Sync with react.dev @ d34c6a2c

src/components/DocsFooter.tsx

@@ -80,7 +80,7 @@ function FooterLink({
       />
       <div className="flex flex-col overflow-hidden">
         <span className="text-sm font-bold tracking-wide no-underline uppercase text-secondary dark:text-secondary-dark group-focus:text-link dark:group-focus:text-link-dark group-focus:text-opacity-100">
-          {type}
+          {type === 'Previous' ? 'Previous' : 'Next'}
         </span>
         <span className="text-lg break-words group-hover:underline">
           {title}

src/components/Icon/IconArrowSmall.tsx

@@ -19,6 +19,7 @@ export const IconArrowSmall = memo<
   const classes = cn(className, {
     'rotate-180': displayDirection === 'left',
     'rotate-180 rtl:rotate-0': displayDirection === 'start',
+    'rtl:rotate-180': displayDirection === 'end',
     'rotate-90': displayDirection === 'down',
   });
   return (

src/components/MDX/Challenges/Navigation.tsx

@@ -108,7 +108,7 @@ export function Navigation({
           onClick={handleScrollLeft}
           aria-label="Scroll left"
           className={cn(
-            'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-l border-gray-20 border-r rtl:rotate-180',
+            'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-l rtl:rounded-r rtl:rounded-l-none border-gray-20 border-r rtl:border-l rtl:border-r-0',
             {
               'text-primary dark:text-primary-dark': canScrollLeft,
               'text-gray-30': !canScrollLeft,
@@ -120,7 +120,7 @@ export function Navigation({
           onClick={handleScrollRight}
           aria-label="Scroll right"
           className={cn(
-            'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-e rtl:rotate-180',
+            'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-e',
             {
               'text-primary dark:text-primary-dark': canScrollRight,
               'text-gray-30': !canScrollRight,

src/content/blog/2025/04/23/react-labs-view-transitions-activity-and-more.md

@@ -2521,7 +2521,7 @@ export default function App() {
   const { url } = useRouter();
 
   // Define a default animation of .slow-fade.
-  // See animations.css for the animation definiton.
+  // See animations.css for the animation definition.
   return (
     <ViewTransition default="slow-fade">
       {url === '/' ? <Home /> : <Details />}

src/content/community/conferences.md

@@ -20,6 +20,11 @@ October 2-4, 2025. Alicante, Spain.
 
 [Website](https://reactalicante.es/) - [Twitter](https://x.com/ReactAlicante) - [Bluesky](https://bsky.app/profile/reactalicante.es) - [YouTube](https://www.youtube.com/channel/UCaSdUaITU1Cz6PvC97A7e0w)
 
+### RenderCon Kenya 2025 {/*rendercon-kenya-2025*/}
+October 04, 2025. Nairobi, Kenya
+
+[Website](https://rendercon.org/) - [Twitter](https://twitter.com/renderconke) - [LinkedIn](https://www.linkedin.com/company/renderconke/) - [YouTube](https://www.youtube.com/channel/UC0bCcG8gHUL4njDOpQGcMIA)
+
 ### React Conf 2025 {/*react-conf-2025*/}
 October 7-8, 2025. Henderson, Nevada, USA and free livestream
 

src/content/community/meetups.md

@@ -58,6 +58,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Manchester](https://www.meetup.com/Manchester-React-User-Group/)
 * [React.JS Girls London](https://www.meetup.com/ReactJS-Girls-London/)
 * [React Advanced London](https://guild.host/react-advanced-london)
+* [React Native Liverpool](https://www.meetup.com/react-native-liverpool/)
 * [React Native London](https://guild.host/RNLDN)
 
 ## Finland {/*finland*/}
@@ -137,6 +138,9 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 ## Portugal {/*portugal*/}
 * [Lisbon](https://www.meetup.com/JavaScript-Lisbon/)
 
+## Scotland (UK) {/*scotland-uk*/}
+* [Edinburgh](https://www.meetup.com/react-edinburgh/)
+
 ## Spain {/*spain*/}
 * [Barcelona](https://www.meetup.com/ReactJS-Barcelona/)
 

src/content/learn/build-a-react-app-from-scratch.md

@@ -122,7 +122,7 @@ For code-splitting instructions, see your build tool docs:
 
 ### Improving Application Performance {/*improving-application-performance*/}
 
-Since the build tool you select only support single page apps (SPAs) you'll need to implement other [rendering patterns](https://www.patterns.dev/vanilla/rendering-patterns) like server-side rendering (SSR), static site generation (SSG), and/or React Server Components (RSC). Even if you don't need these features at first, in the future there may be some routes that would benefit SSR, SSG or RSC.
+Since the build tool you select only supports single page apps (SPAs), you'll need to implement other [rendering patterns](https://www.patterns.dev/vanilla/rendering-patterns) like server-side rendering (SSR), static site generation (SSG), and/or React Server Components (RSC). Even if you don't need these features at first, in the future there may be some routes that would benefit SSR, SSG or RSC.
 
