Merge branch 'main' of https://github.com/reactjs/react.dev into sync-65d297e9

react-translations-bot · react-translations-bot · commit ab03cb3c6c17 · 2025-05-19T03:27:13.000Z
diff --git a/public/fonts/Source-Code-Pro-Bold.woff2 b/public/fonts/Source-Code-Pro-Bold.woff2
diff --git a/public/fonts/Source-Code-Pro-Regular.woff2 b/public/fonts/Source-Code-Pro-Regular.woff2
diff --git a/public/images/blog/react-labs-april-2025/flip.gif b/public/images/blog/react-labs-april-2025/flip.gif
diff --git a/src/components/Layout/HomeContent.js b/src/components/Layout/HomeContent.js
@@ -859,7 +859,8 @@ function ExampleLayout({
           </div>
           <div
             ref={contentRef}
-            className="relative mt-0 lg:-my-20 w-full p-2.5 xs:p-5 lg:p-10 flex grow justify-center">
+            className="relative mt-0 lg:-my-20 w-full p-2.5 xs:p-5 lg:p-10 flex grow justify-center"
+            dir="ltr">
             {right}
             <div
               className={cn(
diff --git a/src/components/MDX/Sandpack/template.ts b/src/components/MDX/Sandpack/template.ts
@@ -1,7 +1,7 @@
 export const template = {
   '/src/index.js': {
     hidden: true,
-    code: `import React, { StrictMode } from "react";
+    code: `import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
 import "./styles.css";
 
diff --git a/src/components/PageHeading.tsx b/src/components/PageHeading.tsx
@@ -27,7 +27,6 @@ function PageHeading({
   tags = [],
   breadcrumbs,
 }: PageHeadingProps) {
-  console.log('version', version);
   return (
     <div className="px-5 sm:px-12 pt-3.5">
       <div className="max-w-4xl ms-0 2xl:mx-auto">
diff --git a/src/components/Seo.tsx b/src/components/Seo.tsx
@@ -124,7 +124,14 @@ export const Seo = withRouter(
         )}
         <link
           rel="preload"
-          href="/fonts/Source-Code-Pro-Regular.woff2"
+          href="https://react.dev/fonts/Source-Code-Pro-Regular.woff2"
+          as="font"
+          type="font/woff2"
+          crossOrigin="anonymous"
+        />
+        <link
+          rel="preload"
+          href="https://react.dev/fonts/Source-Code-Pro-Bold.woff2"
           as="font"
           type="font/woff2"
           crossOrigin="anonymous"
diff --git a/src/content/community/index.md b/src/content/community/index.md
@@ -29,4 +29,4 @@ Each community consists of many thousands of React users.
 
 ## News {/*news*/}
 
-For the latest news about React, [follow **@reactjs** on Twitter](https://twitter.com/reactjs) and the [official React blog](/blog/) on this website.
+For the latest news about React, [follow **@reactjs** on Twitter](https://twitter.com/reactjs), [**@react.dev** on Bluesky](https://bsky.app/profile/react.dev) and the [official React blog](/blog/) on this website.
diff --git a/src/content/community/meetups.md b/src/content/community/meetups.md
@@ -38,7 +38,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 
 ## Canada {/*canada*/}
 * [Halifax, NS](https://www.meetup.com/Halifax-ReactJS-Meetup/)
-* [Montreal, QC - React Native](https://www.meetup.com/fr-FR/React-Native-MTL/)
+* [Montreal, QC](https://guild.host/react-montreal/)
 * [Vancouver, BC](https://www.meetup.com/ReactJS-Vancouver-Meetup/)
 * [Ottawa, ON](https://www.meetup.com/Ottawa-ReactJS-Meetup/)
 * [Saskatoon, SK](https://www.meetup.com/saskatoon-react-meetup/)
diff --git a/src/content/learn/build-a-react-app-from-scratch.md b/src/content/learn/build-a-react-app-from-scratch.md
@@ -116,7 +116,7 @@ Similarly, if you rely on the apps using your framework to split the code, you m
 Splitting code by route, when integrated with bundling and data fetching, can reduce the initial load time of your app and the time it takes for the largest visible content of the app to render ([Largest Contentful Paint](https://web.dev/articles/lcp)).
 
