Merge branch 'canary' into fix-image-preload-tag

.github/workflows/build_test_deploy.yml

@@ -96,8 +96,8 @@ jobs:
     steps:
       - run: exit 0
 
-  testWebpack5:
-    name: webpack 5 (Basic, Production, Acceptance)
+  testFutureDependencies:
+    name: React 17 + webpack 5 (Basic, Production, Acceptance)
     runs-on: ubuntu-latest
     env:
       NEXT_TELEMETRY_DISABLED: 1
@@ -108,6 +108,8 @@ jobs:
       - uses: actions/checkout@v2
       - run: git fetch --depth=1 origin +refs/tags/*:refs/tags/*
       - run: cat package.json | jq '.resolutions.webpack = "^5.0.0-beta.22"' > package.json.tmp && mv package.json.tmp package.json
+      - run: cat package.json | jq '.resolutions.react = "^17.0.0-rc.1"' > package.json.tmp && mv package.json.tmp package.json
+      - run: cat package.json | jq '.resolutions."react-dom" = "^17.0.0-rc.1"' > package.json.tmp && mv package.json.tmp package.json
       - run: yarn install --check-files
       - run: node run-tests.js test/integration/production/test/index.test.js
       - run: node run-tests.js test/integration/basic/test/index.test.js

docs/basic-features/fast-refresh.md

@@ -6,6 +6,13 @@ description:
 
 # Fast Refresh
 
+<details open>
+  <summary><b>Examples</b></summary>
+  <ul>
+    <li><a href="https://github.com/vercel/next.js/tree/canary/examples/fast-refresh-demo">Fast Refresh Demo</a></li>
+  </ul>
+</details>
+
 Fast Refresh is a Next.js feature that gives you instantaneous feedback on
 edits made to your React components. Fast Refresh is enabled by default in all
 Next.js applications on **9.4 or newer**. With Next.js Fast Refresh enabled,

examples/fast-refresh-demo/.gitignore

@@ -0,0 +1,34 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.js
+
+# testing
+/coverage
+
+# next.js
+/.next/
+/out/
+
+# production
+/build
+
+# misc
+.DS_Store
+*.pem
+
+# debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# local env files
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# vercel
+.vercel

examples/fast-refresh-demo/README.md

@@ -0,0 +1,23 @@
+# Fast Refresh Demo
+
+Next.js ships with [Fast Refresh](https://nextjs.org/docs/basic-features/fast-refresh) which gives you instantaneous feedback on edits made to your React components.
+
+This demos shows how the state of an auto incrementing value and a classic counter is preserved after edits or if there are errors.
+
+## Deploy your own
+
+Deploy the example using [Vercel](https://vercel.com):
+
+[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/import/project?template=https://github.com/vercel/next.js/tree/canary/examples/fast-refresh-demo)
+
+## How to use
+
+Execute [`create-next-app`](https://github.com/vercel/next.js/tree/canary/packages/create-next-app) with [npm](https://docs.npmjs.com/cli/init) or [Yarn](https://yarnpkg.com/lang/en/docs/cli/create/) to bootstrap the example:
+
+```bash
+npx create-next-app --example fast-refresh-demo fast-refresh-demo
+# or
+yarn create next-app --example fast-refresh-demo fast-refresh-demo
+```
+
+Deploy it to the cloud with [Vercel](https://vercel.com/import?filter=next.js&utm_source=github&utm_medium=readme&utm_campaign=next-example) ([Documentation](https://nextjs.org/docs/deployment)).

examples/fast-refresh-demo/components/Button.js

@@ -0,0 +1,5 @@
+import styles from './Button.module.css'
+
+export default function Button(props) {
+  return <button type="button" className={styles.btn} {...props} />
+}

examples/fast-refresh-demo/components/Button.module.css

@@ -0,0 +1,32 @@
+button.btn {
+  margin: 0;
+  border: 1px solid #d1d1d1;
+  border-radius: 5px;
+  padding: 0.5em;
+  vertical-align: middle;
+  white-space: normal;
+  background: none;
+  line-height: 1;
+  font-size: 1rem;
+  font-family: inherit;
+  transition: all 0.2s ease;
+}
+
+button.btn {
+  padding: 0.65em 1em;
+  background: #0076ff;
+  color: #fff;
+  border: none;
+  cursor: pointer;
+  transition: all 0.2s ease;
+}
+button.btn:focus {
+  outline: 0;
+  border-color: #0076ff;
+}
+button.btn:hover {
+  background: rgba(0, 118, 255, 0.8);
+}
+button.btn:focus {
+  box-shadow: 0 0 0 2px rgba(0, 118, 255, 0.5);
+}

