Merge remote-tracking branch 'upstream/canary' into patch-1

.github/workflows/build_test_deploy.yml

@@ -156,15 +156,15 @@ jobs:
     steps:
       - run: exit 0
 
-  testFutureDependencies:
-    name: Webpack 5 (Basic, Production, Acceptance)
+  testLegacyWebpack:
+    name: Webpack 4 (Basic, Production, Acceptance)
     runs-on: ubuntu-latest
     needs: build
     env:
       NEXT_TELEMETRY_DISABLED: 1
       NEXT_TEST_JOB: 1
       HEADLESS: true
-      NEXT_PRIVATE_TEST_WEBPACK5_MODE: 1
+      NEXT_PRIVATE_TEST_WEBPACK4_MODE: 1
 
     steps:
       - uses: actions/cache@v2
@@ -174,43 +174,9 @@ jobs:
           path: ./*
           key: ${{ github.sha }}
 
-      - run: xvfb-run node run-tests.js test/integration/{fallback-modules,link-ref,production,basic,async-modules,font-optimization,ssr-ctx}/test/index.test.js test/acceptance/*.test.js
+      - run: xvfb-run node run-tests.js test/integration/{basic,fallback-modules,link-ref,production,async-modules,font-optimization,ssr-ctx}/test/index.test.js test/acceptance/*.test.js
         if: ${{needs.build.outputs.docsChange != 'docs only change'}}
 
-  testLegacyReact:
-    name: React 16 + Webpack 4 (Basic, Production, Acceptance)
-    runs-on: ubuntu-latest
-    env:
-      NEXT_TELEMETRY_DISABLED: 1
-      NEXT_TEST_JOB: 1
-      HEADLESS: true
-
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          fetch-depth: 25
-
-      - run: echo ::set-output name=DOCS_CHANGE::$(node skip-docs-change.js echo 'not-docs-only-change')
-        id: docs-change
-
-      - run: git fetch --depth=1 origin +refs/tags/*:refs/tags/*
-        if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs only change' }}
-
-      - run: cat package.json | jq '.resolutions.react = "^16.14.0"' > package.json.tmp && mv package.json.tmp package.json
-        if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs only change' }}
-
-      - run: cat package.json | jq '.resolutions."react-dom" = "^16.14.0"' > package.json.tmp && mv package.json.tmp package.json
-        if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs only change' }}
-
-      - run: yarn install --check-files
-        if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs only change' }}
-
-      - run: yarn list react react-dom
-        if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs only change' }}
-
-      - run: xvfb-run node run-tests.js test/integration/{link-ref,production,basic,async-modules,font-optimization,ssr-ctx,worker-loader}/test/index.test.js test/acceptance/*.test.js
-        if: ${{ steps.docs-change.outputs.DOCS_CHANGE != 'docs only change' }}
-
   testFirefox:
     name: Test Firefox (production)
     runs-on: ubuntu-latest

contributing.md

@@ -1,6 +1,6 @@
 # Contributing to Next.js
 
-Our Commitment to Open Source can be found [here](https://vercel.com/oss).
+Read about our [Commitment to Open Source](https://vercel.com/oss).
 
