From 5d449bd2c59a03aa1f405fe4feed00acf373d860 Mon Sep 17 00:00:00 2001
From: Bartosz Kaszubowski <gosimek@gmail.com>
Date: Mon, 30 Nov 2020 11:33:28 +0100
Subject: [PATCH 1/4] fix several lint warnings, add missing types, cleanup

---
 .../index.js                                  |  6 +-
 .../src/remark/transformImage/index.js        | 17 +++---
 packages/docusaurus-migrate/package.json      |  3 +-
 packages/docusaurus-migrate/src/index.ts      | 40 +++++++-------
 packages/docusaurus-migrate/src/sanitizeMD.ts | 10 +---
 packages/docusaurus-migrate/src/transform.ts  | 55 ++++++++++---------
 .../src/collectRedirects.ts                   | 10 ++--
 .../src/createRedirectPageContent.ts          |  4 +-
 .../src/blogUtils.ts                          |  2 +-
 .../src/types.ts                              | 14 +++--
 .../docusaurus-plugin-content-blog/types.d.ts |  2 +-
 .../src/docs.ts                               | 12 ++--
 .../src/sidebars.ts                           |  4 +-
 .../src/slug.ts                               |  2 +-
 .../src/types.ts                              | 14 +++--
 .../docusaurus-plugin-content-docs/types.d.ts |  2 +-
 .../src/index.ts                              |  2 +-
 .../src/types.ts                              | 14 +++--
 .../types.d.ts                                |  2 +-
 .../src/createSitemap.ts                      | 22 ++++----
 .../docusaurus-plugin-sitemap/src/types.ts    |  3 +-
 .../docusaurus-theme-classic/src/index.ts     |  2 +-
 .../src/theme/BlogSidebar/index.tsx           |  2 +-
 .../src/theme/CodeBlock/index.tsx             |  9 ++-
 .../src/theme/DocItem/index.tsx               | 18 +++---
 .../src/theme/LayoutProviders/index.tsx       |  3 +-
 .../src/theme/SearchMetadatas/index.tsx       |  2 +-
 .../docusaurus-theme-classic/src/types.d.ts   |  9 +++
 .../src/utils/pathUtils.ts                    |  2 +-
 .../src/utils/searchUtils.ts                  |  5 +-
 packages/docusaurus-types/src/index.d.ts      |  5 +-
 .../src/__tests__/validationSchemas.test.ts   |  4 +-
 .../src/validationUtils.ts                    |  2 +-
 packages/docusaurus-utils/src/index.ts        |  6 +-
 packages/docusaurus/package.json              |  1 +
 packages/docusaurus/src/choosePort.ts         | 12 ++--
 .../docusaurus/src/client/LinksCollector.tsx  |  4 +-
 .../src/client/PendingNavigation.tsx          |  5 +-
 .../baseUrlIssueBanner/BaseUrlIssueBanner.tsx |  2 +-
 .../src/client/exports/isInternalUrl.ts       |  2 +-
 packages/docusaurus/src/server/brokenLinks.ts |  2 +-
 .../docusaurus/src/server/duplicateRoutes.ts  |  7 +--
 .../docusaurus/src/server/plugins/init.ts     |  7 +--
 .../src/server/plugins/pluginIds.ts           |  4 +-
 packages/docusaurus/src/webpack/base.ts       |  4 +-
 packages/docusaurus/src/webpack/utils.ts      | 12 +++-
 yarn.lock                                     | 21 ++++++-
 47 files changed, 224 insertions(+), 168 deletions(-)

diff --git a/packages/docusaurus-cssnano-preset/src/remove-overridden-custom-properties/index.js b/packages/docusaurus-cssnano-preset/src/remove-overridden-custom-properties/index.js
index 2ee67fec8948..40058dfbc42f 100644
--- a/packages/docusaurus-cssnano-preset/src/remove-overridden-custom-properties/index.js
+++ b/packages/docusaurus-cssnano-preset/src/remove-overridden-custom-properties/index.js
@@ -28,11 +28,13 @@ module.exports = postcss.plugin(
         const sameProperties =
           decl.parent.nodes.filter((n) => n.prop === decl.prop) || [];
         const hasImportantProperties = sameProperties.some((p) =>
-          p.hasOwnProperty('important'),
+          Object.prototype.hasOwnProperty.call(p, 'important'),
         );
 
         const overriddenProperties = hasImportantProperties
-          ? sameProperties.filter((p) => !p.hasOwnProperty('important'))
+          ? sameProperties.filter(
+              (p) => !Object.prototype.hasOwnProperty.call(p, 'important'),
+            )
           : sameProperties.slice(0, -1);
 
         overriddenProperties.map((p) => p.remove());
diff --git a/packages/docusaurus-mdx-loader/src/remark/transformImage/index.js b/packages/docusaurus-mdx-loader/src/remark/transformImage/index.js
index 4d67ef9cd758..e7e178e59d17 100644
--- a/packages/docusaurus-mdx-loader/src/remark/transformImage/index.js
+++ b/packages/docusaurus-mdx-loader/src/remark/transformImage/index.js
@@ -18,21 +18,22 @@ const {
 } = getFileLoaderUtils();
 
 const createJSX = (node, pathUrl) => {
-  node.type = 'jsx';
-  node.value = `<img ${node.alt ? `alt={"${escapeHtml(node.alt)}"} ` : ''}${
+  const jsxNode = node;
+  jsxNode.type = 'jsx';
+  jsxNode.value = `<img ${node.alt ? `alt={"${escapeHtml(node.alt)}"} ` : ''}${
     node.url
       ? `src={require("${inlineMarkdownImageFileLoader}${pathUrl}").default}`
       : ''
   }${node.title ? ` title="${escapeHtml(node.title)}"` : ''} />`;
 
-  if (node.url) {
-    delete node.url;
+  if (jsxNode.url) {
+    delete jsxNode.url;
   }
-  if (node.alt) {
-    delete node.alt;
+  if (jsxNode.alt) {
+    delete jsxNode.alt;
   }
-  if (node.title) {
-    delete node.title;
+  if (jsxNode.title) {
+    delete jsxNode.title;
   }
 };
 
diff --git a/packages/docusaurus-migrate/package.json b/packages/docusaurus-migrate/package.json
index 02334da15c0c..0edf29ecdec3 100644
--- a/packages/docusaurus-migrate/package.json
+++ b/packages/docusaurus-migrate/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@docusaurus/migrate",
   "version": "2.0.0-alpha.69",
-  "description": "A cli tool to migrate between different version of docusuarus",
+  "description": "A cli tool to migrate between different version of Docusuarus",
   "main": "lib/index.js",
   "license": "MIT",
   "engines": {
@@ -43,6 +43,7 @@
     "unist-util-visit": "^2.0.2"
   },
   "devDependencies": {
+    "@types/color": "^3.0.1",
     "@types/jscodeshift": "^0.7.1"
   }
 }
diff --git a/packages/docusaurus-migrate/src/index.ts b/packages/docusaurus-migrate/src/index.ts
index 58050295070b..c39b668d9852 100644
--- a/packages/docusaurus-migrate/src/index.ts
+++ b/packages/docusaurus-migrate/src/index.ts
@@ -12,10 +12,10 @@ import glob from 'glob';
 import Color from 'color';
 
 import {
-  VersionOneConfig,
-  VersionTwoConfig,
   ClassicPresetEntries,
   SidebarEntries,
+  VersionOneConfig,
+  VersionTwoConfig,
 } from './types';
 import extractMetadata, {shouldQuotifyFrontMatter} from './frontMatter';
 import migratePage from './transform';
@@ -229,9 +229,9 @@ export function createConfigFile({
   const homePageId = siteConfig.headerLinks?.filter((value) => value.doc)[0]
     .doc;
 