examples/fast-refresh-demo/components/ClickCount.js

@@ -0,0 +1,11 @@
+import { useCallback, useState } from 'react'
+import Button from './Button'
+
+export default function ClickCount() {
+  const [count, setCount] = useState(0)
+  const increment = useCallback(() => {
+    setCount((v) => v + 1)
+  }, [setCount])
+
+  return <Button onClick={increment}>Clicks: {count}</Button>
+}

examples/fast-refresh-demo/global.css

@@ -0,0 +1,14 @@
+body {
+  font-family: 'SF Pro Text', 'SF Pro Icons', 'Helvetica Neue', 'Helvetica',
+    'Arial', sans-serif;
+  margin: 0 auto;
+  font-size: 16px;
+  line-height: 1.65;
+  word-break: break-word;
+  font-kerning: auto;
+  font-variant: normal;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+  text-rendering: optimizeLegibility;
+  hyphens: auto;
+}

examples/fast-refresh-demo/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "fast-refresh-demo",
+  "version": "1.0.0",
+  "scripts": {
+    "dev": "next",
+    "build": "next build",
+    "start": "next start"
+  },
+  "dependencies": {
+    "next": "latest",
+    "react": "^16.13.1",
+    "react-dom": "^16.13.1"
+  },
+  "license": "MIT"
+}

examples/fast-refresh-demo/pages/_app.js

@@ -0,0 +1,5 @@
+import '../global.css'
+
+export default function MyApp({ Component, pageProps }) {
+  return <Component {...pageProps} />
+}

examples/fast-refresh-demo/pages/index.js

@@ -0,0 +1,71 @@
+import { useCallback, useEffect, useState } from 'react'
+import Button from '../components/Button'
+import ClickCount from '../components/ClickCount'
+import styles from '../styles/home.module.css'
+
+function throwError() {
+  console.log(
+    // The function body() is not defined
+    document.body()
+  )
+}
+
+function Home() {
+  const [count, setCount] = useState(0)
+  const increment = useCallback(() => {
+    setCount((v) => v + 1)
+  }, [setCount])
+
+  useEffect(() => {
+    const r = setInterval(() => {
+      increment()
+    }, 1000)
+
+    return () => {
+      clearInterval(r)
+    }
+  }, [increment])
+
+  return (
+    <main className={styles.main}>
+      <h1>Fast Refresh Demo</h1>
+      <p>
+        Fast Refresh is a Next.js feature that gives you instantaneous feedback
+        on edits made to your React components, without ever losing component
+        state.
+      </p>
+      <hr className={styles.hr} />
+      <div>
+        <p>
+          Auto incrementing value. The counter won't reset after edits or if
+          there are errors.
+        </p>
+        <p>Current value: {count}</p>
+      </div>
+      <hr className={styles.hr} />
+      <div>
+        <p>Component with state.</p>
+        <ClickCount />
+      </div>
+      <hr className={styles.hr} />
+      <div>
+        <p>
+          The button below will throw 2 errors. You'll see the error overlay to
+          let you know about the errors but it won't break the page or reset
+          your state.
+        </p>
+        <Button
+          onClick={(e) => {
+            setTimeout(() => document.parentNode(), 0)
+            throwError()
+          }}
+        >
+          Throw an Error
+        </Button>
+      </div>
+      <hr className={styles.hr} />
+    </main>
+  )
+}
+
+export default Home

examples/fast-refresh-demo/styles/home.module.css

@@ -0,0 +1,11 @@
+.main {
+  padding: 20px 20px 60px;
+  max-width: 680px;
+  margin: 0 auto;
+}
+
+.hr {
+  border: none;
+  border-bottom: 1px solid #efefef;
+  margin: 3em auto;
+}

examples/with-framer-motion/components/Gallery.js

@@ -35,7 +35,7 @@ const Thumbnail = ({ id, i }) => (
       >
         <Link href="/image/[index]" as={`/image/${i}`} scroll={false}>
           <motion.img
-            src={`https://static1.squarespace.com/static/5b475b2c50a54f54f9b4e1dc/t/${id}.jpg?format=1500w`}
+            src={`https://images.unsplash.com/${id}?auto=format&fit=crop&w=1500`}
             alt="The Barbican"
             variants={imageVariants}
             transition={transition}
@@ -69,7 +69,7 @@ const Thumbnail = ({ id, i }) => (
 
 const Gallery = () => (
   <>
-    <h1>Barbican</h1>
+    <h1>Motion</h1>
     <div className="gallery">
       <motion.div
         className="thumbnails"
@@ -118,14 +118,14 @@ const Gallery = () => (
              bottom: -130px;
            }
          }
-         
+
          @media screen and (min-width: 800px) {
            h1 {
              font-size: 180px;
              bottom: -170px;
            }
          }
-         
+
          @media screen and (min-width: 1000px) {
            h1 {
              font-size: 220px;

