Merge pull request #51 from reactjs/sync-4bdb87b1

Sync with react.dev @ 4bdb87b

.env.production

@@ -1 +1 @@
-NEXT_PUBLIC_GA_TRACKING_ID = 'UA-41298772-4'
+NEXT_PUBLIC_GA_TRACKING_ID = 'G-B1E83PJ3RT'

package.json

@@ -30,13 +30,12 @@
     "classnames": "^2.2.6",
     "date-fns": "^2.16.1",
     "debounce": "^1.2.1",
-    "ga-lite": "^2.1.4",
     "github-slugger": "^1.3.0",
     "next": "^13.4.1",
     "next-remote-watch": "^1.0.0",
     "parse-numeric-range": "^1.2.0",
     "react": "^0.0.0-experimental-16d053d59-20230506",
-    "react-collapsed": "npm:@gaearon/[email protected]",
+    "react-collapsed": "4.0.4",
     "react-dom": "^0.0.0-experimental-16d053d59-20230506",
     "remark-frontmatter": "^4.0.1",
     "remark-gfm": "^3.0.1"

src/components/Layout/Feedback.tsx

@@ -4,7 +4,6 @@
 
 import {useState} from 'react';
 import {useRouter} from 'next/router';
-import {ga} from '../../utils/analytics';
 
 export function Feedback({onSubmit = () => {}}: {onSubmit?: () => void}) {
   const {asPath} = useRouter();
@@ -48,14 +47,12 @@ const thumbsDownIcon = (
 function sendGAEvent(isPositive: boolean) {
   // Fragile. Don't change unless you've tested the network payload
   // and verified that the right events actually show up in GA.
-  ga(
-    'send',
-    'event',
-    'button',
-    'feedback',
-    window.location.pathname,
-    isPositive ? '1' : '0'
-  );
+  // @ts-ignore
+  gtag('event', 'feedback', {
+    event_category: 'button',
+    event_label: window.location.pathname,
+    value: isPositive ? 1 : 0,
+  });
 }
 
 function SendFeedback({onSubmit}: {onSubmit: () => void}) {

src/components/Layout/Page.tsx

@@ -28,7 +28,12 @@ interface PageProps {
   children: React.ReactNode;
   toc: Array<TocItem>;
   routeTree: RouteItem;
-  meta: {title?: string; canary?: boolean; description?: string};
+  meta: {
+    title?: string;
+    titleForTitleTag?: string;
+    canary?: boolean;
+    description?: string;
+  };
   section: 'learn' | 'reference' | 'community' | 'blog' | 'home' | 'unknown';
 }
 
@@ -107,6 +112,7 @@ export function Page({children, toc, routeTree, meta, section}: PageProps) {
     <>
       <Seo
         title={title}
+        titleForTitleTag={meta.titleForTitleTag}
         isHomePage={isHomePage}
         image={`/images/og-` + section + '.png'}
         searchOrder={searchOrder}

src/components/Layout/Sidebar/SidebarRouteTree.tsx

@@ -7,7 +7,7 @@ import {useRef, useLayoutEffect, Fragment} from 'react';
 import cn from 'classnames';
 import {useRouter} from 'next/router';
 import {SidebarLink} from './SidebarLink';
-import useCollapse from 'react-collapsed';
+import {useCollapse} from 'react-collapsed';
 import usePendingRoute from 'hooks/usePendingRoute';
 import type {RouteItem} from 'components/Layout/getRouteMeta';
 

src/components/MDX/Sandpack/Preview.tsx

@@ -52,6 +52,12 @@ export function Preview({
     rawError = null;
   }
 
+  // When throwing a new Error in Sandpack - we want to disable the dev error dialog
+  // to show the Error Boundary fallback
+  if (rawError && rawError.message.includes(`throw Error('Example error')`)) {
+    rawError = null;
+  }
+
   // Memoized because it's fed to debouncing.
   const firstLintError = useMemo(() => {
     if (lintErrors.length === 0) {