-  const customConfigFields: Record<string, any> = {};
+  const customConfigFields: Record<string, unknown> = {};
   // add fields that are unknown to v2 to customConfigFields
-  Object.keys(siteConfig).forEach((key: any) => {
+  Object.keys(siteConfig).forEach((key) => {
     const knownFields = [
       'title',
       'tagline',
@@ -289,7 +289,7 @@ export function createConfigFile({
     v2DocsPath = path.relative(newDir, absoluteDocsPath);
   }
 
-  const result: VersionTwoConfig = {
+  return {
     title: siteConfig.title ?? '',
     tagline: siteConfig.tagline,
     url: siteConfig.url ?? '',
@@ -330,22 +330,24 @@ export function createConfigFile({
           : undefined,
         items: (siteConfig.headerLinks ?? [])
           .map((link) => {
-            if (link.doc) {
+            const {doc, href, label, page} = link;
+            const position = 'left';
+            if (doc) {
               return {
-                to: `docs/${link.doc === homePageId ? '' : link.doc}`,
-                label: link.label,
-                position: 'left',
+                to: `docs/${doc === homePageId ? '' : doc}`,
+                label,
+                position,
               };
             }
-            if (link.page) {
+            if (page) {
               return {
-                to: `/${link.page}`,
-                label: link.label,
-                position: 'left',
+                to: `/${page}`,
+                label,
+                position,
               };
             }
-            if (link.href) {
-              return {href: link.href, label: link.label, position: 'left'};
+            if (href) {
+              return {href, label, position};
             }
             return null;
           })
@@ -379,7 +381,6 @@ export function createConfigFile({
         : undefined,
     },
   };
-  return result;
 }
 
 function createClientRedirects(
@@ -476,7 +477,7 @@ function handleVersioning(
     const loadedVersions: Array<string> = JSON.parse(
       String(fs.readFileSync(path.join(siteDir, 'versions.json'))),
     );
-    fs.copyFile(
+    fs.copyFileSync(
       path.join(siteDir, 'versions.json'),
       path.join(newDir, 'versions.json'),
     );
@@ -732,11 +733,10 @@ function migrateLatestDocs(
   classicPreset: ClassicPresetEntries,
 ): void {
   if (fs.existsSync(path.join(siteDir, '..', 'docs'))) {
-    const docsPath = path.join(
+    classicPreset.docs.path = path.join(
       path.relative(newDir, path.join(siteDir, '..')),
       'docs',
     );
-    classicPreset.docs.path = docsPath;
     const files = walk(path.join(siteDir, '..', 'docs'));
     files.forEach((file) => {
       const content = String(fs.readFileSync(file));
@@ -797,5 +797,5 @@ export async function migrateMDToMDX(
       sanitizedFileContent(String(fs.readFileSync(file)), true),
     );
   });
-  console.log(`Succesfully migrated ${siteDir} to ${newDir}`);
+  console.log(`Successfully migrated ${siteDir} to ${newDir}`);
 }
diff --git a/packages/docusaurus-migrate/src/sanitizeMD.ts b/packages/docusaurus-migrate/src/sanitizeMD.ts
index c06843756763..c182073ffbb5 100644
--- a/packages/docusaurus-migrate/src/sanitizeMD.ts
+++ b/packages/docusaurus-migrate/src/sanitizeMD.ts
@@ -20,9 +20,7 @@ const tags = htmlTags.reduce((acc: {[key: string]: boolean}, tag) => {
 }, {});
 
 export default function sanitizeMD(code: string): string {
-  const markdownTree = unified()
-    .use(markdown as any)
-    .parse(code);
+  const markdownTree = unified().use(markdown).parse(code);
   visit(markdownTree, 'code', (node) => {
     node.value = `\n<!--${node.value}-->\n`;
   });
@@ -31,12 +29,10 @@ export default function sanitizeMD(code: string): string {
   });
 
   const markdownString = unified()
-    .use(remarkStringify as any, {fence: '`', fences: true})
+    .use(remarkStringify, {fence: '`', fences: true})
     .stringify(markdownTree);
 
-  const htmlTree = unified()
-    .use(parse as any)
-    .parse(markdownString);
+  const htmlTree = unified().use(parse).parse(markdownString);
   visit(htmlTree, 'element', (node) => {
     if (!tags[node.tagName as string]) {
       node.type = 'text';
diff --git a/packages/docusaurus-migrate/src/transform.ts b/packages/docusaurus-migrate/src/transform.ts
index e8e7577dd5a6..6c034dadc78b 100644
--- a/packages/docusaurus-migrate/src/transform.ts
+++ b/packages/docusaurus-migrate/src/transform.ts
@@ -5,7 +5,14 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import jscodeshift from 'jscodeshift';
+import jscodeshift, {
+  ArrowFunctionExpression,
+  AssignmentExpression,
+  ASTPath,
+  Collection,
+  TemplateElement,
+  VariableDeclarator,
+} from 'jscodeshift';
 
 const empty = () =>
   jscodeshift.arrowFunctionExpression(
@@ -18,16 +25,14 @@ const empty = () =>
     ),
   );
 
-const property = (key: string, value: jscodeshift.ArrowFunctionExpression) =>
+const property = (key: string, value: ArrowFunctionExpression) =>
   jscodeshift.objectProperty(jscodeshift.identifier(key), value);
 
-const processCallExpression = (
-  node: jscodeshift.ASTPath<jscodeshift.VariableDeclarator>,
-) => {
+const processCallExpression = (node: ASTPath<VariableDeclarator>) => {
   const args = (node?.value?.init as any)?.arguments[0];
   if (args.type === 'Literal') {
     if (args.value.includes('../../core/CompLibrary')) {
-      const newDeclartor = jscodeshift.variableDeclarator(
+      const newDeclarator = jscodeshift.variableDeclarator(
         node.value.id,
         jscodeshift.objectExpression([
           property('Container', empty()),
@@ -35,32 +40,30 @@ const processCallExpression = (
           property('MarkdownBlock', empty()),
         ]),
       );
-      jscodeshift(node).replaceWith(newDeclartor);
+      jscodeshift(node).replaceWith(newDeclarator);
     }
   }
   if (args.type === 'TemplateLiteral') {
     if (
       args.quasis
-        .map((element: jscodeshift.TemplateElement) => element.value.raw)
+        .map((element: TemplateElement) => element.value.raw)
         .join('')
         .match(/\/core\//)
     ) {
-      const newDeclartor = jscodeshift.variableDeclarator(
+      const newDeclarator = jscodeshift.variableDeclarator(
         node.value.id,
         empty(),
       );
-      jscodeshift(node).replaceWith(newDeclartor);
+      jscodeshift(node).replaceWith(newDeclarator);
     }
   }
 };
 
-const processMemberExpression = (
-  node: jscodeshift.ASTPath<jscodeshift.VariableDeclarator>,
-) => {
+const processMemberExpression = (node: ASTPath<VariableDeclarator>) => {
   const args = (node?.value?.init as any)?.object?.arguments[0];
   if (args.type === 'Literal') {
     if (args.value === '../../core/CompLibrary.js') {
-      const newDeclartor = jscodeshift.variableDeclarator(
+      const newDeclarator = jscodeshift.variableDeclarator(
         node.value.id,
         jscodeshift.objectExpression([
           property('Container', empty()),
@@ -68,27 +71,27 @@ const processMemberExpression = (
           property('MarkdownBlock', empty()),
         ]),
       );
-      jscodeshift(node).replaceWith(newDeclartor);
+      jscodeshift(node).replaceWith(newDeclarator);
     } else if (args.value.match(/server/)) {
-      const newDeclartor = jscodeshift.variableDeclarator(
+      const newDeclarator = jscodeshift.variableDeclarator(
         node.value.id,
         empty(),
       );
-      jscodeshift(node).replaceWith(newDeclartor);
+      jscodeshift(node).replaceWith(newDeclarator);
     }
   }
   if (args.type === 'TemplateLiteral') {
     if (
       args.quasis
-        .map((ele: jscodeshift.TemplateElement) => ele.value.raw)
+        .map((ele: TemplateElement) => ele.value.raw)
         .join('')
         .match(/\/core\//)
     ) {
-      const newDeclartor = jscodeshift.variableDeclarator(
+      const newDeclarator = jscodeshift.variableDeclarator(
         node.value.id,
         empty(),
       );
-      jscodeshift(node).replaceWith(newDeclartor);
+      jscodeshift(node).replaceWith(newDeclarator);
     }
   }
 };
@@ -113,7 +116,7 @@ export default function transformer(file: string): string {
   }
 
   root
-    .find(jscodeshift.AssignmentExpression, {
+    .find(AssignmentExpression, {
       operator: '=',
       left: {
         type: 'MemberExpression',
@@ -164,10 +167,10 @@ export default function transformer(file: string): string {
   return root.toSource();
 }
 
