refactor: fix a lot of errors in type-aware linting (#7477)

__tests__/validate-package-json.test.ts

@@ -70,7 +70,6 @@ describe('packages', () => {
         packageJsonFile.content.name?.startsWith('@'),
       )
       .forEach((packageJsonFile) => {
-        if (packageJsonFile) {
         // Unfortunately jest custom message do not exist in loops,
         // so using an exception instead to show failing package file
         // (see https://github.com/facebook/jest/issues/3293)
@@ -81,7 +80,6 @@ describe('packages', () => {
             `Package ${packageJsonFile.file} does not have publishConfig.access: 'public'`,
           );
         }
-        }
       });
   });
 });

admin/new.docusaurus.io/functions/codesandbox.ts

@@ -8,6 +8,5 @@
 import {createPlaygroundResponse} from '../functionUtils/playgroundUtils';
 import type {Handler} from '@netlify/functions';
 
-export const handler: Handler = async function handler() {
+export const handler: Handler = () =>
-  return createPlaygroundResponse('codesandbox');
+  Promise.resolve(createPlaygroundResponse('codesandbox'));
-};

admin/new.docusaurus.io/functions/stackblitz.ts

@@ -8,6 +8,5 @@
 import {createPlaygroundResponse} from '../functionUtils/playgroundUtils';
 import type {Handler} from '@netlify/functions';
 
-export const handler: Handler = async function handler() {
+export const handler: Handler = () =>
-  return createPlaygroundResponse('stackblitz');
+  Promise.resolve(createPlaygroundResponse('stackblitz'));
-};

packages/create-docusaurus/src/index.ts

@@ -65,6 +65,7 @@ async function askForPackageManagerChoice(): Promise<PackageManager> {
     .map((p) => ({title: p, value: p}));
 
   return (
+    (
       (await prompts(
         {
           type: 'select',
@@ -78,7 +79,8 @@ async function askForPackageManagerChoice(): Promise<PackageManager> {
           },
         },
       )) as {packageManager: PackageManager}
-  ).packageManager;
+    ).packageManager ?? defaultPackageManager
+  );
 }
 
 async function getPackageManager(
@@ -101,8 +103,7 @@ async function getPackageManager(
     (await findPackageManagerFromLockFile('.')) ??
     findPackageManagerFromUserAgent() ??
     // This only happens if the user has a global installation in PATH
-    (skipInstall ? defaultPackageManager : askForPackageManagerChoice()) ??
+    (skipInstall ? defaultPackageManager : askForPackageManagerChoice())
-    defaultPackageManager
   );
 }
 
@@ -215,7 +216,7 @@ async function getGitCommand(gitStrategy: GitStrategy): Promise<string> {
             logger.info`Falling back to code=${'git clone'}`;
           },
         },
-      )) as {command: string};
+      )) as {command?: string};
       return command ?? 'git clone';
     }
     case 'deep':
@@ -362,7 +363,7 @@ async function getSource(
     )) as {gitRepoUrl: string};
     let strategy = cliOptions.gitStrategy;
     if (!strategy) {
-      ({strategy} = await prompts(
+      ({strategy} = (await prompts(
         {
           type: 'select',
           name: 'strategy',
@@ -385,7 +386,7 @@ async function getSource(
             logger.info`Falling back to name=${'deep'}`;
           },
         },
-      ));
+      )) as {strategy?: GitStrategy});
     }
     return {
       type: 'git',
@@ -426,13 +427,13 @@ async function getSource(
   }
   let useTS = cliOptions.typescript;
   if (!useTS && template.tsVariantPath) {
-    ({useTS} = await prompts({
+    ({useTS} = (await prompts({
       type: 'confirm',
       name: 'useTS',
       message:
         'This template is available in TypeScript. Do you want to use the TS variant?',
       initial: false,
-    }));
+    })) as {useTS?: boolean});
   }
   return {
     type: 'template',

packages/docusaurus-logger/src/index.ts

@@ -9,10 +9,10 @@ import chalk from 'chalk';
 
 type InterpolatableValue = string | number | (string | number)[];
 
-const path = (msg: unknown): string => chalk.cyan.underline(`"${msg}"`);
+const path = (msg: unknown): string => chalk.cyan.underline(`"${String(msg)}"`);
 const url = (msg: unknown): string => chalk.cyan.underline(msg);
 const name = (msg: unknown): string => chalk.blue.bold(msg);
-const code = (msg: unknown): string => chalk.cyan(`\`${msg}\``);
+const code = (msg: unknown): string => chalk.cyan(`\`${String(msg)}\``);
 const subdue = (msg: unknown): string => chalk.gray(msg);
 const num = (msg: unknown): string => chalk.yellow(msg);
 

packages/docusaurus-mdx-loader/src/index.ts

@@ -21,7 +21,7 @@ export type LoadedMDXContent<FrontMatter, Metadata, Assets = undefined> = {
   /** As provided by the content plugin. */
   readonly metadata: Metadata;
   /** A list of TOC items (headings). */
-  readonly toc: readonly TOCItem[];
+  readonly toc?: readonly TOCItem[];
   /** First h1 title before any content. */
   readonly contentTitle: string | undefined;
   /**

packages/docusaurus-mdx-loader/src/loader.ts

@@ -55,7 +55,7 @@ export type MDXOptions = {
   beforeDefaultRehypePlugins: MDXPlugin[];
 };
 
-export type Options = MDXOptions & {
+export type Options = Partial<MDXOptions> & {
   staticDirs: string[];
   siteDir: string;
   isMDXPartial?: (filePath: string) => boolean;
@@ -138,7 +138,7 @@ export async function mdxLoader(
 ): Promise<void> {
   const callback = this.async();
   const filePath = this.resourcePath;
-  const reqOptions = this.getOptions() ?? {};
+  const reqOptions = this.getOptions();
 
   const {frontMatter, content: contentWithTitle} = parseFrontMatter(fileString);
 

packages/docusaurus-mdx-loader/src/remark/headings/index.ts

@@ -17,7 +17,7 @@ export default function plugin(): Transformer {
   return (root) => {
     const slugs = createSlugger();
     visit(root, 'heading', (headingNode: Heading) => {
-      const data = headingNode.data || (headingNode.data = {});
+      const data = headingNode.data ?? (headingNode.data = {});
       const properties = (data.hProperties || (data.hProperties = {})) as {
         id: string;
       };
@@ -36,7 +36,7 @@ export default function plugin(): Transformer {
         // Support explicit heading IDs
         const parsedHeading = parseMarkdownHeadingId(heading);
 
-        id = parsedHeading.id || slugs.slug(heading);
+        id = parsedHeading.id ?? slugs.slug(heading);
 
         if (parsedHeading.id) {
           // When there's an id, it is always in the last child node

packages/docusaurus-mdx-loader/src/remark/transformLinks/index.ts

@@ -110,8 +110,9 @@ async function processLinkNode(node: Link, context: Context) {
   if (!node.url) {
     // Try to improve error feedback
     // see https://github.com/facebook/docusaurus/issues/3309#issuecomment-690371675
-    const title = node.title || (node.children[0] as Literal)?.value || '?';
+    const title =
-    const line = node?.position?.start?.line || '?';
+      node.title ?? (node.children[0] as Literal | undefined)?.value ?? '?';
+    const line = node.position?.start.line ?? '?';
     throw new Error(
       `Markdown link URL is mandatory in "${toMessageRelativeFilePath(
         context.filePath,

packages/docusaurus-mdx-loader/src/remark/utils/index.ts

@@ -15,7 +15,7 @@ export function stringifyContent(node: Parent): string {
 }
 
 export function toValue(node: PhrasingContent | Heading): string {
-  switch (node?.type) {
+  switch (node.type) {
     case 'text':
       return escapeHtml(node.value);
     case 'heading':

packages/docusaurus-migrate/src/__tests__/index.test.ts

@@ -19,22 +19,22 @@ async function testMigration(siteDir: string, newDir: string) {
   await migrateDocusaurusProject(siteDir, newDir, true, true);
   expect(
     writeMock.mock.calls.sort((a, b) =>
-      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+      posixPath(a[0]).localeCompare(posixPath(b[0])),
     ),
   ).toMatchSnapshot('write');
   expect(
     mkdirpMock.mock.calls.sort((a, b) =>
-      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+      posixPath(a[0]).localeCompare(posixPath(b[0])),
     ),
   ).toMatchSnapshot('mkdirp');
   expect(
     mkdirsMock.mock.calls.sort((a, b) =>
-      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+      posixPath(a[0]).localeCompare(posixPath(b[0])),
     ),
   ).toMatchSnapshot('mkdirs');
   expect(
     copyMock.mock.calls.sort((a, b) =>
-      posixPath(a[0] as string).localeCompare(posixPath(b[0] as string)),
+      posixPath(a[0]).localeCompare(posixPath(b[0])),
     ),
   ).toMatchSnapshot('copy');
   writeMock.mockRestore();

packages/docusaurus-migrate/src/frontMatter.ts

@@ -40,12 +40,7 @@ export default function extractMetadata(content: string): Data {
   lines.slice(0, -1).forEach((line) => {
     const keyValue = line.split(':') as [string, ...string[]];
     const key = keyValue[0].trim();
-    let value = keyValue.slice(1).join(':').trim();
+    const value = keyValue.slice(1).join(':').trim();
-    try {
-      value = JSON.parse(value);
-    } catch (err) {
-      // Ignore the error as it means it's not a JSON value.
-    }
     metadata[key] = value;
   });
   return {metadata, rawContent: both.content};