 For code-splitting instructions, see your build tool docs:
-- [Vite build optimizations](https://v3.vitejs.dev/guide/features.html#build-optimizations)
+- [Vite build optimizations](https://vite.dev/guide/features.html#build-optimizations)
 - [Parcel code splitting](https://parceljs.org/features/code-splitting/)
 - [Rsbuild code splitting](https://rsbuild.dev/guide/optimization/code-splitting)
 
diff --git a/src/content/learn/preserving-and-resetting-state.md b/src/content/learn/preserving-and-resetting-state.md
@@ -2011,7 +2011,7 @@ export default function ContactList() {
       <label>
         <input
           type="checkbox"
-          value={reverse}
+          checked={reverse}
           onChange={e => {
             setReverse(e.target.checked)
           }}
@@ -2110,7 +2110,7 @@ export default function ContactList() {
       <label>
         <input
           type="checkbox"
-          value={reverse}
+          checked={reverse}
           onChange={e => {
             setReverse(e.target.checked)
           }}
diff --git a/src/content/learn/removing-effect-dependencies.md b/src/content/learn/removing-effect-dependencies.md
@@ -1241,7 +1241,7 @@ export default function Timer() {
 
 </Sandpack>
 
-Instead of reading `count` inside the Effect, you pass a `c => c + 1` instruction ("increment this number!") to React. React will apply it on the next render. And since you don't need to read the value of `count` inside your Effect anymore, so you can keep your Effect's dependencies empty (`[]`). This prevents your Effect from re-creating the interval on every tick.
+Instead of reading `count` inside the Effect, you pass a `c => c + 1` instruction ("increment this number!") to React. React will apply it on the next render. And since you don't need to read the value of `count` inside your Effect anymore, you can keep your Effect's dependencies empty (`[]`). This prevents your Effect from re-creating the interval on every tick.
 
 </Solution>
 
diff --git a/src/content/learn/reusing-logic-with-custom-hooks.md b/src/content/learn/reusing-logic-with-custom-hooks.md
@@ -820,7 +820,7 @@ export default function ChatRoom({ roomId }) {
   // ...
 ```
 
-and pass it as an input to another Hook:
+and passing it as an input to another Hook:
 
 ```js {6}
 export default function ChatRoom({ roomId }) {
@@ -2081,7 +2081,6 @@ Write `useInterval` in the `useInterval.js` file and import it into the `useCoun
 <Sandpack>
 
 ```js
-import { useState } from 'react';
 import { useCounter } from './useCounter.js';
 
 export default function Counter() {
diff --git a/src/content/learn/separating-events-from-effects.md b/src/content/learn/separating-events-from-effects.md
@@ -439,7 +439,7 @@ function ChatRoom({ roomId, theme }) {
   // ...
 ```
 
-This solves the problem. Note that you had to *remove* `onConnected` from the list of your Effect's dependencies. **Effect Events are not reactive and must be omitted from dependencies.**
+This solves the problem. Note that you had to *remove* `theme` from the list of your Effect's dependencies, because it's no longer used in the Effect. You also don't need to *add* `onConnected` to it, because **Effect Events are not reactive and must be omitted from dependencies.**
 
 Verify that the new behavior works as you would expect:
 
diff --git a/src/content/reference/react-dom/preinit.md b/src/content/reference/react-dom/preinit.md
@@ -48,7 +48,7 @@ The `preinit` function provides the browser with a hint that it should start dow
 * `options`: an object. It contains the following properties:
   *  `as`: a required string. The type of resource. Its possible values are `script` and `style`.
   * `precedence`: a string. Required with stylesheets. Says where to insert the stylesheet relative to others. Stylesheets with higher precedence can override those with lower precedence. The possible values are `reset`, `low`, `medium`, `high`. 
-  *  `crossOrigin`: a string. The [CORS policy](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/crossorigin) to use. Its possible values are `anonymous` and `use-credentials`. It is required when `as` is set to `"fetch"`.
+  *  `crossOrigin`: a string. The [CORS policy](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/crossorigin) to use. Its possible values are `anonymous` and `use-credentials`.
   *  `integrity`: a string. A cryptographic hash of the resource, to [verify its authenticity](https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity).
   *  `nonce`: a string. A cryptographic [nonce to allow the resource](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/nonce) when using a strict Content Security Policy. 
   *  `fetchPriority`: a string. Suggests a relative priority for fetching the resource. The possible values are `auto` (the default), `high`, and `low`.
diff --git a/src/content/reference/react/useTransition.md b/src/content/reference/react/useTransition.md
@@ -163,7 +163,7 @@ function CheckoutForm() {
 
