Publish Canary

- @vercel/frameworks@0.0.16-canary.1
 - @vercel/build-utils@2.4.1-canary.2
 - vercel@19.1.2-canary.18
 - @vercel/client@8.1.1-canary.2
 - @vercel/next@2.6.9-canary.0

.editorconfig

@@ -19,6 +19,11 @@ indent_style = space
 [*.py]
 indent_size = 4
 
+[*.go]
+indent_style = tab
+indent_size = 4
+tab_width = 4
+
 [*.asm]
 indent_size = 8
 

.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

DEVELOPING_A_RUNTIME.md

@@ -1,10 +1,33 @@
 # Runtime Developer Reference
 
-The following page is a reference for how to create a Runtime using the available Runtime API.
+The following page is a reference for how to create a Runtime by implementing
+the Runtime API interface.
 
-A Runtime is an npm module that exposes a `build` function and optionally an `analyze` function and `prepareCache` function.
-Official Runtimes are published to [npmjs.com](https://npmjs.com) as a package and referenced in the `use` property of the `vercel.json` configuration file.
-However, the `use` property will work with any [npm install argument](https://docs.npmjs.com/cli/install) such as a git repo url which is useful for testing your Runtime.
+A Runtime is an npm module that implements the following interface:
+
+```typescript
+interface Runtime {
+  version: number;
+  build: (options: BuildOptions) => Promise<BuildResult>;
+  analyze?: (options: AnalyzeOptions) => Promise<string>;
+  prepareCache?: (options: PrepareCacheOptions) => Promise<CacheOutputs>;
+  shouldServe?: (options: ShouldServeOptions) => Promise<boolean>;
+  startDevServer?: (
+    options: StartDevServerOptions
+  ) => Promise<StartDevServerResult>;
+}
+```
+
+The `version` property and the `build()` function are the only _required_ fields.
+The rest are optional extensions that a Runtime _may_ implement in order to
+enhance functionality. These functions are documented in more detail below.
+
+Official Runtimes are published to [the npm registry](https://npmjs.com) as a package and referenced in the `use` property of the `vercel.json` configuration file.
+
+> **Note:** The `use` property in the `builds` array will work with any [npm
+> install argument](https://docs.npmjs.com/cli/install) such as a git repo URL,
+> which is useful for testing your Runtime. Alternatively, the `functions` property
+> requires that you specify a specifc tag published to npm, for stability purposes.
 
 See the [Runtimes Documentation](https://vercel.com/docs/runtimes) to view example usage.
 
@@ -16,146 +39,170 @@ A **required** exported constant that decides which version of the Runtime API t
 
 The latest and suggested version is `3`.
 
-### `analyze`
+**Example:**
 
-An **optional** exported function that returns a unique fingerprint used for the purpose of [build de-duplication](https://vercel.com/docs/v2/platform/deployments#deduplication). If the `analyze` function is not supplied, a random fingerprint is assigned to each build.
-
-```js
-export analyze({
-  files: Files,
-  entrypoint: String,
-  workPath: String,
-  config: Object
-}) : String fingerprint
+```typescript
+export const version = 3;
 ```
 
-If you are using TypeScript, you should use the following types:
+### `build()`
 
-```ts
-import { AnalyzeOptions } from '@vercel/build-utils'
+A **required** exported function that returns a Serverless Function.
 
-export analyze(options: AnalyzeOptions) {
-  return 'fingerprint goes here'
+> What's a Serverless Function? Read about [Serverless Functions](https://vercel.com/docs/v2/serverless-functions/introduction) to learn more.
+
+**Example:**
+
+```typescript
+import { BuildOptions, createLambda } from '@vercel/build-utils';
+
+export async function build(options: BuildOptions) {
+  // Build the code here…
+
+  const lambda = createLambda(/* … */);
+  return {
+    output: lambda,
+    watch: [
+      // Dependent files to trigger a rebuild in `vercel dev` go here…
+    ],
+    routes: [
+      // If your Runtime needs to define additional routing, define it here…
+    ],
+  };
 }
 ```
 
-### `build`
+### `analyze()`
 
-A **required** exported function that returns a [Serverless Function](#serverless-function).
+An **optional** exported function that returns a unique fingerprint used for the
+purpose of [build
+de-duplication](https://vercel.com/docs/v2/platform/deployments#deduplication).
+If the `analyze()` function is not supplied, then a random fingerprint is
+assigned to each build.
 
-What's a Serverless Function? Read about [Serverless Functions](https://vercel.com/docs/v2/serverless-functions/introduction) to learn more.
+**Example:**
 
-```js
-build({
-  files: Files,
-  entrypoint: String,
-  workPath: String,
-  config: Object,
-  meta?: {
-    isDev?: Boolean,
-    requestPath?: String,
-    filesChanged?: Array<String>,
-    filesRemoved?: Array<String>
-  }
-}) : {
-  watch?: Array<String>,
-  output: Lambda,
-  routes?: Object
+```typescript
+import { AnalyzeOptions } from '@vercel/build-utils';
+
+export async function analyze(options: AnalyzeOptions) {
+  // Do calculations to generate a fingerprint based off the source code here…
+
+  return 'fingerprint goes here';
 }
 ```
 
-If you are using TypeScript, you should use the following types:
+### `prepareCache()`
 
-```ts
-import { BuildOptions } from '@vercel/build-utils'
+An **optional** exported function that is executed after [`build()`](#build) is
+completed. The implementation should return an object of `File`s that will be
+pre-populated in the working directory for the next build run in the user's
+project. An example use-case is that `@vercel/node` uses this function to cache
+the `node_modules` directory, making it faster to install npm dependencies for
+future builds.
 
-export build(options: BuildOptions) {
-  // Build the code here
+**Example:**
+
+```typescript
+import { PrepareCacheOptions } from '@vercel/build-utils';
+
+export async function prepareCache(options: PrepareCacheOptions) {
+  // Create a mapping of file names and `File` object instances to cache here…
 
   return {
-    output: {
-      'path-to-file': File,
-      'path-to-lambda': Lambda
-    },
-    watch: [],
-    routes: {}
-  }
+    'path-to-file': File,
+  };
 }
 ```
 
-### `prepareCache`
+### `shouldServe()`
 
-An **optional** exported function that is equivalent to [`build`](#build), but it executes the instructions necessary to prepare a cache for the next run.
+An **optional** exported function that is only used by `vercel dev` in [Vercel
+CLI](https://vercel.com/download) and indicates whether a
+[Runtime](https://vercel.com/docs/runtimes) wants to be responsible for responding
+to a certain request path.
 
-```js
-prepareCache({
-  files: Files,
-  entrypoint: String,
-  workPath: String,
-  cachePath: String,
-  config: Object
-}) : Files cacheOutput
-```
+**Example:**
 
-If you are using TypeScript, you can import the types for each of these functions by using the following:
+```typescript
+import { ShouldServeOptions } from '@vercel/build-utils';
 
-```ts
-import { PrepareCacheOptions } from '@vercel/build-utils'
+export async function shouldServe(options: ShouldServeOptions) {
+  // Determine whether or not the Runtime should respond to the request path here…
 
-export prepareCache(options: PrepareCacheOptions) {
-  return { 'path-to-file': File }
+  return options.requestPath === options.entrypoint;
 }
 ```
 
-### `shouldServe`
+If this function is not defined, Vercel CLI will use the [default implementation](https://github.com/vercel/vercel/blob/52994bfe26c5f4f179bdb49783ee57ce19334631/packages/now-build-utils/src/should-serve.ts).
 
-An **optional** exported function that is only used by `vercel dev` in [Vercel CLI](https:///download) and indicates whether a [Runtime](https://vercel.com/docs/runtimes) wants to be responsible for building a certain request path.
+### `startDevServer()`
 
-```js
-shouldServe({
-  entrypoint: String,
-  files: Files,
-  config: Object,
-  requestPath: String,
-  workPath: String
-}) : Boolean
-```
+An **optional** exported function that is only used by `vercel dev` in [Vercel
+CLI](https://vercel.com/download). If this function is defined, Vercel CLI will
+**not** invoke the `build()` function, and instead invoke this function for every
+HTTP request. It is an opportunity to provide an optimized development experience
+rather than going through the entire `build()` process that is used in production.
 
-If you are using TypeScript, you can import the types for each of these functions by using the following:
+This function is invoked _once per HTTP request_ and is expected to spawn a child
+process which creates an HTTP server that will execute the entrypoint code when
+an HTTP request is received. This child process is _single-serve_ (only used for
+a single HTTP request). After the HTTP response is complete, `vercel dev` sends
+a shut down signal to the child process.
 
-```ts
-import { ShouldServeOptions } from '@vercel/build-utils'
+The `startDevServer()` function returns an object with the `port` number that the
+child process' HTTP server is listening on (which should be an [ephemeral
+port](https://stackoverflow.com/a/28050404/376773)) as well as the child process'
+Process ID, which `vercel dev` uses to send the shut down signal to.
 
-export shouldServe(options: ShouldServeOptions) {
-  return Boolean
+> **Hint:** To determine which ephemeral port the child process is listening on,
+> some form of [IPC](https://en.wikipedia.org/wiki/Inter-process_communication) is
+> required. For example, in `@vercel/go` the child process writes the port number
+> to [_file descriptor 3_](https://en.wikipedia.org/wiki/File_descriptor), which is read by the `startDevServer()` function
+> implementation.
+
+It may also return `null` to opt-out of this behavior for a particular request
+path or entrypoint.
+
+**Example:**
+
+```typescript
+import { spawn } from 'child_process';
+import { StartDevServerOptions } from '@vercel/build-utils';
+
+export async function startDevServer(options: StartDevServerOptions) {
+  // Create a child process which will create an HTTP server.
+  //
+  // Note: `my-runtime-dev-server` is an example dev server program name.
+  // Your implementation will spawn a different program specific to your runtime.
+  const child = spawn('my-runtime-dev-server', [options.entrypoint], {
+    stdio: ['ignore', 'inherit', 'inherit', 'pipe'],
+  });
+
+  // In this example, the child process will write the port number to FD 3…
+  const portPipe = child.stdio[3];
+  const childPort = await new Promise(resolve => {
+    portPipe.setEncoding('utf8');
+    portPipe.once('data', data => {
+      resolve(Number(data));
+    });
+  });
+
+  return { pid: child.pid, port: childPort };
 }
 ```
 
-If this method is not defined, Vercel CLI will default to [this function](https://github.com/vercel/vercel/blob/52994bfe26c5f4f179bdb49783ee57ce19334631/packages/now-build-utils/src/should-serve.ts).
-
-### Runtime Options
-
-The exported functions [`analyze`](#analyze), [`build`](#build), and [`prepareCache`](#preparecache) receive one argument with the following properties.
-
-**Properties:**
-
-- `files`: All source files of the project as a [Files](#files) data structure.
-- `entrypoint`: Name of entrypoint file for this particular build job. Value `files[entrypoint]` is guaranteed to exist and be a valid [File](#files) reference. `entrypoint` is always a discrete file and never a glob, since globs are expanded into separate builds at deployment time.
-- `workPath`: A writable temporary directory where you are encouraged to perform your build process. This directory will be populated with the restored cache from the previous run (if any) for [`analyze`](#analyze) and [`build`](#build).
-- `cachePath`: A writable temporary directory where you can build a cache for the next run. This is only passed to `prepareCache`.
-- `config`: An arbitrary object passed from by the user in the [Build definition](#defining-the-build-step) in `vercel.json`.
-
-## Examples
-
-Check out our [Node.js Runtime](https://github.com/vercel/vercel/tree/master/packages/now-node), [Go Runtime](https://github.com/vercel/vercel/tree/master/packages/now-go), [Python Runtime](https://github.com/vercel/vercel/tree/master/packages/now-python) or [Ruby Runtime](https://github.com/vercel/vercel/tree/master/packages/now-ruby) for examples of how to build one.
-
-## Technical Details
-
 ### Execution Context
 
-A [Serverless Function](https://vercel.com/docs/v2/serverless-functions/introduction) is created where the Runtime logic is executed. The lambda is run using the Node.js 8 runtime. A brand new sandbox is created for each deployment, for security reasons. The sandbox is cleaned up between executions to ensure no lingering temporary files are shared from build to build.
+- Runtimes are executed in a Linux container that closely matches the Servereless Function runtime environment.
+- The Runtime code is executed using Node.js version **12.x**.
+- A brand new sandbox is created for each deployment, for security reasons.
+- The sandbox is cleaned up between executions to ensure no lingering temporary files are shared from build to build.
 
-All the APIs you export ([`analyze`](#analyze), [`build`](#build) and [`prepareCache`](#preparecache)) are not guaranteed to be run in the same process, but the filesystem we expose (e.g.: `workPath` and the results of calling [`getWriteableDirectory`](#getWriteableDirectory) ) is retained.
+All the APIs you export ([`analyze()`](#analyze), [`build()`](#build),
+[`prepareCache()`](#preparecache), etc.) are not guaranteed to be run in the
+same process, but the filesystem we expose (e.g.: `workPath` and the results
+of calling [`getWritableDirectory`](#getWritableDirectory) ) is retained.
 