 * **Single-page apps (SPA)** load a single HTML page and dynamically updates the page as the user interacts with the app. SPAs are easier to get started with, but they can have slower initial load times. SPAs are the default architecture for most build tools.
 

src/content/learn/manipulating-the-dom-with-refs.md

@@ -211,7 +211,7 @@ This is because **Hooks must only be called at the top-level of your component.*
 
 One possible way around this is to get a single ref to their parent element, and then use DOM manipulation methods like [`querySelectorAll`](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll) to "find" the individual child nodes from it. However, this is brittle and can break if your DOM structure changes.
 
-Another solution is to **pass a function to the `ref` attribute.** This is called a [`ref` callback.](/reference/react-dom/components/common#ref-callback) React will call your ref callback with the DOM node when it's time to set the ref, and with `null` when it's time to clear it. This lets you maintain your own array or a [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map), and access any ref by its index or some kind of ID.
+Another solution is to **pass a function to the `ref` attribute.** This is called a [`ref` callback.](/reference/react-dom/components/common#ref-callback) React will call your ref callback with the DOM node when it's time to set the ref, and call the cleanup function returned from the callback when it's time to clear it. This lets you maintain your own array or a [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map), and access any ref by its index or some kind of ID.
 
 This example shows how you can use this approach to scroll to an arbitrary node in a long list:
 
@@ -247,13 +247,13 @@ export default function CatFriends() {
       <nav>
         <button onClick={() => scrollToCat(catList[0])}>Neo</button>
         <button onClick={() => scrollToCat(catList[5])}>Millie</button>
-        <button onClick={() => scrollToCat(catList[9])}>Bella</button>
+        <button onClick={() => scrollToCat(catList[8])}>Bella</button>
       </nav>
       <div>
         <ul>
           {catList.map((cat) => (
             <li
-              key={cat}
+              key={cat.id}
               ref={(node) => {
                 const map = getMap();
                 map.set(cat, node);
@@ -263,7 +263,7 @@ export default function CatFriends() {
                 };
               }}
             >
-              <img src={cat} />
+              <img src={cat.imageUrl} />
             </li>
           ))}
         </ul>
@@ -273,11 +273,22 @@ export default function CatFriends() {
 }
 
 function setupCatList() {
-  const catList = [];
-  for (let i = 0; i < 10; i++) {
-    catList.push("https://loremflickr.com/320/240/cat?lock=" + i);
+  const catCount = 10;
+  const catList = new Array(catCount)
+  for (let i = 0; i < catCount; i++) {
+    let imageUrl = '';
+    if (i < 5) {
+      imageUrl = "https://placecats.com/neo/320/240";
+    } else if (i < 8) {
+      imageUrl = "https://placecats.com/millie/320/240";
+    } else {
+      imageUrl = "https://placecats.com/bella/320/240";
+    }
+    catList[i] = {
+      id: i,
+      imageUrl,
+    };
   }
-
   return catList;
 }
 
@@ -876,12 +887,30 @@ export default function CatFriends() {
   );
 }
 
-const catList = [];
-for (let i = 0; i < 10; i++) {
-  catList.push({
+const catCount = 10;
+const catList = new Array(catCount);
+for (let i = 0; i < catCount; i++) {
+  const bucket = Math.floor(Math.random() * catCount) % 2;
+  let imageUrl = '';
+  switch (bucket) {
+    case 0: {
+      imageUrl = "https://placecats.com/neo/250/200";
+      break;
+    }
+    case 1: {
+      imageUrl = "https://placecats.com/millie/250/200";
+      break;
+    }
+    case 2:
+    default: {
+      imageUrl = "https://placecats.com/bella/250/200";
+      break;
+    }
+  }
+  catList[i] = {
     id: i,
-    imageUrl: 'https://loremflickr.com/250/200/cat?lock=' + i
-  });
+    imageUrl,
+  };
 }
 
 ```
@@ -961,7 +990,7 @@ export default function CatFriends() {
             behavior: 'smooth',
             block: 'nearest',
             inline: 'center'
-          });            
+          });
         }}>
           Next
         </button>
@@ -993,12 +1022,30 @@ export default function CatFriends() {
   );
 }
 
-const catList = [];
-for (let i = 0; i < 10; i++) {
-  catList.push({
+const catCount = 10;
+const catList = new Array(catCount);
+for (let i = 0; i < catCount; i++) {
+  const bucket = Math.floor(Math.random() * catCount) % 2;
+  let imageUrl = '';
+  switch (bucket) {
+    case 0: {
+      imageUrl = "https://placecats.com/neo/250/200";
+      break;
+    }
+    case 1: {
+      imageUrl = "https://placecats.com/millie/250/200";
+      break;
+    }
+    case 2:
+    default: {
+      imageUrl = "https://placecats.com/bella/250/200";
+      break;
+    }
+  }
+  catList[i] = {
     id: i,
-    imageUrl: 'https://loremflickr.com/250/200/cat?lock=' + i
-  });
+    imageUrl,
+  };
 }
 
