feat(v2): Provide type definitions for MDXPage from page plugin (#3354)

packages/docusaurus-plugin-content-pages/package.json

@@ -3,6 +3,7 @@
   "version": "2.0.0-alpha.61",
   "description": "Pages content plugin for Docusaurus",
   "main": "lib/index.js",
+  "types": "src/plugin-content-pages.d.ts",
   "scripts": {
     "build": "tsc",
     "watch": "tsc --watch"

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

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+declare module '@theme/MDXPage' {
+  import type {MarkdownRightTableOfContents} from '@docusaurus/types';
+
+  export type Props = {
+    readonly content: {
+      readonly frontMatter: {
+        readonly title: string;
+        readonly description: string;
+      };
+      readonly metadata: {readonly permalink: string};
+      readonly rightToc: readonly MarkdownRightTableOfContents[];
+      (): JSX.Element;
+    };
+  };
+
+  const MDXPage: (props: Props) => JSX.Element;
+  export default MDXPage;
+}

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

@@ -9,8 +9,9 @@ import React from 'react';
 import Layout from '@theme/Layout';
 import {MDXProvider} from '@mdx-js/react';
 import MDXComponents from '@theme/MDXComponents';
+import type {Props} from '@theme/MDXPage';
 
-function MDXPage(props) {
+function MDXPage(props: Props): JSX.Element {
   const {content: MDXPageContent} = props;
   const {frontMatter, metadata} = MDXPageContent;
   const {title, description} = frontMatter;

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

@@ -10,6 +10,7 @@
 /// <reference types="@docusaurus/module-type-aliases" />
 /// <reference types="@docusaurus/plugin-content-blog" />
 /// <reference types="@docusaurus/plugin-content-docs" />
+/// <reference types="@docusaurus/plugin-content-pages" />
 
 declare module '@theme/AnnouncementBar' {
   const AnnouncementBar: () => JSX.Element | null;
@@ -271,8 +272,6 @@ declare module '@theme/MDXComponents' {
   export default MDXComponents;
 }
 
-// TODO @theme/MDXPage
-
 declare module '@theme/Navbar' {
   const Navbar: () => JSX.Element;
   export default Navbar;