Merge remote-tracking branch 'msky/develop' into renovate/major-backend-update-dependencies

2026-05-19 17:05:35 +02:00 · 2025-11-29 22:16:11 +09:00
parent cf88d2357c 1ae8e7900d
commit fc43017439
20 changed files with 253 additions and 456 deletions
--- a/packages/backend/src/core/FetchInstanceMetadataService.ts
+++ b/packages/backend/src/core/FetchInstanceMetadataService.ts
@@ -5,9 +5,9 @@

 import { URL } from 'node:url';
 import { Inject, Injectable } from '@nestjs/common';
-import { JSDOM } from 'jsdom';
 import tinycolor from 'tinycolor2';
 import * as Redis from 'ioredis';
+import * as htmlParser from 'node-html-parser';
 import type { MiInstance } from '@/models/Instance.js';
 import type Logger from '@/logger.js';
 import { DI } from '@/di-symbols.js';
@@ -15,7 +15,6 @@ import { LoggerService } from '@/core/LoggerService.js';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { bindThis } from '@/decorators.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
-import type { DOMWindow } from 'jsdom';

 type NodeInfo = {
 	openRegistrations?: unknown;
@@ -59,7 +58,7 @@ export class FetchInstanceMetadataService {
 		return await this.redisClient.set(
 			`fetchInstanceMetadata:mutex:v2:${host}`, '1',
 			'EX', 30, // 30秒したら自動でロック解除 https://github.com/misskey-dev/misskey/issues/13506#issuecomment-1975375395
-			'GET' // 古い値を返す（なかったらnull）
+			'GET', // 古い値を返す（なかったらnull）
 		);
 	}

@@ -181,15 +180,14 @@ export class FetchInstanceMetadataService {
 	}

 	@bindThis
-	private async fetchDom(instance: MiInstance): Promise<Document> {
+	private async fetchDom(instance: MiInstance): Promise<htmlParser.HTMLElement> {
 		this.logger.info(`Fetching HTML of ${instance.host} ...`);

 		const url = 'https://' + instance.host;

 		const html = await this.httpRequestService.getHtml(url);

-		const { window } = new JSDOM(html);
-		const doc = window.document;
+		const doc = htmlParser.parse(html);

 		return doc;
 	}
@@ -206,12 +204,12 @@ export class FetchInstanceMetadataService {
 	}

 	@bindThis
-	private async fetchFaviconUrl(instance: MiInstance, doc: Document | null): Promise<string | null> {
+	private async fetchFaviconUrl(instance: MiInstance, doc: htmlParser.HTMLElement | null): Promise<string | null> {
 		const url = 'https://' + instance.host;

 		if (doc) {
 			// https://github.com/misskey-dev/misskey/pull/8220#issuecomment-1025104043
-			const href = Array.from(doc.getElementsByTagName('link')).reverse().find(link => link.relList.contains('icon'))?.href;
+			const href = Array.from(doc.getElementsByTagName('link')).reverse().find(link => link.attributes.rel === 'icon')?.attributes.href;

 			if (href) {
 				return (new URL(href, url)).href;
@@ -232,7 +230,7 @@ export class FetchInstanceMetadataService {
 	}

 	@bindThis
-	private async fetchIconUrl(instance: MiInstance, doc: Document | null, manifest: Record<string, any> | null): Promise<string | null> {
+	private async fetchIconUrl(instance: MiInstance, doc: htmlParser.HTMLElement | null, manifest: Record<string, any> | null): Promise<string | null> {
 		if (manifest && manifest.icons && manifest.icons.length > 0 && manifest.icons[0].src) {
 			const url = 'https://' + instance.host;
 			return (new URL(manifest.icons[0].src, url)).href;
@@ -246,9 +244,9 @@ export class FetchInstanceMetadataService {
 			// https://github.com/misskey-dev/misskey/pull/8220/files/0ec4eba22a914e31b86874f12448f88b3e58dd5a#r796487559
 			const href =
 				[
-					links.find(link => link.relList.contains('apple-touch-icon-precomposed'))?.href,
-					links.find(link => link.relList.contains('apple-touch-icon'))?.href,
-					links.find(link => link.relList.contains('icon'))?.href,
+					links.find(link => link.attributes.rel?.split(/\s+/).includes('apple-touch-icon-precomposed'))?.attributes.href,
+					links.find(link => link.attributes.rel?.split(/\s+/).includes('apple-touch-icon'))?.attributes.href,
+					links.find(link => link.attributes.rel?.split(/\s+/).includes('icon'))?.attributes.href,
 				]
 					.find(href => href);

