refactor: fix more type-aware linting errors (#7479)

.eslintrc.js

@@ -83,7 +83,7 @@ module.exports = {
     'no-restricted-exports': OFF,
     'no-restricted-properties': [
       ERROR,
-      ...[
+      .../** @type {[string, string][]} */ ([
         // TODO: TS doesn't make Boolean a narrowing function yet,
         // so filter(Boolean) is problematic type-wise
         // ['compact', 'Array#filter(Boolean)'],
@@ -114,7 +114,7 @@ module.exports = {
         ['take', 'Array#slice(0, n)'],
         ['takeRight', 'Array#slice(-n)'],
         ['tail', 'Array#slice(1)'],
-      ].map(([property, alternative]) => ({
+      ]).map(([property, alternative]) => ({
         object: '_',
         property,
         message: `Use ${alternative} instead.`,

admin/scripts/generateExamples.js

@@ -44,8 +44,9 @@ async function generateTemplateExample(template) {
       `npm init docusaurus@latest examples/${template} ${command}`,
     );
 
-    const templatePackageJson = await fs.readJSON(
+    const templatePackageJson =
-      `examples/${template}/package.json`,
+      await /** @type {Promise<import("../../packages/create-docusaurus/templates/classic/package.json") & { scripts: { [name: string]: string }; description: string }>} */ (
+        fs.readJSON(`examples/${template}/package.json`)
       );
 
     // Attach the dev script which would be used in code sandbox by default

packages/create-docusaurus/bin/index.js

@@ -14,7 +14,9 @@ import logger from '@docusaurus/logger';
 import semver from 'semver';
 import {program} from 'commander';
 
-const packageJson = createRequire(import.meta.url)('../package.json');
+const packageJson = /** @type {import("../package.json")} */ (
+  createRequire(import.meta.url)('../package.json')
+);
 const requiredVersion = packageJson.engines.node;
 
 if (!semver.satisfies(process.version, requiredVersion)) {

packages/create-docusaurus/src/index.ts

@@ -78,7 +78,7 @@ async function askForPackageManagerChoice(): Promise<PackageManager> {
             logger.info`Falling back to name=${defaultPackageManager}`;
           },
         },
-      )) as {packageManager: PackageManager}
+      )) as {packageManager?: PackageManager}
     ).packageManager ?? defaultPackageManager
   );
 }

packages/docusaurus-migrate/bin/index.mjs

@@ -15,7 +15,9 @@ import semver from 'semver';
 import cli from 'commander';
 
 const moduleRequire = createRequire(import.meta.url);
-const requiredVersion = moduleRequire('../package.json').engines.node;
+const requiredVersion = /** @type {import("../package.json")} */ (
+  moduleRequire('../package.json')
+).engines.node;
 
 if (!semver.satisfies(process.version, requiredVersion)) {
   logger.error('Minimum Node.js version not met :(');
@@ -25,7 +27,7 @@ if (!semver.satisfies(process.version, requiredVersion)) {
 
 // See https://github.com/facebook/docusaurus/pull/6860
 const {migrateDocusaurusProject, migrateMDToMDX} =
-  moduleRequire('../lib/index.js');
+  /** @type {import("../lib/index.js")} */ (moduleRequire('../lib/index.js'));
 
 cli
   .command('migrate [siteDir] [newDir]')

packages/docusaurus-module-type-aliases/src/index.d.ts

@@ -323,16 +323,27 @@ declare module '@docusaurus/renderRoutes' {
 declare module '@docusaurus/useGlobalData' {
   import type {GlobalData, UseDataOptions} from '@docusaurus/types';
 
+  export function useAllPluginInstancesData(
+    pluginName: string,
+    options: {failfast: true},
+  ): GlobalData[string];
+
   export function useAllPluginInstancesData(
     pluginName: string,
     options?: UseDataOptions,
   ): GlobalData[string] | undefined;
 
+  export function usePluginData(
+    pluginName: string,
+    pluginId: string | undefined,
+    options: {failfast: true},
+  ): NonNullable<GlobalData[string][string]>;
+
   export function usePluginData(
     pluginName: string,
     pluginId?: string,
     options?: UseDataOptions,
-  ): GlobalData[string][string] | undefined;
+  ): GlobalData[string][string];
 
   export default function useGlobalData(): GlobalData;
 }

packages/docusaurus-plugin-content-blog/src/__tests__/feed.test.ts

@@ -133,7 +133,9 @@ describe.each(['atom', 'rss', 'json'])('%s', (feedType) => {
       } as PluginOptions,
     );
 
-    expect(fsMock.mock.calls.map((call) => call[1])).toMatchSnapshot();
+    expect(
+      fsMock.mock.calls.map((call) => call[1] as string),
+    ).toMatchSnapshot();
     fsMock.mockClear();
   });
 });

packages/docusaurus-plugin-content-docs/src/cli.ts

@@ -14,6 +14,7 @@ import {
   getVersionDocsDirPath,
   getVersionSidebarsPath,
   getDocsDirPathLocalized,
+  readVersionsFile,
 } from './versions/files';
 import {validateVersionName} from './versions/validation';
 import {loadSidebarsFileUnsafe} from './sidebars';
@@ -69,12 +70,7 @@ export async function cliDocsVersionCommand(
     throw err;
   }
 