 If you need to share state between those steps, use the filesystem.
 
@@ -173,11 +220,11 @@ The env and secrets specified by the user as `build.env` are passed to the Runti
 
 When you publish your Runtime to npm, make sure to not specify `@vercel/build-utils` (as seen below in the API definitions) as a dependency, but rather as part of `peerDependencies`.
 
-## Types
+## `@vercel/build-utils` Types
 
 ### `Files`
 
-```ts
+```typescript
 import { File } from '@vercel/build-utils';
 type Files = { [filePath: string]: File };
 ```
@@ -188,7 +235,7 @@ When used as an input, the `Files` object will only contain `FileRefs`. When `Fi
 
 An example of a valid output `Files` object is:
 
-```json
+```javascript
 {
   "index.html": FileRef,
   "api/index.js": Lambda
@@ -199,7 +246,7 @@ An example of a valid output `Files` object is:
 
 This is an abstract type that can be imported if you are using TypeScript.
 
-```ts
+```typescript
 import { File } from '@vercel/build-utils';
 ```
 
@@ -211,71 +258,71 @@ Valid `File` types include:
 
 ### `FileRef`
 
-```ts
+```typescript
 import { FileRef } from '@vercel/build-utils';
 ```
 
-This is a [JavaScript class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents an abstract file instance stored in our platform, based on the file identifier string (its checksum). When a `Files` object is passed as an input to `analyze` or `build`, all its values will be instances of `FileRef`.
+This is a [class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents an abstract file instance stored in our platform, based on the file identifier string (its checksum). When a `Files` object is passed as an input to `analyze` or `build`, all its values will be instances of `FileRef`.
 
 **Properties:**
 
-- `mode : Number` file mode
-- `digest : String` a checksum that represents the file
+- `mode: Number` file mode
+- `digest: String` a checksum that represents the file
 
 **Methods:**
 
-- `toStream() : Stream` creates a [Stream](https://nodejs.org/api/stream.html) of the file body
+- `toStream(): Stream` creates a [Stream](https://nodejs.org/api/stream.html) of the file body
 
 ### `FileFsRef`
 
-```ts
+```typescript
 import { FileFsRef } from '@vercel/build-utils';
 ```
 
-This is a [JavaScript class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents an abstract instance of a file present in the filesystem that the build process is executing in.
+This is a [class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents an abstract instance of a file present in the filesystem that the build process is executing in.
 
 **Properties:**
 
-- `mode : Number` file mode
-- `fsPath : String` the absolute path of the file in file system
+- `mode: Number` file mode
+- `fsPath: String` the absolute path of the file in file system
 
 **Methods:**
 
-- `static async fromStream({ mode : Number, stream : Stream, fsPath : String }) : FileFsRef` creates an instance of a [FileFsRef](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object) from `Stream`, placing file at `fsPath` with `mode`
-- `toStream() : Stream` creates a [Stream](https://nodejs.org/api/stream.html) of the file body
+- `static async fromStream({ mode: Number, stream: Stream, fsPath: String }): FileFsRef` creates an instance of a [FileFsRef](#FileFsRef) from `Stream`, placing file at `fsPath` with `mode`
+- `toStream(): Stream` creates a [Stream](https://nodejs.org/api/stream.html) of the file body
 
 ### `FileBlob`
 
-```ts
+```typescript
 import { FileBlob } from '@vercel/build-utils';
 ```
 
-This is a [JavaScript class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents an abstract instance of a file present in memory.
+This is a [class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents an abstract instance of a file present in memory.
 
 **Properties:**
 
-- `mode : Number` file mode
-- `data : String | Buffer` the body of the file
+- `mode: Number` file mode
+- `data: String | Buffer` the body of the file
 
 **Methods:**
 
-- `static async fromStream({ mode : Number, stream : Stream }) :FileBlob` creates an instance of a [FileBlob](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object) from [`Stream`](https://nodejs.org/api/stream.html) with `mode`
-- `toStream() : Stream` creates a [Stream](https://nodejs.org/api/stream.html) of the file body
+- `static async fromStream({ mode: Number, stream: Stream }): FileBlob` creates an instance of a [FileBlob](#FileBlob) from [`Stream`](https://nodejs.org/api/stream.html) with `mode`
+- `toStream(): Stream` creates a [Stream](https://nodejs.org/api/stream.html) of the file body
 
 ### `Lambda`
 
-```ts
+```typescript
 import { Lambda } from '@vercel/build-utils';
 ```
 
-This is a [JavaScript class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes), called a Serverless Function, that can be created by supplying `files`, `handler`, `runtime`, and `environment` as an object to the [`createLambda`](#createlambda) helper. The instances of this class should not be created directly. Instead, invoke the [`createLambda`](#createlambda) helper function.
+This is a [class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) that represents a Serverless Function. An instance can be created by supplying `files`, `handler`, `runtime`, and `environment` as an object to the [`createLambda`](#createlambda) helper. The instances of this class should not be created directly. Instead, invoke the [`createLambda`](#createlambda) helper function.
 
 **Properties:**
 
-- `files : Files` the internal filesystem of the lambda
-- `handler : String` path to handler file and (optionally) a function name it exports
-- `runtime : LambdaRuntime` the name of the lambda runtime
-- `environment : Object` key-value map of handler-related (aside of those passed by user) environment variables
+- `files: Files` the internal filesystem of the lambda
+- `handler: String` path to handler file and (optionally) a function name it exports
+- `runtime: LambdaRuntime` the name of the lambda runtime
+- `environment: Object` key-value map of handler-related (aside of those passed by user) environment variables
 
 ### `LambdaRuntime`
 
@@ -291,15 +338,15 @@ This is an abstract enumeration type that is implemented by one of the following
 - `ruby2.5`
 - `provided`
 
-## JavaScript API
+## `@vercel/build-utils` Helper Functions
 
 The following is exposed by `@vercel/build-utils` to simplify the process of writing Runtimes, manipulating the file system, using the above types, etc.
 
-### `createLambda`
+### `createLambda()`
 
-Signature: `createLambda(Object spec) : Lambda`
+Signature: `createLambda(Object spec): Lambda`
 
-```ts
+```typescript
 import { createLambda } from '@vercel/build-utils';
 ```
 
@@ -316,29 +363,33 @@ await createLambda({
 });
 ```
 
-### `download`
+### `download()`
 
-Signature: `download() : Files`
+Signature: `download(): Files`
 
-```ts
+```typescript
 import { download } from '@vercel/build-utils';
 ```
 
-This utility allows you to download the contents of a [`Files`](#files) data structure, therefore creating the filesystem represented in it.
+This utility allows you to download the contents of a [`Files`](#files) data
+structure, therefore creating the filesystem represented in it.
 
-Since `Files` is an abstract way of representing files, you can think of `download` as a way of making that virtual filesystem _real_.
+Since `Files` is an abstract way of representing files, you can think of
+`download()` as a way of making that virtual filesystem _real_.
 
-If the **optional** `meta` property is passed (the argument for [build](#build)), only the files that have changed are downloaded. This is decided using `filesRemoved` and `filesChanged` inside that object.
+If the **optional** `meta` property is passed (the argument for
+[`build()`](#build)), only the files that have changed are downloaded.
+This is decided using `filesRemoved` and `filesChanged` inside that object.
 
 ```js
 await download(files, workPath, meta);
 ```
 
-### `glob`
+### `glob()`
 
-Signature: `glob() : Files`
+Signature: `glob(): Files`
 
-```ts
+```typescript
 import { glob } from '@vercel/build-utils';
 ```
 
@@ -355,21 +406,21 @@ exports.build = ({ files, workPath }) => {
 }
 ```
 
-### `getWriteableDirectory`
+### `getWritableDirectory()`
 
-Signature: `getWriteableDirectory() : String`
+Signature: `getWritableDirectory(): String`
 
-```ts
-import { getWriteableDirectory } from '@vercel/build-utils';
+```typescript
+import { getWritableDirectory } from '@vercel/build-utils';
 ```
 
 In some occasions, you might want to write to a temporary directory.
 