 1. [Fork](https://help.github.com/articles/fork-a-repo/) this repository to your own GitHub account and then [clone](https://help.github.com/articles/cloning-a-repository/) it to your local device.
 2. Create a new branch: `git checkout -b MY_BRANCH_NAME`
@@ -124,12 +124,19 @@ When you add an example to the [examples](examples) directory, don’t forget to
 - To add additional installation instructions, please add it where appropriate.
 - To add additional notes, add `## Notes` section at the end.
 - Remove the `Deploy your own` section if your example can’t be immediately deployed to Vercel.
+- Remove the `Preview` section if the example doesn't work on [StackBlitz](http://stackblitz.com/) and file an issue [here](https://github.com/stackblitz/webcontainer-core).
 
 ````markdown
 # Example Name
 
 Description
 
+## Preview
+
+Preview the example live on [StackBlitz](http://stackblitz.com/):
+
+[![Open in StackBlitz](https://developer.stackblitz.com/img/open_in_stackblitz.svg)](https://stackblitz.com/github/vercel/next.js/tree/canary/examples/DIRECTORY_NAME)
+
 ## Deploy your own
 
 Deploy the example using [Vercel](https://vercel.com?utm_source=github&utm_medium=readme&utm_campaign=next-example):

docs/advanced-features/amp-support/typescript.md

@@ -6,4 +6,4 @@ description: Using AMP with TypeScript? Extend your typings to allow AMP compone
 
 AMP currently doesn't have built-in types for TypeScript, but it's in their roadmap ([#13791](https://github.com/ampproject/amphtml/issues/13791)).
 
-As a workaround you can manually create a file called `amp.d.ts` inside your project and add the custom types described [here](https://stackoverflow.com/a/50601125).
+As a workaround you can manually create a file called `amp.d.ts` inside your project and add these [custom types](https://stackoverflow.com/a/50601125).

docs/advanced-features/measuring-performance.md

@@ -175,7 +175,7 @@ export function reportWebVitals(metric) {
 > }
 > ```
 >
-> Read more about sending results to Google Analytics [here](https://github.com/GoogleChrome/web-vitals#send-the-results-to-google-analytics).
+> Read more about [sending results to Google Analytics](https://github.com/GoogleChrome/web-vitals#send-the-results-to-google-analytics).
 
 ## TypeScript
 

docs/api-reference/cli.md

@@ -86,12 +86,15 @@ npx next start -p 4000
 
 ## Lint
 
-`next lint` runs ESLint for all files in the `pages` directory and provides a guided setup to install any required dependencies if ESLint is not already configured in your application.
+`next lint` runs ESLint for all files in the `pages`, `components`, and `lib` directories. It also
+provides a guided setup to install any required dependencies if ESLint is not already configured in
+your application.
 
-You can also run ESLint on other directories with the `--dir` flag:
+If you have other directories that you would like to lint, you can specify them using the `--dir`
+flag:
 
 ```bash
-next lint --dir components
+next lint --dir utils
 ```
 
 ## Telemetry

docs/api-reference/create-next-app.md

@@ -19,6 +19,7 @@ yarn create next-app
 - **-e, --example [name]|[github-url]** - An example to bootstrap the app with. You can use an example name from the [Next.js repo](https://github.com/vercel/next.js/tree/master/examples) or a GitHub URL. The URL can use any branch and/or subdirectory.
 - **--example-path [path-to-example]** - In a rare case, your GitHub URL might contain a branch name with a slash (e.g. bug/fix-1) and the path to the example (e.g. foo/bar). In this case, you must specify the path to the example separately: `--example-path foo/bar`
 - **--use-npm** - Explicitly tell the CLI to bootstrap the app using npm. To bootstrap using yarn we recommend to run `yarn create next-app`
+- **--typescript or --ts** - Creates the default template with TypeScript instead of JavaScript.
 
 ### Why use Create Next App?
 

docs/api-reference/next.config.js/ignoring-eslint.md

@@ -0,0 +1,39 @@
+---
+description: Next.js reports ESLint errors and warnings during builds by default. Learn how to opt-out of this behavior here.
+---
+
+# Ignoring ESLint
+
+When ESLint is detected in your project, Next.js fails your **production build** (`next build`) when errors are present.
+
+If you'd like Next.js to dangerously produce production code even when your application has ESLint errors, you can disable the built-in linting step completely.
+
+> Be sure you have configured ESLint to run in a separate part of your workflow (for example, in CI or a pre-commit hook).
+
+Open `next.config.js` and enable the `ignoreDuringBuilds` option in the `eslint` config:
+
+```js
+module.exports = {
+  eslint: {
+    // Warning: Dangerously allow production builds to successfully complete even if
+    // your project has ESLint errors.
+    ignoreDuringBuilds: true,
+  },
+}
+```
+
+## Related
+
+<div class="card">
+  <a href="/docs/api-reference/next.config.js/introduction.md">
+    <b>Introduction to next.config.js:</b>
+    <small>Learn more about the configuration file used by Next.js.</small>
+  </a>
+</div>
+
+<div class="card">
+  <a href="/docs/basic-features/eslint.md">
+    <b>ESLint:</b>
+    <small>Get started with ESLint in Next.js.</small>
+  </a>
+</div>

docs/api-reference/next.config.js/introduction.md

@@ -26,7 +26,7 @@ module.exports = (phase, { defaultConfig }) => {
 }
 ```
 