-  // Load existing versions.
+  const versions = (await readVersionsFile(siteDir, pluginId)) ?? [];
-  let versions: string[] = [];
-  const versionsJSONFile = getVersionsFilePath(siteDir, pluginId);
-  if (await fs.pathExists(versionsJSONFile)) {
-    versions = await fs.readJSON(versionsJSONFile);
-  }
 
   // Check if version already exists.
   if (versions.includes(version)) {
@@ -137,7 +133,7 @@ export async function cliDocsVersionCommand(
   // Update versions.json file.
   versions.unshift(version);
   await fs.outputFile(
-    versionsJSONFile,
+    getVersionsFilePath(siteDir, pluginId),
     `${JSON.stringify(versions, null, 2)}\n`,
   );
 

packages/docusaurus-plugin-content-docs/src/versions/files.ts

@@ -89,7 +89,7 @@ export function getVersionsFilePath(siteDir: string, pluginId: string): string {
  * @throws Throws if validation fails, i.e. `versions.json` doesn't contain an
  * array of valid version names.
  */
-async function readVersionsFile(
+export async function readVersionsFile(
   siteDir: string,
   pluginId: string,
 ): Promise<string[] | null> {

packages/docusaurus-theme-classic/src/index.ts

@@ -19,8 +19,9 @@ import type webpack from 'webpack';
 const requireFromDocusaurusCore = createRequire(
   require.resolve('@docusaurus/core/package.json'),
 );
-const ContextReplacementPlugin: typeof webpack.ContextReplacementPlugin =
+const ContextReplacementPlugin = requireFromDocusaurusCore(
-  requireFromDocusaurusCore('webpack/lib/ContextReplacementPlugin');
+  'webpack/lib/ContextReplacementPlugin',
+) as typeof webpack.ContextReplacementPlugin;
 
 // Need to be inlined to prevent dark mode FOUC
 // Make sure the key is the same as the one in `/theme/hooks/useTheme.js`

packages/docusaurus-theme-classic/src/theme-classic.d.ts

@@ -816,7 +816,6 @@ declare module '@theme/NavbarItem/NavbarNavLink' {
 
 declare module '@theme/NavbarItem/DropdownNavbarItem' {
   import type {Props as NavbarNavLinkProps} from '@theme/NavbarItem/NavbarNavLink';
-
   import type {LinkLikeNavbarItemProps} from '@theme/NavbarItem';
 
   export type DesktopOrMobileNavBarItemProps = NavbarNavLinkProps & {
@@ -976,7 +975,7 @@ declare module '@theme/NavbarItem' {
         } & SearchNavbarItemProps)
     );
 
-  export type Types = Props['type'];
+  export type NavbarItemType = Props['type'];
 
   export default function NavbarItem(props: Props): JSX.Element;
 }

packages/docusaurus-theme-classic/src/theme/MDXComponents/Details.tsx

@@ -10,11 +10,13 @@ import Details from '@theme/Details';
 import type {Props} from '@theme/MDXComponents/Details';
 
 export default function MDXDetails(props: Props): JSX.Element {
-  const items = React.Children.toArray(props.children) as ReactElement[];
+  const items = React.Children.toArray(props.children);
   // Split summary item from the rest to pass it as a separate prop to the
   // Details theme component
-  const summary: ReactElement<ComponentProps<'summary'>> | undefined =
+  const summary = items.find(
-    items.find((item) => item?.props?.mdxType === 'summary');
+    (item): item is ReactElement<ComponentProps<'summary'>> =>
+      React.isValidElement(item) && item.props?.mdxType === 'summary',
+  );
   const children = <>{items.filter((item) => item !== summary)}</>;
 
   return (

packages/docusaurus-theme-classic/src/theme/MDXComponents/Head.tsx

@@ -11,8 +11,10 @@ import type {Props} from '@theme/MDXComponents/Head';
 
 // MDX elements are wrapped through the MDX pragma. In some cases (notably usage
 // with Head/Helmet) we need to unwrap those elements.
-function unwrapMDXElement(element: ReactElement) {
+function unwrapMDXElement(
-  if (element?.props?.mdxType && element?.props?.originalType) {
+  element: ReactElement<{mdxType?: string; originalType?: string} | undefined>,
+) {
+  if (element.props?.mdxType && element.props.originalType) {
     const {mdxType, originalType, ...newProps} = element.props;
     return React.createElement(element.props.originalType, newProps);
   }
@@ -21,7 +23,7 @@ function unwrapMDXElement(element: ReactElement) {
 