packages/docusaurus-migrate/src/index.ts

@@ -474,7 +474,7 @@ async function migrateVersionedDocs(
     versions.reverse().map(async (version, index) => {
       if (index === 0) {
         await fs.copy(
-          path.join(siteDir, '..', context.v1Config.customDocsPath || 'docs'),
+          path.join(siteDir, '..', context.v1Config.customDocsPath ?? 'docs'),
           path.join(newDir, 'versioned_docs', `version-${version}`),
         );
         await fs.copy(
@@ -551,7 +551,9 @@ async function migrateVersionedSidebar(
       const newSidebar = Object.entries(sidebarEntries).reduce(
         (topLevel: SidebarEntries, value) => {
           const key = value[0].replace(versionRegex, '');
-          topLevel[key] = Object.entries(value[1]).reduce((acc, val) => {
+          topLevel[key] = Object.entries(value[1]).reduce<{
+            [key: string]: Array<string | {[key: string]: unknown}>;
+          }>((acc, val) => {
             acc[val[0].replace(versionRegex, '')] = (
               val[1] as SidebarEntry[]
             ).map((item) => {
@@ -565,7 +567,7 @@ async function migrateVersionedSidebar(
               };
             });
             return acc;
-          }, {} as {[key: string]: Array<string | {[key: string]: unknown}>});
+          }, {});
           return topLevel;
         },
         {},
@@ -574,8 +576,9 @@ async function migrateVersionedSidebar(
     }
     await Promise.all(
       sidebars.map(async (sidebar) => {
-        const newSidebar = Object.entries(sidebar.entries).reduce(
+        const newSidebar = Object.entries(
-          (acc, val) => {
+          sidebar.entries,
+        ).reduce<SidebarEntries>((acc, val) => {
           const key = `version-${sidebar.version}/${val[0]}`;
           acc[key] = Object.entries(val[1]).map((value) => ({
             type: 'category',
@@ -598,9 +601,7 @@ async function migrateVersionedSidebar(
             }),
           }));
           return acc;
-          },
+        }, {});
-          {} as SidebarEntries,
-        );
         await fs.outputFile(
           path.join(
             newDir,
@@ -702,12 +703,12 @@ async function migrateLatestDocs(context: MigrationContext) {
 
 async function migratePackageFile(context: MigrationContext): Promise<void> {
   const {deps, siteDir, newDir} = context;
-  const packageFile = importFresh(`${siteDir}/package.json`) as {
+  const packageFile = importFresh<{
     scripts?: {[key: string]: string};
     dependencies?: {[key: string]: string};
     devDependencies?: {[key: string]: string};
     [otherKey: string]: unknown;
-  };
+  }>(`${siteDir}/package.json`);
   packageFile.scripts = {
     ...packageFile.scripts,
     start: 'docusaurus start',

packages/docusaurus-migrate/src/sanitizeMD.ts

@@ -37,7 +37,7 @@ export default function sanitizeMD(code: string): string {
   const htmlTree = unified().use(parse).parse(markdownString);
 
   visit(htmlTree, 'element', (node: Element) => {
-    if (!tags[node.tagName as string]) {
+    if (!tags[node.tagName]) {
       (node as Element | Text).type = 'text';
       (node as Element & Partial<Omit<Text, 'type'>>).value =
         node.tagName + toText(node);

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

@@ -8,7 +8,7 @@
 declare module '@generated/client-modules' {
   import type {ClientModule} from '@docusaurus/types';
 
-  const clientModules: readonly (ClientModule & {default: ClientModule})[];
+  const clientModules: readonly (ClientModule & {default?: ClientModule})[];
   export default clientModules;
 }
 

packages/docusaurus-plugin-client-redirects/src/__tests__/writeRedirectFiles.test.ts

@@ -17,7 +17,7 @@ import writeRedirectFiles, {
 // - https://github.com/facebook/docusaurus/issues/3886
 // - https://github.com/facebook/docusaurus/issues/3925
 describe('createToUrl', () => {
-  it('creates appropriate redirect urls', async () => {
+  it('creates appropriate redirect urls', () => {
     expect(createToUrl('/', '/docs/something/else')).toBe(
       '/docs/something/else',
     );
@@ -29,7 +29,7 @@ describe('createToUrl', () => {
     );
   });
 
-  it('creates appropriate redirect urls with baseUrl', async () => {
+  it('creates appropriate redirect urls with baseUrl', () => {
     expect(createToUrl('/baseUrl/', '/docs/something/else')).toBe(
       '/baseUrl/docs/something/else',
     );
@@ -43,7 +43,7 @@ describe('createToUrl', () => {
 });
 
 describe('toRedirectFilesMetadata', () => {
-  it('creates appropriate metadata trailingSlash=undefined', async () => {
+  it('creates appropriate metadata trailingSlash=undefined', () => {
     const pluginContext = {
       outDir: '/tmp/someFixedOutDir',
       baseUrl: 'https://docusaurus.io',
@@ -70,7 +70,7 @@ describe('toRedirectFilesMetadata', () => {
     );
   });
 
-  it('creates appropriate metadata trailingSlash=true', async () => {
+  it('creates appropriate metadata trailingSlash=true', () => {
     const pluginContext = {
       outDir: '/tmp/someFixedOutDir',
       baseUrl: 'https://docusaurus.io',
@@ -97,7 +97,7 @@ describe('toRedirectFilesMetadata', () => {
     );
   });
 
-  it('creates appropriate metadata trailingSlash=false', async () => {
+  it('creates appropriate metadata trailingSlash=false', () => {
     const pluginContext = {
       outDir: '/tmp/someFixedOutDir',
       baseUrl: 'https://docusaurus.io',
@@ -127,7 +127,7 @@ describe('toRedirectFilesMetadata', () => {
     );
   });
 
-  it('creates appropriate metadata for root baseUrl', async () => {
+  it('creates appropriate metadata for root baseUrl', () => {
     const pluginContext = {
       outDir: '/tmp/someFixedOutDir',
       baseUrl: '/',
@@ -142,7 +142,7 @@ describe('toRedirectFilesMetadata', () => {
     );
   });
 
-  it('creates appropriate metadata for empty baseUrl', async () => {
+  it('creates appropriate metadata for empty baseUrl', () => {
     const pluginContext = {
       outDir: '/tmp/someFixedOutDir',
       baseUrl: '',

packages/docusaurus-plugin-client-redirects/src/index.ts

@@ -18,7 +18,7 @@ import type {PluginOptions, Options} from './options';
 export default function pluginClientRedirectsPages(
   context: LoadContext,
   options: PluginOptions,
-): Plugin<unknown> {
+): Plugin<void> {
   const {trailingSlash} = context.siteConfig;
 
   return {

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

@@ -89,6 +89,7 @@ describe.each(['atom', 'rss', 'json'])('%s', (feedType) => {
         },
         readingTime: ({content, defaultReadingTime}) =>
           defaultReadingTime({content}),
+        truncateMarker: /<!--\s*truncate\s*-->/,
       } as PluginOptions,
     );
 
@@ -128,6 +129,7 @@ describe.each(['atom', 'rss', 'json'])('%s', (feedType) => {
         },
         readingTime: ({content, defaultReadingTime}) =>
           defaultReadingTime({content}),
+        truncateMarker: /<!--\s*truncate\s*-->/,
       } as PluginOptions,
     );
 

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

@@ -76,7 +76,7 @@ const getPlugin = async (
         editUrl: BaseEditUrl,
         ...pluginOptions,
       },
-    }) as PluginOptions,
+    }),
   );
 };
 

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

@@ -74,7 +74,7 @@ function getSampleTranslationFilesTranslated() {
 }
 
 describe('getContentTranslationFiles', () => {
-  it('returns translation files matching snapshot', async () => {
+  it('returns translation files matching snapshot', () => {
     expect(getSampleTranslationFiles()).toMatchSnapshot();
   });
 });

packages/docusaurus-plugin-content-blog/src/authors.ts

@@ -44,7 +44,11 @@ const AuthorsMapSchema = Joi.object<AuthorsMap>()
   });
 
 export function validateAuthorsMap(content: unknown): AuthorsMap {
-  return Joi.attempt(content, AuthorsMapSchema);
+  const {error, value} = AuthorsMapSchema.validate(content);
+  if (error) {
+    throw error;
+  }
+  return value;
 }
 
 export async function getAuthorsMap(params: {

packages/docusaurus-plugin-content-blog/src/blogUtils.ts

@@ -264,7 +264,7 @@ async function processBlogSourceFile(
   const title = frontMatter.title ?? contentTitle ?? parsedBlogFileName.text;
   const description = frontMatter.description ?? excerpt ?? '';
 
-  const slug = frontMatter.slug || parsedBlogFileName.slug;
+  const slug = frontMatter.slug ?? parsedBlogFileName.slug;
 
   const permalink = normalizeUrl([baseUrl, routeBasePath, slug]);
 
