Documentation updates (vercel#16503)

Fixes vercel#16502

Check the issue for more details.

docs/advanced-features/custom-error-page.md

@@ -2,6 +2,8 @@
 description: Override and extend the built-in Error page to handle custom errors.
 ---
 
+# Custom Error Page
+
 ## 404 Page
 
 A 404 page may be accessed very often. Server-rendering an error page for every visit increases the load of the Next.js server. This can result in increased costs and slow experiences.

docs/advanced-features/static-html-export.md

@@ -21,7 +21,7 @@ The exported app supports almost every feature of Next.js, including dynamic rou
 >
 > If you're looking to make a hybrid site where only _some_ pages are prerendered to static HTML, Next.js already does that automatically for you! Read up on [Automatic Static Optimization](/docs/advanced-features/automatic-static-optimization.md) for details.
 >
-> `next export` also causes features like Incremental Static Generation and Regeneration to be disabled, as they require `next start` or a serverless deployment to function.
+> `next export` also causes features like [Incremental Static Generation](/docs/basic-features/data-fetching.md#fallback-true) and [Regeneration](/docs/basic-features/data-fetching.md#incremental-static-regeneration) to be disabled, as they require [`next start`](/docs/api-reference/cli.md#production) or a serverless deployment to function.
 
 ## How to use it
 
@@ -53,7 +53,9 @@ For more advanced scenarios, you can define a parameter called [`exportPathMap`]
 
 ## Deployment
 
-You can read about deploying your Next.js application in the [deployment section](/docs/deployment.md).
+By default, `next export` will generate an `out` directory, which can be served by any static hosting service or CDN.
+
+> We strongly recommend using [Vercel](https://vercel.com/) even if your Next.js app is fully static. [Vercel](https://vercel.com/) is optimized to make static Next.js apps blazingly fast. `next export` works with Zero Config deployments on Vercel.
 
 ## Caveats
 
@@ -62,11 +64,10 @@ You can read about deploying your Next.js application in the [deployment section
   - `getInitialProps` cannot be used alongside `getStaticProps` or `getStaticPaths` on any given page. If you have dynamic routes, instead of using `getStaticPaths` you'll need to configure the [`exportPathMap`](/docs/api-reference/next.config.js/exportPathMap.md) parameter in your [`next.config.js`](/docs/api-reference/next.config.js/introduction.md) file to let the exporter know which HTML files it should output.
   - When `getInitialProps` is called during export, the `req` and `res` fields of its [`context`](/docs/api-reference/data-fetching/getInitialProps.md#context-object) parameter will be empty objects, since during export there is no server running.
   - `getInitialProps` **will be called on every client-side navigation**, if you'd like to only fetch data at build-time, switch to `getStaticProps`.
-  - `getInitialProps` cannot use Node.js-specific libraries or the file system like `getStaticProps` can. `getInitialProps` must fetch from an API.
+  - `getInitialProps` should fetch from an API and cannot use Node.js-specific libraries or the file system like `getStaticProps` can.
 
-  For static export, the `getStaticProps` API is always preferred over `getInitialProps`: it's recommended you convert your pages to use the `getStaticProps` if possible.
+  It's recommended to use and migrate towards `getStaticProps` over `getInitialProps` whenever possible.
 
-- The `fallback: true` mode of `getStaticPaths` is not supported when using `next export`.
-- You won't be able to render HTML dynamically when static exporting, as the HTML files are pre-build. Your application can be a hybrid of [Static Generation](/docs/basic-features/pages.md#static-generation) and [Server-Side Rendering](/docs/basic-features/pages.md#server-side-rendering) when you don't use `next export`. You can learn more about it in the [pages section](/docs/basic-features/pages.md).
+- The [`fallback: true`](/docs/basic-features/data-fetching.md#fallback-true) mode of `getStaticPaths` is not supported when using `next export`.
 - [API Routes](/docs/api-routes/introduction.md) are not supported by this method because they can't be prerendered to HTML.
 - [`getServerSideProps`](/docs/basic-features/data-fetching.md#getserversideprops-server-side-rendering) cannot be used within pages because the method requires a server. Consider using [`getStaticProps`](/docs/basic-features/data-fetching.md#getstaticprops-static-generation) instead.

docs/api-reference/cli.md

@@ -48,7 +48,7 @@ NODE_OPTIONS='--inspect' next
 
 The first load is colored green, yellow, or red. Aim for green for performant applications.
 