 export default function MDXHead(props: Props): JSX.Element {
   const unwrappedChildren = React.Children.map(props.children, (child) =>
-    unwrapMDXElement(child as ReactElement),
+    React.isValidElement(child) ? unwrapMDXElement(child) : child,
   );
   return (
     <Head {...(props as ComponentProps<typeof Head>)}>{unwrappedChildren}</Head>

packages/docusaurus-theme-classic/src/theme/MDXComponents/Pre.tsx

@@ -14,8 +14,8 @@ export default function MDXPre(props: Props): JSX.Element {
     <CodeBlock
       // If this pre is created by a ``` fenced codeblock, unwrap the children
       {...(isValidElement(props.children) &&
-      props.children.props.originalType === 'code'
+      props.children.props?.originalType === 'code'
-        ? props.children?.props
+        ? props.children.props
         : {...props})}
     />
   );

packages/docusaurus-theme-classic/src/theme/Navbar/Content/index.tsx

@@ -11,13 +11,12 @@ import {
   useNavbarMobileSidebar,
   useThemeConfig,
 } from '@docusaurus/theme-common';
-import NavbarItem from '@theme/NavbarItem';
+import NavbarItem, {type Props as NavbarItemConfig} from '@theme/NavbarItem';
 import NavbarColorModeToggle from '@theme/Navbar/ColorModeToggle';
 import SearchBar from '@theme/SearchBar';
 import NavbarMobileSidebarToggle from '@theme/Navbar/MobileSidebar/Toggle';
 import NavbarLogo from '@theme/Navbar/Logo';
 import NavbarSearch from '@theme/Navbar/Search';
-import type {Props as NavbarItemConfig} from '@theme/NavbarItem';
 
 import styles from './styles.module.css';
 

packages/docusaurus-theme-classic/src/theme/Navbar/MobileSidebar/PrimaryMenu/index.tsx

@@ -7,8 +7,7 @@
 
 import React from 'react';
 import {useNavbarMobileSidebar, useThemeConfig} from '@docusaurus/theme-common';
-import NavbarItem from '@theme/NavbarItem';
+import NavbarItem, {type Props as NavbarItemConfig} from '@theme/NavbarItem';
-import type {Props as NavbarItemConfig} from '@theme/NavbarItem';
 
 function useNavbarItems() {
   // TODO temporary casting until ThemeConfig type is improved

packages/docusaurus-theme-classic/src/theme/NavbarItem/DocsVersionDropdownNavbarItem.tsx

@@ -38,13 +38,13 @@ export default function DocsVersionDropdownNavbarItem({
     // We try to link to the same doc, in another version
     // When not possible, fallback to the "main doc" of the version
     const versionDoc =
-      activeDocContext?.alternateDocVersions[version.name] ??
+      activeDocContext.alternateDocVersions[version.name] ??
       getVersionMainDoc(version);
     return {
       isNavLink: true,
       label: version.label,
       to: versionDoc.path,
-      isActive: () => version === activeDocContext?.activeVersion,
+      isActive: () => version === activeDocContext.activeVersion,
       onClick: () => savePreferredVersionName(version.name),
     };
   });

packages/docusaurus-theme-classic/src/theme/NavbarItem/DropdownNavbarItem.tsx

@@ -15,12 +15,11 @@ import {
   useLocalPathname,
 } from '@docusaurus/theme-common';
 import NavbarNavLink from '@theme/NavbarItem/NavbarNavLink';
-import NavbarItem from '@theme/NavbarItem';
+import NavbarItem, {type LinkLikeNavbarItemProps} from '@theme/NavbarItem';
 import type {
   DesktopOrMobileNavBarItemProps,
   Props,
 } from '@theme/NavbarItem/DropdownNavbarItem';
-import type {LinkLikeNavbarItemProps} from '@theme/NavbarItem';
 
 const dropdownLinkActiveClass = 'dropdown__link--active';
 

packages/docusaurus-theme-classic/src/theme/NavbarItem/index.tsx

@@ -7,31 +7,22 @@
 
 import React from 'react';
 import ComponentTypes from '@theme/NavbarItem/ComponentTypes';
-import {type Props as DropdownNavbarItemProps} from '@theme/NavbarItem/DropdownNavbarItem';
+import type {NavbarItemType, Props} from '@theme/NavbarItem';
-import type {Types, Props} from '@theme/NavbarItem';
 
-const getNavbarItemComponent = (type: NonNullable<Types>) => {
+function normalizeComponentType(type: NavbarItemType, props: object) {
-  const component = ComponentTypes[type];
-  if (!component) {
-    throw new Error(`No NavbarItem component found for type "${type}".`);
-  }
-  return component;
-};
-
-function getComponentType(type: Types, isDropdown: boolean) {
   // Backward compatibility: navbar item with no type set
   // but containing dropdown items should use the type "dropdown"
   if (!type || type === 'default') {
-    return isDropdown ? 'dropdown' : 'default';
+    return 'items' in props ? 'dropdown' : 'default';
   }
-  return type as NonNullable<Types>;
+  return type;
 }
 