@@ -323,7 +323,7 @@ async function processBlogSourceFile(
             defaultReadingTime,
           })
         : undefined,
-      truncated: truncateMarker?.test(content) || false,
+      truncated: truncateMarker.test(content),
       authors,
       frontMatter,
     },

packages/docusaurus-plugin-content-blog/src/index.ts

@@ -176,10 +176,6 @@ export default async function pluginContentBlog(
     },
 
     async contentLoaded({content: blogContents, actions}) {
-      if (!blogContents) {
-        return;
-      }
-
       const {
         blogListComponent,
         blogPostComponent,
@@ -500,11 +496,7 @@ export default async function pluginContentBlog(
     },
 
     injectHtmlTags({content}) {
-      if (!content.blogPosts.length) {
+      if (!content.blogPosts.length || !options.feedOptions.type) {
-        return {};
-      }
-
-      if (!options.feedOptions?.type) {
         return {};
       }
 

packages/docusaurus-plugin-content-blog/src/markdownLoader.ts

@@ -34,5 +34,5 @@ export default function markdownLoader(
     finalContent = truncate(finalContent, markdownLoaderOptions.truncateMarker);
   }
 
-  return callback?.(null, finalContent);
+  return callback(null, finalContent);
 }

packages/docusaurus-plugin-content-blog/src/options.ts

@@ -136,9 +136,6 @@ export function validateOptions({
   validate,
   options,
 }: OptionValidationContext<Options, PluginOptions>): PluginOptions {
-  const validatedOptions = validate(
+  const validatedOptions = validate(PluginOptionSchema, options);
-    PluginOptionSchema,
-    options,
-  ) as PluginOptions;
   return validatedOptions;
 }

packages/docusaurus-plugin-content-docs/src/__tests__/__snapshots__/translations.test.ts.snap

@@ -90,13 +90,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc1 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc1 title",
+          },
           "id": "doc1",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc1 title",
           "slug": "any",
           "source": "any",
           "title": "doc1 title",
@@ -106,13 +108,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc2 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc2 title",
+          },
           "id": "doc2",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc2 title",
           "slug": "any",
           "source": "any",
           "title": "doc2 title",
@@ -122,13 +126,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc3 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc3 title",
+          },
           "id": "doc3",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc3 title",
           "slug": "any",
           "source": "any",
           "title": "doc3 title",
@@ -138,13 +144,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc4 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc4 title",
+          },
           "id": "doc4",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc4 title",
           "slug": "any",
           "source": "any",
           "title": "doc4 title",
@@ -154,13 +162,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc5 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc5 title",
+          },
           "id": "doc5",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc5 title",
           "slug": "any",
           "source": "any",
           "title": "doc5 title",
@@ -232,13 +242,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc1 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc1 title",
+          },
           "id": "doc1",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc1 title",
           "slug": "any",
           "source": "any",
           "title": "doc1 title",
@@ -248,13 +260,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc2 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc2 title",
+          },
           "id": "doc2",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc2 title",
           "slug": "any",
           "source": "any",
           "title": "doc2 title",
@@ -264,13 +278,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc3 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc3 title",
+          },
           "id": "doc3",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc3 title",
           "slug": "any",
           "source": "any",
           "title": "doc3 title",
@@ -280,13 +296,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc4 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc4 title",
+          },
           "id": "doc4",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc4 title",
           "slug": "any",
           "source": "any",
           "title": "doc4 title",
@@ -296,13 +314,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc5 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc5 title",
+          },
           "id": "doc5",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc5 title",
           "slug": "any",
           "source": "any",
           "title": "doc5 title",
@@ -374,13 +394,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc1 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc1 title",
+          },
           "id": "doc1",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc1 title",
           "slug": "any",
           "source": "any",
           "title": "doc1 title",
@@ -390,13 +412,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc2 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc2 title",
+          },
           "id": "doc2",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc2 title",
           "slug": "any",
           "source": "any",
           "title": "doc2 title",
@@ -406,13 +430,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc3 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc3 title",
+          },
           "id": "doc3",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc3 title",
           "slug": "any",
           "source": "any",
           "title": "doc3 title",
@@ -422,13 +448,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc4 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc4 title",
+          },
           "id": "doc4",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc4 title",
           "slug": "any",
           "source": "any",
           "title": "doc4 title",
@@ -438,13 +466,15 @@ exports[`translateLoadedContent returns translated loaded content 1`] = `
         {
           "description": "doc5 description",
           "editUrl": "any",
+          "frontMatter": {
+            "sidebar_label": "doc5 title",
+          },
           "id": "doc5",
           "lastUpdatedAt": 0,
           "lastUpdatedBy": "any",
           "next": undefined,
           "permalink": "any",
           "previous": undefined,
-          "sidebar_label": "doc5 title",
           "slug": "any",
           "source": "any",
           "title": "doc5 title",

packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts

@@ -119,7 +119,7 @@ function createTestUtils({
 
   async function testSlug(docFileSource: string, expectedPermalink: string) {
     const docFile = await readDoc(docFileSource);
-    const metadata = await processDocMetadata({
+    const metadata = processDocMetadata({
       docFile,
       versionMetadata,
       context,

packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts

@@ -54,9 +54,9 @@ const createFakeActions = (contentDir: string) => {
     addRoute: (config: RouteConfig) => {
       routeConfigs.push(config);
     },
-    createData: async (name: string, content: unknown) => {
+    createData: (name: string, content: unknown) => {
       dataContainer[name] = content;
-      return path.join(contentDir, name);
+      return Promise.resolve(path.join(contentDir, name));
     },
     setGlobalData: (data: unknown) => {
       globalDataContainer.pluginName = {pluginId: data};

packages/docusaurus-plugin-content-docs/src/__tests__/options.test.ts

@@ -31,11 +31,11 @@ const defaultOptions = {
 };
 
 describe('normalizeDocsPluginOptions', () => {
-  it('returns default options for undefined user options', async () => {
+  it('returns default options for undefined user options', () => {
     expect(testValidate({})).toEqual(defaultOptions);
   });
 
-  it('accepts correctly defined user options', async () => {
+  it('accepts correctly defined user options', () => {
     const userOptions = {
       path: 'my-docs', // Path to data on filesystem, relative to site dir.
       routeBasePath: 'my-docs', // URL Route.
@@ -83,7 +83,7 @@ describe('normalizeDocsPluginOptions', () => {
     });
   });
 
-  it('accepts correctly defined remark and rehype plugin options', async () => {
+  it('accepts correctly defined remark and rehype plugin options', () => {
     const userOptions = {
       beforeDefaultRemarkPlugins: [],
       beforeDefaultRehypePlugins: [markdownPluginsFunctionStub],
@@ -100,7 +100,7 @@ describe('normalizeDocsPluginOptions', () => {
     });
   });
 
-  it('accepts admonitions false', async () => {
+  it('accepts admonitions false', () => {
     const admonitionsFalse = {
       admonitions: false,
     };
@@ -110,7 +110,7 @@ describe('normalizeDocsPluginOptions', () => {
     });
   });
 
-  it('rejects admonitions true', async () => {
+  it('rejects admonitions true', () => {
     const admonitionsTrue = {
       admonitions: true,
     };

packages/docusaurus-plugin-content-docs/src/__tests__/translations.test.ts

@@ -30,7 +30,9 @@ function createSampleDoc(doc: Pick<DocMetadata, 'id'>): DocMetadata {
     unversionedId: 'any',
     version: 'any',
     title: `${doc.id} title`,
+    frontMatter: {
       sidebar_label: `${doc.id} title`,
+    },
     description: `${doc.id} description`,
     ...doc,
   };
@@ -136,7 +138,7 @@ function getSampleTranslationFilesTranslated() {
 }
 
 describe('getLoadedContentTranslationFiles', () => {
-  it('returns translation files', async () => {
+  it('returns translation files', () => {
     expect(getSampleTranslationFiles()).toMatchSnapshot();
   });
 });

packages/docusaurus-plugin-content-docs/src/client/docsClientUtils.ts

@@ -126,6 +126,6 @@ export function getDocVersionSuggestions(
   const latestVersion = getLatestVersion(data);
   const activeDocContext = getActiveDocContext(data, pathname);
   const latestDocSuggestion: GlobalDoc | undefined =
-    activeDocContext?.alternateDocVersions[latestVersion.name];
+    activeDocContext.alternateDocVersions[latestVersion.name];
   return {latestDocSuggestion, latestVersionSuggestion: latestVersion};
 }

packages/docusaurus-plugin-content-docs/src/client/index.ts

@@ -34,9 +34,11 @@ const StableEmptyObject = {};
 // In blog-only mode, docs hooks are still used by the theme. We need a fail-
 // safe fallback when the docs plugin is not in use
 export const useAllDocsData = (): {[pluginId: string]: GlobalPluginData} =>
-  (useAllPluginInstancesData('docusaurus-plugin-content-docs') as {
+  (useAllPluginInstancesData('docusaurus-plugin-content-docs') as
+    | {
         [pluginId: string]: GlobalPluginData;
-  }) ?? StableEmptyObject;
+      }
+    | undefined) ?? StableEmptyObject;
 
 export const useDocsData = (pluginId: string | undefined): GlobalPluginData =>
   usePluginData('docusaurus-plugin-content-docs', pluginId, {