-### `rename`
+### `rename()`
 
-Signature: `rename(Files) : Files`
+Signature: `rename(Files, Function): Files`
 
-```ts
+```typescript
 import { rename } from '@vercel/build-utils';
 ```
 

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)

examples/blitzjs/.babelrc.js

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: ["next/babel"],
+  plugins: [],
+}

examples/blitzjs/.eslintrc.js

@@ -0,0 +1,10 @@
+module.exports = {
+  extends: ["react-app", "plugin:jsx-a11y/recommended"],
+  plugins: ["jsx-a11y"],
+  rules: {
+    "import/no-anonymous-default-export": "error",
+    "import/no-webpack-loader-syntax": "off",
+    "react/react-in-jsx-scope": "off", // React is always in scope with Blitz
+    "jsx-a11y/anchor-is-valid": "off", //Doesn't play well with Blitz/Next <Link> usage
+  },
+}

examples/blitzjs/.gitignore

@@ -0,0 +1,56 @@
+# dependencies
+node_modules
+.yarn/cache
+.yarn/unplugged
+.yarn/build-state.yml
+.pnp.*
+.npm
+web_modules/
+
+# blitz
+/.blitz/
+/.next/
+*.sqlite
+.now
+.vercel
+.blitz-console-history
+blitz-log.log
+
+# misc
+.DS_Store
+
+# local env files
+.env
+.envrc
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# Logs
+logs
+*.log
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Testing
+coverage
+*.lcov
+.nyc_output
+lib-cov
+
+# Caches
+*.tsbuildinfo
+.eslintcache
+.node_repl_history
+.yarn-integrity
+
+# Serverless directories
+.serverless/
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test

examples/blitzjs/.npmrc

@@ -0,0 +1 @@
+save-exact=true

examples/blitzjs/.prettierignore

@@ -0,0 +1,6 @@
+.gitkeep
+.env
+*.ico
+*.lock
+db/migrations
+

examples/blitzjs/README.md

@@ -0,0 +1,21 @@
+![Blitz Logo](https://github.com/vercel/vercel/blob/master/packages/frameworks/logos/blitz.svg)
+
+This is a [Blitz.js](https://blitzjs.com/) project bootstrapped with `blitz new`.
+
+## Getting Started
+
+First, run the development server:
+
+```bash
+npx blitz start
+```
+
+Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.
+
+## Learn More
+
+To learn more about Blitz.js, view [Blitzjs.com](https://blitzjs.com)
+
+## Deploy on Vercel
+
+View the [documentation on deploying to Vercel](https://blitzjs.com/docs/deploy-vercel)

examples/blitzjs/app/components/ErrorBoundary.tsx

@@ -0,0 +1,21 @@
+import React from "react"
+
+export default class ErrorBoundary extends React.Component<{
+  fallback: (error: any) => React.ReactNode
+}> {
+  state = { hasError: false, error: null }
+
+  static getDerivedStateFromError(error: any) {
+    return {
+      hasError: true,
+      error,
+    }
+  }
+
+  render() {
+    if (this.state.hasError) {
+      return this.props.fallback(this.state.error)
+    }
+    return this.props.children
+  }
+}

examples/blitzjs/app/pages/_app.tsx

@@ -0,0 +1,5 @@
+import { AppProps } from "blitz"
+
+export default function MyApp({ Component, pageProps }: AppProps) {
+  return <Component {...pageProps} />
+}

examples/blitzjs/app/pages/_document.tsx

@@ -0,0 +1,23 @@
+import { Document, Html, DocumentHead, Main, BlitzScript /*DocumentContext*/ } from "blitz"
+
+class MyDocument extends Document {
+  // Only uncomment if you need to customize this behaviour
+  // static async getInitialProps(ctx: DocumentContext) {
+  //   const initialProps = await Document.getInitialProps(ctx)
+  //   return {...initialProps}
+  // }
+
+  render() {
+    return (
+      <Html lang="en">
+        <DocumentHead />
+        <body>
+          <Main />
+          <BlitzScript />
+        </body>
+      </Html>
+    )
+  }
+}
+
+export default MyDocument

examples/blitzjs/app/pages/index.tsx

@@ -0,0 +1,197 @@
+import { Head, Link } from "blitz"
+
+const Home = () => (
+  <div className="container">
+    <Head>
+      <title>blitzjs</title>
+      <link rel="icon" href="/favicon.ico" />
+    </Head>
+
+    <main>
+      <div className="logo">
+        <img src="/logo.png" alt="blitz.js" />
+      </div>
+      <p>1. Run this command in your terminal:</p>
+      <pre>
+        <code>blitz generate all project name:string</code>
+      </pre>
+      <p>2. Then run this command:</p>
+      <pre>
+        <code>blitz db migrate</code>
+      </pre>
+
+      <p>
+        3. Go to{" "}
+        <Link href="/projects">
+          <a>/projects</a>
+        </Link>
+      </p>
+      <div className="buttons">
+        <a
+          className="button"
+          href="https://github.com/blitz-js/blitz/blob/master/USER_GUIDE.md?utm_source=blitz-new&utm_medium=app-template&utm_campaign=blitz-new"
+          target="_blank"
+          rel="noopener noreferrer"
+        >
+          Documentation
+        </a>
+        <a
+          className="button-outline"
+          href="https://github.com/blitz-js/blitz"
+          target="_blank"
+          rel="noopener noreferrer"
+        >
+          Github Repo
+        </a>
+        <a
+          className="button-outline"
+          href="https://slack.blitzjs.com"
+          target="_blank"
+          rel="noopener noreferrer"
+        >
+          Slack Community
+        </a>
+      </div>
+    </main>
+
+    <footer>
+      <a
+        href="https://blitzjs.com?utm_source=blitz-new&utm_medium=app-template&utm_campaign=blitz-new"
+        target="_blank"
+        rel="noopener noreferrer"
+      >
+        Powered by Blitz.js
+      </a>
+    </footer>
+
+    <style jsx>{`
+      .container {
+        min-height: 100vh;
+        display: flex;
+        flex-direction: column;
+        justify-content: center;
+        align-items: center;
+      }
+
+      main {
+        padding: 5rem 0;
+        flex: 1;
+        display: flex;
+        flex-direction: column;
+        justify-content: center;
+        align-items: center;
+      }
+
+      main p {
+        font-size: 1.2rem;
+      }
+
+      footer {
+        width: 100%;
+        height: 60px;
+        border-top: 1px solid #eaeaea;
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        background-color: #45009d;
+      }
+
+      footer a {
+        display: flex;
+        justify-content: center;
+        align-items: center;
+      }
+
+      footer a {
+        color: #f4f4f4;
+        text-decoration: none;
+      }
+
+      .logo {
+        margin-bottom: 2rem;
+      }
+
+      .logo img {
+        width: 300px;
+      }
+
+      .buttons {
+        display: grid;
+        grid-template-columns: 1fr 1fr 1fr;
+        grid-gap: 0.5rem;
+        margin-top: 6rem;
+      }
+
+      a.button {
+        background-color: #6700eb;
+        padding: 1rem 2rem;
+        color: #f4f4f4;
+        text-align: center;
+      }
+
+      a.button:hover {
+        background-color: #45009d;
+      }
+
+      a.button-outline {
+        border: 2px solid #6700eb;
+        padding: 1rem 2rem;
+        color: #6700eb;
+        text-align: center;
+      }
+
+      a.button-outline:hover {
+        border-color: #45009d;
+        color: #45009d;
+      }
+
+      pre {
+        background: #fafafa;
+        border-radius: 5px;
+        padding: 0.75rem;
+      }
+      code {
+        font-size: 0.9rem;
+        font-family: Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono,
+          Bitstream Vera Sans Mono, Courier New, monospace;
+      }
+
+      .grid {
+        display: flex;
+        align-items: center;
+        justify-content: center;
+        flex-wrap: wrap;
+
+        max-width: 800px;
+        margin-top: 3rem;
+      }
+
+      @media (max-width: 600px) {
+        .grid {
+          width: 100%;
+          flex-direction: column;
+        }
+      }
+    `}</style>
+
+    <style jsx global>{`
+      @import url("https://fonts.googleapis.com/css2?family=Libre+Franklin:wght@300;700&display=swap");
+
+      html,
+      body {
+        padding: 0;
+        margin: 0;
+        font-family: "Libre Franklin", -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen,
+          Ubuntu, Cantarell, Fira Sans, Droid Sans, Helvetica Neue, sans-serif;
+      }
+
+      * {
+        -webkit-font-smoothing: antialiased;
+        -moz-osx-font-smoothing: grayscale;
+        box-sizing: border-box;
+      }
+    `}</style>
+  </div>
+)
+
+export default Home

examples/blitzjs/blitz.config.js

@@ -0,0 +1,15 @@
+module.exports = {
+  /*
+  webpack: (config, { buildId, dev, isServer, defaultLoaders, webpack }) => {
+    // Note: we provide webpack above so you should not `require` it
+    // Perform customizations to webpack config
+    // Important: return the modified config
+    return config
+  },
+  webpackDevMiddleware: (config) => {
+    // Perform customizations to webpack dev middleware config
+    // Important: return the modified config
+    return config
+  },
+  */
+}

examples/blitzjs/db/index.ts

@@ -0,0 +1,15 @@
+import { PrismaClient } from "@prisma/client"
+export * from "@prisma/client"
+
+let prisma: PrismaClient
+
+if (process.env.NODE_ENV === "production") {
+  prisma = new PrismaClient()
+} else {
+  // Ensure the prisma instance is re-used during hot-reloading
+  // Otherwise, a new client will be created on every reload
+  global["prisma"] = global["prisma"] || new PrismaClient()
+  prisma = global["prisma"]
+}
+
+export default prisma

examples/blitzjs/db/schema.prisma

@@ -0,0 +1,27 @@
+// This is your Prisma schema file,
+// learn more about it in the docs: https://pris.ly/d/prisma-schema
+
+datasource sqlite {
+  provider = "sqlite"
+  url      = "file:./db.sqlite"
+}
+
+// SQLite is easy to start with, but if you use Postgres in production
+// you should also use it in development with the following:
+//datasource postgresql {
+//  provider = "postgresql"
+//  url      = env("DATABASE_URL")
+//}
+
+generator client {
+  provider = "prisma-client-js"
+}
+
+
+// --------------------------------------
+
+//model Project {
+//  id        Int      @default(autoincrement()) @id
+//  name      String
+//}
+

examples/blitzjs/package.json

@@ -0,0 +1,55 @@
+{
+  "name": "blitzjs",
+  "version": "1.0.0",
+  "scripts": {
+    "start": "blitz start",
+    "studio": "blitz db studio",
+    "build": "blitz build",
+    "lint": "eslint --ignore-path .gitignore --ext .js,.ts,.tsx .",
+    "test": "echo \"No tests yet\""
+  },
+  "browserslist": [
+    "defaults"
+  ],
+  "prettier": {
+    "semi": false,
+    "printWidth": 100
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged && pretty-quick --staged",
+      "pre-push": "blitz test"
+    }
+  },
+  "lint-staged": {
+    "*.{js,ts,tsx}": [
+      "eslint --fix"
+    ]
+  },
+  "dependencies": {
+    "@prisma/cli": "latest",
+    "@prisma/client": "latest",
+    "blitz": "latest",
+    "react": "experimental",
+    "react-dom": "experimental"
+  },
+  "devDependencies": {
+    "@types/react": "16.9.36",
+    "@typescript-eslint/eslint-plugin": "2.x",
+    "@typescript-eslint/parser": "2.x",
+    "babel-eslint": "10.1.0",
+    "eslint": "6.8.0",
+    "eslint-config-react-app": "5.2.1",
+    "eslint-plugin-flowtype": "4.7.0",
+    "eslint-plugin-import": "2.21.2",
+    "eslint-plugin-jsx-a11y": "6.2.3",
+    "eslint-plugin-react": "7.20.0",
+    "eslint-plugin-react-hooks": "3.0.0",
+    "husky": "4.2.5",
+    "lint-staged": "10.2.10",
+    "prettier": "2.0.5",
+    "pretty-quick": "2.0.1",
+    "typescript": "3.9.5"
+  },
+  "private": true
+}

examples/blitzjs/tsconfig.json

@@ -0,0 +1,20 @@
+{
+  "compilerOptions": {
+    "target": "es5",
+    "lib": ["dom", "dom.iterable", "esnext"],
+    "baseUrl": "./",
+    "allowJs": true,
+    "skipLibCheck": true,
+    "strict": false,
+    "forceConsistentCasingInFileNames": true,
+    "noEmit": true,
+    "esModuleInterop": true,
+    "module": "esnext",
+    "moduleResolution": "node",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "jsx": "preserve"
+  },
+  "exclude": ["node_modules"],
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx"]
+}

package.json

@@ -20,6 +20,7 @@
     "@zeit/ncc": "0.20.4",
     "async-retry": "1.2.3",
     "buffer-replace": "1.0.0",
+    "cheerio": "1.0.0-rc.3",
     "eslint": "6.2.2",
     "eslint-config-prettier": "6.1.0",
     "eslint-plugin-jest": "23.8.2",
@@ -28,7 +29,7 @@
     "lint-staged": "9.2.5",
     "node-fetch": "2.6.0",
     "npm-package-arg": "6.1.0",
-    "prettier": "1.18.2"
+    "prettier": "2.0.5"
   },
   "scripts": {
     "lerna": "lerna",

packages/frameworks/frameworks.json

@@ -1,4 +1,31 @@
 [
+  {
+    "name": "Blitz.js",
+    "slug": "blitzjs",
+    "logo": "https://raw.githubusercontent.com/vercel/vercel/master/packages/frameworks/logos/blitz.svg",
+    "tagline": "Blitz.js: The Fullstack React Framework",
+    "description": "A brand new Blitz.js app: the output of running `blitz new`",
+    "website": "https://blitzjs.com",
+    "detectors": {
+      "every": [
+        {
+          "path": "package.json",
+          "matchContent": "\"(dev)?(d|D)ependencies\":\\s*{[^}]*\"blitz\":\\s*\".+?\"[^}]*}"
+        }
+      ]
+    },
+    "settings": {
+      "buildCommand": {
+        "placeholder": "`npm run build` or `blitz build`"
+      },
+      "devCommand": {
+        "value": "blitz start"
+      },
+      "outputDirectory": {
+        "placeholder": "Next.js default"
+      }
+    }
+  },
   {
     "name": "Next.js",
     "slug": "nextjs",
@@ -640,7 +667,7 @@
     },
     "settings": {
       "buildCommand": {
-        "placeholder": "`npm run build` or `nuxt build`"
+        "placeholder": "`npm run build` or `nuxt generate`"
       },
       "devCommand": {
         "value": "nuxt"

packages/frameworks/logos/blitz.svg

@@ -0,0 +1,30 @@
+<svg width="500" height="500" viewBox="0 0 500 500" fill="none" xmlns="http://www.w3.org/2000/svg">
+<g clip-path="url(#clip0)">