 export default function NavbarItem({type, ...props}: Props): JSX.Element {
-  const componentType = getComponentType(
+  const componentType = normalizeComponentType(type, props);
-    type,
+  const NavbarItemComponent = ComponentTypes[componentType];
-    (props as DropdownNavbarItemProps).items !== undefined,
+  if (!NavbarItemComponent) {
-  );
+    throw new Error(`No NavbarItem component found for type "${type}".`);
-  const NavbarItemComponent = getNavbarItemComponent(componentType);
+  }
   return <NavbarItemComponent {...(props as never)} />;
 }

packages/docusaurus-theme-classic/src/theme/Tabs/index.tsx

@@ -75,7 +75,7 @@ function TabsComponent(props: Props): JSX.Element {
       ? defaultValueProp
       : defaultValueProp ??
         children.find((child) => child.props.default)?.props.value ??
-        children[0]?.props.value;
+        children[0]!.props.value;
   if (defaultValue !== null && !values.some((a) => a.value === defaultValue)) {
     throw new Error(
       `Docusaurus error: The <Tabs> has a defaultValue "${defaultValue}" but none of its children has the corresponding value. Available values are: ${values
@@ -126,12 +126,12 @@ function TabsComponent(props: Props): JSX.Element {
     switch (event.key) {
       case 'ArrowRight': {
         const nextTab = tabRefs.indexOf(event.currentTarget) + 1;
-        focusElement = tabRefs[nextTab] || tabRefs[0]!;
+        focusElement = tabRefs[nextTab] ?? tabRefs[0]!;
         break;
       }
       case 'ArrowLeft': {
         const prevTab = tabRefs.indexOf(event.currentTarget) - 1;
-        focusElement = tabRefs[prevTab] || tabRefs[tabRefs.length - 1]!;
+        focusElement = tabRefs[prevTab] ?? tabRefs[tabRefs.length - 1]!;
         break;
       }
       default:

packages/docusaurus-theme-common/src/components/Details/index.tsx

@@ -92,7 +92,7 @@ export function Details({
         }
       }}>
       {/* eslint-disable-next-line @docusaurus/no-untranslated-text */}
-      {summary || <summary>Details</summary>}
+      {summary ?? <summary>Details</summary>}
 
       <Collapsible
         lazy={false} // Content might matter for SEO in this case

packages/docusaurus-theme-common/src/hooks/useTOCHighlight.ts

@@ -151,7 +151,7 @@ export function useTOCHighlight(config: TOCHighlightConfig | undefined): void {
     function updateLinkActiveClass(link: HTMLAnchorElement, active: boolean) {
       if (active) {
         if (lastActiveLinkRef.current && lastActiveLinkRef.current !== link) {
-          lastActiveLinkRef.current?.classList.remove(linkActiveClassName);
+          lastActiveLinkRef.current.classList.remove(linkActiveClassName);
         }
         link.classList.add(linkActiveClassName);
         lastActiveLinkRef.current = link;

packages/docusaurus-theme-common/src/utils/codeBlockUtils.ts

@@ -97,7 +97,7 @@ export function parseCodeBlockTitle(metastring?: string): string {
 }
 
 export function containsLineNumbers(metastring?: string): boolean {
-  return metastring?.includes('showLineNumbers') || false;
+  return Boolean(metastring?.includes('showLineNumbers'));
 }
 
 /**
@@ -209,7 +209,9 @@ export function parseLines(
       lineNumber += 1;
       continue;
     }
-    const directive = match.slice(1).find((item) => item !== undefined)!;
+    const directive = match
+      .slice(1)
+      .find((item: string | undefined) => item !== undefined)!;
     if (lineToClassName[directive]) {
       blocks[lineToClassName[directive]!]!.range += `${lineNumber},`;
     } else if (blockStartToClassName[directive]) {

packages/docusaurus-theme-common/src/utils/useThemeConfig.ts

@@ -85,10 +85,10 @@ export type FooterBase = {
 };
 
 export type MultiColumnFooter = FooterBase & {
-  links: Array<{
+  links: {
     title: string | null;
     items: FooterLinkItem[];
-  }>;
+  }[];
 };
 
 export type SimpleFooter = FooterBase & {
@@ -123,7 +123,7 @@ export type ThemeConfig = {
   prism: PrismConfig;
   footer?: Footer;
   image?: string;
-  metadata: Array<{[key: string]: string}>;
+  metadata: {[key: string]: string}[];
   tableOfContents: TableOfContents;
 };
 

packages/docusaurus-theme-live-codeblock/src/theme/Playground/index.tsx

@@ -98,7 +98,7 @@ export default function Playground({
       {/* @ts-expect-error: type incompatibility with refs */}
       <LiveProvider
         code={children.replace(/\n$/, '')}
-        transformCode={transformCode || ((code) => `${code};`)}
+        transformCode={transformCode ?? ((code) => `${code};`)}
         theme={prismTheme}
         {...props}>
         {playgroundPosition === 'top' ? (

