Sync with react.dev @ a8790ca8

.env.production

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

package.json

@@ -30,7 +30,6 @@
     "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",

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/getRouteMeta.tsx

@@ -58,13 +58,13 @@ export interface RouteMeta {
   order?: number;
 }
 
-type TravesalContext = RouteMeta & {
+type TraversalContext = RouteMeta & {
   currentIndex: number;
 };
 
 export function getRouteMeta(cleanedPath: string, routeTree: RouteItem) {
   const breadcrumbs = getBreadcrumbs(cleanedPath, routeTree);
-  const ctx: TravesalContext = {
+  const ctx: TraversalContext = {
     currentIndex: 0,
   };
   buildRouteMeta(cleanedPath, routeTree, ctx);
@@ -79,7 +79,7 @@ export function getRouteMeta(cleanedPath: string, routeTree: RouteItem) {
 function buildRouteMeta(
   searchPath: string,
   currentRoute: RouteItem,
-  ctx: TravesalContext
+  ctx: TraversalContext
 ) {
   ctx.currentIndex++;
 

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>;
@@ -36,7 +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,
@@ -47,14 +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/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023.md

@@ -74,7 +74,7 @@ Making plain JavaScript in React components reactive requires a compiler with a
 
 ## Offscreen Rendering {/*offscreen-rendering*/}
 
-Offscreen rendering is an upcoming capability in React for rendering screens in the background without additional performance overhead. You can think of it as a version of the [`content-visiblity` CSS property](https://developer.mozilla.org/en-US/docs/Web/CSS/content-visibility) that works not only for DOM elements but React components, too. During our research, we've discovered a variety of use cases:
+Offscreen rendering is an upcoming capability in React for rendering screens in the background without additional performance overhead. You can think of it as a version of the [`content-visibility` CSS property](https://developer.mozilla.org/en-US/docs/Web/CSS/content-visibility) that works not only for DOM elements but React components, too. During our research, we've discovered a variety of use cases:
 
 - A router can prerender screens in the background so that when a user navigates to them, they're instantly available.
 - A tab switching component can preserve the state of hidden tabs, so the user can switch between them without losing their progress.

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

@@ -530,13 +530,21 @@ 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>
+<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>
+<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. 
 

src/content/learn/passing-data-deeply-with-context.md

@@ -985,7 +985,7 @@ export const places = [{
 }, {
   id: 5, 
   name: 'Chefchaouen, Marocco',
-  description: 'There are a few theories on why the houses are painted blue, including that the color repells mosquitos or that it symbolizes sky and heaven.',
+  description: 'There are a few theories on why the houses are painted blue, including that the color repels mosquitos or that it symbolizes sky and heaven.',
   imageId: 'rTqKo46'
 }, {
   id: 6,
@@ -1124,7 +1124,7 @@ export const places = [{
 }, {
   id: 5, 
   name: 'Chefchaouen, Marocco',
-  description: 'There are a few theories on why the houses are painted blue, including that the color repells mosquitos or that it symbolizes sky and heaven.',
+  description: 'There are a few theories on why the houses are painted blue, including that the color repels mosquitos or that it symbolizes sky and heaven.',
   imageId: 'rTqKo46'
 }, {
   id: 6,

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/understanding-your-ui-as-a-tree.md

@@ -253,7 +253,7 @@ With conditional rendering, across different renders, the render tree may render
 
 In this example, depending on what `inspiration.type` is, we may render `<FancyText>` or `<Color>`. The render tree may be different for each render pass.
 
-Although render trees may differ across render pases, these trees are generally helpful for identifying what the top-level and leaf components are in a React app. Top-level components are the components nearest to the root component and affect the rendering performance of all the components beneath them and often contain the most complexity. Leaf components are near the bottom of the tree and have no child components and are often frequently re-rendered.
+Although render trees may differ across render passes, these trees are generally helpful for identifying what the *top-level* and *leaf components* are in a React app. Top-level components are the components nearest to the root component and affect the rendering performance of all the components beneath them and often contain the most complexity. Leaf components are near the bottom of the tree and have no child components and are often frequently re-rendered.
 
 Identifying these categories of components are useful for understanding data flow and performance of your app.