examples/with-framer-motion/components/SingleImage.js

@@ -28,7 +28,7 @@ const SingleImage = ({ index }) => (
     <motion.div className="single" initial="exit" animate="enter" exit="exit">
       <motion.img
         variants={imageVariants}
-        src={`https://static1.squarespace.com/static/5b475b2c50a54f54f9b4e1dc/t/${images[index]}.jpg?format=1500w`}
+        src={`https://images.unsplash.com/${images[index]}?auto=format&fit=crop&w=1500`}
         alt="The Barbican"
       />
       <motion.div className="back" variants={backVariants}>

examples/with-framer-motion/constants.js

@@ -1,8 +1,8 @@
 export const images = [
-  '5b5a3938562fa764113169a6/1532639559620/DSCF3338',
-  '5b5a3628f950b7390fbfc5f8/1532639027872/DSCF3246',
-  '5b5a3741575d1fccb5ac6b3f/1532639066455/DSCF3268',
-  '5b5a376b0e2e728eeeaca8e4/1532683586969/DSCF3274',
-  '5b5c228403ce64f3c80d4d8e/1532764845121/DSCF3348',
-  '5b5a3b800e2e728eeead9575/1532640158813/DSCF3375',
+  'photo-1520517601640-32ec514e4a15',
+  'photo-1518780535463-bc357fa46e64',
+  'photo-1555068178-89125fb6356d',
+  'photo-1553503359-d4ff2537a6ea',
+  'photo-1585211751845-37663b4ab614',
+  'photo-1496467115032-c504ef76521b',
 ]

examples/with-framer-motion/pages/image/[index].js

@@ -17,7 +17,6 @@ export async function getStaticProps({ params }) {
 export async function getStaticPaths() {
   return {
     paths: images.map((_id, index) => {
-      console.log(index)
       return {
         params: {
           index: `${index}`,

examples/with-react-intl/lang/en.json

@@ -1,7 +1,7 @@
 {
-  "11754": "An example app integrating React Intl with Next.js",
-  "65a8e": "Hello, World!",
-  "8cf04": "Home",
-  "8f7f4": "About",
-  "9c817": "React Intl Next.js Example"
+  "AvQcw8": "React Intl Next.js Example",
+  "N015Sp": "Hello, World!",
+  "ejEGdx": "Home",
+  "fnfXnF": "An example app integrating React Intl with Next.js",
+  "g5pX+a": "About"
 }

examples/with-react-intl/lang/fr.json

@@ -1,7 +1,7 @@
 {
-  "11754": "Un exemple d'application intégrant React Intl avec Next.js",
-  "65a8e": "Bonjour le monde!",
-  "8cf04": "Accueil",
-  "8f7f4": "À propos de nous",
-  "9c817": "React Intl Next.js Exemple"
+  "AvQcw8": "Un exemple d'application intégrant React Intl avec Next.js",
+  "N015Sp": "Bonjour le monde!",
+  "ejEGdx": "Accueil",
+  "fnfXnF": "À propos de nous",
+  "g5pX+a": "React Intl Next.js Exemple"
 }

examples/with-react-intl/package.json

@@ -4,7 +4,7 @@
   "scripts": {
     "dev": "cross-env NODE_ICU_DATA=node_modules/full-icu ts-node --project tsconfig.server.json server.ts",
     "build": "npm run extract:i18n && npm run compile:i18n && next build && tsc -p tsconfig.server.json",
-    "extract:i18n": "formatjs extract '{pages,components}/*.{js,ts,tsx}' --format simple --out-file lang/en.json",
+    "extract:i18n": "formatjs extract '{pages,components}/*.{js,ts,tsx}' --format simple --id-interpolation-pattern '[sha512:contenthash:base64:6]' --out-file lang/en.json",
     "compile:i18n": "formatjs compile-folder --ast --format simple lang/ compiled-lang/",
     "start": "cross-env NODE_ENV=production NODE_ICU_DATA=node_modules/full-icu node dist/server"
   },

examples/with-react-intl/pages/_app.tsx

@@ -27,7 +27,7 @@ const getInitialProps: typeof App.getInitialProps = async appContext => {
   const {
     ctx: {req},
   } = appContext;
-  const locale = (req as any)?.locale ?? 'en';
+  const locale = (req as any)?.locale || (window as any).LOCALE || 'en';
 
   const [appProps, messages] = await Promise.all([
     polyfill(locale),