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

@@ -143,7 +143,7 @@ export default async function pluginContentDocs(
             )}".`,
           );
         }
-        async function processVersionDoc(docFile: DocFile) {
+        function processVersionDoc(docFile: DocFile) {
           return processDocMetadata({
             docFile,
             versionMetadata,

packages/docusaurus-plugin-content-docs/src/markdown/index.ts

@@ -16,5 +16,5 @@ export default function markdownLoader(
   const fileString = source;
   const callback = this.async();
   const options = this.getOptions();
-  return callback?.(null, linkify(fileString, this.resourcePath, options));
+  return callback(null, linkify(fileString, this.resourcePath, options));
 }

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

@@ -165,7 +165,7 @@ export function validateOptions({
     }
   }
 
-  const normalizedOptions = validate(OptionsSchema, options) as PluginOptions;
+  const normalizedOptions = validate(OptionsSchema, options);
 
   if (normalizedOptions.admonitions) {
     normalizedOptions.remarkPlugins = normalizedOptions.remarkPlugins.concat([

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

@@ -51,7 +51,7 @@ Available document ids are:
     } = docMetadata;
     return {
       type: 'link',
-      label: sidebarLabel || item.label || title,
+      label: sidebarLabel ?? item.label ?? title,
       href: permalink,
       className: item.className,
       customProps:

packages/docusaurus-plugin-content-docs/src/sidebars/__tests__/generator.test.ts

@@ -463,7 +463,7 @@ describe('DefaultSidebarItemsGenerator', () => {
     expect(sidebarSlice).toMatchSnapshot();
   });
 
-  it('throws for unknown index link', async () => {
+  it('throws for unknown index link', () => {
     const generateSidebar = () =>
       DefaultSidebarItemsGenerator({
         numberPrefixParser: DefaultNumberPrefixParser,
@@ -499,7 +499,7 @@ describe('DefaultSidebarItemsGenerator', () => {
         },
       });
 
-    await expect(generateSidebar).rejects.toThrowErrorMatchingInlineSnapshot(`
+    expect(() => generateSidebar()).toThrowErrorMatchingInlineSnapshot(`
             "Can't find any doc with ID foo.
             Available doc IDs:
             - intro"

packages/docusaurus-plugin-content-docs/src/sidebars/__tests__/processor.test.ts

@@ -26,7 +26,7 @@ describe('processSidebars', () => {
   function createStaticSidebarItemGenerator(
     sidebarSlice: SidebarItem[],
   ): SidebarItemsGenerator {
-    return jest.fn(async () => sidebarSlice);
+    return jest.fn(() => sidebarSlice);
   }
 
   const StaticGeneratedSidebarSlice: NormalizedSidebar = [
@@ -40,7 +40,7 @@ describe('processSidebars', () => {
   // @ts-expect-error: good enough for this test
   const version: VersionMetadata = {
     versionName: '1.0.0',
-    versionPath: '/docs/1.0.0',
+    path: '/docs/1.0.0',
   };
 
   const params: SidebarProcessorParams = {

packages/docusaurus-plugin-content-docs/src/sidebars/__tests__/utils.test.ts

@@ -134,11 +134,11 @@ describe('createSidebarsUtils', () => {
     getFirstLink,
   } = createSidebarsUtils(sidebars);
 
-  it('getFirstDocIdOfFirstSidebar', async () => {
+  it('getFirstDocIdOfFirstSidebar', () => {
     expect(getFirstDocIdOfFirstSidebar()).toBe('doc1');
   });
 
-  it('getSidebarNameByDocId', async () => {
+  it('getSidebarNameByDocId', () => {
     expect(getSidebarNameByDocId('doc1')).toBe('sidebar1');
     expect(getSidebarNameByDocId('doc2')).toBe('sidebar1');
     expect(getSidebarNameByDocId('doc3')).toBe('sidebar2');
@@ -149,7 +149,7 @@ describe('createSidebarsUtils', () => {
     expect(getSidebarNameByDocId('unknown_id')).toBeUndefined();
   });
 
-  it('getDocNavigation', async () => {
+  it('getDocNavigation', () => {
     expect(getDocNavigation('doc1', 'doc1', undefined)).toEqual({
       sidebarName: 'sidebar1',
       previous: undefined,
@@ -229,7 +229,7 @@ describe('createSidebarsUtils', () => {
     });
   });
 
-  it('getCategoryGeneratedIndexNavigation', async () => {
+  it('getCategoryGeneratedIndexNavigation', () => {
     expect(
       getCategoryGeneratedIndexNavigation('/s3-subcategory-index-permalink'),
     ).toMatchObject({
@@ -259,7 +259,7 @@ describe('createSidebarsUtils', () => {
     });
   });
 
-  it('getCategoryGeneratedIndexList', async () => {
+  it('getCategoryGeneratedIndexList', () => {
     expect(getCategoryGeneratedIndexList()).toMatchObject([
       {
         type: 'category',
@@ -301,7 +301,7 @@ describe('createSidebarsUtils', () => {
 });
 
 describe('collectSidebarDocItems', () => {
-  it('can collect docs', async () => {
+  it('can collect docs', () => {
     const sidebar: Sidebar = [
       {
         type: 'category',
@@ -357,7 +357,7 @@ describe('collectSidebarDocItems', () => {
 });
 
 describe('collectSidebarCategories', () => {
-  it('can collect categories', async () => {
+  it('can collect categories', () => {
     const sidebar: Sidebar = [
       {
         type: 'category',
@@ -415,7 +415,7 @@ describe('collectSidebarCategories', () => {
 });
 
 describe('collectSidebarLinks', () => {
-  it('can collect links', async () => {
+  it('can collect links', () => {
     const sidebar: Sidebar = [
       {
         type: 'category',
@@ -453,7 +453,7 @@ describe('collectSidebarLinks', () => {
 });
 
 describe('collectSidebarsDocIds', () => {
-  it('can collect sidebars doc items', async () => {
+  it('can collect sidebars doc items', () => {
     const sidebar1: Sidebar = [
       {
         type: 'category',
@@ -499,7 +499,7 @@ describe('collectSidebarsDocIds', () => {
 });
 
 describe('transformSidebarItems', () => {
-  it('can transform sidebar items', async () => {
+  it('can transform sidebar items', () => {
     const sidebar: Sidebar = [
       {
         type: 'category',

packages/docusaurus-plugin-content-docs/src/sidebars/__tests__/validation.test.ts

@@ -9,7 +9,7 @@ import {validateSidebars, validateCategoryMetadataFile} from '../validation';
 import type {SidebarsConfig, CategoryMetadataFile} from '../types';
 
 describe('validateSidebars', () => {
-  it('throw for bad value', async () => {
+  it('throw for bad value', () => {
     expect(() => validateSidebars({sidebar: [{type: 42}]}))
       .toThrowErrorMatchingInlineSnapshot(`
       "{
@@ -21,12 +21,12 @@ describe('validateSidebars', () => {
     `);
   });
 
-  it('accept empty object', async () => {
+  it('accept empty object', () => {
     const sidebars: SidebarsConfig = {};
     validateSidebars(sidebars);
   });
 
-  it('accept valid values', async () => {
+  it('accept valid values', () => {
     const sidebars: SidebarsConfig = {
       sidebar1: [
         {type: 'doc', id: 'doc1'},
@@ -207,7 +207,7 @@ describe('validateSidebars', () => {
     ).toThrowErrorMatchingInlineSnapshot(`"sidebar.forEach is not a function"`);
   });
 
-  it('sidebars item doc but id is not a string', async () => {
+  it('sidebars item doc but id is not a string', () => {
     expect(() =>
       validateSidebars({
         docs: [
@@ -267,18 +267,18 @@ describe('validateSidebars', () => {
 describe('validateCategoryMetadataFile', () => {
   // TODO add more tests
 
-  it('throw for bad value', async () => {
+  it('throw for bad value', () => {
     expect(() =>
       validateCategoryMetadataFile(42),
     ).toThrowErrorMatchingInlineSnapshot(`""value" must be of type object"`);
   });
 
-  it('accept empty object', async () => {
+  it('accept empty object', () => {
     const content: CategoryMetadataFile = {};
     expect(validateCategoryMetadataFile(content)).toEqual(content);
   });
 
-  it('accept valid values', async () => {
+  it('accept valid values', () => {
     const content: CategoryMetadataFile = {
       className: 'className',
       label: 'Category Label',
@@ -295,7 +295,7 @@ describe('validateCategoryMetadataFile', () => {
     expect(validateCategoryMetadataFile(content)).toEqual(content);
   });
 
-  it('rejects permalink', async () => {
+  it('rejects permalink', () => {
     const content: CategoryMetadataFile = {
       className: 'className',
       label: 'Category Label',

packages/docusaurus-plugin-content-docs/src/sidebars/generator.ts

@@ -46,7 +46,7 @@ type Dir = {
 };
 