src/components/Seo.tsx

@@ -9,6 +9,7 @@ import {siteConfig} from '../siteConfig';
 
 export interface SeoProps {
   title: string;
+  titleForTitleTag: undefined | string;
   description?: string;
   image?: string;
   // jsonld?: JsonLDType | Array<JsonLDType>;
@@ -22,6 +23,7 @@ const deployedTranslations = [
   'zh-hans',
   'es',
   'fr',
+  'ja',
   // We'll add more languages when they have enough content.
   // Please DO NOT edit this list without a discussion in the reactjs/react.dev repo.
   // It must be the same between all translations.
@@ -35,7 +37,7 @@ function getDomain(languageCode: string): string {
 export const Seo = withRouter(
   ({
     title,
-    description = 'The library for web and native user interfaces',
+    titleForTitleTag,
     image = '/images/og-default.png',
     router,
     children,
@@ -46,14 +48,20 @@ export const Seo = withRouter(
     const canonicalUrl = `https://${siteDomain}${
       router.asPath.split(/[\?\#]/)[0]
     }`;
-    const pageTitle = isHomePage ? title : title + ' – React';
+    // Allow setting a different title for Google results
+    const pageTitle =
+      (titleForTitleTag ?? title) + (isHomePage ? '' : ' – React');
     // Twitter's meta parser is not very good.
     const twitterTitle = pageTitle.replace(/[<>]/g, '');
+    let description = isHomePage
+      ? 'React is the library for web and native user interfaces. Build user interfaces out of individual pieces called components written in JavaScript. React is designed to let you seamlessly combine components written by independent people, teams, and organizations.'
+      : 'The library for web and native user interfaces';
     return (
       <Head>
         <meta name="viewport" content="width=device-width, initial-scale=1" />
         {title != null && <title key="title">{pageTitle}</title>}
-        {description != null && (
+        {isHomePage && (
+          // Let Google figure out a good description for each page.
           <meta name="description" key="description" content={description} />
         )}
         <link rel="canonical" href={canonicalUrl} />

src/content/community/meetups.md

@@ -48,6 +48,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Montreal, QC - React Native](https://www.meetup.com/fr-FR/React-Native-MTL/)
 * [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/)
 * [Toronto, ON](https://www.meetup.com/Toronto-React-Native/events/)
 
 ## Chile {/*chile*/}

src/content/learn/describing-the-ui.md

@@ -10,6 +10,7 @@ React ແມ່ນ JavaScript library ສຳລັບສະແດງຜົນໜ
 
 <YouWillLearn isChapter={true}>
 
+<<<<<<< HEAD
 * [ວິທີຂຽນ React component ທຳອິດຂອງທ່ານ](/learn/your-first-component)
 * [ເມືອໃດ ແລະ ວິທີການສ້າງຫຼາຍຟາຍ component](/learn/importing-and-exporting-components)
 * [ວິທີການເພີ່ມ markup ໃສ່ JavaScript ດ້ວຍ JSX](/learn/writing-markup-with-jsx)
@@ -18,6 +19,17 @@ React ແມ່ນ JavaScript library ສຳລັບສະແດງຜົນໜ
 * [ວິທີການສະແດງ component ແບບມີເງື່ອນໄຂ](/learn/conditional-rendering)
 * [ວິທີການສະແດງຫຼາຍ component ພ້ອມກັນ](/learn/rendering-lists)
 * [ວິທີການຫຼີກເວັ້ນຂໍ້ຜິດພາດໂດຍການຮັກສາໃຫ້ component pure ທີ່ສຸດ](/learn/keeping-components-pure)
+=======
+* [How to write your first React component](/learn/your-first-component)
+* [When and how to create multi-component files](/learn/importing-and-exporting-components)
+* [How to add markup to JavaScript with JSX](/learn/writing-markup-with-jsx)
+* [How to use curly braces with JSX to access JavaScript functionality from your components](/learn/javascript-in-jsx-with-curly-braces)
+* [How to configure components with props](/learn/passing-props-to-a-component)
+* [How to conditionally render components](/learn/conditional-rendering)
+* [How to render multiple components at a time](/learn/rendering-lists)
+* [How to avoid confusing bugs by keeping components pure](/learn/keeping-components-pure)
+* [Why understanding your UI as trees is useful](/learn/understanding-your-ui-as-a-tree)
+>>>>>>> 4bdb87b172a7723d56d03a5630c8a9870f6f03ec
 