-You can enable production profiling for React with the `--profile` flag in `next build`. This requires Next.js 9.5:
+You can enable production profiling for React with the `--profile` flag in `next build`. This requires [Next.js 9.5](https://nextjs.org/blog/next-9-5):
 
 ```bash
 next build --profile

docs/api-reference/data-fetching/getInitialProps.md

@@ -4,19 +4,11 @@ description: Enable Server-Side Rendering in a page and do initial data populati
 
 # getInitialProps
 
-> **Recommended: [`getStaticProps`](/docs/basic-features/data-fetching.md#getstaticprops-static-generation) or [`getServerSideProps`](/docs/basic-features/data-fetching.md#getserversideprops-server-side-rendering)**
+> **Recommended: [`getStaticProps`](/docs/basic-features/data-fetching.md#getstaticprops-static-generation) or [`getServerSideProps`](/docs/basic-features/data-fetching.md#getserversideprops-server-side-rendering)**.
 >
 > If you're using Next.js 9.3 or newer, we recommend that you use `getStaticProps` or `getServerSideProps` instead of `getInitialProps`.
 >
-> These new data fetching methods allow you to have a granular choice between static generation and server-side rendering.
-> Learn more on the documentation for [Pages](/docs/basic-features/pages.md) and [Data fetching](/docs/basic-features/data-fetching.md):
-
-<details>
-  <summary><b>Examples</b></summary>
-  <ul>
-    <li><a href="https://github.com/vercel/next.js/tree/canary/examples/data-fetch">Data fetch</a></li>
-  </ul>
-</details>
+> These new data fetching methods allow you to have a granular choice between static generation and server-side rendering. Learn more on the documentation for [Pages](/docs/basic-features/pages.md) and [Data fetching](/docs/basic-features/data-fetching.md).
 
 `getInitialProps` enables [server-side rendering](/docs/basic-features/pages.md#server-side-rendering) in a page and allows you to do **initial data population**, it means sending the [page](/docs/basic-features/pages.md) with the data already populated from the server. This is especially useful for [SEO](https://en.wikipedia.org/wiki/Search_engine_optimization).
 

docs/api-reference/next.config.js/environment-variables.md

@@ -4,7 +4,7 @@ description: Learn to add and access environment variables in your Next.js appli
 
 # Environment Variables
 
-> Since the release of Next.js 9.4 we now have a more intuitive and ergonomic experience for [adding environment variables](/docs/basic-features/environment-variables.md). Give it a try!
+> Since the release of [Next.js 9.4](https://nextjs.org/blog/next-9-4) we now have a more intuitive and ergonomic experience for [adding environment variables](/docs/basic-features/environment-variables.md). Give it a try!
 
 <details>
   <summary><b>Examples</b></summary>

docs/api-routes/dynamic-api-routes.md

@@ -31,7 +31,7 @@ Now, a request to `/api/post/abc` will respond with the text: `Post: abc`.
 
 A very common RESTful pattern is to set up routes like this:
 
-- `GET api/posts/` - gets a list of posts, probably paginated
+- `GET api/posts` - gets a list of posts, probably paginated
 - `GET api/posts/12345` - gets post id 12345
 
 We can model this in two ways:
@@ -40,11 +40,10 @@ We can model this in two ways:
   - `/api/posts.js`
   - `/api/posts/[postId].js`
 - Option 2:
-
   - `/api/posts/index.js`
   - `/api/posts/[postId].js`
 
-Both are equivalent. A third option of only using `/api/posts/[postId].js` is not valid because Dynamic Routes (including Catch-all routes - see below) do not have an `undefined` state and `GET api/posts/` will not match `/api/posts/[postId].js` under any circumstances.
+Both are equivalent. A third option of only using `/api/posts/[postId].js` is not valid because Dynamic Routes (including Catch-all routes - see below) do not have an `undefined` state and `GET api/posts` will not match `/api/posts/[postId].js` under any circumstances.
 
 ### Catch all API routes
 

docs/api-routes/introduction.md

@@ -17,7 +17,7 @@ description: Next.js supports API Routes, which allow you to build your API with
 
 API routes provide a straightforward solution to build your **API** with Next.js.
 
-Any file inside the folder `pages/api` is mapped to `/api/*` and will be treated as an API endpoint instead of a `page`.
+Any file inside the folder `pages/api` is mapped to `/api/*` and will be treated as an API endpoint instead of a `page`. They are server-side only bundles and won't increase your client-side bundle size.
 
 For example, the following API route `pages/api/user.js` handles a `json` response:
 
@@ -48,9 +48,10 @@ export default (req, res) => {
 
 To fetch API endpoints, take a look into any of the examples at the start of this section.
 