 // Comment for this feature: https://github.com/facebook/docusaurus/issues/3464#issuecomment-818670449
-export const DefaultSidebarItemsGenerator: SidebarItemsGenerator = async ({
+export const DefaultSidebarItemsGenerator: SidebarItemsGenerator = ({
   numberPrefixParser,
   isCategoryIndex,
   docs: allDocs,

packages/docusaurus-plugin-content-docs/src/sidebars/postProcessor.ts

@@ -84,7 +84,7 @@ function postProcessSidebarItem(
       };
     }
     // A non-collapsible category can't be collapsed!
-    if (category.collapsible === false) {
+    if (!category.collapsible) {
       category.collapsed = false;
     }
     return category;

packages/docusaurus-plugin-content-docs/src/sidebars/types.ts

@@ -251,7 +251,7 @@ export type SidebarItemsGeneratorArgs = {
 };
 export type SidebarItemsGenerator = (
   generatorArgs: SidebarItemsGeneratorArgs,
-) => Promise<NormalizedSidebar>;
+) => NormalizedSidebar | Promise<NormalizedSidebar>;
 
 export type SidebarItemsGeneratorOption = (
   generatorArgs: {
@@ -262,7 +262,7 @@ export type SidebarItemsGeneratorOption = (
      */
     defaultSidebarItemsGenerator: SidebarItemsGenerator;
   } & SidebarItemsGeneratorArgs,
-) => Promise<NormalizedSidebarItem[]>;
+) => NormalizedSidebar | Promise<NormalizedSidebar>;
 
 export type SidebarProcessorParams = {
   sidebarItemsGenerator: SidebarItemsGeneratorOption;

packages/docusaurus-plugin-content-docs/src/sidebars/utils.ts

@@ -257,7 +257,7 @@ export function createSidebarsUtils(sidebars: Sidebars): SidebarsUtils {
     ): boolean {
       return (
         item.type === 'category' &&
-        item.link?.type === 'generated-index' &&
+        item.link.type === 'generated-index' &&
         item.link.permalink === categoryGeneratedIndexPermalink
       );
     }

packages/docusaurus-plugin-content-docs/src/sidebars/validation.ts

@@ -144,7 +144,7 @@ function validateSidebarItem(
   // manually
   Joi.assert(item, sidebarItemSchema);
 
-  if ((item as NormalizedSidebarItemCategory).type === 'category') {
+  if ((item as NormalizedSidebarItem).type === 'category') {
     (item as NormalizedSidebarItemCategory).items.forEach(validateSidebarItem);
   }
 }
@@ -170,5 +170,9 @@ const categoryMetadataFileSchema = Joi.object<CategoryMetadataFile>({
 export function validateCategoryMetadataFile(
   unsafeContent: unknown,
 ): CategoryMetadataFile {
-  return Joi.attempt(unsafeContent, categoryMetadataFileSchema);
+  const {error, value} = categoryMetadataFileSchema.validate(unsafeContent);
+  if (error) {
+    throw error;
+  }
+  return value;
 }

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

@@ -58,7 +58,7 @@ export default function getSlug({
     ) {
       return dirNameSlug;
     }
-    const baseSlug = frontMatterSlug || baseID;
+    const baseSlug = frontMatterSlug ?? baseID;
     return resolvePathname(baseSlug, getDirNameSlug());
   }
 

packages/docusaurus-plugin-content-docs/src/versions/__tests__/index.test.ts

@@ -604,7 +604,7 @@ describe('readVersionsMetadata', () => {
           context: defaultContext,
         }),
       ).rejects.toThrowErrorMatchingInlineSnapshot(
-        `"Versions should be strings. Found type "number" for version "1.1"."`,
+        `"Versions should be strings. Found type "number" for version 1.1."`,
       );
       jsonMock.mockImplementationOnce(() => ['   ']);
 

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

@@ -11,7 +11,9 @@ import type {VersionsOptions} from '@docusaurus/plugin-content-docs';
 export function validateVersionName(name: unknown): asserts name is string {
   if (typeof name !== 'string') {
     throw new Error(
-      `Versions should be strings. Found type "${typeof name}" for version "${name}".`,
+      `Versions should be strings. Found type "${typeof name}" for version ${JSON.stringify(
+        name,
+      )}.`,
     );
   }
   if (!name.trim()) {

packages/docusaurus-plugin-content-pages/src/__tests__/index.test.ts

@@ -16,7 +16,7 @@ describe('docusaurus-plugin-content-pages', () => {
   it('loads simple pages', async () => {
     const siteDir = path.join(__dirname, '__fixtures__', 'website');
     const context = await loadContext({siteDir});
-    const plugin = await pluginContentPages(
+    const plugin = pluginContentPages(
       context,
       validateOptions({
         validate: normalizePluginOptions,
@@ -33,7 +33,7 @@ describe('docusaurus-plugin-content-pages', () => {
   it('loads simple pages with french translations', async () => {
     const siteDir = path.join(__dirname, '__fixtures__', 'website');
     const context = await loadContext({siteDir});
-    const plugin = await pluginContentPages(
+    const plugin = pluginContentPages(
       {
         ...context,
         i18n: {

packages/docusaurus-plugin-content-pages/src/index.ts

@@ -39,10 +39,10 @@ export function getContentPathList(contentPaths: PagesContentPaths): string[] {
 const isMarkdownSource = (source: string) =>
   source.endsWith('.md') || source.endsWith('.mdx');
 
-export default async function pluginContentPages(
+export default function pluginContentPages(
   context: LoadContext,
   options: PluginOptions,
-): Promise<Plugin<LoadedContent | null>> {
+): Plugin<LoadedContent | null> {
   if (options.admonitions) {
     options.remarkPlugins = options.remarkPlugins.concat([
       [admonitions, options.admonitions],

packages/docusaurus-plugin-content-pages/src/markdownLoader.ts

@@ -18,5 +18,5 @@ export default function markdownLoader(
   // TODO provide additional md processing here? like interlinking pages?
   // fileString = linkify(fileString)
 
-  return callback?.(null, fileString);
+  return callback(null, fileString);
 }

packages/docusaurus-plugin-content-pages/src/options.ts

@@ -28,7 +28,7 @@ export const DEFAULT_OPTIONS: PluginOptions = {
   admonitions: {},
 };
 
-const PluginOptionSchema = Joi.object({
+const PluginOptionSchema = Joi.object<PluginOptions>({
   path: Joi.string().default(DEFAULT_OPTIONS.path),
   routeBasePath: Joi.string().default(DEFAULT_OPTIONS.routeBasePath),
   include: Joi.array().items(Joi.string()).default(DEFAULT_OPTIONS.include),

packages/docusaurus-plugin-debug/src/theme/DebugSiteMetadata/index.tsx

@@ -20,7 +20,7 @@ export default function DebugMetadata(): JSX.Element {
       </div>
       <div>
         Site Version:{' '}
-        <code>{siteMetadata.siteVersion || 'No version specified'}</code>
+        <code>{siteMetadata.siteVersion ?? 'No version specified'}</code>
       </div>
       <h3 className={styles.sectionTitle}>Plugins and themes</h3>
       <ul className="clean-list">

packages/docusaurus-plugin-google-gtag/src/index.ts

@@ -25,7 +25,7 @@ export default function pluginGoogleGtag(
   return {
     name: 'docusaurus-plugin-google-gtag',
 
-    async contentLoaded({actions}) {
+    contentLoaded({actions}) {
       actions.setGlobalData(options);
     },
 

packages/docusaurus-plugin-ideal-image/src/index.ts

@@ -80,7 +80,7 @@ export function validateOptions({
   validate,
   options,
 }: OptionValidationContext<PluginOptions, PluginOptions>): PluginOptions {
-  const pluginOptionsSchema = Joi.object({
+  const pluginOptionsSchema = Joi.object<PluginOptions>({
     disableInDev: Joi.boolean().default(true),
   }).unknown();
   return validate(pluginOptionsSchema, options);

packages/docusaurus-plugin-ideal-image/src/theme/IdealImage/index.tsx

@@ -22,9 +22,9 @@ function bytesToSize(bytes: number) {
   }
   const scale = Math.floor(Math.log(bytes) / Math.log(1024));
   if (scale === 0) {
-    return `${bytes} ${sizes[scale]}`;
+    return `${bytes} ${sizes[scale]!}`;
   }
-  return `${(bytes / 1024 ** scale).toFixed(1)} ${sizes[scale]}`;
+  return `${(bytes / 1024 ** scale).toFixed(1)} ${sizes[scale]!}`;
 }
 
 // Adopted from https://github.com/endiliey/react-ideal-image/blob/master/src/components/IdealImage/index.js#L43-L75
@@ -100,8 +100,8 @@ export default function IdealImage(props: Props): JSX.Element {
       {...props}
       alt={alt}
       className={className}
-      height={img.src.height || 100}
+      height={img.src.height ?? 100}
-      width={img.src.width || 100}
+      width={img.src.width ?? 100}
       placeholder={{lqip: img.preSrc}}
       src={img.src.src}
       srcSet={img.src.images.map((image) => ({

packages/docusaurus-plugin-pwa/src/index.ts

@@ -89,7 +89,7 @@ export default function pluginPWA(
           new webpack.EnvironmentPlugin({
             PWA_DEBUG: debug,
             PWA_SERVICE_WORKER_URL: path.posix.resolve(
-              `${config.output?.publicPath || '/'}`,
+              `${(config.output?.publicPath as string) || '/'}`,
               'sw.js',
             ),
             PWA_OFFLINE_MODE_ACTIVATION_STRATEGIES:
@@ -102,7 +102,7 @@ export default function pluginPWA(
 
     injectHtmlTags() {
       const headTags: HtmlTags = [];
-      if (isProd && pwaHead) {
+      if (isProd) {
         pwaHead.forEach(({tagName, ...attributes}) => {
           (['href', 'content'] as const).forEach((attribute) => {
             const attributeValue = attributes[attribute];
@@ -160,7 +160,7 @@ export default function pluginPWA(
         plugins: [
           new webpack.EnvironmentPlugin({
             // Fallback value required with Webpack 5
-            PWA_SW_CUSTOM: swCustom || '',
+            PWA_SW_CUSTOM: swCustom ?? '',
           }),
           new LogPlugin({
             name: 'Service Worker',
@@ -189,7 +189,7 @@ export default function pluginPWA(
           '**/*.{png,jpg,jpeg,gif,svg,ico}',
           '**/*.{woff,woff2,eot,ttf,otf}',
           // @ts-expect-error: internal API?
-          ...(injectManifest.globPatterns ?? []),
+          ...((injectManifest.globPatterns as string[] | undefined) ?? []),
         ],
         // Those attributes are not overrideable
         swDest,

packages/docusaurus-plugin-pwa/src/options.ts

@@ -23,7 +23,7 @@ const DEFAULT_OPTIONS = {
   reloadPopup: '@theme/PwaReloadPopup',
 };
 