+<path d="M95.4242 249.857H173.991C203.89 249.857 232.049 263.909 250.026 287.799L327.526 390.789C328.991 392.736 329.212 395.349 328.095 397.513L283.421 484.069C281.278 488.221 275.532 488.71 272.719 484.978L95.4242 249.857Z" fill="url(#paint0_linear)"/>
+<g filter="url(#filter0_d)">
+<path d="M404.558 249.991H325.991C296.093 249.991 267.933 235.939 249.956 212.049L172.456 109.059C170.991 107.112 170.771 104.499 171.888 102.335L216.561 15.7794C218.705 11.6267 224.45 11.1382 227.264 14.8695L404.558 249.991Z" fill="url(#paint1_linear)"/>
+</g>
+</g>
+<defs>
+<filter id="filter0_d" x="71.1812" y="-39.6553" width="433.377" height="437.646" filterUnits="userSpaceOnUse" color-interpolation-filters="sRGB">
+<feFlood flood-opacity="0" result="BackgroundImageFix"/>
+<feColorMatrix in="SourceAlpha" type="matrix" values="0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 127 0"/>
+<feOffset dy="48"/>
+<feGaussianBlur stdDeviation="50"/>
+<feColorMatrix type="matrix" values="0 0 0 0 0.270588 0 0 0 0 0 0 0 0 0 0.615686 0 0 0 0.2 0"/>
+<feBlend mode="normal" in2="BackgroundImageFix" result="effect1_dropShadow"/>
+<feBlend mode="normal" in="SourceGraphic" in2="effect1_dropShadow" result="shape"/>
+</filter>
+<linearGradient id="paint0_linear" x1="163.936" y1="392.775" x2="316.429" y2="155.244" gradientUnits="userSpaceOnUse">
+<stop stop-color="#6700EB"/>
+<stop offset="1" stop-color="#45009D"/>
+</linearGradient>
+<linearGradient id="paint1_linear" x1="336.047" y1="107.073" x2="183.554" y2="344.604" gradientUnits="userSpaceOnUse">
+<stop stop-color="#6700EB"/>
+<stop offset="1" stop-color="#45009D"/>
+</linearGradient>
+<clipPath id="clip0">
+<rect width="500" height="500" fill="white"/>
+</clipPath>
+</defs>
+</svg>

packages/frameworks/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/frameworks",
-  "version": "0.0.15-canary.3",
+  "version": "0.0.16-canary.1",
   "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": "2.4.1-canary.2",
   "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,
   };
 }
 
@@ -456,7 +462,7 @@ function detectFrontBuilder(
     });
   }
 
-  if (framework === 'nextjs') {
+  if (framework === 'nextjs' || framework === 'blitzjs') {
     return { src: 'package.json', use: `@vercel/next${withTag}`, config };
   }
 
@@ -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 +33,83 @@ interface Props {
    * link to more information about this error.
    */
   link?: string;
+  /**
+   * Optional "action" to display before the `link`, such as "More details".
+   */
+  action?: string;
+}
+
+export function getPrettyError(obj: {
+  dataPath?: string;
+  message?: string;
+  params: any;
+}): NowBuildError {
+  const docsUrl = 'https://vercel.com/docs/configuration';
+  try {
+    const { dataPath, params, message: ajvMessage } = obj;
+    const prop = getTopLevelPropertyName(dataPath);
+    let message =
+      dataPath && dataPath.startsWith('.') ? `\`${dataPath.slice(1)}\` ` : '';
+
+    if (params && typeof params.additionalProperty === 'string') {
+      const suggestion = getSuggestion(prop, params.additionalProperty);
+      message += `should NOT have additional property \`${params.additionalProperty}\`. ${suggestion}`;
+    } else if (params && typeof params.missingProperty === 'string') {
+      message += `missing required property \`${params.missingProperty}\`.`;
+    } else {
+      message += `${ajvMessage}.`;
+    }
+
+    return new NowBuildError({
+      code: 'DEV_VALIDATE_CONFIG',
+      message: message,
+      link: prop ? `${docsUrl}#project/${prop.toLowerCase()}` : docsUrl,
+      action: 'View Documentation',
+    });
+  } catch (e) {
+    return new NowBuildError({
+      code: 'DEV_VALIDATE_CONFIG',
+      message: `Failed to validate configuration.`,
+      link: docsUrl,
+      action: 'View Documentation',
+    });
+  }
+}
+
+/**
+ * Get the top level property from the dataPath.
+ * `.cleanUrls` => `cleanUrls`
+ * `.headers[0].source` => `headers`
+ * `.headers[0].headers[0]` => `headers`
+ * `` => ``
+ */
+function getTopLevelPropertyName(dataPath?: string): string {
+  if (dataPath && dataPath.startsWith('.')) {
+    const lastIndex = dataPath.indexOf('[');
+    return lastIndex > -1 ? dataPath.slice(1, lastIndex) : dataPath.slice(1);
+  }
+  return '';
+}
+
+const mapTypoToSuggestion: { [key: string]: { [key: string]: string } } = {
+  '': {
+    builder: 'builds',
+    'build.env': '{ "build": { "env": {"name": "value"} } }',
+    'builds.env': '{ "build": { "env": {"name": "value"} } }',
+  },
+  rewrites: { src: 'source', dest: 'destination' },
+  redirects: { src: 'source', dest: 'destination', status: 'statusCode' },
+  headers: { src: 'source', header: 'headers' },
+  routes: {
+    source: 'src',
+    destination: 'dest',
+    header: 'headers',
+    method: 'methods',
+  },
+};
+
+function getSuggestion(topLevelProp: string, additionalProperty: string) {
+  const choices = mapTypoToSuggestion[topLevelProp];
+  const choice = choices ? choices[additionalProperty] : undefined;
+  return choice ? `Did you mean \`${choice}\`?` : 'Please remove it.';
 }

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

@@ -493,7 +493,7 @@ describe('Test `detectBuilders`', () => {
   });
 
   it('use a custom runtime', async () => {
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/user.php'];
     const { builders, errors } = await detectBuilders(files, null, {
       functions,
@@ -501,11 +501,11 @@ describe('Test `detectBuilders`', () => {
 
     expect(errors).toBe(null);
     expect(builders!.length).toBe(1);
-    expect(builders![0].use).toBe('now-php@0.0.8');
+    expect(builders![0].use).toBe('vercel-php@0.1.0');
   });
 
   it('use a custom runtime but without a source', async () => {
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/team.js'];
     const { errors } = await detectBuilders(files, null, {
       functions,
@@ -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 () => {
@@ -1489,7 +1538,7 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
   });
 
   it('use a custom runtime', async () => {
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/user.php'];
     const { builders, errors } = await detectBuilders(files, null, {
       functions,
@@ -1498,11 +1547,11 @@ describe('Test `detectBuilders` with `featHandleMiss=true`', () => {
 
     expect(errors).toBe(null);
     expect(builders!.length).toBe(1);
-    expect(builders![0].use).toBe('now-php@0.0.8');
+    expect(builders![0].use).toBe('vercel-php@0.1.0');
   });
 
   it('use a custom runtime but without a source', async () => {
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/team.js'];
     const { errors } = await detectBuilders(files, null, {
       functions,
@@ -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 () => {
@@ -2009,7 +2081,7 @@ it('Test `detectRoutes`', async () => {
 
   {
     // use a custom runtime
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/user.php'];
 
     const { defaultRoutes } = await detectBuilders(files, null, { functions });
@@ -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);
+    });
   }
 
   {
@@ -2279,7 +2393,7 @@ it('Test `detectRoutes` with `featHandleMiss=true`', async () => {
 
   {
     // use a custom runtime
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/user.php'];
 
     const { defaultRoutes, rewriteRoutes } = await detectBuilders(files, null, {
@@ -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);
@@ -2570,7 +2692,7 @@ it('Test `detectRoutes` with `featHandleMiss=true`, `cleanUrls=true`', async ()
 
   {
     // use a custom runtime
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/user.php'];
 
     const {
@@ -2819,7 +2941,7 @@ it('Test `detectRoutes` with `featHandleMiss=true`, `cleanUrls=true`, `trailingS
 
   {
     // use a custom runtime
-    const functions = { 'api/user.php': { runtime: 'now-php@0.0.8' } };
+    const functions = { 'api/user.php': { runtime: 'vercel-php@0.1.0' } };
     const files = ['api/user.php'];
 
     const {

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

@@ -1,9 +1,9 @@
 {
   "name": "vercel",
-  "version": "19.0.2-canary.8",
+  "version": "19.1.2-canary.18",
   "preferGlobal": true,
   "license": "Apache-2.0",
-  "description": "The command-line interface for Now",
+  "description": "The command-line interface for Vercel",
   "homepage": "https://vercel.com",
   "repository": {
     "type": "git",
@@ -12,7 +12,7 @@
   },
   "scripts": {
     "preinstall": "node ./scripts/preinstall.js",
-    "test-unit": "nyc ava test/unit.js test/dev-builder.unit.js test/dev-router.unit.js test/dev-server.unit.js --serial --fail-fast --verbose",
+    "test-unit": "nyc ava test/unit.js test/dev-builder.unit.js test/dev-router.unit.js test/dev-server.unit.js test/dev-validate.unit.js --serial --fail-fast --verbose",
     "test-integration-cli": "ava test/integration.js --serial --fail-fast --verbose",
     "test-integration-v1": "ava test/integration-v1.js --serial --fail-fast",
     "test-integration-dev": "ava test/dev/integration.js --serial --fail-fast --verbose",
@@ -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": "2.4.1-canary.2",
+    "@vercel/go": "1.1.3-canary.1",
+    "@vercel/next": "2.6.9-canary.0",
+    "@vercel/node": "1.7.2-canary.1",
+    "@vercel/python": "1.2.2",
+    "@vercel/ruby": "1.2.3-canary.0",
+    "@vercel/static-build": "0.17.5-canary.0"
   },
   "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

@@ -3,8 +3,8 @@ import bytes from 'bytes';
 import { join } from 'path';
 import { write as copy } from 'clipboardy';
 import chalk from 'chalk';
-import title from 'title';
 import { fileNameSymbol } from '@vercel/client';
+import { getPrettyError } from '@vercel/build-utils';
 import Client from '../../util/client';
 import { handleError } from '../../util/error';
 import getArgs from '../../util/get-args';
@@ -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'],
@@ -730,53 +738,10 @@ function handleCreateDeployError(output, error, localConfig) {
     return 1;
   }
   if (error instanceof SchemaValidationFailed) {
-    const { message, params, keyword, dataPath } = error.meta;
-
-    if (params && params.additionalProperty) {
-      const prop = params.additionalProperty;
-
-      output.error(
-        `The property ${code(prop)} is not allowed in ${highlight(
-          localConfig[fileNameSymbol]
-        )} – please remove it.`
-      );
-
-      if (prop === 'build.env' || prop === 'builds.env') {
-        output.note(
-          `Do you mean ${code('build')} (object) with a property ${code(
-            'env'
-          )} (object) instead of ${code(prop)}?`
-        );
-      }
-
-      return 1;
-    }
-
-    if (dataPath === '.name') {
-      output.error(message);
-      return 1;
-    }
-
-    if (keyword === 'type') {
-      const prop = dataPath.substr(1, dataPath.length);
-
-      output.error(
-        `The property ${code(prop)} in ${highlight(
-          localConfig[fileNameSymbol]
-        )} can only be of type ${code(title(params.type))}.`
-      );
-
-      return 1;
-    }
-
-    const link = 'https://vercel.com/docs/configuration';
-
-    output.error(
-      `Failed to validate ${highlight(
-        localConfig[fileNameSymbol]
-      )}: ${message}\nDocumentation: ${link}`
-    );
-
+    const niceError = getPrettyError(error.meta);
+    const fileName = localConfig[fileNameSymbol] || 'vercel.json';
+    niceError.message = `Invalid ${fileName} - ${niceError.message}`;
+    output.prettyError(niceError);
     return 1;
   }
   if (error instanceof TooManyRequests) {

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

@@ -9,6 +9,7 @@ import { getLinkedProject } from '../../util/projects/link';
 import { getFrameworks } from '../../util/get-frameworks';
 import { isSettingValue } from '../../util/is-setting-value';
 import { getCommandName } from '../../util/pkg-name';
+import { ProjectSettings } from '../../types';
 
 type Options = {
   '--debug'?: boolean;
@@ -50,21 +51,26 @@ export default async function dev(
     return 1;
   }
 
-  let devCommand: undefined | string;
-  let frameworkSlug: null | string = null;
+  let devCommand: string | undefined;
+  let frameworkSlug: string | undefined;
+  let projectSettings: ProjectSettings | undefined;
   if (link.status === 'linked') {
     const { project, org } = link;
     client.currentTeam = org.type === 'team' ? org.id : undefined;
 
+    projectSettings = project;
+
     if (project.devCommand) {
       devCommand = project.devCommand;
     } else if (project.framework) {
       const framework = frameworks.find(f => f.slug === project.framework);
 
       if (framework) {
-        frameworkSlug = framework.slug;
-        const defaults = framework.settings.devCommand;
+        if (framework.slug) {
+          frameworkSlug = framework.slug;
+        }
 
+        const defaults = framework.settings.devCommand;
         if (isSettingValue(defaults)) {
           devCommand = defaults.value;
         }
@@ -81,6 +87,7 @@ export default async function dev(
     debug,
     devCommand,
     frameworkSlug,
+    projectSettings,
   });
 
   process.once('SIGINT', () => devServer.stop());

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

@@ -10,6 +10,7 @@ import handleError from '../../util/handle-error';
 import createOutput from '../../util/output/create-output';
 import logo from '../../util/output/logo';
 import cmd from '../../util/output/cmd';
+import highlight from '../../util/output/highlight';
 import dev from './dev';
 import readPackage from '../../util/read-package';
 import readConfig from '../../util/config/read-config';
@@ -119,7 +120,22 @@ export default async function main(ctx: NowContext) {
   try {