-> API Routes [do not specify CORS headers](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS), meaning they are **same-origin only** by default. You can customize such behavior by wrapping the request handler with the [cors middleware](/docs/api-routes/api-middlewares.md#connectexpress-middleware-support).
+## Caveats
 
-> API Routes do not increase your client-side bundle size. They are server-side only bundles.
+- API Routes [do not specify CORS headers](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS), meaning they are **same-origin only** by default. You can customize such behavior by wrapping the request handler with the [cors middleware](/docs/api-routes/api-middlewares.md#connectexpress-middleware-support).
+- API Routes can't be used with [`next export`](/docs/advanced-features/static-html-export.md)
 
 ## Related
 

docs/basic-features/supported-browsers-features.md

@@ -26,7 +26,7 @@ In addition to `fetch()` on the client side, Next.js polyfills `fetch()` in the
 
 If your own code or any external npm dependencies require features not supported by your target browsers, you need to add polyfills yourself.
 
-In this case, you should add a top-level import for the **specific polyfill** you need in your [Custom `<App>`](docs/advanced-features/custom-app.md) or the individual component.
+In this case, you should add a top-level import for the **specific polyfill** you need in your [Custom `<App>`](/docs/advanced-features/custom-app.md) or the individual component.
 
 ## JavaScript Language Features
 

docs/deployment.md

@@ -72,6 +72,4 @@ Make sure your `package.json` has the `"build"` and `"start"` scripts:
 
 ### Static HTML Export
 
-If you’d like to do a static HTML export of your Next.js app, follow the directions on [our documentation](/docs/advanced-features/static-html-export.md). By default, `next export` will generate an `out` directory, which can be served by any static hosting service or CDN.
-
-> We strongly recommend using [Vercel](https://vercel.com/) even if your Next.js app is fully static. [Vercel](https://vercel.com/) is optimized to make static Next.js apps blazingly fast. `next export` works with Zero Config deployments on Vercel.
+If you’d like to do a static HTML export of your Next.js app, follow the directions on [our documentation](/docs/advanced-features/static-html-export.md).

docs/faq.md

@@ -74,6 +74,6 @@ description: Get to know more about Next.js with the frequently asked questions.
 </details>
 
 <details>
-  <summary>Can I make a Next.js Progressive Web App?</summary>
-   <p>Yes! Here's an <a href="https://github.com/vercel/next.js/tree/canary/examples/progressive-web-app">example</a>.</p>
+  <summary>Can I make a Next.js Progressive Web App (PWA)?</summary>
+   <p>Yes! Check out our <a href="https://github.com/vercel/next.js/tree/canary/examples/progressive-web-app">PWA Example</a> to see how it works.</p>
 </details>

examples/data-fetch/README.md

@@ -1,9 +1,9 @@
 # Data fetch example
 
 Next.js was conceived to make it easy to create universal apps. That's why fetching data
-on the server and the client when necessary is so easy with Next.
+on the server and the client when necessary is so easy with Next.js.
 
-Using `getStaticProps` fetches data at build time from a page, Next.js will pre-render this page at build time.
+By using `getStaticProps` Next.js will fetch data at build time from a page, and pre-render the page to static assets.
 
 ## Deploy your own
 
@@ -13,8 +13,6 @@ Deploy the example using [Vercel](https://vercel.com):
 
 ## How to use
 
-### Using `create-next-app`
-
 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
@@ -23,23 +21,4 @@ npx create-next-app --example data-fetch data-fetch-app
 yarn create next-app --example data-fetch data-fetch-app
 ```
 
-### Download manually
-
-Download the example:
-
-```bash
-curl https://codeload.github.com/vercel/next.js/tar.gz/canary | tar -xz --strip=2 next.js-canary/examples/data-fetch
-cd data-fetch
-```
-
-Install it and run:
-
-```bash
-npm install
-npm run dev
-# or
-yarn
-yarn dev
-```
-
 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/data-fetch/package.json

@@ -8,9 +8,8 @@
   },
   "dependencies": {
     "next": "latest",
-    "node-fetch": "^2.6.0",
-    "react": "^16.8.4",
-    "react-dom": "^16.8.4"
+    "react": "^16.13.1",
+    "react-dom": "^16.13.1"
   },
-  "license": "ISC"
+  "license": "MIT"
 }

examples/data-fetch/pages/index.js

@@ -1,5 +1,4 @@
 import Link from 'next/link'
-import fetch from 'node-fetch'
 
 function Index({ stars }) {
   return (

examples/data-fetch/pages/preact-stars.js

@@ -1,5 +1,4 @@
 import Link from 'next/link'
-import fetch from 'node-fetch'
 
 function PreactStars({ stars }) {
   return (