-const Schema = Joi.object({
+const optionsSchema = Joi.object<PluginOptions>({
   debug: Joi.bool().default(DEFAULT_OPTIONS.debug),
   offlineModeActivationStrategies: Joi.array()
     .items(
@@ -58,5 +58,5 @@ export function validateOptions({
   validate,
   options,
 }: OptionValidationContext<PluginOptions, PluginOptions>): PluginOptions {
-  return validate(Schema, options);
+  return validate(optionsSchema, options);
 }

packages/docusaurus-plugin-pwa/src/registerSw.ts

@@ -9,7 +9,7 @@ import {createStorageSlot} from '@docusaurus/theme-common';
 
 // First: read the env variables (provided by Webpack)
 /* eslint-disable prefer-destructuring */
-const PWA_SERVICE_WORKER_URL = process.env.PWA_SERVICE_WORKER_URL;
+const PWA_SERVICE_WORKER_URL = process.env.PWA_SERVICE_WORKER_URL!;
 const PWA_RELOAD_POPUP = process.env.PWA_RELOAD_POPUP;
 const PWA_OFFLINE_MODE_ACTIVATION_STRATEGIES = process.env
   .PWA_OFFLINE_MODE_ACTIVATION_STRATEGIES as unknown as (keyof typeof OfflineModeActivationStrategiesImplementations)[];
@@ -34,7 +34,7 @@ async function clearRegistrations() {
   }
   await Promise.all(
     registrations.map(async (registration) => {
-      const result = await registration?.unregister();
+      const result = await registration.unregister();
       if (debug) {
         console.log(
           `[Docusaurus-PWA][registerSw]: unregister() service worker registration`,
@@ -69,7 +69,7 @@ async function isAppInstalledEventFired() {
 declare global {
   interface Navigator {
     getInstalledRelatedApps: () => Promise<{platform: string}[]>;
-    connection: {effectiveType: string; saveData: boolean};
+    connection?: {effectiveType: string; saveData: boolean};
   }
 }
 

packages/docusaurus-plugin-sitemap/src/options.ts

@@ -29,7 +29,8 @@ export const DEFAULT_OPTIONS: PluginOptions = {
   ignorePatterns: [],
 };
 
-const PluginOptionSchema = Joi.object({
+const PluginOptionSchema = Joi.object<PluginOptions>({
+  // @ts-expect-error: forbidden
   cacheTime: Joi.forbidden().messages({
     'any.unknown':
       'Option `cacheTime` in sitemap config is deprecated. Please remove it.',

packages/docusaurus-remark-plugin-npm2yarn/src/index.ts

@@ -62,8 +62,8 @@ const nodeForImport: Literal = {
 const plugin: Plugin<[PluginOptions?]> = (options = {}) => {
   const {sync = false} = options;
   return (root) => {
-    let transformed = false;
+    let transformed = false as boolean;
-    let alreadyImported = false;
+    let alreadyImported = false as boolean;
     visit(root, (node: Node) => {
       if (isImport(node) && node.value.includes('@theme/Tabs')) {
         alreadyImported = true;

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

@@ -177,7 +177,7 @@ export default function themeClassic(
         const plugin: PostCssPlugin = {
           postcssPlugin: 'RtlCssPlugin',
           prepare: (result) => {
-            const file = result.root?.source?.input?.file;
+            const file = result.root.source?.input.file;
             // Skip Infima as we are using the its RTL version.
             if (file === resolvedInfimaFile) {
               return {};

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

@@ -21,12 +21,14 @@
 // in their tsconfig.
 
 declare module '@docusaurus/theme-classic' {
-  import type {LoadContext, Plugin} from '@docusaurus/types';
+  import type {LoadContext, Plugin, PluginModule} from '@docusaurus/types';
 
   export type Options = {
     customCss?: string | string[];
   };
 
+  export const getSwizzleConfig: PluginModule['getSwizzleConfig'];
+
   export default function themeClassic(
     context: LoadContext,
     options: Options,

packages/docusaurus-theme-classic/src/theme/CodeBlock/Content/String.tsx

@@ -52,7 +52,7 @@ export default function CodeBlockString({
     magicComments,
   });
   const showLineNumbers =
-    showLineNumbersProp || containsLineNumbers(metastring);
+    showLineNumbersProp ?? containsLineNumbers(metastring);
 
   return (
     <Container

packages/docusaurus-theme-classic/src/theme/DocSidebarItem/Html/index.tsx

@@ -23,7 +23,7 @@ export default function DocSidebarItemHtml({
       className={clsx(
         ThemeClassNames.docs.docSidebarItemLink,
         ThemeClassNames.docs.docSidebarItemLinkLevel(level),
-        defaultStyle && `${styles.menuHtmlItem} menu__list-item`,
+        defaultStyle && [styles.menuHtmlItem, 'menu__list-item'],
         className,
       )}
       key={index}

packages/docusaurus-theme-classic/src/theme/Footer/Links/MultiColumn/index.tsx

@@ -21,7 +21,7 @@ function ColumnLinkItem({item}: {item: ColumnItemType}) {
       dangerouslySetInnerHTML={{__html: item.html}}
     />
   ) : (
-    <li key={item.href || item.to} className="footer__item">
+    <li key={item.href ?? item.to} className="footer__item">
       <LinkItem item={item} />
     </li>
   );

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

@@ -27,7 +27,7 @@ export function useCollapsible({
   initialState,
 }: {
   /** The initial state. Will be non-collapsed by default. */
-  initialState: boolean | (() => boolean);
+  initialState?: boolean | (() => boolean);
 }): {
   collapsed: boolean;
   setCollapsed: Dispatch<SetStateAction<boolean>>;

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

@@ -40,7 +40,7 @@ export function useSkipToContent(): {
     e.preventDefault();
 
     const targetElement: HTMLElement | null =
-      document.querySelector('main:first-of-type') ||
+      document.querySelector('main:first-of-type') ??
       document.querySelector(`.${ThemeClassNames.wrapper.main}`);
 
     if (targetElement) {

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

@@ -38,15 +38,12 @@ function getAnchors({
 }: {
   minHeadingLevel: number;
   maxHeadingLevel: number;
-}) {
+}): HTMLElement[] {
   const selectors = [];
   for (let i = minHeadingLevel; i <= maxHeadingLevel; i += 1) {
     selectors.push(`h${i}.anchor`);
   }
-
+  return Array.from(document.querySelectorAll(selectors.join()));
-  return Array.from(
-    document.querySelectorAll(selectors.join()),
-  ) as HTMLElement[];
 }
 
 function getActiveAnchor(

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

@@ -171,7 +171,7 @@ export function parseLines(
     const metastringRangeClassName = magicComments[0]!.className;
     const lines = rangeParser(linesRange)
       .filter((n) => n > 0)
-      .map((n) => [n - 1, [metastringRangeClassName]]);
+      .map((n) => [n - 1, [metastringRangeClassName]] as [number, string[]]);
     return {lineClassNames: Object.fromEntries(lines), code};
   }
   if (language === undefined) {
@@ -189,7 +189,7 @@ export function parseLines(
   const lineToClassName: {[comment: string]: string} = Object.fromEntries(
     magicComments
       .filter((d) => d.line)
-      .map(({className, line}) => [line, className]),
+      .map(({className, line}) => [line!, className] as [string, string]),
   );
   const blockStartToClassName: {[comment: string]: string} = Object.fromEntries(
     magicComments

packages/docusaurus-theme-common/src/utils/reactUtils.tsx

@@ -70,7 +70,7 @@ export class ReactContextError extends Error {
     this.name = 'ReactContextError';
     this.message = `Hook ${
       this.stack?.split('\n')[1]?.match(/at (?:\w+\.)?(?<name>\w+)/)?.groups!
-        .name
+        .name ?? ''
     } is called outside the <${providerName}>. ${additionalInfo || ''}`;
   }
 }

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

@@ -18,7 +18,7 @@ export function isSamePath(
   path2: string | undefined,
 ): boolean {
   const normalize = (pathname: string | undefined) =>
-    (!pathname || pathname?.endsWith('/')
+    (!pathname || pathname.endsWith('/')
       ? pathname
       : `${pathname}/`
     )?.toLowerCase();

packages/docusaurus-theme-common/src/utils/scrollUtils.tsx

@@ -112,11 +112,7 @@ export function useScrollPosition(
         return;
       }
       const currentPosition = getScrollPosition()!;
-
-      if (dynamicEffect) {
       dynamicEffect(currentPosition, lastPositionRef.current);
-      }
-
       lastPositionRef.current = currentPosition;
     };
 