     return await dev(ctx, argv, args, output);
   } catch (err) {
-    output.error(err.message);
+    if (err.code === 'ENOTFOUND') {
+      // Error message will look like the following:
+      // "request to https://api.vercel.com/www/user failed, reason: getaddrinfo ENOTFOUND api.vercel.com"
+      const matches = /getaddrinfo ENOTFOUND (.*)$/.exec(err.message || '');
+      if (matches && matches[1]) {
+        const hostname = matches[1];
+        output.error(
+          `The hostname ${highlight(
+            hostname
+          )} could not be resolved. Please verify your internet connectivity and DNS configuration.`
+        );
+      }
+      output.debug(err.stack);
+      return 1;
+    }
+    output.prettyError(err);
     output.debug(stringifyError(err));
     return 1;
   }

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

@@ -9,16 +9,39 @@ import getDecryptedSecret from '../../util/env/get-decrypted-secret';
 import param from '../../util/output/param';
 import withSpinner from '../../util/with-spinner';
 import { join } from 'path';
-import { promises, existsSync } from 'fs';
+import { promises, openSync, closeSync, readSync } from 'fs';
 import { emoji, prependEmoji } from '../../util/emoji';
 import { getCommandName } from '../../util/pkg-name';
 const { writeFile } = promises;
 
+const CONTENTS_PREFIX = '# Created by Vercel CLI\n';
+
 type Options = {
   '--debug': boolean;
   '--yes': boolean;
 };
 
+function readHeadSync(path: string, length: number) {
+  const buffer = Buffer.alloc(length);
+  const fd = openSync(path, 'r');
+  try {
+    readSync(fd, buffer, 0, buffer.length, null);
+  } finally {
+    closeSync(fd);
+  }
+  return buffer.toString();
+}
+
+function tryReadHeadSync(path: string, length: number) {
+  try {
+    return readHeadSync(path, length);
+  } catch (err) {
+    if (err.code !== 'ENOENT') {
+      throw err;
+    }
+  }
+}
+
 export default async function pull(
   client: Client,
   project: Project,
@@ -35,10 +58,14 @@ export default async function pull(
 
   const [filename = '.env'] = args;
   const fullPath = join(process.cwd(), filename);
-  const exists = existsSync(fullPath);
   const skipConfirmation = opts['--yes'];
 
-  if (
+  const head = tryReadHeadSync(fullPath, Buffer.byteLength(CONTENTS_PREFIX));
+  const exists = typeof head !== 'undefined';
+
+  if (head === CONTENTS_PREFIX) {
+    output.print(`Overwriting existing ${chalk.bold(filename)} file\n`);
+  } else if (
     exists &&
     !skipConfirmation &&
     !(await promptBool(
@@ -83,6 +110,7 @@ export default async function pull(
   });
 
   const contents =
+    CONTENTS_PREFIX +
     records
       .filter(obj => {
         if (!obj.found) {
@@ -95,7 +123,8 @@ export default async function pull(
         return true;
       })
       .map(({ key, value }) => `${key}="${escapeValue(value)}"`)
-      .join('\n') + '\n';
+      .join('\n') +
+    '\n';
 
   await writeFile(fullPath, contents, 'utf8');
 

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;
   }
 
@@ -313,21 +314,6 @@ const main = async argv_ => {
     // need to migrate.
     if (authConfig.credentials) {
       authConfigExists = false;
-    } else if (
-      !authConfig.token &&
-      !subcommandsWithoutToken.includes(targetOrSubcommand) &&
-      !argv['--help'] &&
-      !argv['--token']
-    ) {
-      console.error(
-        error(
-          `The content of "${hp(VERCEL_AUTH_CONFIG_PATH)}" is invalid. ` +
-            `No \`token\` property found inside. Run ${getCommandName(
-              'login'
-            )} to authorize.`
-        )
-      );
-      return 1;
     }
   } else {
     const results = await getDefaultAuthConfig(authConfig);
@@ -529,7 +515,7 @@ 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.`
     );
@@ -637,34 +623,19 @@ const main = async argv_ => {
         .send();
     }
   } catch (err) {
-    if (err.code === 'ENOTFOUND' && err.hostname === 'api.vercel.com') {
-      output.error(
-        `The hostname ${highlight(
-          'api.vercel.com'
-        )} could not be resolved. Please verify your internet connectivity and DNS configuration.`
-      );
-      output.debug(err.stack);
-
-      return 1;
-    }
-
-    await reportError(Sentry, err, apiUrl, configFiles);
-
-    // If there is a code we should not consider the error unexpected
-    // but instead show the message. Any error that is handled by this should
-    // actually be handled in the sub command instead. Please make sure
-    // that happens for anything that lands here. It should NOT bubble up to here.
-    if (err.code) {
-      output.debug(err.stack);
-      output.error(err.message);
-
-      if (shouldCollectMetrics) {
-        metric
-          .event(eventCategory, '1', pkg.version)
-          .exception(err.message)
-          .send();
+    if (err.code === 'ENOTFOUND') {
+      // Error message will look like the following:
+      // "request to https://api.vercel.com/www/user failed, reason: getaddrinfo ENOTFOUND api.vercel.com"
+      const matches = /getaddrinfo ENOTFOUND (.*)$/.exec(err.message || '');
+      if (matches && matches[1]) {
+        const hostname = matches[1];
+        output.error(
+          `The hostname ${highlight(
+            hostname
+          )} could not be resolved. Please verify your internet connectivity and DNS configuration.`
+        );
       }
-
+      output.debug(err.stack);
       return 1;
     }
 
@@ -675,9 +646,23 @@ 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 +673,6 @@ const main = async argv_ => {
   return exitCode;
 };
 
-debug('start');
-
 const handleRejection = async err => {
   debug('handling rejection');
 

packages/now-cli/src/types.ts

@@ -244,15 +244,20 @@ export interface ProjectEnvVariable {
   system?: boolean;
 }
 
-export interface Project {
+export interface ProjectSettings {
+  framework?: string | null;
+  devCommand?: string | null;
+  buildCommand?: string | null;
+  outputDirectory?: string | null;
+  rootDirectory?: string | null;
+}
+
+export interface Project extends ProjectSettings {
   id: string;
   name: string;
   accountId: string;
   updatedAt: number;
   createdAt: number;
-  devCommand?: string | null;
-  framework?: string | null;
-  rootDirectory?: string | null;
   latestDeployments?: Partial<Deployment>[];
 }
 

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/builder.ts

@@ -56,6 +56,8 @@ async function createBuildProcess(
   workPath: string,
   output: Output
 ): Promise<ChildProcess> {
+  output.debug(`Creating build process for "${match.entrypoint}"`);
+
   const builderWorkerPath = join(__dirname, 'builder-worker.js');
 
   // Ensure that `node` is in the builder's `PATH`
@@ -78,7 +80,7 @@ async function createBuildProcess(
 
   buildProcess.on('exit', (code, signal) => {
     output.debug(
-      `Build process for ${match.src} exited with ${signal || code}`
+      `Build process for "${match.entrypoint}" exited with ${signal || code}`
     );
     match.buildProcess = undefined;
   });
@@ -128,7 +130,6 @@ export async function executeBuild(
 
   let { buildProcess } = match;
   if (!runInProcess && !buildProcess) {
-    devServer.output.debug(`Creating build process for ${entrypoint}`);
     buildProcess = await createBuildProcess(
       match,
       envConfigs,
@@ -431,7 +432,7 @@ export async function getBuildMatches(
     }
 
     const files = fileList
-      .filter(name => name === src || minimatch(name, src))
+      .filter(name => name === src || minimatch(name, src, { dot: true }))
       .map(name => join(cwd, name));
 
     if (files.length === 0) {

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

@@ -4,7 +4,7 @@ import PCRE from 'pcre-to-regexp';
 import isURL from './is-url';
 import DevServer from './server';
 
-import { HttpHeadersConfig, RouteResult } from './types';
+import { NowConfig, HttpHeadersConfig, RouteResult } from './types';
 import { isHandler, Route, HandleValue } from '@vercel/routing-utils';
 
 export function resolveRouteParameters(
@@ -29,7 +29,7 @@ export function resolveRouteParameters(
 export function getRoutesTypes(routes: Route[] = []) {
   const handleMap = new Map<HandleValue | null, Route[]>();
   let prevHandle: HandleValue | null = null;
-  routes.forEach(route => {
+  routes.forEach((route) => {
     if (isHandler(route)) {
       prevHandle = route.handle;
     } else {
@@ -50,6 +50,7 @@ export async function devRouter(
   reqMethod?: string,
   routes?: Route[],
   devServer?: DevServer,
+  nowConfig?: NowConfig,
   previousHeaders?: HttpHeadersConfig,
   missRoutes?: Route[],
   phase?: HandleValue | null
@@ -117,9 +118,12 @@ export async function devRouter(
           continue;
         }
 
-        if (routeConfig.check && devServer && phase !== 'hit') {
+        if (routeConfig.check && devServer && nowConfig && phase !== 'hit') {
           const { pathname = '/' } = url.parse(destPath);
-          const hasDestFile = await devServer.hasFilesystem(pathname);
+          const hasDestFile = await devServer.hasFilesystem(
+            pathname,
+            nowConfig
+          );
 
           if (!hasDestFile) {
             if (routeConfig.status && phase !== 'miss') {
@@ -131,6 +135,7 @@ export async function devRouter(
                 reqMethod,
                 missRoutes,
                 devServer,
+                nowConfig,
                 combinedHeaders,
                 [],
                 'miss'

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

@@ -12,12 +12,13 @@ import { randomBytes } from 'crypto';
 import serveHandler from 'serve-handler';
 import { watch, FSWatcher } from 'chokidar';
 import { parse as parseDotenv } from 'dotenv';
-import { basename, dirname, extname, join } from 'path';
+import path, { isAbsolute, basename, dirname, extname, join } from 'path';
 import once from '@tootallnate/once';
 import directoryTemplate from 'serve-handler/src/directory';
 import getPort from 'get-port';
 import { ChildProcess } from 'child_process';
 import isPortReachable from 'is-port-reachable';
+import deepEqual from 'fast-deep-equal';
 import which from 'which';
 
 import { getVercelIgnore, fileNameSymbol } from '@vercel/client';
@@ -48,18 +49,8 @@ import getNowConfigPath from '../config/local-path';
 import { MissingDotenvVarsError } from '../errors-ts';
 import cliPkg from '../pkg';
 import { getVercelDirectory } from '../projects/link';
-import { staticFiles as getFiles, getAllProjectFiles } from '../get-files';
-import {
-  validateNowConfigBuilds,
-  validateNowConfigRoutes,
-  validateNowConfigCleanUrls,
-  validateNowConfigHeaders,
-  validateNowConfigRedirects,
-  validateNowConfigRewrites,
-  validateNowConfigTrailingSlash,
-  validateNowConfigFunctions,
-} from './validate';
-
+import { staticFiles as getFiles } from '../get-files';
+import { validateConfig } from './validate';
 import { devRouter, getRoutesTypes } from './router';
 import getMimeType from './mime-type';
 import { executeBuild, getBuildMatches, shutdownBuilder } from './builder';
@@ -92,12 +83,17 @@ import {
   HttpHeadersConfig,
   EnvConfigs,
 } from './types';
+import { ProjectSettings } from '../../types';
 
 interface FSEvent {
   type: string;
   path: string;
 }
 
+type WithFileNameSymbol<T> = T & {
+  [fileNameSymbol]: string;
+};
+
 function sortBuilders(buildA: Builder, buildB: Builder) {
   if (buildA && buildA.use && isOfficialRuntime('static-build', buildA.use)) {
     return 1;
@@ -114,8 +110,9 @@ export default class DevServer {
   public cwd: string;
   public debug: boolean;
   public output: Output;
+  public proxy: httpProxy;
   public envConfigs: EnvConfigs;
-  public frameworkSlug: string | null;
+  public frameworkSlug?: string;
   public files: BuilderInputs;
   public address: string;
   public devCacheDir: string;
@@ -124,7 +121,6 @@ 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>;
@@ -139,6 +135,7 @@ export default class DevServer {
   private devProcess?: ChildProcess;
   private devProcessPort?: number;
   private devServerPids: Set<number>;
+  private projectSettings?: ProjectSettings;
 
   private getNowConfigPromise: Promise<NowConfig> | null;
   private blockingBuildsPromise: Promise<void> | null;
@@ -153,6 +150,7 @@ export default class DevServer {
     this.files = {};
     this.address = '';
     this.devCommand = options.devCommand;
+    this.projectSettings = options.projectSettings;
     this.frameworkSlug = options.frameworkSlug;
     this.cachedNowConfig = null;
     this.caseSensitive = false;
@@ -178,10 +176,8 @@ export default class DevServer {
     this.watchAggregationEvents = [];
     this.watchAggregationTimeout = 500;
 
-    this.filter = path => Boolean(path);
-    this.podId = Math.random()
-      .toString(32)
-      .slice(-5);
+    this.filter = (path) => Boolean(path);
+    this.podId = Math.random().toString(32).slice(-5);
 
     this.devServerPids = new Set();
   }
@@ -219,8 +215,8 @@ export default class DevServer {
       }
     }
 
-    events = events.filter(event =>
-      distPaths.every(distPath => !event.path.startsWith(distPath))
+    events = events.filter((event) =>
+      distPaths.every((distPath) => !event.path.startsWith(distPath))
     );
 
     // First, update the `files` mapping of source files
@@ -234,8 +230,17 @@ 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 [runEnv, buildEnv] = await Promise.all([
+      this.getLocalEnv('.env', nowConfig.env),
+      this.getLocalEnv('.env.build', nowConfig.build?.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];
@@ -279,18 +284,19 @@ export default class DevServer {
       for (const [result, [requestPath, match]] of needsRebuild) {