-function getDefaultImportDeclarators(rootAst: jscodeshift.Collection) {
+function getDefaultImportDeclarators(rootAst: Collection) {
   // var ... = require('y')
   return rootAst
-    .find(jscodeshift.VariableDeclarator, {
+    .find(VariableDeclarator, {
       init: {
         callee: {
           name: 'require',
@@ -179,9 +182,9 @@ function getDefaultImportDeclarators(rootAst: jscodeshift.Collection) {
     });
 }
 
-function getNamedImportDeclarators(rootAst: jscodeshift.Collection) {
+function getNamedImportDeclarators(rootAst: Collection) {
   // var ... = require('y').x
-  return rootAst.find(jscodeshift.VariableDeclarator, {
+  return rootAst.find(VariableDeclarator, {
     init: {
       object: {
         callee: {
@@ -192,7 +195,7 @@ function getNamedImportDeclarators(rootAst: jscodeshift.Collection) {
   });
 }
 
-function getImportDeclaratorPaths(variableDeclaration: jscodeshift.Collection) {
+function getImportDeclaratorPaths(variableDeclaration: Collection) {
   const defaultImports = getDefaultImportDeclarators(variableDeclaration);
 
   const namedImports = getNamedImportDeclarators(variableDeclaration);
diff --git a/packages/docusaurus-plugin-client-redirects/src/collectRedirects.ts b/packages/docusaurus-plugin-client-redirects/src/collectRedirects.ts
index 1a2541897d90..599990b2a436 100644
--- a/packages/docusaurus-plugin-client-redirects/src/collectRedirects.ts
+++ b/packages/docusaurus-plugin-client-redirects/src/collectRedirects.ts
@@ -85,11 +85,11 @@ It is not possible to redirect the same pathname to multiple destinations:
       }
     },
   );
-  redirects = uniqBy(redirects, (redirect) => redirect.from);
+  const collectedRedirects = uniqBy(redirects, (redirect) => redirect.from);
 
   // We don't want to override an already existing route with a redirect file!
-  const redirectsOverridingExistingPath = redirects.filter((redirect) =>
-    pluginContext.relativeRoutesPaths.includes(redirect.from),
+  const redirectsOverridingExistingPath = collectedRedirects.filter(
+    (redirect) => pluginContext.relativeRoutesPaths.includes(redirect.from),
   );
   if (redirectsOverridingExistingPath.length > 0) {
     console.error(
@@ -100,11 +100,9 @@ It is not possible to redirect the same pathname to multiple destinations:
       ),
     );
   }
-  redirects = redirects.filter(
+  return collectedRedirects.filter(
     (redirect) => !pluginContext.relativeRoutesPaths.includes(redirect.from),
   );
-
-  return redirects;
 }
 
 // For each plugin config option, create the appropriate redirects
diff --git a/packages/docusaurus-plugin-client-redirects/src/createRedirectPageContent.ts b/packages/docusaurus-plugin-client-redirects/src/createRedirectPageContent.ts
index 34cba18517fa..86f4060712d6 100644
--- a/packages/docusaurus-plugin-client-redirects/src/createRedirectPageContent.ts
+++ b/packages/docusaurus-plugin-client-redirects/src/createRedirectPageContent.ts
@@ -17,14 +17,14 @@ const getCompiledRedirectPageTemplate = memoize(() => {
   return eta.compile(redirectPageTemplate.trim());
 });
 
-function renderRedirectPageTemplate(data: object) {
+function renderRedirectPageTemplate(data: Record<string, unknown>) {
   const compiled = getCompiledRedirectPageTemplate();
   return compiled(data, eta.defaultConfig);
 }
 
 export default function createRedirectPageContent({
   toUrl,
-}: CreateRedirectPageOptions) {
+}: CreateRedirectPageOptions): string {
   return renderRedirectPageTemplate({
     toUrl: encodeURI(toUrl),
   });
diff --git a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
index 6c1963cd8f8a..e9486fe65daf 100644
--- a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
+++ b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
@@ -272,6 +272,6 @@ export function linkify({
 }
 
 // Order matters: we look in priority in localized folder
-export function getContentPathList(contentPaths: BlogContentPaths) {
+export function getContentPathList(contentPaths: BlogContentPaths): string[] {
   return [contentPaths.contentPathLocalized, contentPaths.contentPath];
 }
diff --git a/packages/docusaurus-plugin-content-blog/src/types.ts b/packages/docusaurus-plugin-content-blog/src/types.ts
index 93554fda5a04..159ecd64afc1 100644
--- a/packages/docusaurus-plugin-content-blog/src/types.ts
+++ b/packages/docusaurus-plugin-content-blog/src/types.ts
@@ -38,9 +38,15 @@ export interface PluginOptions {
   blogDescription: string;
   blogSidebarCount: number | 'ALL';
   blogSidebarTitle: string;
-  remarkPlugins: ([Function, object] | Function)[];
-  beforeDefaultRehypePlugins: ([Function, object] | Function)[];
-  beforeDefaultRemarkPlugins: ([Function, object] | Function)[];
+  remarkPlugins: ([Function, Record<string, unknown>] | Function)[];
+  beforeDefaultRehypePlugins: (
+    | [Function, Record<string, unknown>]
+    | Function
+  )[];
+  beforeDefaultRemarkPlugins: (
+    | [Function, Record<string, unknown>]
+    | Function
+  )[];
   rehypePlugins: string[];
   truncateMarker: RegExp;
   showReadingTime: boolean;
@@ -52,7 +58,7 @@ export interface PluginOptions {
     language?: string;
   };
   editUrl?: string;
-  admonitions: any;
+  admonitions: Record<string, unknown>;
 }
 
 export interface BlogTags {
diff --git a/packages/docusaurus-plugin-content-blog/types.d.ts b/packages/docusaurus-plugin-content-blog/types.d.ts
index c0c9f3a8ec03..c9976d8a584b 100644
--- a/packages/docusaurus-plugin-content-blog/types.d.ts
+++ b/packages/docusaurus-plugin-content-blog/types.d.ts
@@ -6,7 +6,7 @@
  */
 
 declare module 'remark-admonitions' {
-  type Options = any;
+  type Options = Record<string, unknown>;
 
   const plugin: (options?: Options) => void;
   export = plugin;
diff --git a/packages/docusaurus-plugin-content-docs/src/docs.ts b/packages/docusaurus-plugin-content-docs/src/docs.ts
index 0439b8e6dc52..a635f91737cb 100644
--- a/packages/docusaurus-plugin-content-docs/src/docs.ts
+++ b/packages/docusaurus-plugin-content-docs/src/docs.ts
@@ -9,21 +9,21 @@ import path from 'path';
 import fs from 'fs-extra';
 import {
   aliasedSitePath,
-  normalizeUrl,
   getEditUrl,
-  parseMarkdownString,
   getFolderContainingFile,
+  normalizeUrl,
+  parseMarkdownString,
 } from '@docusaurus/utils';
 import {LoadContext} from '@docusaurus/types';
 
 import {getFileLastUpdate} from './lastUpdate';
 import {
+  DocFile,
   DocMetadataBase,
   LastUpdateData,
   MetadataOptions,
-  VersionMetadata,
-  DocFile,
   PluginOptions,
+  VersionMetadata,
 } from './types';
 import getSlug from './slug';
 import {CURRENT_VERSION_NAME} from './constants';
@@ -173,7 +173,7 @@ export function processDocMetadata({
   // NodeJS optimization.
   // Adding properties to object after instantiation will cause hidden
   // class transitions.
-  const metadata: DocMetadataBase = {
+  return {
     unversionedId,
     id,
     isDocsHomePage,
@@ -188,6 +188,4 @@ export function processDocMetadata({
     lastUpdatedAt: lastUpdate.lastUpdatedAt,
     sidebar_label,
   };
-
-  return metadata;
 }
diff --git a/packages/docusaurus-plugin-content-docs/src/sidebars.ts b/packages/docusaurus-plugin-content-docs/src/sidebars.ts
index fba543f0558d..8d2926aeebd5 100644
--- a/packages/docusaurus-plugin-content-docs/src/sidebars.ts
+++ b/packages/docusaurus-plugin-content-docs/src/sidebars.ts
@@ -268,7 +268,9 @@ export function collectSidebarsDocIds(
   });
 }
 
