
     /Setting target to production/gm,
     formatOutput(targetCall)
   );
+  t.regex(call.stdout, /https:\/\//gm);
 
   const { host } = new URL(call.stdout);
   const deployment = await apiFetch(
@@ -2554,7 +2556,7 @@ test('should prefill "project name" prompt with --name', async t => {
   let isDeprecated = false;
 
   await waitForPrompt(now, chunk => {
-    if (chunk.includes('The "--name" flag is deprecated')) {
+    if (chunk.includes('The "--name" option is deprecated')) {
       isDeprecated = true;
     }
 
@@ -2895,3 +2897,40 @@ test('deploys with only vercel.json and README.md', async t => {
   const text = await res.text();
   t.regex(text, /readme contents/);
 });
+
+test('reject conflicting `vercel.json` and `now.json` files', async t => {
+  const directory = fixture('conflicting-now-json-vercel-json');
+
+  const { exitCode, stderr, stdout } = await execa(
+    binaryPath,
+    [...defaultArgs, '--confirm'],
+    {
+      cwd: directory,
+      reject: false,
+    }
+  );
+
+  t.is(exitCode, 1, formatOutput({ stderr, stdout }));
+  t.true(
+    stderr.includes(
+      'Cannot use both a `vercel.json` and `now.json` file. Please delete the `now.json` file.'
+    ),
+    formatOutput({ stderr, stdout })
+  );
+});
+
+test('`vc --debug project ls` should output the projects listing', async t => {
+  const { exitCode, stderr, stdout } = await execa(
+    binaryPath,
+    [...defaultArgs, '--debug', 'project', 'ls'],
+    {
+      reject: false,
+    }
+  );
+
+  t.is(exitCode, 0, formatOutput({ stderr, stdout }));
+  t.true(
+    stdout.includes('> Projects found under'),
+    formatOutput({ stderr, stdout })
+  );
+});

packages/now-cli/test/unit.js

@@ -1,4 +1,4 @@
-import { join, sep } from 'path';
+import { basename, join, sep } from 'path';
 import { send } from 'micro';
 import test from 'ava';
 import sinon from 'sinon';
@@ -24,6 +24,7 @@ import { isValidName } from '../src/util/is-valid-name';
 import preferV2Deployment from '../src/util/prefer-v2-deployment';
 import getUpdateCommand from '../src/util/get-update-command';
 import { isCanary } from '../src/util/is-canary';
+import { getVercelDirectory } from '../src/util/projects/link';
 
 const output = createOutput({ debug: false });
 const prefix = `${join(__dirname, 'fixtures', 'unit')}${sep}`;
@@ -1091,3 +1092,29 @@ test('detect update command', async t => {
   const updateCommand = await getUpdateCommand();
   t.is(updateCommand, `yarn add vercel@${isCanary() ? 'canary' : 'latest'}`);
 });
+
+test('`getVercelDirectory()` returns ".vercel"', t => {
+  const cwd = fixture('get-vercel-directory');
+  const dir = getVercelDirectory(cwd);
+  t.is(basename(dir), '.vercel');
+});
+
+test('`getVercelDirectory()` returns ".now"', t => {
+  const cwd = fixture('get-vercel-directory-legacy');
+  const dir = getVercelDirectory(cwd);
+  t.is(basename(dir), '.now');
+});
+
+test('`getVercelDirectory()` throws an error if ".vercel" and ".now" exist', t => {
+  let err;
+  const cwd = fixture('get-vercel-directory-error');
+  try {
+    getVercelDirectory(cwd);
+  } catch (_err) {
+    err = _err;
+  }
+  t.is(
+    err.message,
+    'Both `.vercel` and `.now` directories exist. Please remove the `.now` directory.'
+  );
+});

packages/now-client/.gitignore

@@ -3,4 +3,6 @@ lib
 node_modules
 *.log
 
-!tests/fixtures/nowignore/node_modules
+!tests/fixtures/nowignore/node_modules
+!tests/fixtures/vercelignore-allow-nodemodules/node_modules
+!tests/fixtures/vercelignore-allow-nodemodules/sub/node_modules

packages/now-client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/client",
-  "version": "8.0.2-canary.1",
+  "version": "8.1.0",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",
   "homepage": "https://vercel.com",
@@ -27,7 +27,7 @@
     "@types/node-fetch": "2.5.4",
     "@types/recursive-readdir": "2.2.0",
     "@zeit/ncc": "0.18.5",
-    "typescript": "3.5.1"
+    "typescript": "3.9.3"
   },
   "jest": {
     "preset": "ts-jest",

packages/now-client/src/check-deployment-status.ts

@@ -93,6 +93,16 @@ export async function* checkDeploymentStatus(
     }
 
     if (isAliasAssigned(deploymentUpdate)) {
+      if (
+        deploymentUpdate.aliasWarning &&
+        deploymentUpdate.aliasWarning.message
+      ) {
+        yield {
+          type: 'warning',
+          payload: deploymentUpdate.aliasWarning.message,
+        };
+      }
+
       debug('Deployment alias assigned');
       return yield { type: 'alias-assigned', payload: deploymentUpdate };
     }