         if (
           requestPath === null ||
-          (await shouldServe(match, this.files, requestPath, this))
+          (await shouldServe(match, this.files, requestPath, this, nowConfig))
         ) {
           this.triggerBuild(
             match,
             requestPath,
             null,
+            nowConfig,
             result,
             filesChangedArray,
             filesRemovedArray
           ).catch((err: Error) => {
             this.output.warn(
-              `An error occurred while rebuilding ${match.src}:`
+              `An error occurred while rebuilding \`${match.src}\`:`
             );
             console.error(err.stack);
           });
@@ -374,12 +380,10 @@ export default class DevServer {
       this,
       fileList
     );
-    const sources = matches.map(m => m.src);
+    const sources = matches.map((m) => m.src);
 
     if (isInitial && fileList.length === 0) {
-      this.output.warn(
-        'There are no files (or only files starting with a dot) inside your deployment.'
-      );
+      this.output.warn('There are no files inside your deployment.');
     }
 
     // Delete build matches that no longer exists
@@ -400,7 +404,7 @@ 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}"`
         );
@@ -435,6 +439,9 @@ export default class DevServer {
             `Cleaning up "blockingBuildsPromise" after error: ${err}`
           );
           this.blockingBuildsPromise = null;
+          if (err) {
+            this.output.prettyError(err);
+          }
         });
     }
 
@@ -517,54 +524,24 @@ export default class DevServer {
       return this.cachedNowConfig;
     }
 
-    const pkg = await this.getPackageJson();
+    const configPath = getNowConfigPath(this.cwd);
 
-    // 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 || {
-      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}`);
-      config = JSON.parse(await fs.readFile(configPath, 'utf8'));
-      config[fileNameSymbol] = configPath;
-    } catch (err) {
-      if (err.code === 'ENOENT') {
-        this.output.debug(err.toString());
-      } else if (err.name === 'SyntaxError') {
-        this.output.warn(
-          `There is a syntax error in ${configPath}: ${err.message}`
-        );
-      } else {
-        throw err;
-      }
-    }
-
-    const allFiles = await getAllProjectFiles(this.cwd, this.output);
-    const files = allFiles.filter(this.filter);
-
-    this.output.debug(
-      `Found ${allFiles.length} and ` +
-        `filtered out ${allFiles.length - files.length} files`
-    );
+    const [
+      pkg = null,
+      // The default empty `vercel.json` is used to serve all
+      // files as static when no `vercel.json` is present
+      config = { version: 2, [fileNameSymbol]: 'vercel.json' },
+    ] = await Promise.all([
+      this.readJsonFile<PackageJson>('package.json'),
+      this.readJsonFile<NowConfig>(configPath),
+    ]);
 
     await this.validateNowConfig(config);
     const { error: routeError, routes: maybeRoutes } = getTransformedRoutes({
       nowConfig: config,
     });
     if (routeError) {
-      this.output.error(routeError.message);
+      this.output.prettyError(routeError);
       await this.exit();
     }
     config.routes = maybeRoutes || [];
@@ -574,6 +551,11 @@ export default class DevServer {
       const featHandleMiss = true; // enable for zero config
       const { projectSettings, cleanUrls, trailingSlash } = config;
 
+      const opts = { output: this.output, isBuilds: true };
+      const files = (await getFiles(this.cwd, config, opts)).map((f) =>
+        relative(this.cwd, f)
+      );
+
       let {
         builders,
         warnings,
@@ -581,10 +563,11 @@ export default class DevServer {
         defaultRoutes,
         redirectRoutes,
         rewriteRoutes,
+        errorRoutes,
       } = await detectBuilders(files, pkg, {
         tag: getDistTag(cliPkg.version) === 'canary' ? 'canary' : 'latest',
         functions: config.functions,
-        ...(projectSettings ? { projectSettings } : {}),
+        projectSettings: projectSettings || this.projectSettings,
         featHandleMiss,
         cleanUrls,
         trailingSlash,
@@ -596,7 +579,7 @@ export default class DevServer {
       }
 
       if (warnings && warnings.length > 0) {
-        warnings.forEach(warning => this.output.warn(warning.message));
+        warnings.forEach((warning) => this.output.warn(warning.message));
       }
 
       if (builders) {
@@ -607,19 +590,26 @@ 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;
+        delete config.functions;
       }
+
+      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)) {
@@ -641,27 +631,35 @@ export default class DevServer {
     return config;
   }
 
-  async getPackageJson(): Promise<PackageJson | null> {
-    const pkgPath = join(this.cwd, 'package.json');
-    let pkg: PackageJson | null = null;
-
-    this.output.debug('Reading `package.json` file');
+  async readJsonFile<T>(
+    filePath: string
+  ): Promise<WithFileNameSymbol<T> | void> {
+    let rel, abs;
+    if (isAbsolute(filePath)) {
+      rel = path.relative(this.cwd, filePath);
+      abs = filePath;
+    } else {
+      rel = filePath;
+      abs = join(this.cwd, filePath);
+    }
+    this.output.debug(`Reading \`${rel}\` file`);
 
     try {
-      pkg = JSON.parse(await fs.readFile(pkgPath, 'utf8'));
+      const raw = await fs.readFile(abs, 'utf8');
+      const parsed: WithFileNameSymbol<T> = JSON.parse(raw);
+      parsed[fileNameSymbol] = rel;
+      return parsed;
     } catch (err) {
       if (err.code === 'ENOENT') {
-        this.output.debug('No `package.json` file present');
+        this.output.debug(`No \`${rel}\` file present`);
       } else if (err.name === 'SyntaxError') {
         this.output.warn(
-          `There is a syntax error in the \`package.json\` file: ${err.message}`
+          `There is a syntax error in the \`${rel}\` file: ${err.message}`
         );
       } else {
         throw err;
       }
     }
-
-    return pkg;
   }
 
   async tryValidateOrExit(
@@ -683,14 +681,12 @@ export default class DevServer {
       return;
     }
 
-    await this.tryValidateOrExit(config, validateNowConfigBuilds);
-    await this.tryValidateOrExit(config, validateNowConfigRoutes);
-    await this.tryValidateOrExit(config, validateNowConfigCleanUrls);
-    await this.tryValidateOrExit(config, validateNowConfigHeaders);
-    await this.tryValidateOrExit(config, validateNowConfigRedirects);
-    await this.tryValidateOrExit(config, validateNowConfigRewrites);
-    await this.tryValidateOrExit(config, validateNowConfigTrailingSlash);
-    await this.tryValidateOrExit(config, validateNowConfigFunctions);
+    const error = validateConfig(config);
+
+    if (error) {
+      this.output.prettyError(error);
+      await this.exit(1);
+    }
   }
 
   validateEnvConfig(type: string, env: Env = {}, localEnv: Env = {}): Env {
@@ -761,13 +757,11 @@ export default class DevServer {
 
     // Retrieve the path of the native module
     const nowConfig = await this.getNowConfig(false);
-    const nowConfigBuild = nowConfig.build || {};
     const [runEnv, buildEnv] = await Promise.all([
       this.getLocalEnv('.env', nowConfig.env),
-      this.getLocalEnv('.env.build', nowConfigBuild.env),
+      this.getLocalEnv('.env.build', nowConfig.build?.env),
     ]);
     const allEnv = { ...buildEnv, ...runEnv };
-    Object.assign(process.env, allEnv);
     this.envConfigs = { buildEnv, runEnv, allEnv };
 
     const opts = { output: this.output, isBuilds: true };
@@ -796,11 +790,11 @@ export default class DevServer {
     // get their "build matches" invalidated so that the new version is used.
     this.updateBuildersTimeout = setTimeout(() => {
       this.updateBuildersPromise = updateBuilders(builders, this.output)
-        .then(updatedBuilders => {
+        .then((updatedBuilders) => {
           this.updateBuildersPromise = null;
           this.invalidateBuildMatches(nowConfig, updatedBuilders);
         })
-        .catch(err => {
+        .catch((err) => {
           this.updateBuildersPromise = null;
           this.output.error(`Failed to update builders: ${err.message}`);
           this.output.debug(err.stack);
@@ -1141,6 +1135,7 @@ export default class DevServer {
     match: BuildMatch,
     requestPath: string | null,
     req: http.IncomingMessage | null,
+    nowConfig: NowConfig,
     previousBuildResult?: BuildResult,
     filesChanged?: string[],
     filesRemoved?: string[]
@@ -1156,10 +1151,11 @@ export default class DevServer {
       // A build for `buildKey` is already in progress, so don't trigger
       // another rebuild for this request - just wait on the existing one.
       let msg = `De-duping build "${buildKey}"`;
-      if (req) msg += ` for "${req.method} ${req.url}"`;
+      if (req) {
+        msg += ` for "${req.method} ${req.url}"`;
+      }
       this.output.debug(msg);
     } else {
-      const nowConfig = await this.getNowConfig();
       if (previousBuildResult) {
         // Tear down any `output` assets from a previous build, so that they
         // are not available to be served while the rebuild is in progress.
@@ -1170,7 +1166,9 @@ export default class DevServer {
         }
       }
       let msg = `Building asset "${buildKey}"`;
-      if (req) msg += ` for "${req.method} ${req.url}"`;
+      if (req) {
+        msg += ` for "${req.method} ${req.url}"`;
+      }
       this.output.debug(msg);
       buildPromise = executeBuild(
         nowConfig,
@@ -1251,7 +1249,7 @@ export default class DevServer {
     const { status, headers, dest } = routeResult;
     const location = headers['location'] || dest;
 
-    if (status && location && (300 <= status && status <= 399)) {
+    if (status && location && 300 <= status && status <= 399) {
       this.output.debug(`Route found with redirect status code ${status}`);
       await this.sendRedirect(req, res, nowRequestId, location, status);
       return true;
@@ -1323,8 +1321,7 @@ 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;
@@ -1342,6 +1339,7 @@ export default class DevServer {
         req.method,
         phaseRoutes,
         this,
+        nowConfig,
         prevHeaders,
         missRoutes,
         phase
@@ -1362,14 +1360,15 @@ 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(
         this.buildMatches,
         this.files,
         routeResult.dest,
-        this
+        this,
+        nowConfig
       );
 
       if (
@@ -1392,6 +1391,7 @@ export default class DevServer {
           req.method,
           missRoutes,
           this,
+          nowConfig,
           routeResult.headers,
           [],
           'miss'
@@ -1401,7 +1401,8 @@ export default class DevServer {
           this.buildMatches,
           this.files,
           routeResult.dest,
-          this
+          this,
+          nowConfig
         );
         if (
           await this.exitWithStatus(
@@ -1424,6 +1425,7 @@ export default class DevServer {
           req.method,
           hitRoutes,
           this,
+          nowConfig,
           routeResult.headers,
           [],
           'hit'
@@ -1431,6 +1433,34 @@ export default class DevServer {
         routeResult.status = prevStatus;
       }
 
+      if (!match && errorRoutes.length > 0) {
+        // error phase
+        const routeResultForError = await devRouter(
+          getReqUrl(routeResult),
+          req.method,
+          errorRoutes,
+          this,
+          nowConfig,
+          routeResult.headers,
+          [],
+          'error'
+        );
+
+        const matchForError = await findBuildMatch(
+          this.buildMatches,
+          this.files,
+          routeResultForError.dest,
+          this,
+          nowConfig
+        );
+
+        if (matchForError) {
+          // error phase only applies if the file was found
+          routeResult = routeResultForError;
+          match = matchForError;
+        }
+      }
+
       statusCode = routeResult.status;
 
       if (match) {
@@ -1469,16 +1499,15 @@ export default class DevServer {
     if (!match) {
       // If the dev command is started, then proxy to it
       if (this.devProcessPort) {
-        debug('Proxying to frontend dev server');
+        const upstream = `http://localhost:${this.devProcessPort}`;
+        debug(`Proxying to frontend dev server: ${upstream}`);
         this.setResponseHeaders(res, nowRequestId);
-        return proxyPass(
-          req,
-          res,
-          `http://localhost:${this.devProcessPort}`,
-          this.proxy,
-          this.output,
-          false
-        );
+        const origUrl = url.parse(req.url || '/', true);
+        delete origUrl.search;
+        origUrl.pathname = dest;
+        Object.assign(origUrl.query, uri_args);
+        req.url = url.format(origUrl);
+        return proxyPass(req, res, upstream, this, nowRequestId, false);
       }
 
       if (
@@ -1510,7 +1539,8 @@ export default class DevServer {
         newUrl,
         req.method,
         buildResult.routes,
-        this
+        this,
+        nowConfig
       );
       if (matchedRoute.found && callLevel === 0) {
         debug(`Found matching route ${matchedRoute.dest} for ${newUrl}`);
@@ -1560,7 +1590,7 @@ export default class DevServer {
           req,
           res,
           nowRequestId,
-          'NO_STATUS_CODE_FROM_DEV_SERVER',
+          'NO_RESPONSE_FROM_FUNCTION',
           502
         );
         return;
@@ -1595,19 +1625,18 @@ export default class DevServer {
           req,
           res,
           `http://localhost:${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) {
