Enable lints for React Components

website-next/.eslintrc.cjs

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+module.exports = {
+  root: false,
+  extends: [
+    'plugin:react/recommended',
+    'plugin:react/jsx-runtime',
+    'plugin:react-hooks/recommended',
+  ],
+  settings: {
+    react: {
+      version: 'detect',
+    },
+  },
+  rules: {
+    'react/prop-types': 'off',
+    'react/no-unstable-nested-components': 'error',
+  },
+};

website-next/package.json

@@ -31,7 +31,9 @@
   "devDependencies": {
     "@docusaurus/module-type-aliases": "3.0.0",
     "@docusaurus/tsconfig": "3.0.0",
-    "@docusaurus/types": "3.0.0"
+    "@docusaurus/types": "3.0.0",
+    "eslint-plugin-react": "^7.33.2",
+    "eslint-plugin-react-hooks": "^4.6.0"
   },
   "browserslist": "> 0.5%, last 2 versions, Firefox ESR, not dead",
   "engines": {

website-next/src/components/EditorToolbar.tsx

@@ -17,29 +17,26 @@ import SuccessIcon from '@theme/Icon/Success';
 import styles from './EditorToolbar.module.css';
 
 export type Props = Readonly<{
-  getCode: () => string;
+  code: string;
   className?: string;
   style?: React.CSSProperties;
 }>;
 
 export default function EditorToolbar({
-  getCode,
+  code,
   className,
   style,
 }: Props): JSX.Element {
-  const handleCopy = useCallback(
-    () => navigator.clipboard.writeText(getCode()),
-    [],
-  );
+  const handleCopy = useCallback(() => {
+    navigator.clipboard.writeText(code);
+  }, [code]);
 
-  const handleShare = useCallback(
-    () =>
-      navigator.clipboard.writeText(
-        window.location.origin +
-          `/playground?code=${encodeURIComponent(btoa(getCode()))}`,
-      ),
-    [],
-  );
+  const handleShare = useCallback(() => {
+    navigator.clipboard.writeText(
+      window.location.origin +
+        `/playground?code=${encodeURIComponent(btoa(code))}`,
+    );
+  }, [code]);
 
   return (
     <div className={clsx(styles.toolbar, className)} style={style}>
@@ -71,7 +68,7 @@ function ToolbarButton({
     copyTimeout.current = window.setTimeout(() => {
       setIsSuccess(false);
     }, 1000);
-  }, []);
+  }, [onClick]);
 
   return (
     <button

website-next/src/components/Playground.tsx

@@ -20,7 +20,6 @@ import React, {
 
 import {usePrismTheme} from '@docusaurus/theme-common';
 import clsx from 'clsx';
-import nullthrows from 'nullthrows';
 import {LiveProvider, LiveEditor, LivePreview, LiveError} from 'react-live';
 import EditorToolbar from './EditorToolbar';
 
@@ -45,82 +44,67 @@ export type Props = Readonly<{
 
 export default function Playground({code, height, autoFocus}: Props) {
   const prismTheme = usePrismTheme();
-  const playgroundRef = useRef<HTMLDivElement>(null);
   const editorScrollRef = useRef<HTMLDivElement>(null);
 
-  const [isLoaded, setIsLoaded] = useState(false);
   const [liveCode, setLiveCode] = useState(code ?? defaultCode);
+  const [hasCodeChanged, setHasCodeChanged] = useState(false);
   const [scrollbarWidth, setScrollbarWidth] = useState(0);
 
-  const LivePreviewWrapper = useCallback(
-    (props: React.ComponentProps<'div'>) => {
-      useEffect(() => {
-        setIsLoaded(true);
-      }, []);
-
-      return <div {...props} className={styles.livePreviewWrapper} />;
-    },
-    [],
-  );
-
+  // Once react-live has hydrated the content-editable area, set focus to it
+  // if requested
   useEffect(() => {
-    // TODO: This is hacky and relies on being called after some operation
-    // "react-live" does which itself can manipulate global focus
-    if (isLoaded && autoFocus) {
-      const codeElem = playgroundRef?.current?.querySelector('.prism-code');
+    if (autoFocus && hasCodeChanged) {
+      const codeElem = editorScrollRef?.current?.querySelector('.prism-code');
       const sel = window.getSelection();
       if (codeElem?.clientHeight && sel != null) {
         sel.selectAllChildren(codeElem);
         sel.collapseToStart();
       }
     }
-  }, [isLoaded, autoFocus]);
+  }, [autoFocus, hasCodeChanged]);
 
   useLayoutEffect(() => {
     // The toolbar is positioned relative to the outside of the scrolling
     // container so it stays in the same place when scrolling, but this means
-    // it isn't automatically adjusted for scrollbar width
+    // it isn't automatically adjusted for scrollbar width. If code change
+    // causes overflow/scrollbar, adjust its position based on its width progrmatically.
     if (editorScrollRef.current) {
       setScrollbarWidth(
         editorScrollRef.current.offsetWidth -
           editorScrollRef.current.clientWidth,
       );
     }
-  });
+  }, [editorScrollRef, code]);
 