@@ -261,7 +259,7 @@ export class FetchInstanceMetadataService {
 	}

 	@bindThis
-	private async getThemeColor(info: NodeInfo | null, doc: Document | null, manifest: Record<string, any> | null): Promise<string | null> {
+	private async getThemeColor(info: NodeInfo | null, doc: htmlParser.HTMLElement | null, manifest: Record<string, any> | null): Promise<string | null> {
 		const themeColor = info?.metadata?.themeColor ?? doc?.querySelector('meta[name="theme-color"]')?.getAttribute('content') ?? manifest?.theme_color;

 		if (themeColor) {
@@ -273,7 +271,7 @@ export class FetchInstanceMetadataService {
 	}

 	@bindThis
-	private async getSiteName(info: NodeInfo | null, doc: Document | null, manifest: Record<string, any> | null): Promise<string | null> {
+	private async getSiteName(info: NodeInfo | null, doc: htmlParser.HTMLElement | null, manifest: Record<string, any> | null): Promise<string | null> {
 		if (info && info.metadata) {
 			if (typeof info.metadata.nodeName === 'string') {
 				return info.metadata.nodeName;
@@ -298,7 +296,7 @@ export class FetchInstanceMetadataService {
 	}

 	@bindThis
-	private async getDescription(info: NodeInfo | null, doc: Document | null, manifest: Record<string, any> | null): Promise<string | null> {
+	private async getDescription(info: NodeInfo | null, doc: htmlParser.HTMLElement | null, manifest: Record<string, any> | null): Promise<string | null> {
 		if (info && info.metadata) {
 			if (typeof info.metadata.nodeDescription === 'string') {
 				return info.metadata.nodeDescription;
--- a/packages/backend/src/core/MfmService.ts
+++ b/packages/backend/src/core/MfmService.ts
@@ -5,26 +5,19 @@

 import { URL } from 'node:url';
 import { Inject, Injectable } from '@nestjs/common';
-import * as parse5 from 'parse5';
-import { type Document, type HTMLParagraphElement, Window, XMLSerializer } from 'happy-dom';
+import * as htmlParser from 'node-html-parser';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
 import { intersperse } from '@/misc/prelude/array.js';
 import { normalizeForSearch } from '@/misc/normalize-for-search.js';
 import type { IMentionedRemoteUsers } from '@/models/Note.js';
 import { bindThis } from '@/decorators.js';
-import type { DefaultTreeAdapterMap } from 'parse5';
+import { escapeHtml } from '@/misc/escape-html.js';
 import type * as mfm from 'mfm-js';

-const treeAdapter = parse5.defaultTreeAdapter;
-type Node = DefaultTreeAdapterMap['node'];
-type ChildNode = DefaultTreeAdapterMap['childNode'];
-
 const urlRegex = /^https?:\/\/[\w\/:%#@$&?!()\[\]~.,=+\-]+/;
 const urlRegexFull = /^https?:\/\/[\w\/:%#@$&?!()\[\]~.,=+\-]+$/;

-export type Appender = (document: Document, body: HTMLParagraphElement) => void;
-
@Injectable()
 export class MfmService {
 	constructor(
@@ -40,68 +33,68 @@ export class MfmService {

 		const normalizedHashtagNames = hashtagNames == null ? undefined : new Set<string>(hashtagNames.map(x => normalizeForSearch(x)));

-		const dom = parse5.parseFragment(html);
+		const doc = htmlParser.parse(`<div>${html}</div>`);

 		let text = '';

-		for (const n of dom.childNodes) {
+		for (const n of doc.childNodes) {
 			analyze(n);
 		}

 		return text.trim();

-		function getText(node: Node): string {
-			if (treeAdapter.isTextNode(node)) return node.value;
-			if (!treeAdapter.isElementNode(node)) return '';
-			if (node.nodeName === 'br') return '\n';
+		function getText(node: htmlParser.Node): string {
+			if (node instanceof htmlParser.TextNode) return node.textContent;
+			if (!(node instanceof htmlParser.HTMLElement)) return '';
+			if (node.tagName === 'BR') return '\n';