 </YouWillLearn>
 
@@ -523,7 +535,42 @@ export default function TeaSet() {
 
 </LearnMore>
 
+<<<<<<< HEAD
 ## ຕໍ່ໄປແມ່ນຫຍັງ? {/*whats-next*/}
+=======
+## Your UI as a tree {/*your-ui-as-a-tree*/}
+
+React uses trees to model the relationships between components and modules. 
+
+A React render tree is a representation of the parent and child relationship between components. 
+
+<Diagram name="generic_render_tree" height={250} width={500} alt="A tree graph with five nodes, with each node representing a component. The root node is located at the top the tree graph and is labelled 'Root Component'. It has two arrows extending down to two nodes labelled 'Component A' and 'Component C'. Each of the arrows is labelled with 'renders'. 'Component A' has a single 'renders' arrow to a node labelled 'Component B'. 'Component C' has a single 'renders' arrow to a node labelled 'Component D'.">
+
+An example React render tree.
+
+</Diagram>
+
+Components near the top of the tree, near the root component, are considered top-level components. Components with no child components are leaf components. This categorization of components is useful for understanding data flow and rendering performance.
+
+Modelling the relationship between JavaScript modules is another useful way to understand your app. We refer to it as a module dependency tree. 
+
+<Diagram name="generic_dependency_tree" height={250} width={500} alt="A tree graph with five nodes. Each node represents a JavaScript module. The top-most node is labelled 'RootModule.js'. It has three arrows extending to the nodes: 'ModuleA.js', 'ModuleB.js', and 'ModuleC.js'. Each arrow is labelled as 'imports'. 'ModuleC.js' node has a single 'imports' arrow that points to a node labelled 'ModuleD.js'.">
+
+An example module dependency tree.
+
+</Diagram>
+
+A dependency tree is often used by build tools to bundle all the relevant JavaScript code for the client to download and render. A large bundle size regresses user experience for React apps. Understanding the module dependency tree is helpful to debug such issues. 
+
+<LearnMore path="/learn/understanding-your-ui-as-a-tree">
+
+Read **[Your UI as a Tree](/learn/understanding-your-ui-as-a-tree)** to learn how to create a render and module dependency trees for a React app and how they're useful mental models for improving user experience and performance.
+
+</LearnMore>
+
+
+## What's next? {/*whats-next*/}
+>>>>>>> 4bdb87b172a7723d56d03a5630c8a9870f6f03ec
 
 ໄປທີ່ [Component ທຳອິດຂອງທ່ານ](/learn/your-first-component) ເພື່ອເລີ່ມອ່ານບົດນີ້ເທື່ອລະໜ້າ!
 

src/content/learn/preserving-and-resetting-state.md

@@ -10,33 +10,17 @@ State is isolated between components. React keeps track of which state belongs t
 
 <YouWillLearn>
 
-* How React "sees" component structures
 * When React chooses to preserve or reset the state
 * How to force React to reset component's state
 * How keys and types affect whether the state is preserved
 
 </YouWillLearn>
 
-## The UI tree {/*the-ui-tree*/}
+## State is tied to a position in the render tree {/*state-is-tied-to-a-position-in-the-tree*/}
 