 The function passed to `startTransition` is called the "Action". You can update state and (optionally) perform side effects within an Action, and the work will be done in the background without blocking user interactions on the page. A Transition can include multiple Actions, and while a Transition is in progress, your UI stays responsive. For example, if the user clicks a tab but then changes their mind and clicks another tab, the second click will be immediately handled without waiting for the first update to finish. 
 
-To give the user feedback about in-progress Transitions, to `isPending` state switches to `true` at the first call to `startTransition`, and stays `true` until all Actions complete and the final state is shown to the user. Transitions ensure side effects in Actions to complete in order to [prevent unwanted loading indicators](#preventing-unwanted-loading-indicators), and you can provide immediate feedback while the Transition is in progress with `useOptimistic`.
+To give the user feedback about in-progress Transitions, the `isPending` state switches to `true` at the first call to `startTransition`, and stays `true` until all Actions complete and the final state is shown to the user. Transitions ensure side effects in Actions to complete in order to [prevent unwanted loading indicators](#preventing-unwanted-loading-indicators), and you can provide immediate feedback while the Transition is in progress with `useOptimistic`.
 
 <Recipes titleText="The difference between Actions and regular event handling">
 
@@ -1948,3 +1948,162 @@ When clicking multiple times, it's possible for previous requests to finish afte
 This is expected, because Actions within a Transition do not guarantee execution order. For common use cases, React provides higher-level abstractions like [`useActionState`](/reference/react/useActionState) and [`<form>` actions](/reference/react-dom/components/form) that handle ordering for you. For advanced use cases, you'll need to implement your own queuing and abort logic to handle this.
 
 
+Example of `useActionState` handling execution order:
+
+<Sandpack>
+
+```json package.json hidden
+{
+  "dependencies": {
+    "react": "beta",
+    "react-dom": "beta"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test --env=jsdom",
+    "eject": "react-scripts eject"
+  }
+}
+```
+
+```js src/App.js
+import { useState, useActionState } from "react";
+import { updateQuantity } from "./api";
+import Item from "./Item";
+import Total from "./Total";
+
+export default function App({}) {
+  // Store the actual quantity in separate state to show the mismatch.
+  const [clientQuantity, setClientQuantity] = useState(1);
+  const [quantity, updateQuantityAction, isPending] = useActionState(
+    async (prevState, payload) => {
+      setClientQuantity(payload);
+      const savedQuantity = await updateQuantity(payload);
+      return savedQuantity; // Return the new quantity to update the state
+    },
+    1 // Initial quantity
+  );
+
+  return (
+    <div>
+      <h1>Checkout</h1>
+      <Item action={updateQuantityAction}/>
+      <hr />
+      <Total clientQuantity={clientQuantity} savedQuantity={quantity} isPending={isPending} />
+    </div>
+  );
+}
+
+```
+
+```js src/Item.js
+import {startTransition} from 'react';
+
+export default function Item({action}) {
+  function handleChange(e) {
+    // Update the quantity in an Action.
+    startTransition(() => {
+      action(e.target.value);
+    });
+  }  
+  return (
+    <div className="item">
+      <span>Eras Tour Tickets</span>
+      <label htmlFor="name">Quantity: </label>
+      <input
+        type="number"
+        onChange={handleChange}
+        defaultValue={1}
+        min={1}
+      />
+    </div>
+  )
+}
+```
+
+```js src/Total.js
+const intl = new Intl.NumberFormat("en-US", {
+  style: "currency",
+  currency: "USD"
+});
+
+export default function Total({ clientQuantity, savedQuantity, isPending }) {
+  return (
+    <div className="total">
+      <span>Total:</span>
+      <div>
+        <div>
+          {isPending
+            ? "🌀 Updating..."
+            : `${intl.format(savedQuantity * 9999)}`}
+        </div>
+        <div className="error">
+          {!isPending &&
+            clientQuantity !== savedQuantity &&
+            `Wrong total, expected: ${intl.format(clientQuantity * 9999)}`}
+        </div>
+      </div>
+    </div>
+  );
+}
+```
+
+```js src/api.js
+let firstRequest = true;
+export async function updateQuantity(newName) {
+  return new Promise((resolve, reject) => {
+    if (firstRequest === true) {
+      firstRequest = false;
+      setTimeout(() => {
+        firstRequest = true;
+        resolve(newName);
+        // Simulate every other request being slower
+      }, 1000);
+    } else {
+      setTimeout(() => {
+        resolve(newName);
+      }, 50);
+    }
+  });
+}
+```
+
+```css
+.item {
+  display: flex;
+  align-items: center;
+  justify-content: start;
+}
+
+.item label {
+  flex: 1;
+  text-align: right;
+}
+
+.item input {
+  margin-left: 4px;
+  width: 60px;
+  padding: 4px;
+}
+
+.total {
+  height: 50px;
+  line-height: 25px;
+  display: flex;
+  align-content: center;
+  justify-content: space-between;
+}
+
+.total div {
+  display: flex;
+  flex-direction: column;
+  align-items: flex-end;
+}
+
+.error {
+  color: red;
+}
+```
+
+</Sandpack>
diff --git a/src/content/reference/rsc/server-functions.md b/src/content/reference/rsc/server-functions.md
@@ -28,7 +28,7 @@ To support Server Functions as a bundler or framework, we recommend pinning to a
 