-      await this.triggerBuild(match, buildRequestPath, req);
+      await this.triggerBuild(match, buildRequestPath, req, nowConfig);
 
       // Since the `asset` was just built, resolve again to get the new asset
       foundAsset = findAsset(match, requestPath, nowConfig);
@@ -1626,8 +1655,8 @@ export default class DevServer {
         req,
         res,
         `http://localhost:${this.devProcessPort}`,
-        this.proxy,
-        this.output,
+        this,
+        nowRequestId,
         false
       );
     }
@@ -1639,8 +1668,9 @@ export default class DevServer {
 
     const { asset, assetKey } = foundAsset;
     debug(
-      `Serving asset: [${asset.type}] ${assetKey} ${(asset as any)
-        .contentType || ''}`
+      `Serving asset: [${asset.type}] ${assetKey} ${
+        (asset as any).contentType || ''
+      }`
     );
 
     /* eslint-disable no-case-declarations */
@@ -1721,7 +1751,7 @@ export default class DevServer {
             req,
             res,
             nowRequestId,
-            'NO_STATUS_CODE_FROM_LAMBDA',
+            'NO_RESPONSE_FROM_FUNCTION',
             502
           );
           return;
@@ -1759,7 +1789,7 @@ export default class DevServer {
 
     const dirs: Set<string> = new Set();
     const files = Array.from(this.buildMatches.keys())
-      .filter(p => {
+      .filter((p) => {
         const base = basename(p);
         if (
           base === 'now.json' ||
@@ -1780,7 +1810,7 @@ export default class DevServer {
         }
         return true;
       })
-      .map(p => {
+      .map((p) => {
         let base = basename(p);
         let ext = '';
         let type = 'file';
@@ -1832,8 +1862,17 @@ export default class DevServer {
     return true;
   }
 
-  async hasFilesystem(dest: string): Promise<boolean> {
-    if (await findBuildMatch(this.buildMatches, this.files, dest, this, true)) {
+  async hasFilesystem(dest: string, nowConfig: NowConfig): Promise<boolean> {
+    if (
+      await findBuildMatch(
+        this.buildMatches,
+        this.files,
+        dest,
+        this,
+        nowConfig,
+        true
+      )
+    ) {
       return true;
     }
     return false;
@@ -1937,24 +1976,27 @@ 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}`);
     }
   );
 }
@@ -2011,15 +2053,37 @@ async function findBuildMatch(
   files: BuilderInputs,
   requestPath: string,
   devServer: DevServer,
-  isFilesystem?: boolean
+  nowConfig: NowConfig,
+  isFilesystem = false
 ): 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 (
+      await shouldServe(
+        match,
+        files,
+        requestPath,
+        devServer,
+        nowConfig,
+        isFilesystem
+      )
+    ) {
+      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(
@@ -2027,14 +2091,14 @@ async function shouldServe(
   files: BuilderInputs,
   requestPath: string,
   devServer: DevServer,
-  isFilesystem?: boolean
+  nowConfig: NowConfig,
+  isFilesystem = false
 ): Promise<boolean> {
   const {
     src,
     config,
     builderWithPkg: { builder },
   } = match;
-  const nowConfig = await devServer.getNowConfig();
   const cleanSrc = src.endsWith('.html') ? src.slice(0, -5) : src;
   const trimmedPath = requestPath.endsWith('/')
     ? requestPath.slice(0, -1)
@@ -2078,7 +2142,7 @@ async function shouldServe(
     return true;
   } else if (
     !isFilesystem &&
-    (await findMatchingRoute(match, requestPath, devServer))
+    (await findMatchingRoute(match, requestPath, devServer, nowConfig))
   ) {
     // If there's no `shouldServe()` function and no matched asset, then look
     // up if there's a matching build route on the `match` that has already
@@ -2091,7 +2155,8 @@ async function shouldServe(
 async function findMatchingRoute(
   match: BuildMatch,
   requestPath: string,
-  devServer: DevServer
+  devServer: DevServer,
+  nowConfig: NowConfig
 ): Promise<RouteResult | void> {
   const reqUrl = `/${requestPath}`;
   for (const buildResult of match.buildResults.values()) {
@@ -2100,7 +2165,8 @@ async function findMatchingRoute(
       reqUrl,
       undefined,
       buildResult.routes,
-      devServer
+      devServer,
+      nowConfig
     );
     if (route.found) {
       return route;
@@ -2155,7 +2221,9 @@ function isIndex(path: string): boolean {
 }
 
 function minimatches(files: string[], pattern: string): boolean {
-  return files.some(file => file === pattern || minimatch(file, pattern));
+  return files.some(
+    (file) => file === pattern || minimatch(file, pattern, { dot: true })
+  );
 }
 
 function fileChanged(
@@ -2184,7 +2252,7 @@ function needsBlockingBuild(buildMatch: BuildMatch): boolean {
 }
 
 async function sleep(n: number) {
-  return new Promise(resolve => setTimeout(resolve, n));
+  return new Promise((resolve) => setTimeout(resolve, n));
 }
 
 async function checkForPort(
@@ -2216,3 +2284,11 @@ 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/dev/types.ts

@@ -17,14 +17,16 @@ import {
 import { NowConfig } from '@vercel/client';
 import { HandleValue, Route } from '@vercel/routing-utils';
 import { Output } from '../output';
+import { ProjectSettings } from '../../types';
 
 export { NowConfig };
 
 export interface DevServerOptions {
   output: Output;
   debug: boolean;
-  devCommand: string | undefined;
-  frameworkSlug: string | null;
+  devCommand?: string;
+  frameworkSlug?: string;
+  projectSettings?: ProjectSettings;
 }
 
 export interface EnvConfigs {

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

@@ -8,71 +8,52 @@ import {
   trailingSlashSchema,
 } from '@vercel/routing-utils';
 import { NowConfig } from './types';
-import { functionsSchema, buildsSchema } from '@vercel/build-utils';
+import {
+  functionsSchema,
+  buildsSchema,
+  NowBuildError,
+  getPrettyError,
+} from '@vercel/build-utils';
+import { fileNameSymbol } from '@vercel/client';
+
+const vercelConfigSchema = {
+  type: 'object',
+  // These are not all possibilities because `vc dev`
+  // doesn't need to know about `regions`, `public`, etc.
+  additionalProperties: true,
+  properties: {
+    builds: buildsSchema,
+    routes: routesSchema,
+    cleanUrls: cleanUrlsSchema,
+    headers: headersSchema,
+    redirects: redirectsSchema,
+    rewrites: rewritesSchema,
+    trailingSlash: trailingSlashSchema,
+    functions: functionsSchema,
+  },
+};
 
 const ajv = new Ajv();
+const validate = ajv.compile(vercelConfigSchema);
 
-const validateBuilds = ajv.compile(buildsSchema);
-const validateRoutes = ajv.compile(routesSchema);
-const validateCleanUrls = ajv.compile(cleanUrlsSchema);
-const validateHeaders = ajv.compile(headersSchema);
-const validateRedirects = ajv.compile(redirectsSchema);
-const validateRewrites = ajv.compile(rewritesSchema);
-const validateTrailingSlash = ajv.compile(trailingSlashSchema);
-const validateFunctions = ajv.compile(functionsSchema);
-
-export function validateNowConfigBuilds(config: NowConfig) {
-  return validateKey(config, 'builds', validateBuilds);
-}
-
-export function validateNowConfigRoutes(config: NowConfig) {
-  return validateKey(config, 'routes', validateRoutes);
-}
-
-export function validateNowConfigCleanUrls(config: NowConfig) {
-  return validateKey(config, 'cleanUrls', validateCleanUrls);
-}
-
-export function validateNowConfigHeaders(config: NowConfig) {
-  return validateKey(config, 'headers', validateHeaders);
-}
-
-export function validateNowConfigRedirects(config: NowConfig) {
-  return validateKey(config, 'redirects', validateRedirects);
-}
-
-export function validateNowConfigRewrites(config: NowConfig) {
-  return validateKey(config, 'rewrites', validateRewrites);
-}
-
-export function validateNowConfigTrailingSlash(config: NowConfig) {
-  return validateKey(config, 'trailingSlash', validateTrailingSlash);
-}
-
-export function validateNowConfigFunctions(config: NowConfig) {
-  return validateKey(config, 'functions', validateFunctions);
-}
-
-function validateKey(
-  config: NowConfig,
-  key: keyof NowConfig,
-  validate: Ajv.ValidateFunction
-) {
-  const value = config[key];
-  if (!value) {
-    return null;
+export function validateConfig(config: NowConfig): NowBuildError | null {
+  if (!validate(config)) {
+    if (validate.errors && validate.errors[0]) {
+      const error = validate.errors[0];
+      const fileName = config[fileNameSymbol] || 'vercel.json';
+      const niceError = getPrettyError(error);
+      niceError.message = `Invalid ${fileName} - ${niceError.message}`;
+      return niceError;
+    }
   }
 
-  if (!validate(value)) {
-    if (!validate.errors) {
-      return null;
-    }
-
-    const error = validate.errors[0];
-
-    return `Invalid \`${String(key)}\` property: ${error.dataPath} ${
-      error.message
-    }`;
+  if (config.functions && config.builds) {
+    return new NowBuildError({
+      code: 'FUNCTIONS_AND_BUILDS',
+      message:
+        'The `functions` property cannot be used in conjunction with the `builds` property. Please remove one of them.',
+      link: 'https://vercel.link/functions-and-builds',
+    });
   }
 
   return null;

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/get-files.ts

@@ -1,7 +1,7 @@
-import { resolve, join } from 'path';
+import { resolve } from 'path';
 import ignore from 'ignore';
 import dockerignore from '@zeit/dockerignore';
-import _glob, { IOptions } from 'glob';
+import _glob, { IOptions as GlobOptions } from 'glob';
 import fs from 'fs-extra';
 import { getVercelIgnore } from '@vercel/client';
 import IGNORED from './ignored';
@@ -12,11 +12,11 @@ import { NowConfig } from './dev/types';
 
 type NullableString = string | null;
 
-const flatten = (
+function flatten(
   arr: NullableString[] | NullableString[][],
   res: NullableString[] = []
-) => {
-  for (let cur of arr) {
+): NullableString[] {
+  for (const cur of arr) {
     if (Array.isArray(cur)) {
       flatten(cur, res);
     } else {
@@ -24,21 +24,17 @@ const flatten = (
     }
   }
   return res;
-};
+}
 
-const glob = async function(pattern: string, options: IOptions) {
-  return new Promise<string[]>((resolve, reject) => {
-    _glob(pattern, options, (error, files) => {
-      if (error) {
-        reject(error);
-      } else {
-        resolve(files);
-      }
+async function glob(pattern: string, options: GlobOptions): Promise<string[]> {
+  return new Promise((resolve, reject) => {
+    _glob(pattern, options, (err, files) => {
+      err ? reject(err) : resolve(files);
     });
   });
-};
+}
 
-interface WalkSyncOptions {
+interface WalkOptions {
   output: Output;
 }
 
@@ -51,27 +47,27 @@ interface WalkSyncOptions {
  *  - `output` {Object} "output" helper object
  * @returns {Array}
  */
-const walkSync = async (
+async function walk(
   dir: string,
   path: string,
   filelist: string[] = [],
-  opts: WalkSyncOptions
-) => {
+  opts: WalkOptions
+) {
   const { debug } = opts.output;
   const dirc = await fs.readdir(asAbsolute(dir, path));
   for (let file of dirc) {
     file = asAbsolute(file, dir);
     try {
-      const file_stat = await fs.stat(file);
-      filelist = file_stat.isDirectory()
-        ? await walkSync(file, path, filelist, opts)
+      const fileStat = await fs.stat(file);
+      filelist = fileStat.isDirectory()
+        ? await walk(file, path, filelist, opts)
         : filelist.concat(file);
     } catch (e) {
       debug(`Ignoring invalid file ${file}`);
     }
   }
   return filelist;
-};
+}
 
 interface FilesInWhitelistOptions {
   output: Output;
@@ -85,7 +81,7 @@ interface FilesInWhitelistOptions {
  *  - `output` {Object} "output" helper object
  * @returns {Array} the expanded list of whitelisted files.
  */
-const getFilesInWhitelist = async function(
+const getFilesInWhitelist = async function (
   whitelist: string[],
   path: string,
   opts: FilesInWhitelistOptions
@@ -97,10 +93,10 @@ const getFilesInWhitelist = async function(
     whitelist.map(async (file: string) => {
       file = asAbsolute(file, path);
       try {
-        const file_stat = await fs.stat(file);
-        if (file_stat.isDirectory()) {
-          const dir_files = await walkSync(file, path, [], opts);
-          files.push(...dir_files);
+        const fileStat = await fs.stat(file);
+        if (fileStat.isDirectory()) {
+          const dirFiles = await walk(file, path, [], opts);
+          files.push(...dirFiles);
         } else {
           files.push(file);
         }
@@ -117,7 +113,7 @@ const getFilesInWhitelist = async function(
  * because ignore doesn't like them :|
  */
 
-const clearRelative = function(str: string) {
+const clearRelative = function (str: string) {
   return str.replace(/(\n|^)\.\//g, '$1');
 };
 
@@ -127,7 +123,7 @@ const clearRelative = function(str: string) {
  * @return {String} results or `''`
  */
 
-const maybeRead = async function<T>(path: string, default_: T) {
+const maybeRead = async function <T>(path: string, default_: T) {
   try {
     return await fs.readFile(path, 'utf8');
   } catch (err) {
@@ -143,7 +139,7 @@ const maybeRead = async function<T>(path: string, default_: T) {
  * @param {String} parent full path
  */
 
-const asAbsolute = function(path: string, parent: string) {
+const asAbsolute = function (path: string, parent: string) {
   if (path[0] === '/') {
     return path;
   }
@@ -272,7 +268,7 @@ export async function npm(
     const search = Array.prototype.concat.apply(
       [],
       await Promise.all(
-        search_.map(file =>
+        search_.map((file) =>
           glob(file, { cwd: path, absolute: true, dot: true })
         )
       )
@@ -364,7 +360,7 @@ export async function docker(
     const search_ = ['.'];
 
     // Convert all filenames into absolute paths