-`phase` is the current context in which the configuration is loaded. You can see the available phases [here](https://github.com/vercel/next.js/blob/canary/packages/next/next-server/lib/constants.ts#L1-L4). Phases can be imported from `next/constants`:
+`phase` is the current context in which the configuration is loaded. You can see the [available phases](https://github.com/vercel/next.js/blob/canary/packages/next/next-server/lib/constants.ts#L1-L4). Phases can be imported from `next/constants`:
 
 ```js
 const { PHASE_DEVELOPMENT_SERVER } = require('next/constants')
@@ -44,7 +44,7 @@ module.exports = (phase, { defaultConfig }) => {
 }
 ```
 
-The commented lines are the place where you can put the configs allowed by `next.config.js`, which are defined [here](https://github.com/vercel/next.js/blob/canary/packages/next/next-server/server/config-shared.ts#L68).
+The commented lines are the place where you can put the configs allowed by `next.config.js`, which are [defined in this file](https://github.com/vercel/next.js/blob/canary/packages/next/next-server/server/config-shared.ts#L68).
 
 However, none of the configs are required, and it's not necessary to understand what each config does. Instead, search for the features you need to enable or modify in this section and they will show you what to do.
 

docs/api-reference/next/amp.md

@@ -11,7 +11,7 @@ description: Enable AMP in a page, and control the way Next.js adds AMP to the p
   </ul>
 </details>
 
-> AMP support is one of our advanced features, you can read more about it [here](/docs/advanced-features/amp-support/introduction.md).
+> AMP support is one of our advanced features, you can [read more about AMP here](/docs/advanced-features/amp-support/introduction.md).
 
 To enable AMP, add the following config to your page:
 

docs/api-routes/introduction.md

@@ -29,8 +29,8 @@ export default function handler(req, res) {
 
 For an API route to work, you need to export a function as default (a.k.a **request handler**), which then receives the following parameters:
 
-- `req`: An instance of [http.IncomingMessage](https://nodejs.org/api/http.html#http_class_http_incomingmessage), plus some pre-built middlewares you can see [here](/docs/api-routes/api-middlewares.md)
-- `res`: An instance of [http.ServerResponse](https://nodejs.org/api/http.html#http_class_http_serverresponse), plus some helper functions you can see [here](/docs/api-routes/response-helpers.md)
+- `req`: An instance of [http.IncomingMessage](https://nodejs.org/api/http.html#http_class_http_incomingmessage), plus some [pre-built middlewares](/docs/api-routes/api-middlewares.md)
+- `res`: An instance of [http.ServerResponse](https://nodejs.org/api/http.html#http_class_http_serverresponse), plus some [helper functions](/docs/api-routes/response-helpers.md)
 
 To handle different HTTP methods in an API route, you can use `req.method` in your request handler, like so:
 