packages/docusaurus-theme-search-algolia/src/theme/SearchBar/index.tsx

@@ -75,7 +75,7 @@ type FacetFilters = Required<
 function mergeFacetFilters(f1: FacetFilters, f2: FacetFilters): FacetFilters {
   const normalize = (
     f: FacetFilters,
-  ): readonly string[] | ReadonlyArray<string | readonly string[]> =>
+  ): readonly string[] | readonly (string | readonly string[])[] =>
     typeof f === 'string' ? [f] : f;
   return [...normalize(f1), ...normalize(f2)] as FacetFilters;
 }

packages/docusaurus-theme-translations/locales/__tests__/locales.test.ts

@@ -22,8 +22,10 @@ describe('theme translations', () => {
       .then((files) =>
         Promise.all(
           files.map(
-            (baseMessagesFile): Promise<{[key: string]: string}> =>
+            (baseMessagesFile) =>
-              fs.readJSON(path.join(baseMessagesDirPath, baseMessagesFile)),
+              fs.readJSON(
+                path.join(baseMessagesDirPath, baseMessagesFile),
+              ) as Promise<{[key: string]: string}>,
           ),
         ),
       )

packages/docusaurus-theme-translations/src/index.ts

@@ -51,7 +51,7 @@ export async function readDefaultCodeTranslationMessages({
     const filePath = path.resolve(dirPath, localeToTry, `${name}.json`);
 
     if (await fs.pathExists(filePath)) {
-      return fs.readJSON(filePath);
+      return fs.readJSON(filePath) as Promise<CodeTranslations>;
     }
   }
 

packages/docusaurus-utils/src/__tests__/pathUtils.test.ts

@@ -37,21 +37,24 @@ describe('isNameTooLong', () => {
     };
     const oldProcessPlatform = process.platform;
     Object.defineProperty(process, 'platform', {value: 'darwin'});
-    Object.keys(asserts).forEach((file) => {
+    (Object.keys(asserts) as (keyof typeof asserts)[]).forEach((file) => {
+      const expected = asserts[file];
       expect(isNameTooLong(file)).toBe(
-        typeof asserts[file] === 'boolean' ? asserts[file] : asserts[file].apfs,
+        typeof expected === 'boolean' ? expected : expected.apfs,
       );
     });
     Object.defineProperty(process, 'platform', {value: 'win32'});
-    Object.keys(asserts).forEach((file) => {
+    (Object.keys(asserts) as (keyof typeof asserts)[]).forEach((file) => {
+      const expected = asserts[file];
       expect(isNameTooLong(file)).toBe(
-        typeof asserts[file] === 'boolean' ? asserts[file] : asserts[file].apfs,
+        typeof expected === 'boolean' ? expected : expected.apfs,
       );
     });
     Object.defineProperty(process, 'platform', {value: 'android'});
-    Object.keys(asserts).forEach((file) => {
+    (Object.keys(asserts) as (keyof typeof asserts)[]).forEach((file) => {
+      const expected = asserts[file];
       expect(isNameTooLong(file)).toBe(
-        typeof asserts[file] === 'boolean' ? asserts[file] : asserts[file].xfs,
+        typeof expected === 'boolean' ? expected : expected.xfs,
       );
     });
     Object.defineProperty(process, 'platform', {value: oldProcessPlatform});
@@ -79,21 +82,24 @@ describe('shortName', () => {
     };
     const oldProcessPlatform = process.platform;
     Object.defineProperty(process, 'platform', {value: 'darwin'});
-    Object.keys(asserts).forEach((file) => {
+    (Object.keys(asserts) as (keyof typeof asserts)[]).forEach((file) => {
+      const expected = asserts[file];
       expect(shortName(file)).toBe(
-        typeof asserts[file] === 'string' ? asserts[file] : asserts[file].apfs,
+        typeof expected === 'string' ? expected : expected.apfs,
       );
     });
     Object.defineProperty(process, 'platform', {value: 'win32'});
-    Object.keys(asserts).forEach((file) => {
+    (Object.keys(asserts) as (keyof typeof asserts)[]).forEach((file) => {
+      const expected = asserts[file];
       expect(shortName(file)).toBe(
-        typeof asserts[file] === 'string' ? asserts[file] : asserts[file].apfs,
+        typeof expected === 'string' ? expected : expected.apfs,
       );
     });
     Object.defineProperty(process, 'platform', {value: 'android'});
-    Object.keys(asserts).forEach((file) => {
+    (Object.keys(asserts) as (keyof typeof asserts)[]).forEach((file) => {
+      const expected = asserts[file];
       expect(shortName(file)).toBe(
-        typeof asserts[file] === 'string' ? asserts[file] : asserts[file].xfs,
+        typeof expected === 'string' ? expected : expected.xfs,
       );
     });
     Object.defineProperty(process, 'platform', {value: oldProcessPlatform});

packages/docusaurus/bin/beforeCli.mjs

@@ -16,7 +16,9 @@ import updateNotifier from 'update-notifier';
 import boxen from 'boxen';
 import {DOCUSAURUS_VERSION} from '@docusaurus/utils';
 