packages/now-client/src/create-deployment.ts

@@ -3,7 +3,7 @@ import { readdir as readRootFolder, lstatSync } from 'fs-extra';
 import { relative, isAbsolute, basename } from 'path';
 import hashes, { mapToObject } from './utils/hashes';
 import { upload } from './upload';
-import { buildFileTree, createDebug, parseNowJSON } from './utils';
+import { buildFileTree, createDebug, parseVercelConfig } from './utils';
 import { DeploymentError } from './errors';
 import {
   NowConfig,
@@ -85,10 +85,24 @@ export default function buildCreateDeployment(version: number) {
     let configPath: string | undefined;
     if (!nowConfig) {
       // If the user did not provide a config file, use the one in the root directory.
-      configPath = fileList
-        .map(f => relative(cwd, f))
-        .find(f => f === 'vercel.json' || f === 'now.json');
-      nowConfig = await parseNowJSON(configPath);
+      const relativePaths = fileList.map(f => relative(cwd, f));
+      const hasVercelConfig = relativePaths.includes('vercel.json');
+      const hasNowConfig = relativePaths.includes('now.json');
+
+      if (hasVercelConfig) {
+        if (hasNowConfig) {
+          throw new DeploymentError({
+            code: 'conflicting_config',
+            message:
+              'Cannot use both a `vercel.json` and `now.json` file. Please delete the `now.json` file.',
+          });
+        }
+        configPath = 'vercel.json';
+      } else if (hasNowConfig) {
+        configPath = 'now.json';
+      }
+
+      nowConfig = await parseVercelConfig(configPath);
     }
 
     if (

packages/now-client/src/utils/index.ts

@@ -7,6 +7,7 @@ import qs from 'querystring';
 import ignore from 'ignore';
 type Ignore = ReturnType<typeof ignore>;
 import { pkgVersion } from '../pkg';
+import { NowBuildError } from '@vercel/build-utils';
 import { NowClientOptions, DeploymentOptions, NowConfig } from '../types';
 import { Sema } from 'async-sema';
 import { readFile } from 'fs-extra';
@@ -48,10 +49,10 @@ export function getApiDeploymentsUrl(
     return '/v10/now/deployments';
   }
 
-  return '/v12/now/deployments';
+  return '/v13/now/deployments';
 }
 
-export async function parseNowJSON(filePath?: string): Promise<NowConfig> {
+export async function parseVercelConfig(filePath?: string): Promise<NowConfig> {
   if (!filePath) {
     return {};
   }
@@ -76,43 +77,22 @@ const maybeRead = async function<T>(path: string, default_: T) {
   }
 };
 
-export async function readdirRelative(
-  path: string,
-  ignores: string[],
-  cwd: string
-): Promise<string[]> {
-  const preprocessedIgnores = ignores.map(ignore => {
-    if (ignore.endsWith('/')) {
-      return ignore.slice(0, -1);
-    }
-    return ignore;
-  });
-  const dirContents = await readdir(path, preprocessedIgnores);
-  return dirContents.map(filePath => relative(cwd, filePath));
-}
-
 export async function buildFileTree(
   path: string | string[],
   isDirectory: boolean,
   debug: Debug
 ): Promise<string[]> {
-  // Get .nowignore
-  let { ig, ignores } = await getVercelIgnore(path);
-
-  debug(`Found ${ig.ignores.length} rules in .nowignore`);
-
   let fileList: string[];
+  let { ig } = await getVercelIgnore(path);
 
+  debug(`Found ${ig.ignores.length} rules in .vercelignore`);
   debug('Building file tree...');
 
   if (isDirectory && !Array.isArray(path)) {
     // Directory path
     const cwd = process.cwd();
-    const relativeFileList = await readdirRelative(path, ignores, cwd);
-    fileList = ig
-      .filter(relativeFileList)
-      .map((relativePath: string) => join(cwd, relativePath));
-
+    const ignores = (absPath: string) => ig.ignores(relative(cwd, absPath));
+    fileList = await readdir(path, [ignores]);
     debug(`Read ${fileList.length} files in the specified directory`);
   } else if (Array.isArray(path)) {
     // Array of file paths
@@ -166,9 +146,12 @@ export async function getVercelIgnore(
         maybeRead(join(cwd, '.nowignore'), ''),
       ]);
       if (vercelignore && nowignore) {
-        throw new Error(
-          'Cannot use both a `.vercelignore` and `.nowignore` file. Please delete the `.nowignore` file.'
-        );
+        throw new NowBuildError({
+          code: 'CONFLICTING_IGNORE_FILES',
+          message:
+            'Cannot use both a `.vercelignore` and `.nowignore` file. Please delete the `.nowignore` file.',
+          link: 'https://vercel.link/combining-old-and-new-config',
+        });
       }
       return vercelignore || nowignore;
     })

packages/now-client/tests/fixtures/vercelignore-allow-nodemodules/.env.local

@@ -0,0 +1 @@
+EXCLUDE="this file should be ignored"

packages/now-client/tests/fixtures/vercelignore-allow-nodemodules/.vercelignore

@@ -0,0 +1,6 @@
+# literally dont ignore the node_modules directory
+# so basically include the node_modules directory recursively
+!node_modules/
+
+# ignore this file in addition to the defaults
+exclude.txt

packages/now-client/tests/fixtures/vercelignore-allow-nodemodules/exclude.txt

@@ -0,0 +1 @@
+Should be ignored

packages/now-client/tests/fixtures/vercelignore-allow-nodemodules/hello.txt

@@ -0,0 +1 @@
+Hello World

packages/now-client/tests/fixtures/vercelignore-allow-nodemodules/sub/include.txt

@@ -0,0 +1 @@
+Should be included