 </Note>
 
-When a Server Functions is defined with the [`"use server"`](/reference/rsc/use-server) directive, your framework will automatically create a reference to the server function, and pass that reference to the Client Component. When that function is called on the client, React will send a request to the server to execute the function, and return the result.
+When a Server Function is defined with the [`"use server"`](/reference/rsc/use-server) directive, your framework will automatically create a reference to the server function, and pass that reference to the Client Component. When that function is called on the client, React will send a request to the server to execute the function, and return the result.
 
 Server Functions can be created in Server Components and passed as props to Client Components, or they can be imported and used in Client Components.
 
diff --git a/src/content/warnings/react-dom-test-utils.md b/src/content/warnings/react-dom-test-utils.md
@@ -2,8 +2,6 @@
 title: react-dom/test-utils Deprecation Warnings
 ---
 
-TODO: update for 19?
-
 ## ReactDOMTestUtils.act() warning {/*reactdomtestutilsact-warning*/}
 
 `act` from `react-dom/test-utils` has been deprecated in favor of `act` from `react`.
diff --git a/src/content/warnings/react-test-renderer.md b/src/content/warnings/react-test-renderer.md
@@ -2,8 +2,6 @@
 title: react-test-renderer Deprecation Warnings
 ---
 
-TODO: Update this for 19?
-
 ## ReactTestRenderer.create() warning {/*reacttestrenderercreate-warning*/}
 
 react-test-renderer is deprecated. A warning will fire whenever calling ReactTestRenderer.create() or ReactShallowRender.render(). The react-test-renderer package will remain available on NPM but will not be maintained and may break with new React features or changes to React's internals.
diff --git a/src/styles/index.css b/src/styles/index.css
@@ -12,7 +12,17 @@
     font-style: normal;
     font-weight: 400;
     font-display: swap;
-    src: url('/fonts/Source-Code-Pro-Regular.woff2') format('woff2');
+    src: url('https://react.dev/fonts/Source-Code-Pro-Regular.woff2')
+      format('woff2');
+  }
+
+  @font-face {
+    font-family: 'Source Code Pro';
+    font-style: normal;
+    font-weight: 700;
+    font-display: swap;
+    src: url('https://react.dev/fonts/Source-Code-Pro-Bold.woff2')
+      format('woff2');
   }
 
   /* Latin */

Original file line number	Diff line number	Diff line change
`@@ -29,4 +29,4 @@ Each community consists of many thousands of React users.`
`29`	`29`
`30`	`30`	`## News {/news/}`
`31`	`31`
`32`		`-For the latest news about React, [follow @reactjs on Twitter](https://twitter.com/reactjs) and the [official React blog](/blog/) on this website.`
	`32`	`+For the latest news about React, [follow @reactjs on Twitter](https://twitter.com/reactjs), [@react.dev on Bluesky](https://bsky.app/profile/react.dev) and the [official React blog](/blog/) on this website.`