-			if (node.childNodes) {
+			if (node.childNodes != null) {
 				return node.childNodes.map(n => getText(n)).join('');
 			}

 			return '';
 		}

-		function appendChildren(childNodes: ChildNode[]): void {
-			if (childNodes) {
+		function analyzeChildren(childNodes: htmlParser.Node[] | null): void {
+			if (childNodes != null) {
 				for (const n of childNodes) {
 					analyze(n);
 				}
 			}
 		}

-		function analyze(node: Node) {
-			if (treeAdapter.isTextNode(node)) {
-				text += node.value;
+		function analyze(node: htmlParser.Node) {
+			if (node instanceof htmlParser.TextNode) {
+				text += node.textContent;
 				return;
 			}

 			// Skip comment or document type node
-			if (!treeAdapter.isElementNode(node)) {
+			if (!(node instanceof htmlParser.HTMLElement)) {
 				return;
 			}

-			switch (node.nodeName) {
-				case 'br': {
+			switch (node.tagName) {
+				case 'BR': {
 					text += '\n';
 					break;
 				}

-				case 'a': {
+				case 'A': {
 					const txt = getText(node);
-					const rel = node.attrs.find(x => x.name === 'rel');
-					const href = node.attrs.find(x => x.name === 'href');
+					const rel = node.attributes.rel;
+					const href = node.attributes.href;

 					// ハッシュタグ
-					if (normalizedHashtagNames && href && normalizedHashtagNames.has(normalizeForSearch(txt))) {
+					if (normalizedHashtagNames && href != null && normalizedHashtagNames.has(normalizeForSearch(txt))) {
 						text += txt;
 						// メンション
-					} else if (txt.startsWith('@') && !(rel && rel.value.startsWith('me '))) {
+					} else if (txt.startsWith('@') && !(rel != null && rel.startsWith('me '))) {
 						const part = txt.split('@');

 						if (part.length === 2 && href) {
 							//#region ホスト名部分が省略されているので復元する
-							const acct = `${txt}@${(new URL(href.value)).hostname}`;
+							const acct = `${txt}@${(new URL(href)).hostname}`;
 							text += acct;
 							//#endregion
 						} else if (part.length === 3) {
@@ -116,17 +109,17 @@ export class MfmService {
 							if (!href) {
 								return txt;
 							}
-							if (!txt || txt === href.value) {	// #6383: Missing text node
-								if (href.value.match(urlRegexFull)) {
-									return href.value;
+							if (!txt || txt === href) {	// #6383: Missing text node
+								if (href.match(urlRegexFull)) {
+									return href;
 								} else {
-									return `<${href.value}>`;
+									return `<${href}>`;
 								}
 							}
-							if (href.value.match(urlRegex) && !href.value.match(urlRegexFull)) {
-								return `[${txt}](<${href.value}>)`;	// #6846
+							if (href.match(urlRegex) && !href.match(urlRegexFull)) {
+								return `[${txt}](<${href}>)`;	// #6846
 							} else {
-								return `[${txt}](${href.value})`;
+								return `[${txt}](${href})`;
 							}
 						};

@@ -135,60 +128,64 @@ export class MfmService {
 					break;
 				}

-				case 'h1': {
+				case 'H1': {
 					text += '【';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					text += '】\n';
 					break;
 				}

-				case 'b':
-				case 'strong': {
+				case 'B':
+				case 'STRONG': {
 					text += '**';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					text += '**';
 					break;
 				}

-				case 'small': {
+				case 'SMALL': {
 					text += '<small>';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					text += '</small>';
 					break;
 				}

-				case 's':
-				case 'del': {
+				case 'S':
+				case 'DEL': {
 					text += '~~';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					text += '~~';
 					break;
 				}

-				case 'i':
-				case 'em': {
+				case 'I':
+				case 'EM': {
 					text += '<i>';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					text += '</i>';
 					break;
 				}