-Browsers use many tree structures to model UI. The [DOM](https://developer.mozilla.org/docs/Web/API/Document_Object_Model/Introduction) represents HTML elements, the [CSSOM](https://developer.mozilla.org/docs/Web/API/CSS_Object_Model) does the same for CSS. There's even an [Accessibility tree](https://developer.mozilla.org/docs/Glossary/Accessibility_tree)!
-
-React also uses tree structures to manage and model the UI you make. React makes **UI trees** from your JSX. Then React DOM updates the browser DOM elements to match that UI tree. (React Native translates these trees into elements specific to mobile platforms.)
-
-<DiagramGroup>
-
-<Diagram name="preserving_state_dom_tree" height={193} width={864} alt="Diagram with three sections arranged horizontally. In the first section, there are three rectangles stacked vertically, with labels 'Component A', 'Component B', and 'Component C'. Transitioning to the next pane is an arrow with the React logo on top labeled 'React'. The middle section contains a tree of components, with the root labeled 'A' and two children labeled 'B' and 'C'. The next section is again transitioned using an arrow with the React logo on top labeled 'React'. The third and final section is a wireframe of a browser, containing a tree of 8 nodes, which has only a subset highlighted (indicating the subtree from the middle section).">
-
-From components, React creates a UI tree which React DOM uses to render the DOM
-
-</Diagram>
-
-</DiagramGroup>
-
-## State is tied to a position in the tree {/*state-is-tied-to-a-position-in-the-tree*/}
-
-When you give a component state, you might think the state "lives" inside the component. But the state is actually held inside React. React associates each piece of state it's holding with the correct component by where that component sits in the UI tree.
+React builds [render trees](learn/understanding-your-ui-as-a-tree#the-render-tree) for the component structure in your UI.
 
+When you give a component state, you might think the state "lives" inside the component. But the state is actually held inside React. React associates each piece of state it's holding with the correct component by where that component sits in the render tree.
 
 Here, there is only one `<Counter />` JSX tag, but it's rendered at two different positions:
 
@@ -190,7 +174,7 @@ Updating state
 </DiagramGroup>
 
 
-React will keep the state around for as long as you render the same component at the same position. To see this, increment both counters, then remove the second component by unchecking "Render the second counter" checkbox, and then add it back by ticking it again:
+React will keep the state around for as long as you render the same component at the same position in the tree. To see this, increment both counters, then remove the second component by unchecking "Render the second counter" checkbox, and then add it back by ticking it again:
 
 <Sandpack>
 

src/content/learn/reacting-to-input-with-state.md

@@ -84,7 +84,7 @@ function submitForm(answer) {
   // Pretend it's hitting the network.
   return new Promise((resolve, reject) => {
     setTimeout(() => {
-      if (answer.toLowerCase() == 'istanbul') {
+      if (answer.toLowerCase() === 'istanbul') {
         resolve();
       } else {
         reject(new Error('Good guess but a wrong answer. Try again!'));

src/content/learn/typescript.md

@@ -284,7 +284,7 @@ export default App = AppTSX;
 
 </Sandpack>
 
-This technique works when you have an default value which makes sense - but there are occasionally cases when you do not, and in those cases `null` can feel reasonable as a default value. However, to allow the type-system to understand your code, you need to explicitly set `ContextShape | null` on the `createContext`. 
+This technique works when you have a default value which makes sense - but there are occasionally cases when you do not, and in those cases `null` can feel reasonable as a default value. However, to allow the type-system to understand your code, you need to explicitly set `ContextShape | null` on the `createContext`. 
 
 This causes the issue that you need to eliminate the `| null` in the type for context consumers. Our recommendation is to have the hook do a runtime check for it's existence and throw an error when not present:
 
@@ -460,4 +460,4 @@ We recommend the following resources:
 
  - [React TypeScript Cheatsheet](https://react-typescript-cheatsheet.netlify.app/) is a community-maintained cheatsheet for using TypeScript with React, covering a lot of useful edge cases and providing more breadth than this document.
 
- - [TypeScript Community Discord](https://discord.com/invite/typescript) is a great place to ask questions and get help with TypeScript and React issues.
+ - [TypeScript Community Discord](https://discord.com/invite/typescript) is a great place to ask questions and get help with TypeScript and React issues.