docs/authentication.md

@@ -48,7 +48,7 @@ const Profile = () => {
 export default Profile
 ```
 
-You can view this example in action [here](https://next-with-iron-session.vercel.app/). Check out the [`with-iron-session`](https://github.com/vercel/next.js/tree/canary/examples/with-iron-session) example to see how it works.
+You can view this [example in action](https://next-with-iron-session.vercel.app/). Check out the [`with-iron-session`](https://github.com/vercel/next.js/tree/canary/examples/with-iron-session) example to see how it works.
 
 ### Authenticating Server-Rendered Pages
 

docs/basic-features/eslint.md

@@ -4,16 +4,24 @@ description: Next.js provides an integrated ESLint experience by default. These
 
 # ESLint
 
-Since version **11.0.0**, Next.js provides an integrated [ESLint](https://eslint.org/) experience out of the box. To get started, run `next lint`:
+Since version **11.0.0**, Next.js provides an integrated [ESLint](https://eslint.org/) experience out of the box. Add `next lint` as a script to `package.json`:
+
+```json
+"scripts": {
+  "lint": "next lint"
+}
+```
+
+Then run `npm run lint` or `yarn lint`:
 
 ```bash
-next lint
+yarn lint
 ```
 
 If you don't already have ESLint configured in your application, you will be guided through the installation of the required packages.
 
 ```bash
-next lint
+yarn lint
 
 # You'll see instructions like these:
 #
@@ -42,25 +50,46 @@ We recommend using an appropriate [integration](https://eslint.org/docs/user-gui
 
 Once ESLint has been set up, it will automatically run during every build (`next build`). Errors will fail the build, while warnings will not.
 
-If you do not want ESLint to run as a build step, it can be disabled using the `--no-lint` flag:
+If you do not want ESLint to run as a build step, refer to the documentation for [Ignoring ESLint](/docs/api-reference/next.config.js/ignoring-eslint.md):
 
-```bash
-next build --no-lint
-```
+## Linting Custom Directories
 
-**This is not recommended** unless you have configured ESLint to run in a separate part of your workflow (for example, in CI or a pre-commit hook).
+By default, Next.js will run ESLint for all files in the `pages/`, `components/`, and `lib/` directories. However, you can specify which directories using the `dirs` option in the `eslint` config in `next.config.js` for production builds:
 
-## Linting Custom Directories
+```js
+module.exports = {
+  eslint: {
+    dirs: ['pages', 'utils'], // Only run ESLint on the 'pages' and 'utils' directories during production builds (next build)
+  },
+}
+```
 
-By default, Next.js will only run ESLint for all files in the `pages/` directory. However, you can specify other custom directories to run by using the `--dir` flag in `next lint`:
+Similarly, the `--dir` flag can be used for `next lint`:
 
 ```bash
-next lint --dir components --dir lib
+yarn lint --dir pages --dir utils
 ```
 
 ## ESLint Plugin
 
-Next.js provides an ESLint plugin, [`eslint-plugin-next`](https://www.npmjs.com/package/@next/eslint-plugin-next), making it easier to catch common issues and problems in a Next.js application. The full set of rules can be found in the [package repository](https://github.com/vercel/next.js/tree/master/packages/eslint-plugin-next/lib/rules).
+Next.js provides an ESLint plugin, [`eslint-plugin-next`](https://www.npmjs.com/package/@next/eslint-plugin-next), making it easier to catch common issues and problems in a Next.js application. The full set of rules is as follows:
+
+|     | Rule                                                                                           | Description                                                      |
+| :-: | ---------------------------------------------------------------------------------------------- | ---------------------------------------------------------------- |
+| ✔️  | [next/google-font-display](https://nextjs.org/docs/messages/google-font-display)               | Enforce optional or swap font-display behavior with Google Fonts |
+| ✔️  | [next/google-font-preconnect](https://nextjs.org/docs/messages/google-font-preconnect)         | Enforce preconnect usage with Google Fonts                       |
+| ✔️  | [next/link-passhref](https://nextjs.org/docs/messages/link-passhref)                           | Enforce passHref prop usage with custom Link components          |
+| ✔️  | [next/no-css-tags](https://nextjs.org/docs/messages/no-css-tags)                               | Prevent manual stylesheet tags                                   |
+| ✔️  | [next/no-document-import-in-page](https://nextjs.org/docs/messages/no-document-import-in-page) | Disallow importing next/document outside of pages/document.js    |
+| ✔️  | [next/no-head-import-in-document](https://nextjs.org/docs/messages/no-head-import-in-document) | Disallow importing next/head in pages/document.js                |
+| ✔️  | [next/no-html-link-for-pages](https://nextjs.org/docs/messages/no-html-link-for-pages)         | Prohibit HTML anchor links to pages without a Link component     |
+| ✔️  | [next/no-img-element](https://nextjs.org/docs/messages/no-img-element)                         | Prohibit usage of HTML <img> element                       |
+| ✔️  | [next/no-page-custom-font](https://nextjs.org/docs/messages/no-page-custom-font)               | Prevent page-only custom fonts                                   |
+| ✔️  | [next/no-sync-scripts](https://nextjs.org/docs/messages/no-sync-scripts)                       | Forbid synchronous scripts                                       |
+| ✔️  | [next/no-title-in-document-head](https://nextjs.org/docs/messages/no-title-in-document-head)   | Disallow using <title> with Head from next/document        |
+| ✔️  | [next/no-unwanted-polyfillio](https://nextjs.org/docs/messages/no-unwanted-polyfillio)         | Prevent duplicate polyfills from Polyfill.io                     |
+
+- ✔: Enabled in the recommended configuration
 