-export function createSidebarsUtils(sidebars: Sidebars) {
+export function createSidebarsUtils(
+  sidebars: Sidebars,
+): Record<string, Function> {
   const sidebarNameToDocIds = collectSidebarsDocIds(sidebars);
 
   function getFirstDocIdOfFirstSidebar(): string | undefined {
diff --git a/packages/docusaurus-plugin-content-docs/src/slug.ts b/packages/docusaurus-plugin-content-docs/src/slug.ts
index 4c25aae6358d..84d0397336a3 100644
--- a/packages/docusaurus-plugin-content-docs/src/slug.ts
+++ b/packages/docusaurus-plugin-content-docs/src/slug.ts
@@ -21,7 +21,7 @@ export default function getSlug({
   frontmatterSlug?: string;
   dirName: string;
 }): string {
-  const baseSlug: string = frontmatterSlug || baseID;
+  const baseSlug = frontmatterSlug || baseID;
   let slug: string;
   if (baseSlug.startsWith('/')) {
     slug = baseSlug;
diff --git a/packages/docusaurus-plugin-content-docs/src/types.ts b/packages/docusaurus-plugin-content-docs/src/types.ts
index 0022ab30294d..0152a211f3ba 100644
--- a/packages/docusaurus-plugin-content-docs/src/types.ts
+++ b/packages/docusaurus-plugin-content-docs/src/types.ts
@@ -59,11 +59,17 @@ export type PluginOptions = MetadataOptions &
     include: string[];
     docLayoutComponent: string;
     docItemComponent: string;
-    remarkPlugins: ([Function, object] | Function)[];
+    remarkPlugins: ([Function, Record<string, unknown>] | Function)[];
     rehypePlugins: string[];
-    beforeDefaultRemarkPlugins: ([Function, object] | Function)[];
-    beforeDefaultRehypePlugins: ([Function, object] | Function)[];
-    admonitions: any;
+    beforeDefaultRemarkPlugins: (
+      | [Function, Record<string, unknown>]
+      | Function
+    )[];
+    beforeDefaultRehypePlugins: (
+      | [Function, Record<string, unknown>]
+      | Function
+    )[];
+    admonitions: Record<string, unknown>;
     disableVersioning: boolean;
     excludeNextVersionDocs?: boolean;
     includeCurrentVersion: boolean;
diff --git a/packages/docusaurus-plugin-content-docs/types.d.ts b/packages/docusaurus-plugin-content-docs/types.d.ts
index c0c9f3a8ec03..c9976d8a584b 100644
--- a/packages/docusaurus-plugin-content-docs/types.d.ts
+++ b/packages/docusaurus-plugin-content-docs/types.d.ts
@@ -6,7 +6,7 @@
  */
 
 declare module 'remark-admonitions' {
-  type Options = any;
+  type Options = Record<string, unknown>;
 
   const plugin: (options?: Options) => void;
   export = plugin;
diff --git a/packages/docusaurus-plugin-content-pages/src/index.ts b/packages/docusaurus-plugin-content-pages/src/index.ts
index 3e7e3db32f87..68c2ea9c08e8 100644
--- a/packages/docusaurus-plugin-content-pages/src/index.ts
+++ b/packages/docusaurus-plugin-content-pages/src/index.ts
@@ -42,7 +42,7 @@ import {
 } from './types';
 import {flatten} from 'lodash';
 
-export function getContentPathList(contentPaths: PagesContentPaths) {
+export function getContentPathList(contentPaths: PagesContentPaths): string[] {
   return [contentPaths.contentPathLocalized, contentPaths.contentPath];
 }
 
diff --git a/packages/docusaurus-plugin-content-pages/src/types.ts b/packages/docusaurus-plugin-content-pages/src/types.ts
index f53e1f115d23..b1b6cab22780 100644
--- a/packages/docusaurus-plugin-content-pages/src/types.ts
+++ b/packages/docusaurus-plugin-content-pages/src/types.ts
@@ -12,11 +12,17 @@ export interface PluginOptions {
   include: string[];
   exclude: string[];
   mdxPageComponent: string;
-  remarkPlugins: ([Function, object] | Function)[];
+  remarkPlugins: ([Function, Record<string, unknown>] | Function)[];
   rehypePlugins: string[];
-  beforeDefaultRemarkPlugins: ([Function, object] | Function)[];
-  beforeDefaultRehypePlugins: ([Function, object] | Function)[];
-  admonitions: any;
+  beforeDefaultRemarkPlugins: (
+    | [Function, Record<string, unknown>]
+    | Function
+  )[];
+  beforeDefaultRehypePlugins: (
+    | [Function, Record<string, unknown>]
+    | Function
+  )[];
+  admonitions: Record<string, unknown>;
 }
 
 export type JSXPageMetadata = {
diff --git a/packages/docusaurus-plugin-content-pages/types.d.ts b/packages/docusaurus-plugin-content-pages/types.d.ts
index c0c9f3a8ec03..c9976d8a584b 100644
--- a/packages/docusaurus-plugin-content-pages/types.d.ts
+++ b/packages/docusaurus-plugin-content-pages/types.d.ts
@@ -6,7 +6,7 @@
  */
 
 declare module 'remark-admonitions' {
-  type Options = any;
+  type Options = Record<string, unknown>;
 
   const plugin: (options?: Options) => void;
   export = plugin;
diff --git a/packages/docusaurus-plugin-sitemap/src/createSitemap.ts b/packages/docusaurus-plugin-sitemap/src/createSitemap.ts
index de3b1cb80b0d..bb2a639863ee 100644
--- a/packages/docusaurus-plugin-sitemap/src/createSitemap.ts
+++ b/packages/docusaurus-plugin-sitemap/src/createSitemap.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import sitemap, {SitemapItemOptions} from 'sitemap';
+import sitemap, {Sitemap, SitemapItemOptions} from 'sitemap';
 import {PluginOptions} from './types';
 import {DocusaurusConfig} from '@docusaurus/types';
 