-const packageJson = createRequire(import.meta.url)('../package.json');
+const packageJson = /** @type {import("../package.json")} */ (
+  createRequire(import.meta.url)('../package.json')
+);
 /** @type {Record<string, any>} */
 let sitePkg;
 try {

packages/docusaurus/src/client/ClientLifecyclesDispatcher.tsx

@@ -15,7 +15,7 @@ export function dispatchLifecycleAction<K extends keyof ClientModule>(
   ...args: Parameters<NonNullable<ClientModule[K]>>
 ): () => void {
   const callbacks = clientModules.map((clientModule) => {
-    const lifecycleFunction = (clientModule?.default?.[lifecycleAction] ??
+    const lifecycleFunction = (clientModule.default?.[lifecycleAction] ??
       clientModule[lifecycleAction]) as
       | ((
           ...a: Parameters<NonNullable<ClientModule[K]>>

packages/docusaurus/src/client/__tests__/flat.test.ts

@@ -41,7 +41,7 @@ describe('flat', () => {
       null: null,
       undefined,
     };
-    Object.keys(primitives).forEach((key) => {
+    (Object.keys(primitives) as (keyof typeof primitives)[]).forEach((key) => {
       const value = primitives[key];
       expect(
         flat({

packages/docusaurus/src/client/docusaurus.ts

@@ -70,7 +70,7 @@ const docusaurus = {
         // In some cases, webpack might decide to optimize further, leading to
         // the chunk assets being merged to another chunk. In this case, we can
         // safely filter it out and don't need to load it.
-        if (chunkAsset && !/undefined/.test(chunkAsset)) {
+        if (chunkAsset && !chunkAsset.includes('undefined')) {
           return prefetchHelper(chunkAsset);
         }
         return Promise.resolve();

packages/docusaurus/src/client/exports/Link.tsx

@@ -47,10 +47,7 @@ function Link(
   const linksCollector = useLinksCollector();
   const innerRef = useRef<HTMLAnchorElement | null>(null);
 
-  useImperativeHandle(
+  useImperativeHandle(forwardedRef, () => innerRef.current!);
-    forwardedRef,
-    () => innerRef.current as HTMLAnchorElement,
-  );
 
   // IMPORTANT: using to or href should not change anything
   // For example, MDX links will ALWAYS give us the href props

packages/docusaurus/src/client/exports/__tests__/useGlobalData.test.tsx

@@ -26,19 +26,6 @@ describe('useGlobalData', () => {
       }).result.current,
     ).toEqual({foo: 'bar'});
   });
-
-  it('throws when global data not found', () => {
-    // Can it actually happen?
-    expect(
-      () =>
-        renderHook(() => useGlobalData(), {
-          wrapper: ({children}) => (
-            // eslint-disable-next-line react/jsx-no-constructed-context-values
-            <Context.Provider value={{}}>{children}</Context.Provider>
-          ),
-        }).result.current,
-    ).toThrowErrorMatchingInlineSnapshot(`"Docusaurus global data not found."`);
-  });
 });
 
 describe('useAllPluginInstancesData', () => {

packages/docusaurus/src/client/exports/isInternalUrl.ts

@@ -6,7 +6,7 @@
  */
 
 export function hasProtocol(url: string): boolean {
-  return /^(?:\w*:|\/\/)/.test(url) === true;
+  return /^(?:\w*:|\/\/)/.test(url);
 }
 
 export default function isInternalUrl(url?: string): boolean {

packages/docusaurus/src/client/exports/useGlobalData.ts

@@ -11,9 +11,6 @@ import type {GlobalData, UseDataOptions} from '@docusaurus/types';
 
 export default function useGlobalData(): GlobalData {
   const {globalData} = useDocusaurusContext();
-  if (!globalData) {
-    throw new Error('Docusaurus global data not found.');
-  }
   return globalData;
 }
 

packages/docusaurus/src/client/flat.ts

@@ -10,7 +10,7 @@ import type {ChunkNames} from '@docusaurus/types';
 type Chunk = ChunkNames[string];
 type Tree = Exclude<Chunk, string>;
 
-const isTree = (x: Chunk): x is Tree =>
+const isTree = (x: unknown): x is Tree =>
   typeof x === 'object' && !!x && Object.keys(x).length > 0;
 
 /**

packages/docusaurus/src/client/prefetch.ts

@@ -8,8 +8,8 @@
 function supports(feature: string) {
   try {
     const fakeLink = document.createElement('link');
-    return fakeLink.relList?.supports?.(feature);
+    return fakeLink.relList.supports(feature);
-  } catch (err) {
+  } catch {
     return false;
   }
 }

packages/docusaurus/src/client/serverEntry.tsx

@@ -115,9 +115,9 @@ async function doRender(locals: Locals & {path: string}) {
   // Using readJSON seems to fail for users of some plugins, possibly because of
   // the eval sandbox having a different `Buffer` instance (native one instead
   // of polyfilled one)
-  const manifest: Manifest = await fs
+  const manifest = (await fs
     .readFile(manifestPath, 'utf-8')
-    .then(JSON.parse);
+    .then(JSON.parse)) as Manifest;
 