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

@@ -39,7 +39,7 @@ export function useContextualSearchFilters(): {locale: string; tags: string[]} {
   // plugin instances.
   function getDocPluginTags(pluginId: string) {
     const activeVersion =
-      activePluginAndVersion?.activePlugin?.pluginId === pluginId
+      activePluginAndVersion?.activePlugin.pluginId === pluginId
         ? activePluginAndVersion.activeVersion
         : undefined;
 

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

@@ -27,7 +27,7 @@ function treeifyTOC(flatTOC: readonly TOCItem[]): TOCTreeNode[] {
   // level <i>. We will modify these indices as we iterate through all headings.
   // e.g. if an ### H3 was last seen at index 2, then prevIndexForLevel[3] === 2
   // indices 0 and 1 will remain unused.
-  const prevIndexForLevel = Array(7).fill(-1);
+  const prevIndexForLevel = Array<number>(7).fill(-1);
 
   headings.forEach((curr, currIndex) => {
     // Take the last seen index for each ancestor level. the highest index will

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

@@ -95,7 +95,11 @@ function selectPluralMessage(
   }
   if (parts.length > localePluralForms.pluralForms.length) {
     console.error(
-      `For locale=${localePluralForms.locale}, a maximum of ${localePluralForms.pluralForms.length} plural forms are expected (${localePluralForms.pluralForms}), but the message contains ${parts.length}: ${pluralMessages}`,
+      `For locale=${localePluralForms.locale}, a maximum of ${
+        localePluralForms.pluralForms.length
+      } plural forms are expected (${localePluralForms.pluralForms.join(
+        ',',
+      )}), but the message contains ${parts.length}: ${pluralMessages}`,
     );
   }
   const pluralForm = localePluralForms.select(count);

packages/docusaurus-theme-live-codeblock/src/validateThemeConfig.ts

@@ -15,7 +15,7 @@ export const DEFAULT_CONFIG = {
   playgroundPosition: 'bottom',
 };
 
-export const Schema = Joi.object({
+export const Schema = Joi.object<ThemeConfig>({
   liveCodeBlock: Joi.object({
     playgroundPosition: Joi.string()
       .equal('top', 'bottom')

packages/docusaurus-theme-search-algolia/src/index.ts

@@ -60,7 +60,7 @@ export default function themeSearchAlgolia(context: LoadContext): Plugin<void> {
       });
     },
 
-    async contentLoaded({actions: {addRoute}}) {
+    contentLoaded({actions: {addRoute}}) {
       if (searchPagePath) {
         addRoute({
           path: normalizeUrl([baseUrl, searchPagePath]),

packages/docusaurus-theme-search-algolia/src/validateThemeConfig.ts

@@ -20,7 +20,7 @@ export const DEFAULT_CONFIG = {
   searchPagePath: 'search',
 };
 
-export const Schema = Joi.object({
+export const Schema = Joi.object<ThemeConfig>({
   algolia: Joi.object({
     // Docusaurus attributes
     contextualSearch: Joi.boolean().default(DEFAULT_CONFIG.contextualSearch),

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

@@ -25,9 +25,9 @@ export function codeTranslationLocalesToTry(locale: string): string[] {
     // unresolved except for simply locales
     locale,
     // "zh-CN" / "pt-BR"
-    `${maximizedLocale.language}-${maximizedLocale.region}`,
+    `${maximizedLocale.language!}-${maximizedLocale.region!}`,
     // "zh-Hans" / "pt-Latn"
-    `${maximizedLocale.language}-${maximizedLocale.script}`,
+    `${maximizedLocale.language!}-${maximizedLocale.script!}`,
     // "zh" / "pt"
     maximizedLocale.language!,
   ];

packages/docusaurus-utils-validation/src/JoiFrontMatter.ts

@@ -28,4 +28,4 @@ const JoiFrontMatterString: Joi.Extension = {
  * @see https://github.com/facebook/docusaurus/issues/4642
  * @see https://github.com/sideway/joi/issues/1442#issuecomment-823997884
  */
-export const JoiFrontMatter: typeof Joi = Joi.extend(JoiFrontMatterString);
+export const JoiFrontMatter = Joi.extend(JoiFrontMatterString) as typeof Joi;

packages/docusaurus-utils/src/pathUtils.ts

@@ -56,7 +56,7 @@ export function shortName(str: string): string {
  * Adopted from https://github.com/sindresorhus/slash/blob/main/index.js
  */
 export function posixPath(str: string): string {
-  const isExtendedLengthPath = /^\\\\\?\\/.test(str);
+  const isExtendedLengthPath = str.startsWith('\\\\?\\');
 
   // Forward slashes are only valid Windows paths when they don't contain non-
   // ascii characters.

packages/docusaurus-utils/src/urlUtils.ts

@@ -72,11 +72,11 @@ export function normalizeUrl(rawUrls: string[]): string {
           /^\/+/,
           // Special case where the first element of rawUrls is empty
           // ["", "/hello"] => /hello
-          component[0] === '/' && !hasStartingSlash ? '/' : '',
+          component.startsWith('/') && !hasStartingSlash ? '/' : '',
         );
       }
 
-      hasEndingSlash = component[component.length - 1] === '/';
+      hasEndingSlash = component.endsWith('/');
       // Removing the ending slashes for each component but the last. For the
       // last component we will combine multiple slashes to a single one.
       component = component.replace(/\/+$/, i < urls.length - 1 ? '' : '/');
@@ -95,7 +95,7 @@ export function normalizeUrl(rawUrls: string[]): string {
 
   // Replace ? in parameters with &.
   const parts = str.split('?');
-  str = parts.shift() + (parts.length > 0 ? '?' : '') + parts.join('&');
+  str = parts.shift()! + (parts.length > 0 ? '?' : '') + parts.join('&');
 
   // Dedupe forward slashes in the entire path, avoiding protocol slashes.
   str = str.replace(/(?<textBefore>[^:/]\/)\/+/g, '$1');

packages/docusaurus/src/client/docusaurus.ts

@@ -19,7 +19,7 @@ declare global {
   // eslint-disable-next-line camelcase, no-underscore-dangle
   const __webpack_require__: {gca: (name: string) => string};
   interface Navigator {
-    connection: {effectiveType: string; saveData: boolean};
+    connection?: {effectiveType: string; saveData: boolean};
   }
 }
 

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

@@ -10,7 +10,7 @@ import {hasProtocol} from './isInternalUrl';
 import type {BaseUrlOptions, BaseUrlUtils} from '@docusaurus/useBaseUrl';
 
 function addBaseUrl(
-  siteUrl: string | undefined,
+  siteUrl: string,
   baseUrl: string,
   url: string,
   {forcePrependBaseUrl = false, absolute = false}: BaseUrlOptions = {},

packages/docusaurus/src/commands/serve.ts

@@ -66,7 +66,7 @@ export async function serve(
 
     // Remove baseUrl before calling serveHandler, because /baseUrl/ should
     // serve /build/index.html, not /build/baseUrl/index.html (does not exist)
-    req.url = req.url?.replace(baseUrl, '/');
+    req.url = req.url.replace(baseUrl, '/');
 
     serveHandler(req, res, {
       cleanUrls: true,

packages/docusaurus/src/commands/swizzle/__tests__/config.test.ts

@@ -9,14 +9,14 @@ import {normalizeSwizzleConfig} from '../config';
 import type {SwizzleConfig} from '@docusaurus/types';
 
 describe('normalizeSwizzleConfig', () => {
-  it(`validate no components config`, async () => {
+  it(`validate no components config`, () => {
     const config: SwizzleConfig = {
       components: {},
     };
     expect(normalizeSwizzleConfig(config)).toEqual(config);
   });
 
-  it(`validate complete config`, async () => {
+  it(`validate complete config`, () => {
     const config: SwizzleConfig = {
       components: {
         SomeComponent: {
@@ -38,7 +38,7 @@ describe('normalizeSwizzleConfig', () => {
     expect(normalizeSwizzleConfig(config)).toEqual(config);
   });
 
-  it(`normalize partial config`, async () => {
+  it(`normalize partial config`, () => {
     const config: SwizzleConfig = {
       components: {
         SomeComponent: {
@@ -59,7 +59,7 @@ describe('normalizeSwizzleConfig', () => {
     expect(normalizeSwizzleConfig(config)).toMatchSnapshot();
   });
 
-  it(`reject missing components`, async () => {
+  it(`reject missing components`, () => {
     // @ts-expect-error: incomplete actions map
     const config: SwizzleConfig = {};
 
@@ -70,7 +70,7 @@ describe('normalizeSwizzleConfig', () => {
     );
   });
 
-  it(`reject invalid action name`, async () => {
+  it(`reject invalid action name`, () => {
     const config: SwizzleConfig = {
       components: {
         MyComponent: {
@@ -91,7 +91,7 @@ describe('normalizeSwizzleConfig', () => {
     );
   });
 
-  it(`reject invalid action status`, async () => {
+  it(`reject invalid action status`, () => {
     const config: SwizzleConfig = {
       components: {
         MyComponent: {

packages/docusaurus/src/commands/swizzle/actions.ts

@@ -109,7 +109,7 @@ export async function wrap({
   const isDirectory = await isDir(path.join(themePath, themeComponentName));
 