@@ -13,28 +13,26 @@ export default function createSitemap(
   siteConfig: DocusaurusConfig,
   routesPaths: string[],
   options: PluginOptions,
-): sitemap.Sitemap {
+): Sitemap {
   const {url: hostname} = siteConfig;
   if (!hostname) {
     throw new Error('url in docusaurus.config.js cannot be empty/undefined');
   }
+  const {cacheTime, changefreq, priority, trailingSlash} = options;
 
   const urls = routesPaths
-    .filter((route: string) => !route.endsWith('404.html'))
+    .filter((route) => !route.endsWith('404.html'))
     .map(
-      (routesPath) =>
-        ({
-          url: `${routesPath}${
-            options.trailingSlash && routesPath !== '/' ? '/' : ''
-          }`,
-          changefreq: options.changefreq,
-          priority: options.priority,
-        } as SitemapItemOptions),
+      (routesPath): SitemapItemOptions => ({
+        url: `${routesPath}${trailingSlash && routesPath !== '/' ? '/' : ''}`,
+        changefreq,
+        priority,
+      }),
     );
 
   return sitemap.createSitemap({
     hostname,
-    cacheTime: options.cacheTime,
+    cacheTime,
     urls,
   });
 }
diff --git a/packages/docusaurus-plugin-sitemap/src/types.ts b/packages/docusaurus-plugin-sitemap/src/types.ts
index ad818c8ae318..fc24fb038991 100644
--- a/packages/docusaurus-plugin-sitemap/src/types.ts
+++ b/packages/docusaurus-plugin-sitemap/src/types.ts
@@ -4,10 +4,11 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
+import {EnumChangefreq} from 'sitemap';
 
 export interface PluginOptions {
   cacheTime?: number;
-  changefreq?: string;
+  changefreq?: EnumChangefreq;
   priority?: number;
   trailingSlash?: boolean;
 }
diff --git a/packages/docusaurus-theme-classic/src/index.ts b/packages/docusaurus-theme-classic/src/index.ts
index 1b2b949a1fab..ad7510a65559 100644
--- a/packages/docusaurus-theme-classic/src/index.ts
+++ b/packages/docusaurus-theme-classic/src/index.ts
@@ -151,7 +151,7 @@ const swizzleAllowedComponents = [
   'prism-include-languages',
 ];
 
-export function getSwizzleComponentList() {
+export function getSwizzleComponentList(): string[] {
   return swizzleAllowedComponents;
 }
 
diff --git a/packages/docusaurus-theme-classic/src/theme/BlogSidebar/index.tsx b/packages/docusaurus-theme-classic/src/theme/BlogSidebar/index.tsx
index 1d755bc295c3..2adf2dbaaff8 100644
--- a/packages/docusaurus-theme-classic/src/theme/BlogSidebar/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/BlogSidebar/index.tsx
@@ -11,7 +11,7 @@ import Link from '@docusaurus/Link';
 import type {Props} from '@theme/BlogSidebar';
 import styles from './styles.module.css';
 
-export default function BlogSidebar({sidebar}: Props) {
+export default function BlogSidebar({sidebar}: Props): JSX.Element | null {
   if (sidebar.items.length === 0) {
     return null;
   }
diff --git a/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx b/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx
index 3c86b916b86d..6bc91278e4a1 100644
--- a/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx
@@ -113,9 +113,7 @@ export default ({
   const prismTheme = usePrismTheme();
 
   // In case interleaved Markdown (e.g. when using CodeBlock as standalone component).
-  if (Array.isArray(children)) {
-    children = children.join('');
-  }
+  const content = Array.isArray(children) ? children.join('') : children;
 
   if (metastring && highlightLinesRangeRegex.test(metastring)) {
     // Tested above
@@ -133,6 +131,7 @@ export default ({
   let language =
     languageClassName &&
     // Force Prism's language union type to `any` because it does not contain all available languages
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
     ((languageClassName.replace(/language-/, '') as Language) as any);
 
   if (!language && prism.defaultLanguage) {
@@ -140,12 +139,12 @@ export default ({
   }
 
   // only declaration OR directive highlight can be used for a block
-  let code = children.replace(/\n$/, '');
+  let code = content.replace(/\n$/, '');
   if (highlightLines.length === 0 && language !== undefined) {
     let range = '';
     const directiveRegex = highlightDirectiveRegex(language);
     // go through line by line
-    const lines = children.replace(/\n$/, '').split('\n');
+    const lines = content.replace(/\n$/, '').split('\n');
     let blockStart;
     // loop through lines
     for (let index = 0; index < lines.length; ) {
diff --git a/packages/docusaurus-theme-classic/src/theme/DocItem/index.tsx b/packages/docusaurus-theme-classic/src/theme/DocItem/index.tsx
index 9e4025237ade..6f0e6627d77b 100644
--- a/packages/docusaurus-theme-classic/src/theme/DocItem/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/DocItem/index.tsx
@@ -27,16 +27,8 @@ function DocItem(props: Props): JSX.Element {
   const {siteConfig} = useDocusaurusContext();
   const {url: siteUrl, title: siteTitle, titleDelimiter} = siteConfig;
   const {content: DocContent} = props;
-  const {metadata} = DocContent;
-  const {
-    description,
-    title,
-    permalink,
-    editUrl,
-    lastUpdatedAt,
-    lastUpdatedBy,
-  } = metadata;
   const {
+    metadata,
     frontMatter: {
       image: metaImage,
       keywords,
@@ -44,6 +36,14 @@ function DocItem(props: Props): JSX.Element {
       hide_table_of_contents: hideTableOfContents,
     },
   } = DocContent;
+  const {
+    description,
+    title,
+    permalink,
+    editUrl,
+    lastUpdatedAt,
+    lastUpdatedBy,
+  } = metadata;
 
   const {pluginId} = useActivePlugin({failfast: true});
   const versions = useVersions(pluginId);
diff --git a/packages/docusaurus-theme-classic/src/theme/LayoutProviders/index.tsx b/packages/docusaurus-theme-classic/src/theme/LayoutProviders/index.tsx
index 710cfb0218a2..3bb0fa48dab6 100644
--- a/packages/docusaurus-theme-classic/src/theme/LayoutProviders/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/LayoutProviders/index.tsx
@@ -9,8 +9,9 @@ import React from 'react';
 import ThemeProvider from '@theme/ThemeProvider';
 import UserPreferencesProvider from '@theme/UserPreferencesProvider';
 import {DocsPreferredVersionContextProvider} from '@docusaurus/theme-common';
+import {Props} from '@theme/LayoutProviders';
 
-export default function LayoutProviders({children}) {
+export default function LayoutProviders({children}: Props): JSX.Element {
   return (
     <ThemeProvider>
       <UserPreferencesProvider>
diff --git a/packages/docusaurus-theme-classic/src/theme/SearchMetadatas/index.tsx b/packages/docusaurus-theme-classic/src/theme/SearchMetadatas/index.tsx
index 6c8886801e5b..bb66c40f5102 100644
--- a/packages/docusaurus-theme-classic/src/theme/SearchMetadatas/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/SearchMetadatas/index.tsx
@@ -22,7 +22,7 @@ export default function SearchMetadatas({
   locale,
   version,
   tag,
-}: SearchTagMetaProps) {
+}: SearchTagMetaProps): JSX.Element {
   return (
     <Head>
       {locale && <meta name="docusaurus_locale" content={`${locale}`} />}
diff --git a/packages/docusaurus-theme-classic/src/types.d.ts b/packages/docusaurus-theme-classic/src/types.d.ts
index 79f7631c4ced..b2668f711b58 100644
--- a/packages/docusaurus-theme-classic/src/types.d.ts
+++ b/packages/docusaurus-theme-classic/src/types.d.ts
@@ -440,6 +440,15 @@ declare module '@theme/UserPreferencesProvider' {
   export default UserPreferencesProvider;
 }
 
+declare module '@theme/LayoutProviders' {
+  import type {ReactNode} from 'react';
+
+  export type Props = {readonly children: ReactNode};
+
+  const LayoutProviders: (props: Props) => JSX.Element;
+  export default LayoutProviders;
+}
+
 declare module '@theme/ThemeContext' {
   import type {Context} from 'react';
   import type {ThemeContextProps} from '@theme/hooks/useThemeContext';
diff --git a/packages/docusaurus-theme-common/src/utils/pathUtils.ts b/packages/docusaurus-theme-common/src/utils/pathUtils.ts
index d2b769cab124..c88e1b6588a1 100644
--- a/packages/docusaurus-theme-common/src/utils/pathUtils.ts
+++ b/packages/docusaurus-theme-common/src/utils/pathUtils.ts
@@ -9,7 +9,7 @@
 export const isSamePath = (
   path1: string | undefined,
   path2: string | undefined,
-) => {
+): boolean => {
   const normalize = (pathname: string | undefined) => {
     return !pathname || pathname?.endsWith('/') ? pathname : `${pathname}/`;
   };
diff --git a/packages/docusaurus-theme-common/src/utils/searchUtils.ts b/packages/docusaurus-theme-common/src/utils/searchUtils.ts
index ae1dba0261ca..daa93c9c4db1 100644
--- a/packages/docusaurus-theme-common/src/utils/searchUtils.ts
+++ b/packages/docusaurus-theme-common/src/utils/searchUtils.ts
@@ -7,6 +7,9 @@
 
 export const DEFAULT_SEARCH_TAG = 'default';
 