   // Get all required assets for this particular page based on client
   // manifest information.

packages/docusaurus/src/server/__tests__/__snapshots__/configValidation.test.ts.snap

@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`normalizeConfig should throw error if plugins is not a string and it's not an array #1 for the input of: [123] 1`] = `
-" => Bad Docusaurus plugin value as path [plugins,0].
+" => Bad Docusaurus plugin value plugins[0].
 Example valid plugin config:
 {
   plugins: [
@@ -17,7 +17,7 @@ Example valid plugin config:
 `;
 
 exports[`normalizeConfig should throw error if plugins is not an array of [string, object][] #1 for the input of: [[Array]] 1`] = `
-" => Bad Docusaurus plugin value as path [plugins,0].
+" => Bad Docusaurus plugin value plugins[0].
 Example valid plugin config:
 {
   plugins: [
@@ -33,7 +33,7 @@ Example valid plugin config:
 `;
 
 exports[`normalizeConfig should throw error if plugins is not an array of [string, object][] #2 for the input of: [[Array]] 1`] = `
-" => Bad Docusaurus plugin value as path [plugins,0].
+" => Bad Docusaurus plugin value plugins[0].
 Example valid plugin config:
 {
   plugins: [
@@ -49,7 +49,7 @@ Example valid plugin config:
 `;
 
 exports[`normalizeConfig should throw error if plugins is not an array of [string, object][] #3 for the input of: [[Array]] 1`] = `
-" => Bad Docusaurus plugin value as path [plugins,0].
+" => Bad Docusaurus plugin value plugins[0].
 Example valid plugin config:
 {
   plugins: [
@@ -70,7 +70,7 @@ exports[`normalizeConfig should throw error if plugins is not array for the inpu
 `;
 
 exports[`normalizeConfig should throw error if themes is not a string and it's not an array #1 for the input of: [123] 1`] = `
-" => Bad Docusaurus theme value as path [themes,0].
+" => Bad Docusaurus theme value themes[0].
 Example valid theme config:
 {
   themes: [
@@ -86,7 +86,7 @@ Example valid theme config:
 `;
 
 exports[`normalizeConfig should throw error if themes is not an array of [string, object][] #1 for the input of: [[Array]] 1`] = `
-" => Bad Docusaurus theme value as path [themes,0].
+" => Bad Docusaurus theme value themes[0].
 Example valid theme config:
 {
   themes: [
@@ -102,7 +102,7 @@ Example valid theme config:
 `;
 
 exports[`normalizeConfig should throw error if themes is not an array of [string, object][] #2 for the input of: [[Array]] 1`] = `
-" => Bad Docusaurus theme value as path [themes,0].
+" => Bad Docusaurus theme value themes[0].
 Example valid theme config:
 {
   themes: [
@@ -118,7 +118,7 @@ Example valid theme config:
 `;
 
 exports[`normalizeConfig should throw error if themes is not an array of [string, object][] #3 for the input of: [[Array]] 1`] = `
-" => Bad Docusaurus theme value as path [themes,0].
+" => Bad Docusaurus theme value themes[0].
 Example valid theme config:
 {
   themes: [

packages/docusaurus/src/server/configValidation.ts

@@ -100,7 +100,9 @@ function createPluginSchema(theme: boolean) {
 
           error.message = ` => Bad Docusaurus ${
             theme ? 'theme' : 'plugin'
-          } value as path [${error.path}].
+          } value ${error.path.reduce((acc, cur) =>
+            typeof cur === 'string' ? `${acc}.${cur}` : `${acc}[${cur}]`,
+          )}.
 ${validConfigExample}
 `;
         });
@@ -247,7 +249,9 @@ export function validateConfig(config: unknown): DocusaurusConfig {
   if (error) {
     const unknownFields = error.details.reduce((formattedError, err) => {
       if (err.type === 'object.unknown') {
-        return `${formattedError}"${err.path}",`;
+        return `${formattedError}"${err.path.reduce((acc, cur) =>
+          typeof cur === 'string' ? `${acc}.${cur}` : `${acc}[${cur}]`,
+        )}",`;
       }
       return formattedError;
     }, '');

packages/docusaurus/src/server/htmlTags.ts

@@ -83,5 +83,5 @@ export function loadHtmlTags(
           .trim(),
       ),
     ),
-  );
+  ) as Pick<Props, 'headTags' | 'preBodyTags' | 'postBodyTags'>;
 }

packages/docusaurus/src/server/plugins/__tests__/__snapshots__/init.test.ts.snap

@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`initPlugins throws user-friendly error message for plugins with bad values 1`] = `
-" => Bad Docusaurus plugin value as path [plugins,0].
+" => Bad Docusaurus plugin value plugins[0].
 Example valid plugin config:
 {
   plugins: [
@@ -13,7 +13,7 @@ Example valid plugin config:
   ],
 };
 