 ```

src/content/learn/react-compiler/introduction.md

@@ -50,6 +50,21 @@ const ExpensiveComponent = memo(function ExpensiveComponent({ data, onClick }) {
 });
 ```
 
+
+<Note>
+
+This manual memoization has a subtle bug that breaks memoization:
+
+```js [[2, 1, "() => handleClick(item)"]]
+<Item key={item.id} onClick={() => handleClick(item)} />
+```
+
+Even though `handleClick` is wrapped in `useCallback`, the arrow function `() => handleClick(item)` creates a new function every time the component renders. This means that `Item` will always receive a new `onClick` prop, breaking memoization.
+
+React Compiler is able to optimize this correctly with or without the arrow function, ensuring that `Item` only re-renders when `props.onClick` changes.
+
+</Note>
+
 ### After React Compiler {/*after-react-compiler*/}
 
 With React Compiler, you write the same code without manual memoization:
@@ -74,7 +89,7 @@ function ExpensiveComponent({ data, onClick }) {
 
 _[See this example in the React Compiler Playground](https://playground.react.dev/#N4Igzg9grgTgxgUxALhAMygOzgFwJYSYAEAogB4AOCmYeAbggMIQC2Fh1OAFMEQCYBDHAIA0RQowA2eOAGsiAXwCURYAB1iROITA4iFGBERgwCPgBEhAogF4iCStVoMACoeO1MAcy6DhSgG4NDSItHT0ACwFMPkkmaTlbIi48HAQWFRsAPlUQ0PFMKRlZFLSWADo8PkC8hSDMPJgEHFhiLjzQgB4+eiyO-OADIwQTM0thcpYBClL02xz2zXz8zoBJMqJZBABPG2BU9Mq+BQKiuT2uTJyomLizkoOMk4B6PqX8pSUFfs7nnro3qEapgFCAFEA)_
 
-React Compiler automatically applies the equivalent optimizations, ensuring your app only re-renders when necessary.
+React Compiler automatically applies the optimal memoization, ensuring your app only re-renders when necessary.
 
 <DeepDive>
 #### What kind of memoization does React Compiler add? {/*what-kind-of-memoization-does-react-compiler-add*/}

src/content/learn/reusing-logic-with-custom-hooks.md

@@ -1419,10 +1419,29 @@ Similar to a [design system,](https://uxdesign.cc/everything-you-need-to-know-ab
 
 #### Will React provide any built-in solution for data fetching? {/*will-react-provide-any-built-in-solution-for-data-fetching*/}
 
+Today, with the [`use`](/reference/react/use#streaming-data-from-server-to-client) API, data can be read in render by passing a [Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise) to `use`:
+
+```js {1,4,11}
+import { use, Suspense } from "react";
+
+function Message({ messagePromise }) {
+  const messageContent = use(messagePromise);
+  return <p>Here is the message: {messageContent}</p>;
+}
+
+export function MessageContainer({ messagePromise }) {
+  return (
+    <Suspense fallback={<p>⌛Downloading message...</p>}>
+      <Message messagePromise={messagePromise} />
+    </Suspense>
+  );
+}
+```
+
 We're still working out the details, but we expect that in the future, you'll write data fetching like this:
 
 ```js {1,4,6}
-import { use } from 'react'; // Not available yet!
+import { use } from 'react';
 
 function ShippingForm({ country }) {
   const cities = use(fetch(`/api/cities?country=${country}`));

src/content/learn/tutorial-tic-tac-toe.md

@@ -283,9 +283,15 @@ In CodeSandbox vedrai tre sezioni principali:
 