-export function docVersionSearchTag(pluginId: string, versionName: string) {
+export function docVersionSearchTag(
+  pluginId: string,
+  versionName: string,
+): string {
   return `docs-${pluginId}-${versionName}`;
 }
diff --git a/packages/docusaurus-types/src/index.d.ts b/packages/docusaurus-types/src/index.d.ts
index 107541525d6b..8b24666380c5 100644
--- a/packages/docusaurus-types/src/index.d.ts
+++ b/packages/docusaurus-types/src/index.d.ts
@@ -336,7 +336,10 @@ export interface ThemeConfigValidationContext<T, E extends Error = Error> {
 
 // TODO we should use a Joi type here
 export interface ValidationSchema<T> {
-  validate(options: Partial<T>, opt: object): ValidationResult<T>;
+  validate(
+    options: Partial<T>,
+    opt: Record<string, unknown>,
+  ): ValidationResult<T>;
   unknown(): ValidationSchema<T>;
   append(data: any): ValidationSchema<T>;
 }
diff --git a/packages/docusaurus-utils-validation/src/__tests__/validationSchemas.test.ts b/packages/docusaurus-utils-validation/src/__tests__/validationSchemas.test.ts
index 19b38f77b8fc..39a4ee55be67 100644
--- a/packages/docusaurus-utils-validation/src/__tests__/validationSchemas.test.ts
+++ b/packages/docusaurus-utils-validation/src/__tests__/validationSchemas.test.ts
@@ -19,7 +19,7 @@ function createTestHelpers({
   schema,
   defaultValue,
 }: {
-  schema: Joi.SchemaLike;
+  schema: Joi.Schema;
   defaultValue?: unknown;
 }) {
   function testOK(value: unknown) {
@@ -36,7 +36,7 @@ function createTestHelpers({
   return {testOK, testFail};
 }
 
-function testMarkdownPluginSchemas(schema: Joi.SchemaLike) {
+function testMarkdownPluginSchemas(schema: Joi.Schema) {
   const {testOK, testFail} = createTestHelpers({
     schema,
     defaultValue: [],
diff --git a/packages/docusaurus-utils-validation/src/validationUtils.ts b/packages/docusaurus-utils-validation/src/validationUtils.ts
index acfc0822142a..5a270dc4f243 100644
--- a/packages/docusaurus-utils-validation/src/validationUtils.ts
+++ b/packages/docusaurus-utils-validation/src/validationUtils.ts
@@ -25,7 +25,7 @@ if (isValidationDisabledEscapeHatch) {
   );
 }
 
-export const logValidationBugReportHint = () => {
+export const logValidationBugReportHint = (): void => {
   console.log(
     `\n${chalk.red('A validation error occured.')}${chalk.cyanBright(
       '\nThe validation system was added recently to Docusaurus as an attempt to avoid user configuration errors.' +
diff --git a/packages/docusaurus-utils/src/index.ts b/packages/docusaurus-utils/src/index.ts
index 88644f48c5c0..22fd61f7b6c3 100644
--- a/packages/docusaurus-utils/src/index.ts
+++ b/packages/docusaurus-utils/src/index.ts
@@ -266,7 +266,7 @@ export function parseMarkdownString(markdownString: string): ParsedMarkdown {
     return {frontMatter, content, excerpt};
   } catch (e) {
     throw new Error(`Error while parsing markdown front matter.
-This can happen if you use special characteres like : in frontmatter values (try using "" around that value)
+This can happen if you use special characters like : in frontmatter values (try using "" around that value)
 ${e.message}`);
   }
 }
@@ -394,7 +394,7 @@ export function isValidPathname(str: string): boolean {
 }
 
 // resolve pathname and fail fast if resolution fails
-export function resolvePathname(to: string, from?: string) {
+export function resolvePathname(to: string, from?: string): string {
   return resolvePathnameUnsafe(to, from);
 }
 export function addLeadingSlash(str: string): string {
@@ -456,7 +456,7 @@ export function getPluginI18nPath({
   pluginName: string;
   pluginId?: string | undefined;
   subPaths?: string[];
-}) {
+}): string {
   return path.join(
     siteDir,
     'i18n',
diff --git a/packages/docusaurus/package.json b/packages/docusaurus/package.json
index 0f51f97c63c7..0021b54af5d2 100644
--- a/packages/docusaurus/package.json
+++ b/packages/docusaurus/package.json
@@ -33,6 +33,7 @@
   "devDependencies": {
     "@docusaurus/module-type-aliases": "2.0.0-alpha.69",
     "@types/detect-port": "^1.3.0",
+    "@types/nprogress": "^0.2.0",
     "tmp-promise": "^3.0.2"
   },
   "dependencies": {
diff --git a/packages/docusaurus/src/choosePort.ts b/packages/docusaurus/src/choosePort.ts
index 8a07bfe2e77a..62f973ec98bb 100644
--- a/packages/docusaurus/src/choosePort.ts
+++ b/packages/docusaurus/src/choosePort.ts
@@ -18,7 +18,7 @@ import inquirer from 'inquirer';
 
 const isInteractive = process.stdout.isTTY;
 
-const execOptions: object = {
+const execOptions: Record<string, unknown> = {
   encoding: 'utf8',
   stdio: [
     'pipe', // stdin (default)
@@ -43,15 +43,13 @@ function getProcessIdOnPort(port: number): string {
 }
 
 // Gets process command
-function getProcessCommand(processId: string): Promise<string | null> | string {
-  let command: Buffer | string = execSync(
+function getProcessCommand(processId: string): string {
+  const command: Buffer = execSync(
     `ps -o command -p ${processId} | sed -n 2p`,
     execOptions,
   );
 
-  command = command.toString().replace(/\n$/, '');
-
-  return command;
+  return command.toString().replace(/\n$/, '');
 }
 
 // Gets directory of a process from its process id
@@ -103,7 +101,7 @@ export default async function choosePort(
         if (isInteractive) {
           clearConsole();
           const existingProcess = getProcessForPort(defaultPort);
-          const question: any = {
+          const question: Record<string, unknown> = {
             type: 'confirm',
             name: 'shouldChangePort',
             message: `${chalk.yellow(
diff --git a/packages/docusaurus/src/client/LinksCollector.tsx b/packages/docusaurus/src/client/LinksCollector.tsx
index f38de070203b..bf15a67d71af 100644
--- a/packages/docusaurus/src/client/LinksCollector.tsx
+++ b/packages/docusaurus/src/client/LinksCollector.tsx
@@ -35,7 +35,7 @@ const Context = createContext<LinksCollector>({
   },
 });
 
-export const useLinksCollector = () => {
+export const useLinksCollector = (): LinksCollector => {
   return useContext(Context);
 };
 
@@ -45,6 +45,6 @@ export const ProvideLinksCollector = ({
 }: {
   children: ReactNode;
   linksCollector: LinksCollector;
-}) => {
+}): JSX.Element => {
   return <Context.Provider value={linksCollector}>{children}</Context.Provider>;
 };
diff --git a/packages/docusaurus/src/client/PendingNavigation.tsx b/packages/docusaurus/src/client/PendingNavigation.tsx
index 1b2ae12ec1e6..0af38d3543ff 100644
--- a/packages/docusaurus/src/client/PendingNavigation.tsx
+++ b/packages/docusaurus/src/client/PendingNavigation.tsx
@@ -7,6 +7,7 @@
 
 import React from 'react';
 import {Route, withRouter} from 'react-router-dom';
+import {RouteConfig} from 'react-router-config';
 import nprogress from 'nprogress';
 
 import clientLifecyclesDispatcher from './client-lifecycles-dispatcher';
@@ -18,7 +19,7 @@ import './nprogress.css';
 nprogress.configure({showSpinner: false});
 
 interface Props {
-  routes: any[];
+  routes: RouteConfig[];
   delay: number;
   location: any;
 }
@@ -104,7 +105,7 @@ class PendingNavigation extends React.Component<Props, State> {
     }
   }
 