 ## Base Configuration
 
@@ -82,14 +111,14 @@ You can see the full details of the shareable configuration in the [`eslint-conf
 
 ## Disabling Rules
 
-If you would like to modify any rules provided by the supported plugins (`react`, `react-hooks`, `next`), you can directly modify them using the `rules` property in your `.eslintrc`:
+If you would like to modify or disable any rules provided by the supported plugins (`react`, `react-hooks`, `next`), you can directly change them using the `rules` property in your `.eslintrc`:
 
 ```js
 {
   "extends": "next",
   "rules": {
     "react/no-unescaped-entities": "off",
-    "@next/next/no-page-custom-font": "error",
+    "@next/next/no-page-custom-font": "off",
   }
 }
 ```

docs/manifest.json

@@ -344,6 +344,10 @@
               "title": "Configuring onDemandEntries",
               "path": "/docs/api-reference/next.config.js/configuring-onDemandEntries.md"
             },
+            {
+              "title": "Ignoring ESLint",
+              "path": "/docs/api-reference/next.config.js/ignoring-eslint.md"
+            },
             {
               "title": "Ignoring TypeScript Errors",
               "path": "/docs/api-reference/next.config.js/ignoring-typescript-errors.md"

docs/upgrading.md

@@ -6,6 +6,22 @@ description: Learn how to upgrade Next.js.
 
 ## Upgrading from version 10 to 11
 
+## Upgrade React version to latest
+
+Most applications already use the latest version of React, with Next.js 11 the minimum React version has been updated to 17.0.2.
+
+To upgrade you can run the following command:
+
+```
+npm install react@latest react-dom@latest
+```
+
+Or using `yarn`:
+
+```
+yarn add react@latest react-dom@latest
+```
+
 ### Remove `super.componentDidCatch()` from `pages/_app.js`
 
 The `next/app` component's `componentDidCatch` has been deprecated since Next.js 9 as it's no longer needed and has since been a no-op, in Next.js 11 it has been removed.

errors/future-webpack5-moved-to-webpack5.md

@@ -0,0 +1,33 @@
+# `future.webpack5` has been moved to `webpack5`
+
+#### Why This Error Occurred
+
+The `future.webpack5` option has been moved to `webpack5` in `next.config.js`.
+
+#### Possible Ways to Fix It
+
+If you had the value `true` you can removed the option as webpack 5 is now the default for all Next.js apps unless opted out.
+
+If you had he value `false` you can update `next.config.js`:
+
+Change `future.webpack5` to `webpack5`.
+
+Current `next.config.js`:
+
+```js
+// next.config.js
+module.exports = {
+  future: {
+    webpack5: false,
+  },
+}
+```
+
+Updated `next.config.js`:
+
+```js
+// next.config.js
+module.exports = {
+  webpack5: false,
+}
+```