   // Top/Parent/ComponentName => ComponentName
-  const componentName = _.last(themeComponentName.split('/'));
+  const componentName = _.last(themeComponentName.split('/'))!;
   const wrapperComponentName = `${componentName}Wrapper`;
 
   const wrapperFileName = `${themeComponentName}${isDirectory ? '/index' : ''}${

packages/docusaurus/src/commands/swizzle/config.ts

@@ -16,9 +16,8 @@ function getModuleSwizzleConfig(
   swizzlePlugin: SwizzlePlugin,
 ): SwizzleConfig | undefined {
   const getSwizzleConfig =
-    swizzlePlugin.plugin.plugin?.getSwizzleConfig ??
+    swizzlePlugin.plugin.plugin.getSwizzleConfig ??
-    swizzlePlugin.plugin.pluginModule?.module.getSwizzleConfig ??
+    swizzlePlugin.plugin.pluginModule?.module.getSwizzleConfig;
-    swizzlePlugin.plugin.pluginModule?.module?.getSwizzleConfig;
 
   if (getSwizzleConfig) {
     return getSwizzleConfig();
@@ -26,9 +25,8 @@ function getModuleSwizzleConfig(
 
   // TODO deprecate getSwizzleComponentList later
   const getSwizzleComponentList =
-    swizzlePlugin.plugin.plugin?.getSwizzleComponentList ??
+    swizzlePlugin.plugin.plugin.getSwizzleComponentList ??
-    swizzlePlugin.plugin.pluginModule?.module.getSwizzleComponentList ??
+    swizzlePlugin.plugin.pluginModule?.module.getSwizzleComponentList;
-    swizzlePlugin.plugin.pluginModule?.module?.getSwizzleComponentList;
 
   if (getSwizzleComponentList) {
     const safeComponents = getSwizzleComponentList() ?? [];

packages/docusaurus/src/commands/swizzle/themes.ts

@@ -15,7 +15,7 @@ import {findStringIgnoringCase, type SwizzlePlugin} from './common';
 export function pluginToThemeName(plugin: SwizzlePlugin): string | undefined {
   if (plugin.instance.getThemePath) {
     return (
-      (plugin.instance.version as {name: string}).name ?? plugin.instance.name
+      (plugin.instance.version as {name?: string}).name ?? plugin.instance.name
     );
   }
   return undefined;
@@ -76,9 +76,7 @@ function handleInvalidThemeName({
   // TODO recover from short theme-names here: "classic" => "@docusaurus/theme-classic"
 
   // No recovery value is possible: print error
-  const suggestion = themeNames.find(
+  const suggestion = themeNames.find((name) => leven(name, themeNameParam) < 4);
-    (name) => leven(name, themeNameParam!) < 4,
-  );
   logger.error`Theme name=${themeNameParam} not found. ${
     suggestion
       ? logger.interpolate`Did you mean name=${suggestion}?`
@@ -87,13 +85,13 @@ function handleInvalidThemeName({
   return process.exit(1);
 }
 
-async function validateThemeName({
+function validateThemeName({
   themeNameParam,
   themeNames,
 }: {
   themeNameParam: string;
   themeNames: string[];
-}): Promise<string> {
+}): string {
   const isValidName = themeNames.includes(themeNameParam);
   if (!isValidName) {
     return handleInvalidThemeName({

packages/docusaurus/src/commands/writeHeadingIds.ts

@@ -37,12 +37,12 @@ async function transformMarkdownFile(
 async function getPathsToWatch(siteDir: string): Promise<string[]> {
   const context = await loadContext({siteDir});
   const plugins = await initPlugins(context);
-  return plugins.flatMap((plugin) => plugin?.getPathsToWatch?.() ?? []);
+  return plugins.flatMap((plugin) => plugin.getPathsToWatch?.() ?? []);
 }
 
 export async function writeHeadingIds(
   siteDir: string,
-  files: string[],
+  files: string[] | undefined,
   options: WriteHeadingIDOptions,
 ): Promise<void> {
   const markdownFiles = await safeGlobby(

packages/docusaurus/src/deps.d.ts

@@ -20,13 +20,13 @@ declare module 'react-loadable-ssr-addon-v5-slorber' {
   export type Manifest = {
     entrypoints: string[];
     origins: {[key: string]: number[]};
-    assets: Array<{[key: string]: Asset[]}>;
+    assets: {[key: string]: Asset[]}[];
   };
 
   export function getBundles(
     manifest: Manifest,
     modulesToBeLoaded: string[],
-  ): {js: Asset[]; css: Asset[]};
+  ): {js?: Asset[]; css?: Asset[]};
 
   export default class ReactLoadableSSRAddon implements WebpackPluginInstance {
     constructor(props: {filename: string});

packages/docusaurus/src/server/plugins/configs.ts

@@ -63,7 +63,7 @@ async function normalizePluginConfig(
     const pluginPath = pluginRequire.resolve(pluginModuleImport);
     const pluginModule = importFresh<ImportedPluginModule>(pluginPath);
     return {
-      plugin: pluginModule?.default ?? pluginModule,
+      plugin: pluginModule.default ?? pluginModule,
       options: {},
       pluginModule: {
         path: pluginModuleImport,
@@ -90,7 +90,7 @@ async function normalizePluginConfig(
     const pluginPath = pluginRequire.resolve(pluginModuleImport);
     const pluginModule = importFresh<ImportedPluginModule>(pluginPath);
     return {
-      plugin: pluginModule?.default ?? pluginModule,
+      plugin: pluginModule.default ?? pluginModule,
       options: pluginConfig[1],
       pluginModule: {
         path: pluginModuleImport,

packages/docusaurus/src/server/plugins/index.ts

@@ -52,7 +52,7 @@ export async function loadPlugins(context: LoadContext): Promise<{
     plugins.map(async (plugin) => {
       const content = await plugin.loadContent?.();
       const rawTranslationFiles =
-        (await plugin?.getTranslationFiles?.({content})) ?? [];
+        (await plugin.getTranslationFiles?.({content})) ?? [];
       const translationFiles = await Promise.all(
         rawTranslationFiles.map((translationFile) =>
           localizePluginTranslationFile({

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

@@ -29,8 +29,8 @@ function getOptionValidationFunction(
   if (normalizedPluginConfig.pluginModule) {
     // Support both CommonJS and ES modules
     return (
-      normalizedPluginConfig.pluginModule.module?.default?.validateOptions ??
+      normalizedPluginConfig.pluginModule.module.default?.validateOptions ??
-      normalizedPluginConfig.pluginModule.module?.validateOptions
+      normalizedPluginConfig.pluginModule.module.validateOptions
     );
   }
   return normalizedPluginConfig.plugin.validateOptions;
@@ -66,7 +66,7 @@ export async function initPlugins(
   ): Promise<PluginVersionInformation> {
     if (normalizedPluginConfig.pluginModule?.path) {
       const pluginPath = pluginRequire.resolve(
-        normalizedPluginConfig.pluginModule?.path,
+        normalizedPluginConfig.pluginModule.path,
       );
       return getPluginVersion(pluginPath, context.siteDir);
     }

packages/docusaurus/src/server/plugins/moduleShorthand.ts

@@ -14,7 +14,10 @@ export function getNamePatterns(
     if (!moduleName.includes('/')) {
       return [`${moduleName}/docusaurus-${moduleType}`];
     }
-    const [scope, packageName] = moduleName.split(/\/(?<rest>.*)/);
+    const [scope, packageName] = moduleName.split(/\/(?<rest>.*)/) as [
+      string,
+      string,
+    ];
     return [
       `${scope}/${packageName}`,
       `${scope}/docusaurus-${moduleType}-${packageName}`,

packages/docusaurus/src/server/plugins/routeConfig.ts

@@ -50,8 +50,8 @@ export function sortConfig(
     }
     // Higher priority get placed first.
     if (a.priority || b.priority) {
-      const priorityA = a.priority || 0;
+      const priorityA = a.priority ?? 0;
-      const priorityB = b.priority || 0;
+      const priorityB = b.priority ?? 0;
       const score = priorityB - priorityA;
 
       if (score !== 0) {

packages/docusaurus/src/server/plugins/synthetic.ts

@@ -89,7 +89,7 @@ export function createMDXFallbackPlugin({
       // processed by content plugins mdx loaders. This works, but a bit
       // hacky... Not sure there's a way to handle that differently in webpack
       function getMDXFallbackExcludedPaths(): string[] {
-        const rules: RuleSetRule[] = config?.module?.rules as RuleSetRule[];
+        const rules: RuleSetRule[] = config.module?.rules as RuleSetRule[];
         return rules.flatMap((rule) => {
           const isMDXRule =
             rule.test instanceof RegExp && rule.test.test('x.mdx');

packages/docusaurus/src/server/routes.ts

@@ -152,7 +152,7 @@ const isModule = (value: unknown): value is Module =>
   typeof value === 'string' ||
   (typeof value === 'object' &&
     // eslint-disable-next-line no-underscore-dangle
-    !!(value as {[key: string]: unknown})?.__import);
+    !!(value as {[key: string]: unknown} | null)?.__import);
 
 /**
  * Takes a {@link Module} (which is nothing more than a path plus some metadata