-  startProgressBar(delay) {
+  startProgressBar(delay: number) {
     this.clearProgressBarTimeout();
     this.progressBarTimeout = setTimeout(() => {
       clientLifecyclesDispatcher.onRouteUpdateDelayed({
diff --git a/packages/docusaurus/src/client/baseUrlIssueBanner/BaseUrlIssueBanner.tsx b/packages/docusaurus/src/client/baseUrlIssueBanner/BaseUrlIssueBanner.tsx
index 25a59b644836..4eb41e5f5761 100644
--- a/packages/docusaurus/src/client/baseUrlIssueBanner/BaseUrlIssueBanner.tsx
+++ b/packages/docusaurus/src/client/baseUrlIssueBanner/BaseUrlIssueBanner.tsx
@@ -18,7 +18,7 @@ import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 // Note: it might create false positives (ie network failures): not a big deal
 // Note: we only inline this for the homepage to avoid polluting all the site's pages
 // See https://github.com/facebook/docusaurus/pull/3621
-export default function BaseUrlIssueBanner() {
+export default function BaseUrlIssueBanner(): JSX.Element | null {
   const {
     siteConfig: {baseUrl, baseUrlIssueBanner},
   } = useDocusaurusContext();
diff --git a/packages/docusaurus/src/client/exports/isInternalUrl.ts b/packages/docusaurus/src/client/exports/isInternalUrl.ts
index d4755e658ab9..eb503cb54c5e 100644
--- a/packages/docusaurus/src/client/exports/isInternalUrl.ts
+++ b/packages/docusaurus/src/client/exports/isInternalUrl.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-export function hasProtocol(url: string) {
+export function hasProtocol(url: string): boolean {
   return /^(\w*:|\/\/)/.test(url) === true;
 }
 
diff --git a/packages/docusaurus/src/server/brokenLinks.ts b/packages/docusaurus/src/server/brokenLinks.ts
index 81bc58fac1c9..a4e0d5c4c48a 100644
--- a/packages/docusaurus/src/server/brokenLinks.ts
+++ b/packages/docusaurus/src/server/brokenLinks.ts
@@ -202,7 +202,7 @@ export async function handleBrokenLinks({
   routes: RouteConfig[];
   baseUrl: string;
   outDir: string;
-}) {
+}): Promise<void> {
   if (onBrokenLinks === 'ignore') {
     return;
   }
diff --git a/packages/docusaurus/src/server/duplicateRoutes.ts b/packages/docusaurus/src/server/duplicateRoutes.ts
index 54af2aa70ad8..147cca896e75 100644
--- a/packages/docusaurus/src/server/duplicateRoutes.ts
+++ b/packages/docusaurus/src/server/duplicateRoutes.ts
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-import {RouteConfig, ReportingSeverity} from '@docusaurus/types';
+import {ReportingSeverity, RouteConfig} from '@docusaurus/types';
 import {reportMessage} from '@docusaurus/utils';
 import {getAllFinalRoutes} from './utils';
 
@@ -15,15 +15,14 @@ export function getAllDuplicateRoutes(
     (routeConfig) => routeConfig.path,
   );
   const seenRoutes: Record<string, any> = {};
-  const duplicateRoutes: string[] = allRoutes.filter(function (route) {
-    if (seenRoutes.hasOwnProperty(route)) {
+  return allRoutes.filter((route) => {
+    if (Object.prototype.hasOwnProperty.call(seenRoutes, route)) {
       return true;
     } else {
       seenRoutes[route] = true;
       return false;
     }
   });
-  return duplicateRoutes;
 }
 
 export function getDuplicateRoutesMessage(
diff --git a/packages/docusaurus/src/server/plugins/init.ts b/packages/docusaurus/src/server/plugins/init.ts
index d7e9de0e4205..4b5979f7cc09 100644
--- a/packages/docusaurus/src/server/plugins/init.ts
+++ b/packages/docusaurus/src/server/plugins/init.ts
@@ -9,11 +9,11 @@ import Module from 'module';
 import {join} from 'path';
 import importFresh from 'import-fresh';
 import {
+  DocusaurusPluginVersionInformation,
   LoadContext,
   Plugin,
-  PluginOptions,
   PluginConfig,
-  DocusaurusPluginVersionInformation,
+  PluginOptions,
 } from '@docusaurus/types';
 import {CONFIG_FILE_NAME, DEFAULT_PLUGIN_ID} from '../../constants';
 import {getPluginVersion} from '../versions';
@@ -74,11 +74,10 @@ export default function initPlugins({
         pluginModule.default?.validateOptions ?? pluginModule.validateOptions;
 
       if (validateOptions) {
-        const normalizedOptions = validateOptions({
+        pluginOptions = validateOptions({
           validate: normalizePluginOptions,
           options: pluginOptions,
         });
-        pluginOptions = normalizedOptions;
       } else {
         // Important to ensure all plugins have an id
         // as we don't go through the Joi schema that adds it
diff --git a/packages/docusaurus/src/server/plugins/pluginIds.ts b/packages/docusaurus/src/server/plugins/pluginIds.ts
index e3fff3b9dd38..7c4c0288337e 100644
--- a/packages/docusaurus/src/server/plugins/pluginIds.ts
+++ b/packages/docusaurus/src/server/plugins/pluginIds.ts
@@ -9,9 +9,9 @@ import {groupBy} from 'lodash';
 import {InitPlugin} from './init';
 import {DEFAULT_PLUGIN_ID} from '../../constants';
 
-// It is forbidden to have 2 plugins of the same name sharind the same id
+// It is forbidden to have 2 plugins of the same name sharing the same id
 // this is required to support multi-instance plugins without conflict
-export function ensureUniquePluginInstanceIds(plugins: InitPlugin[]) {
+export function ensureUniquePluginInstanceIds(plugins: InitPlugin[]): void {
   const pluginsByName = groupBy(plugins, (p) => p.name);
   Object.entries(pluginsByName).forEach(([pluginName, pluginInstances]) => {
     const pluginInstancesById = groupBy(
diff --git a/packages/docusaurus/src/webpack/base.ts b/packages/docusaurus/src/webpack/base.ts
index fff5da0a1748..fb5264ec0192 100644
--- a/packages/docusaurus/src/webpack/base.ts
+++ b/packages/docusaurus/src/webpack/base.ts
@@ -36,11 +36,11 @@ export function excludeJS(modulePath: string): boolean {
   );
 }
 
-export function getDocusaurusAliases() {
+export function getDocusaurusAliases(): Record<string, string> {
   const dirPath = path.resolve(__dirname, '../client/exports');
   const extensions = ['.js', '.ts', '.tsx'];
 
-  const aliases: Record<string, string> = {};
+  const aliases = {};
 
   fs.readdirSync(dirPath)
     .filter((fileName) => extensions.includes(path.extname(fileName)))
diff --git a/packages/docusaurus/src/webpack/utils.ts b/packages/docusaurus/src/webpack/utils.ts
index e079671e914e..a30faeca92d6 100644
--- a/packages/docusaurus/src/webpack/utils.ts
+++ b/packages/docusaurus/src/webpack/utils.ts
@@ -8,7 +8,13 @@
 import MiniCssExtractPlugin from 'mini-css-extract-plugin';
 import env from 'std-env';
 import merge from 'webpack-merge';
-import webpack, {Configuration, Loader, RuleSetRule, Stats} from 'webpack';
+import webpack, {
+  Configuration,
+  Loader,
+  Plugin,
+  RuleSetRule,
+  Stats,
+} from 'webpack';
 import fs from 'fs-extra';
 import TerserPlugin from 'terser-webpack-plugin';
 import OptimizeCSSAssetsPlugin from 'optimize-css-assets-webpack-plugin';
@@ -228,7 +234,7 @@ export function compile(config: Configuration[]): Promise<void> {
 type AssetFolder = 'images' | 'files' | 'medias';
 