-    const search = search_.map(file => asAbsolute(file, path));
+    const search = search_.map((file) => asAbsolute(file, path));
 
     // Compile list of ignored patterns and files
     const dockerIgnore = await maybeRead(resolve(path, '.dockerignore'), null);
@@ -382,7 +378,7 @@ export async function docker(
       .createFilter();
 
     const prefixLength = path.length + 1;
-    const accepts = function(file: string) {
+    const accepts = function (file: string) {
       const relativePath = file.substr(prefixLength);
 
       if (relativePath === '') {
@@ -415,24 +411,6 @@ export async function docker(
   return uniqueStrings(files);
 }
 
-/**
- * Get a list of all files inside the project folder
- *
- * @param {String} of the current working directory
- * @param {Object} output instance
- * @return {Array} of {String}s with the found files
- */
-export async function getAllProjectFiles(cwd: string, { debug }: Output) {
-  // We need a slash at the end to remove it later on from the matched files
-  const current = join(resolve(cwd), '/');
-  debug(`Searching files inside of ${current}`);
-
-  const list = await glob('**', { cwd: current, absolute: true, nodir: true });
-
-  // We need to replace \ with / for windows
-  return list.map(file => file.replace(current.replace(/\\/g, '/'), ''));
-}
-
 interface ExplodeOptions {
   accepts: (file: string) => boolean;
   output: Output;
@@ -482,7 +460,7 @@ async function explode(
     if (s.isDirectory()) {
       const all = await fs.readdir(file);
       /* eslint-disable no-use-before-define */
-      const recursive = many(all.map(subdir => asAbsolute(subdir, file)));
+      const recursive = many(all.map((subdir) => asAbsolute(subdir, file)));
       return (recursive as any) as Promise<string | null>;
       /* eslint-enable no-use-before-define */
     }
@@ -494,7 +472,7 @@ async function explode(
     return path;
   };
 
-  const many = (all: string[]) => Promise.all(all.map(file => list(file)));
+  const many = (all: string[]) => Promise.all(all.map((file) => list(file)));
   const arrayOfArrays = await many(paths);
   return flatten(arrayOfArrays).filter(notNull);
 }

packages/now-cli/src/util/index.js

@@ -145,6 +145,7 @@ export default class Now extends EventEmitter {
       regions,
       target: target || undefined,
       projectSettings,
+      source: 'cli',
     };
 
     // Ignore specific items from vercel.json

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-validate.unit.js

@@ -0,0 +1,283 @@
+import test from 'ava';
+import { validateConfig } from '../src/util/dev/validate';
+
+test('[dev-validate] should not error with empty config', async (t) => {
+  const config = {};
+  const error = validateConfig(config);
+  t.deepEqual(error, null);
+});
+
+test('[dev-validate] should not error with complete config', async (t) => {
+  const config = {
+    version: 2,
+    public: true,
+    regions: ['sfo1', 'iad1'],
+    cleanUrls: true,
+    headers: [{ source: '/', headers: [{ key: 'x-id', value: '123' }] }],
+    rewrites: [{ source: '/help', destination: '/support' }],
+    redirects: [{ source: '/kb', destination: 'https://example.com' }],
+    trailingSlash: false,
+    functions: { 'api/user.go': { memory: 128, maxDuration: 5 } },
+  };
+  const error = validateConfig(config);
+  t.deepEqual(error, null);
+});
+
+test('[dev-validate] should not error with builds and routes', async (t) => {
+  const config = {
+    builds: [{ src: 'api/index.js', use: '@vercel/node' }],
+    routes: [{ src: '/(.*)', dest: '/api/index.js' }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(error, null);
+});
+
+test('[dev-validate] should error with invalid rewrites due to additional property and offer suggestion', async (t) => {
+  const config = {
+    rewrites: [{ src: '/(.*)', dest: '/api/index.js' }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `rewrites[0]` should NOT have additional property `src`. Did you mean `source`?'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/rewrites'
+  );
+});
+
+test('[dev-validate] should error with invalid routes due to additional property and offer suggestion', async (t) => {
+  const config = {
+    routes: [{ source: '/(.*)', destination: '/api/index.js' }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `routes[0]` should NOT have additional property `source`. Did you mean `src`?'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/routes'
+  );
+});
+
+test('[dev-validate] should error with invalid routes array type', async (t) => {
+  const config = {
+    routes: { src: '/(.*)', dest: '/api/index.js' },
+  };
+  const error = validateConfig(config);
+  t.deepEqual(error.message, 'Invalid vercel.json - `routes` should be array.');
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/routes'
+  );
+});
+
+test('[dev-validate] should error with invalid redirects array object', async (t) => {
+  const config = {
+    redirects: [
+      {
+        /* intentionally empty */
+      },
+    ],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `redirects[0]` missing required property `source`.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/redirects'
+  );
+});
+
+test('[dev-validate] should error with invalid redirects.permanent poperty', async (t) => {
+  const config = {
+    redirects: [{ source: '/', destination: '/go', permanent: 'yes' }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `redirects[0].permanent` should be boolean.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/redirects'
+  );
+});
+
+test('[dev-validate] should error with invalid cleanUrls type', async (t) => {
+  const config = {
+    cleanUrls: 'true',
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `cleanUrls` should be boolean.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/cleanurls'
+  );
+});
+
+test('[dev-validate] should error with invalid trailingSlash type', async (t) => {
+  const config = {
+    trailingSlash: [true],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `trailingSlash` should be boolean.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/trailingslash'
+  );
+});
+
+test('[dev-validate] should error with invalid headers property', async (t) => {
+  const config = {
+    headers: [{ 'Content-Type': 'text/html' }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `headers[0]` should NOT have additional property `Content-Type`. Please remove it.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/headers'
+  );
+});
+
+test('[dev-validate] should error with invalid headers.source type', async (t) => {
+  const config = {
+    headers: [{ source: [{ 'Content-Type': 'text/html' }] }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `headers[0].source` should be string.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/headers'
+  );
+});
+
+test('[dev-validate] should error with invalid headers additional property', async (t) => {
+  const config = {
+    headers: [{ source: '/', stuff: [{ 'Content-Type': 'text/html' }] }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `headers[0]` should NOT have additional property `stuff`. Please remove it.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/headers'
+  );
+});
+
+test('[dev-validate] should error with invalid headers wrong nested headers type', async (t) => {
+  const config = {
+    headers: [{ source: '/', headers: [{ 'Content-Type': 'text/html' }] }],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `headers[0].headers[0]` should NOT have additional property `Content-Type`. Please remove it.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/headers'
+  );
+});
+
+test('[dev-validate] should error with invalid headers wrong nested headers additional property', async (t) => {
+  const config = {
+    headers: [
+      { source: '/', headers: [{ key: 'Content-Type', val: 'text/html' }] },
+    ],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `headers[0].headers[0]` should NOT have additional property `val`. Please remove it.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/headers'
+  );
+});
+
+test('[dev-validate] should error with too many redirects', async (t) => {
+  const config = {
+    redirects: Array.from({ length: 5000 }).map((_, i) => ({
+      source: `/${i}`,
+      destination: `/v/${i}`,
+    })),
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `redirects` should NOT have more than 1024 items.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/redirects'
+  );
+});
+
+test('[dev-validate] should error with too many nested headers', async (t) => {
+  const config = {
+    headers: [
+      {
+        source: '/',
+        headers: [{ key: `x-id`, value: `123` }],
+      },
+      {
+        source: '/too-many',
+        headers: Array.from({ length: 5000 }).map((_, i) => ({
+          key: `${i}`,
+          value: `${i}`,
+        })),
+      },
+    ],
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'Invalid vercel.json - `headers[1].headers` should NOT have more than 1024 items.'
+  );
+  t.deepEqual(
+    error.link,
+    'https://vercel.com/docs/configuration#project/headers'
+  );
+});
+
+test('[dev-validate] should error with "functions" and "builds"', async (t) => {
+  const config = {
+    builds: [
+      {
+        src: 'index.html',
+        use: '@vercel/static',
+      },
+    ],
+    functions: {
+      'api/test.js': {
+        memory: 1024,
+      },
+    },
+  };
+  const error = validateConfig(config);
+  t.deepEqual(
+    error.message,
+    'The `functions` property cannot be used in conjunction with the `builds` property. Please remove one of them.'
+  );
+  t.deepEqual(error.link, 'https://vercel.link/functions-and-builds');
+});

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

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

packages/now-cli/test/dev/fixtures/00-list-directory/.well-known/keybase.txt

@@ -0,0 +1 @@
+proof goes here

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/06-gridsome/package.json

@@ -3,7 +3,7 @@
   "private": true,
   "scripts": {
     "build": "gridsome build",
-    "develop": "gridsome develop",
+    "dev": "gridsome develop -p $PORT",
     "explore": "gridsome explore"
   },
   "dependencies": {

packages/now-cli/test/dev/fixtures/06-gridsome/src/pages/404.vue

@@ -0,0 +1,14 @@
+<template>
+  <Layout>
+    <h1>Not Found</h1>
+    <p>This is a Custom Gridsome 404.</p>
+  </Layout>
+</template>
+
+<script>
+export default {
+  metaInfo: {
+    title: 'Not Found'
+  }
+}
+</script>

packages/now-cli/test/dev/fixtures/06-gridsome/src/pages/Index.vue

@@ -1,11 +1,11 @@
 <template>
   <Layout>
-    
+
     <!-- Learn how to use images here: https://gridsome.org/docs/images -->
     <g-image alt="Example image" src="~/favicon.png" width="135" />
-    
-    <h1>Hello, world!</h1>
-   
+
+    <h1>Gridsome on Vercel</h1>
+
     <p>
       Lorem ipsum dolor sit amet, consectetur adipisicing elit. Pariatur excepturi labore tempore expedita, et iste tenetur suscipit explicabo! Dolores, aperiam non officia eos quod asperiores
     </p>

packages/now-cli/test/dev/fixtures/06-gridsome/vercel.json

@@ -0,0 +1,3 @@
+{
+  "redirects": [{ "source": "/support", "destination": "/about?ref=support" }]
+}

packages/now-cli/test/dev/fixtures/07-hexo-node/source/contact.html

@@ -0,0 +1 @@
+<h1>Contact Us</h1>

packages/now-cli/test/dev/fixtures/07-hexo-node/vercel.json

@@ -0,0 +1,3 @@
+{
+  "rewrites": [{ "source": "/support", "destination": "/contact.html" }]
+}

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/10-nextjs-node/pages/contact.js

@@ -0,0 +1,3 @@
+export default function Contact() {
+  return <h1>Contact Page</h1>;
+}

packages/now-cli/test/dev/fixtures/10-nextjs-node/vercel.json

@@ -0,0 +1,3 @@
+{
+  "rewrites": [{ "source": "/support", "destination": "/contact" }]
+}

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/go/.gitignore

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

packages/now-cli/test/dev/fixtures/go/api/[segment].go

@@ -0,0 +1,10 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func Handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "Req Path: %s", r.URL.Path)
+}

packages/now-cli/test/dev/fixtures/go/api/another.go

@@ -0,0 +1,10 @@
+package another
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func Another(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "This is another page")
+}

packages/now-cli/test/dev/fixtures/go/api/index.go

@@ -0,0 +1,10 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func Handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "This is the index page")
+}

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/monorepo-dynamic-paths/blog/next.config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  assetPrefix: '/blog',
+  env: {
+    ASSET_PREFIX: '/blog',
+  },
+};

packages/now-cli/test/dev/fixtures/monorepo-dynamic-paths/blog/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "with-zones-blog",
+  "version": "1.0.0",
+  "dependencies": {
+    "next": "latest",
+    "react": "latest",
+    "react-dom": "latest"
+  },
+  "license": "ISC"
+}

packages/now-cli/test/dev/fixtures/monorepo-dynamic-paths/blog/pages/blog/index.js

@@ -0,0 +1,22 @@
+import Link from 'next/link';
+
+export default function Blog() {
+  return (
+    <div>
+      <h3>This is our blog</h3>
+      <ul>
+        <li>
+          <Link href="/blog/post/[id]" as="/blog/post/1">
+            <a>Post 1</a>
+          </Link>
+        </li>
+        <li>
+          <Link href="/blog/post/[id]" as="/blog/post/2">
+            <a>Post 2</a>
+          </Link>
+        </li>
+      </ul>
+      <a href="/">Home</a>
+    </div>
+  );
+}