   const heightStyle = height
     ? ({'--yg-playground-height': height} as React.CSSProperties)
     : undefined;
 
   return (
-    <LiveProvider code={liveCode} theme={prismTheme} scope={{Layout, Node}}>
-      <div className={styles.wrapper} ref={playgroundRef} style={heightStyle}>
+    <LiveProvider
+      code={liveCode}
+      theme={prismTheme}
+      scope={{Node: LiveNode, Layout: RootLiveNode}}>
+      <div className={styles.wrapper} style={heightStyle}>
         <div className={clsx(styles.playgroundRow, 'container')}>
           <div className={clsx(styles.editorColumn, 'playground-editor')}>
             <div className={styles.editorScroll} ref={editorScrollRef}>
               <EditorToolbar
+                code={liveCode}
                 className={styles.editorToolbar}
                 style={{paddingRight: scrollbarWidth + 'px'}}
-                getCode={useCallback(
-                  () =>
-                    nullthrows(
-                      playgroundRef.current?.querySelector('.prism-code')
-                        ?.textContent,
-                    ),
-                  [],
-                )}
               />
               <LiveEditor
                 className={clsx(styles.playgroundEditor)}
-                onChange={setLiveCode}
+                onChange={useCallback((code: string) => {
+                  setHasCodeChanged(true);
+                  setLiveCode(code);
+                }, [])}
               />
             </div>
           </div>
           <div className={clsx(styles.previewColumn)}>
-            <LivePreview
-              className={clsx(styles.livePreview)}
-              Component={LivePreviewWrapper}
-            />
+            <LivePreview className={clsx(styles.livePreview)} />
             <LiveError className={clsx(styles.liveError)} />
           </div>
         </div>
@@ -129,22 +113,22 @@ export default function Playground({code, height, autoFocus}: Props) {
   );
 }
 
-type LayoutProps = Readonly<{
+type RootLiveNodeProps = Readonly<{
   children: React.ReactNode;
   config?: {useWebDefaults?: boolean};
 }>;
 
-function Layout({children, config}: LayoutProps) {
+function RootLiveNode({children, config}: RootLiveNodeProps) {
   if (React.Children.count(children) !== 1) {
     return null;
   }
 
   const child = React.Children.only(children);
-  if (!React.isValidElement(child) || child.type !== Node) {
+  if (!React.isValidElement(child) || child.type !== LiveNode) {
     return null;
   }
 
-  const styleNode = styleNodeFromYogaNode(child as unknown as Node);
+  const styleNode = styleNodeFromLiveNode(child as unknown as LiveNode);
 
   return (
     <Suspense fallback={null}>
@@ -156,26 +140,26 @@ function Layout({children, config}: LayoutProps) {
   );
 }
 
-type NodeProps = Readonly<{
+type LiveNodeProps = Readonly<{
   children: React.ReactNode;
   style: FlexStyle;
 }>;
 
-class Node extends React.PureComponent<NodeProps> {}
+class LiveNode extends React.PureComponent<LiveNodeProps> {}
 
-function styleNodeFromYogaNode(
-  yogaNode: React.ElementRef<typeof Node>,
+function styleNodeFromLiveNode(
+  liveNode: React.ElementRef<typeof LiveNode>,
 ): StyleNode {
   const children: StyleNode[] = [];
 
-  React.Children.forEach(yogaNode.props.children, child => {
-    if (React.isValidElement(child) && child.type === Node) {
-      children.push(styleNodeFromYogaNode(child as unknown as Node));
+  React.Children.forEach(liveNode.props.children, child => {
+    if (React.isValidElement(child) && child.type === LiveNode) {
+      children.push(styleNodeFromLiveNode(child as unknown as LiveNode));
     }
   });
 
   return {
-    style: yogaNode.props.style,
+    style: liveNode.props.style,
     children,
   };
 }

website-next/src/components/YogaViewer.tsx

@@ -7,7 +7,7 @@
  * @format
  */
 
-import React, {useMemo} from 'react';
+import {useMemo} from 'react';
 import Yoga, {Direction, Overflow, Node as YogaNode} from 'yoga-layout';
 import {FlexStyle, applyStyle} from './FlexStyle';
 import LayoutBox from './LayoutBox';
@@ -36,7 +36,7 @@ export default function YogaViewer({
 }: Props) {
   const layout = useMemo(
     () => layoutStyleTree(rootNode, width, height, {useWebDefaults}),
-    [rootNode, width, height],
+    [rootNode, width, height, useWebDefaults],
   );
   return <LayoutBox metrics={layout} depth={0} className={className} />;
 }

website-next/src/pages/index.tsx

@@ -5,7 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import React from 'react';
 import clsx from 'clsx';
 import Link from '@docusaurus/Link';
 import Layout from '@theme/Layout';

website-next/src/pages/playground.tsx

@@ -5,7 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import React from 'react';
 import Layout from '@theme/Layout';
 import {useLocation} from '@docusaurus/router';