 // Inspired by https://github.com/gatsbyjs/gatsby/blob/8e6e021014da310b9cc7d02e58c9b3efe938c665/packages/gatsby/src/utils/webpack-utils.ts#L447
-export function getFileLoaderUtils() {
+export function getFileLoaderUtils(): Record<string, any> {
   // files/images < 10kb will be inlined as base64 strings directly in the html
   const urlLoaderLimit = 10000;
 
@@ -375,7 +381,7 @@ function getTerserParallel() {
   return terserParallel;
 }
 
-export function getMinimizer(useSimpleCssMinifier = false) {
+export function getMinimizer(useSimpleCssMinifier = false): Plugin[] {
   const minimizer = [
     new TerserPlugin({
       cache: true,
diff --git a/yarn.lock b/yarn.lock
index 4c1246cc271c..2be74fe5cfaa 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3197,11 +3197,25 @@
   dependencies:
     "@types/node" "*"
 
-"@types/color-name@^1.1.1":
+"@types/color-convert@*":
+  version "1.9.0"
+  resolved "https://registry.yarnpkg.com/@types/color-convert/-/color-convert-1.9.0.tgz#bfa8203e41e7c65471e9841d7e306a7cd8b5172d"
+  integrity sha512-OKGEfULrvSL2VRbkl/gnjjgbbF7ycIlpSsX7Nkab4MOWi5XxmgBYvuiQ7lcCFY5cPDz7MUNaKgxte2VRmtr4Fg==
+  dependencies:
+    "@types/color-name" "*"
+
+"@types/color-name@*", "@types/color-name@^1.1.1":
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/@types/color-name/-/color-name-1.1.1.tgz#1c1261bbeaa10a8055bbc5d8ab84b7b2afc846a0"
   integrity sha512-rr+OQyAjxze7GgWrSaJwydHStIhHq2lvY3BOC2Mj7KnzI7XK0Uw1TOOdI9lDoajEbSWLiYgoo4f1R51erQfhPQ==
 
+"@types/color@^3.0.1":
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/@types/color/-/color-3.0.1.tgz#2900490ed04da8116c5058cd5dba3572d5a25071"
+  integrity sha512-oeUWVaAwI+xINDUx+3F2vJkl/vVB03VChFF/Gl3iQCdbcakjuoJyMOba+3BXRtnBhxZ7uBYqQBi9EpLnvSoztA==
+  dependencies:
+    "@types/color-convert" "*"
+
 "@types/connect-history-api-fallback@*":
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/@types/connect-history-api-fallback/-/connect-history-api-fallback-1.3.3.tgz#4772b79b8b53185f0f4c9deab09236baf76ee3b4"
@@ -3537,6 +3551,11 @@
   resolved "https://registry.yarnpkg.com/@types/normalize-package-data/-/normalize-package-data-2.4.0.tgz#e486d0d97396d79beedd0a6e33f4534ff6b4973e"
   integrity sha512-f5j5b/Gf71L+dbqxIpQ4Z2WlmI/mPJ0fOkGGmFgtb6sAu97EPczzbS3/tJKxmcYDj55OX6ssqwDAWOHIYDRDGA==
 
+"@types/nprogress@^0.2.0":
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/@types/nprogress/-/nprogress-0.2.0.tgz#86c593682d4199212a0509cc3c4d562bbbd6e45f"
+  integrity sha512-1cYJrqq9GezNFPsWTZpFut/d4CjpZqA0vhqDUPFWYKF1oIyBz5qnoYMzR+0C/T96t3ebLAC1SSnwrVOm5/j74A==
+
 "@types/parse-json@^4.0.0":
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/@types/parse-json/-/parse-json-4.0.0.tgz#2f8bb441434d163b35fb8ffdccd7138927ffb8c0"

From 01c629f97b67c203a0df7ff2c943a9ac27c7db56 Mon Sep 17 00:00:00 2001
From: Bartosz Kaszubowski <gosimek@gmail.com>
Date: Mon, 30 Nov 2020 12:07:32 +0100
Subject: [PATCH 2/4] fix EnumChangefreq issue

---
 packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts b/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts
index 389e301e3b2f..78a98809af04 100644
--- a/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts
+++ b/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts
@@ -5,11 +5,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 import * as Joi from 'joi';
+import {EnumChangefreq} from 'sitemap';
 import {PluginOptions} from './types';
 
 export const DEFAULT_OPTIONS: Required<PluginOptions> = {
   cacheTime: 600 * 1000, // 600 sec - cache purge period.
-  changefreq: 'weekly',
+  changefreq: 'weekly' as EnumChangefreq,
   priority: 0.5,
   trailingSlash: false,
 };

From 1f8a5d0c9f61de9bc6e3c3db5e3a8e3f8f8d9f52 Mon Sep 17 00:00:00 2001
From: Bartosz Kaszubowski <gosimek@gmail.com>
Date: Mon, 30 Nov 2020 12:33:22 +0100
Subject: [PATCH 3/4] better utilization of EnumChangefreq type

---
 packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts b/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts
index 78a98809af04..a15384e3615c 100644
--- a/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts
+++ b/packages/docusaurus-plugin-sitemap/src/pluginOptionSchema.ts
@@ -10,7 +10,7 @@ import {PluginOptions} from './types';
 
 export const DEFAULT_OPTIONS: Required<PluginOptions> = {
   cacheTime: 600 * 1000, // 600 sec - cache purge period.
-  changefreq: 'weekly' as EnumChangefreq,
+  changefreq: EnumChangefreq.WEEKLY,
   priority: 0.5,
   trailingSlash: false,
 };
@@ -18,7 +18,7 @@ export const DEFAULT_OPTIONS: Required<PluginOptions> = {
 export const PluginOptionSchema = Joi.object({
   cacheTime: Joi.number().positive().default(DEFAULT_OPTIONS.cacheTime),
   changefreq: Joi.string()
-    .valid('always', 'hourly', 'daily', 'weekly', 'monthly', 'yearly', 'never')
+    .valid(...Object.values(EnumChangefreq))
     .default(DEFAULT_OPTIONS.changefreq),
   priority: Joi.number().min(0).max(1).default(DEFAULT_OPTIONS.priority),
   trailingSlash: Joi.bool().default(false),

From e98959f0e450459c6dc5014e74eee59dd0cf8d37 Mon Sep 17 00:00:00 2001
From: Bartosz Kaszubowski <gosimek@gmail.com>
Date: Mon, 30 Nov 2020 12:42:11 +0100
Subject: [PATCH 4/4] update test snapshot

---
 .../src/__tests__/pluginOptionSchema.test.ts                    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/docusaurus-plugin-sitemap/src/__tests__/pluginOptionSchema.test.ts b/packages/docusaurus-plugin-sitemap/src/__tests__/pluginOptionSchema.test.ts
index 91abdcccdb57..b7f7cbbc7e9e 100644
--- a/packages/docusaurus-plugin-sitemap/src/__tests__/pluginOptionSchema.test.ts
+++ b/packages/docusaurus-plugin-sitemap/src/__tests__/pluginOptionSchema.test.ts
@@ -59,7 +59,7 @@ describe('normalizeSitemapPluginOptions', () => {
         changefreq: 'annually',
       });
     }).toThrowErrorMatchingInlineSnapshot(
-      `"\\"changefreq\\" must be one of [always, hourly, daily, weekly, monthly, yearly, never]"`,
+      `"\\"changefreq\\" must be one of [daily, monthly, always, hourly, weekly, yearly, never]"`,
     );
   });
 });