 ![CodeSandbox con codice iniziale](../images/tutorial/react-starter-code-codesandbox.png)
 
+<<<<<<< HEAD
 1. La sezione _Files_ con una lista di file come `App.js`, `index.js`, `styles.css` e una cartella chiamata `public`
 1. L'_editor del codice_ dove vedrai il codice sorgente del tuo file selezionato
 1. La sezione _browser_ dove vedrai come il codice che hai scritto sarà visualizzato
+=======
+1. The _Files_ section with a list of files like `App.js`, `index.js`, `styles.css` in `src` folder and a folder called `public`
+1. The _code editor_ where you'll see the source code of your selected file
+1. The _browser_ section where you'll see how the code you've written will be displayed
+>>>>>>> d34c6a2c6fa49fc6f64b07aa4fa979d86d41c4e8
 
 Il file `App.js` dovrebbe essere selezionato nella sezione _Files_. Il contenuto di quel file nell'_editor del codice_ dovrebbe essere:
 

src/content/learn/typescript.md

@@ -32,13 +32,13 @@ All [production-grade React frameworks](/learn/start-a-new-react-project#full-st
 To install the latest version of React's type definitions:
 
 <TerminalBlock>
-npm install @types/react @types/react-dom
+npm install --save-dev @types/react @types/react-dom
 </TerminalBlock>
 
 The following compiler options need to be set in your `tsconfig.json`:
 
 1. `dom` must be included in [`lib`](https://www.typescriptlang.org/tsconfig/#lib) (Note: If no `lib` option is specified, `dom` is included by default).
-1. [`jsx`](https://www.typescriptlang.org/tsconfig/#jsx) must be set to one of the valid options. `preserve` should suffice for most applications.
+2. [`jsx`](https://www.typescriptlang.org/tsconfig/#jsx) must be set to one of the valid options. `preserve` should suffice for most applications.
   If you're publishing a library, consult the [`jsx` documentation](https://www.typescriptlang.org/tsconfig/#jsx) on what value to choose.
 
 ## TypeScript with React Components {/*typescript-with-react-components*/}

src/content/reference/react-dom/components/form.md

@@ -38,7 +38,7 @@ To create interactive controls for submitting information, render the [built-in
 
 `<form>` supports all [common element props.](/reference/react-dom/components/common#common-props)
 
-[`action`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/form#action): a URL or function. When a URL is passed to `action` the form will behave like the HTML form component. When a function is passed to `action` the function will handle the form submission. The function passed to `action` may be async and will be called with a single argument containing the [form data](https://developer.mozilla.org/en-US/docs/Web/API/FormData) of the submitted form. The `action` prop can be overridden by a `formAction` attribute on a `<button>`, `<input type="submit">`, or `<input type="image">` component.
+[`action`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/form#action): a URL or function. When a URL is passed to `action` the form will behave like the HTML form component. When a function is passed to `action` the function will handle the form submission in a Transition following [the Action prop pattern](/reference/react/useTransition#exposing-action-props-from-components). The function passed to `action` may be async and will be called with a single argument containing the [form data](https://developer.mozilla.org/en-US/docs/Web/API/FormData) of the submitted form. The `action` prop can be overridden by a `formAction` attribute on a `<button>`, `<input type="submit">`, or `<input type="image">` component.
 
 #### Caveats {/*caveats*/}
 
@@ -229,7 +229,7 @@ export async function deliverMessage(message) {
 
 </Sandpack>
 
-[//]: # 'Uncomment the next line, and delete this line after the `useOptimistic` reference documentatino page is published'
+[//]: # 'Uncomment the next line, and delete this line after the `useOptimistic` reference documentation page is published'
 [//]: # 'To learn more about the `useOptimistic` Hook see the [reference documentation](/reference/react/useOptimistic).'
 
 ### Handling form submission errors {/*handling-form-submission-errors*/}

src/content/reference/react-dom/components/style.md

@@ -49,7 +49,7 @@ React can move `<style>` components to the document's `<head>`, de-duplicate ide
 
 To opt into this behavior, provide the `href` and `precedence` props. React will de-duplicate styles if they have the same `href`. The precedence prop tells React where to rank the `<style>` DOM node relative to others in the document `<head>`, which determines which stylesheet can override the other.
 
-This special treatment comes with two caveats:
+This special treatment comes with three caveats:
 
 * React will ignore changes to props after the style has been rendered. (React will issue a warning in development if this happens.)
 * React will drop all extraneous props when using the `precedence` prop (beyond `href` and `precedence`).