- => Bad Docusaurus plugin value as path [plugins,1].
+ => Bad Docusaurus plugin value plugins[1].
 Example valid plugin config:
 {
   plugins: [

packages/docusaurus/src/server/plugins/__tests__/init.test.ts

@@ -21,7 +21,7 @@ describe('initPlugins', () => {
 
   it('parses plugins correctly and loads them in correct order', async () => {
     const {context, plugins} = await loadSite();
-    expect(context.siteConfig.plugins?.length).toBe(4);
+    expect(context.siteConfig.plugins).toHaveLength(4);
     expect(plugins).toHaveLength(8);
 
     expect(plugins[0].name).toBe('preset-plugin1');

packages/docusaurus/src/server/translations/translationsExtractor.ts

@@ -184,7 +184,7 @@ function extractSourceCodeAstTranslations(
   sourceCodeFilePath: string,
 ): SourceCodeFileTranslations {
   function sourceWarningPart(node: Node) {
-    return `File: ${sourceCodeFilePath} at line ${node.loc?.start.line}
+    return `File: ${sourceCodeFilePath} at line ${node.loc?.start.line ?? '?'}
 Full code: ${generate(node).code}`;
   }
 
@@ -313,7 +313,9 @@ ${sourceWarningPart(path.node)}`);
         if (isJSXText || isJSXExpressionContainer) {
           message = isJSXText
             ? singleChildren.node.value.trim().replace(/\s+/g, ' ')
-            : (singleChildren.get('expression') as NodePath).evaluate().value;
+            : String(
+                (singleChildren.get('expression') as NodePath).evaluate().value,
+              );
 
           translations[id ?? message] = {
             message,

packages/docusaurus/src/webpack/utils.ts

@@ -198,7 +198,7 @@ export function applyConfigurePostCss(
   configurePostCss: NonNullable<Plugin['configurePostCss']>,
   config: Configuration,
 ): Configuration {
-  type LocalPostCSSLoader = unknown & {
+  type LocalPostCSSLoader = object & {
     options: {postcssOptions: PostCssOptions};
   };
 

packages/lqip-loader/src/index.ts

@@ -6,7 +6,7 @@
  */
 
 import * as lqip from './lqip';
-import type {LoaderContext} from 'webpack';
+import type {LoaderContext, LoaderModule} from 'webpack';
 
 type Options = {
   base64: boolean;
@@ -36,8 +36,9 @@ export default async function lqipLoader(
   } else {
     if (!contentIsFileExport) {
       // eslint-disable-next-line global-require, @typescript-eslint/no-var-requires
-      const fileLoader = require('file-loader') as typeof import('file-loader');
+      const fileLoader = require('file-loader') as LoaderModule['default'];
-      content = fileLoader.call(this, contentBuffer);
+      // @ts-expect-error: type is a bit unwieldy...
+      content = fileLoader!.call(this, contentBuffer) as string;
     }
     source = content.match(
       /^(?:export default|module.exports =) (?<source>.*);/,

packages/stylelint-copyright/src/__tests__/index.test.ts

@@ -43,9 +43,8 @@ function getOutputCss(output: stylelint.LinterResult) {
 function testStylelintRule(config: stylelint.Config, tests: TestSuite) {
   describe(`${tests.ruleName}`, () => {
     const checkTestCaseContent = (testCase: TestCase) =>
-      testCase.description || testCase.code;
+      testCase.description ?? testCase.code;
 
-    if (tests.accept?.length) {
     describe('accept cases', () => {
       tests.accept.forEach((testCase) => {
         it(`${checkTestCaseContent(testCase)}`, async () => {
@@ -65,9 +64,7 @@ function testStylelintRule(config: stylelint.Config, tests: TestSuite) {
         });
       });
     });
-    }
 
-    if (tests.reject?.length) {
     describe('reject cases', () => {
       tests.reject.forEach((testCase) => {
         it(`${checkTestCaseContent(testCase)}`, async () => {
@@ -104,7 +101,6 @@ function testStylelintRule(config: stylelint.Config, tests: TestSuite) {
         });
       });
     });
-    }
 
     expect.extend({
       toHaveMessage(testCase: TestCase) {

tsconfig.json

@@ -51,6 +51,7 @@
     "allowJs": true,
     "skipLibCheck": true // @types/webpack and webpack/types.d.ts are not the same thing
   },
+  "include": ["./**/*", "./**/.eslintrc.js"],
   "exclude": [
     "node_modules",
     "coverage/**",

website/src/pages/versions.tsx

@@ -45,7 +45,7 @@ export default function Version(): JSX.Element {
   const pastVersions = versions.filter(
     (version) => version !== latestVersion && version.name !== 'current',
   );
-  const repoUrl = `https://github.com/${organizationName}/${projectName}`;
+  const repoUrl = `https://github.com/${organizationName!}/${projectName!}`;
 
   return (
     <Layout