-				case 'ruby': {
+				case 'RUBY': {
 					let ruby: [string, string][] = [];
 					for (const child of node.childNodes) {
-						if (child.nodeName === 'rp') {
+						if ((child instanceof htmlParser.TextNode) && !/\s|\[|\]/.test(child.textContent)) {
+							ruby.push([child.textContent, '']);
 							continue;
 						}
-						if (treeAdapter.isTextNode(child) && !/\s|\[|\]/.test(child.value)) {
-							ruby.push([child.value, '']);
+
+						if (!(child instanceof htmlParser.HTMLElement)) continue;
+
+						if (child.tagName === 'RP') {
 							continue;
 						}
-						if (child.nodeName === 'rt' && ruby.length > 0) {
+
+						if (child.tagName === 'RT' && ruby.length > 0) {
 							const rt = getText(child);
 							if (/\s|\[|\]/.test(rt)) {
 								// If any space is included in rt, it is treated as a normal text
 								ruby = [];
-								appendChildren(node.childNodes);
+								analyzeChildren(node.childNodes);
 								break;
 							} else {
 								ruby.at(-1)![1] = rt;
@@ -197,7 +194,7 @@ export class MfmService {
 						}
 						// If any other element is included in ruby, it is treated as a normal text
 						ruby = [];
-						appendChildren(node.childNodes);
+						analyzeChildren(node.childNodes);
 						break;
 					}
 					for (const [base, rt] of ruby) {
@@ -207,26 +204,30 @@ export class MfmService {
 				}

 				// block code (<pre><code>)
-				case 'pre': {
-					if (node.childNodes.length === 1 && node.childNodes[0].nodeName === 'code') {
+				case 'PRE': {
+					if (node.childNodes.length === 1 && (node.childNodes[0] instanceof htmlParser.HTMLElement) && node.childNodes[0].tagName === 'CODE') {
 						text += '\n```\n';
 						text += getText(node.childNodes[0]);
 						text += '\n```\n';
+					} else if (node.childNodes.length === 1 && (node.childNodes[0] instanceof htmlParser.TextNode) && node.childNodes[0].textContent.startsWith('<code>') && node.childNodes[0].textContent.endsWith('</code>')) {
+						text += '\n```\n';
+						text += node.childNodes[0].textContent.slice(6, -7);
+						text += '\n```\n';
 					} else {
-						appendChildren(node.childNodes);
+						analyzeChildren(node.childNodes);
 					}
 					break;
 				}

 				// inline code (<code>)
-				case 'code': {
+				case 'CODE': {
 					text += '`';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					text += '`';
 					break;
 				}

-				case 'blockquote': {
+				case 'BLOCKQUOTE': {
 					const t = getText(node);
 					if (t) {
 						text += '\n> ';
@@ -235,33 +236,33 @@ export class MfmService {
 					break;
 				}

-				case 'p':
-				case 'h2':
-				case 'h3':
-				case 'h4':
-				case 'h5':
-				case 'h6': {
+				case 'P':
+				case 'H2':
+				case 'H3':
+				case 'H4':
+				case 'H5':
+				case 'H6': {
 					text += '\n\n';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					break;
 				}

 				// other block elements
-				case 'div':
-				case 'header':
-				case 'footer':
-				case 'article':
-				case 'li':
-				case 'dt':
-				case 'dd': {
+				case 'DIV':
+				case 'HEADER':
+				case 'FOOTER':
+				case 'ARTICLE':
+				case 'LI':
+				case 'DT':
+				case 'DD': {
 					text += '\n';
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					break;
 				}

 				default:	// includes inline elements
 				{
-					appendChildren(node.childNodes);
+					analyzeChildren(node.childNodes);
 					break;
 				}
 			}
@@ -269,52 +270,35 @@ export class MfmService {
 	}

 	@bindThis
-	public toHtml(nodes: mfm.MfmNode[] | null, mentionedRemoteUsers: IMentionedRemoteUsers = [], additionalAppenders: Appender[] = []) {
+	public toHtml(nodes: mfm.MfmNode[] | null, mentionedRemoteUsers: IMentionedRemoteUsers = [], extraHtml: string | null = null) {
 		if (nodes == null) {
 			return null;
 		}

-		const { happyDOM, window } = new Window();
-
-		const doc = window.document;
-
-		const body = doc.createElement('p');
-
-		function appendChildren(children: mfm.MfmNode[], targetElement: any): void {
-			if (children) {
-				for (const child of children.map(x => (handlers as any)[x.type](x))) targetElement.appendChild(child);
-			}
+		function toHtml(children?: mfm.MfmNode[]): string {
+			if (children == null) return '';
+			return children.map(x => handlers[x.type](x)).join('');
 		}

 		function fnDefault(node: mfm.MfmFn) {
-			const el = doc.createElement('i');
-			appendChildren(node.children, el);
-			return el;
+			return `<i>${toHtml(node.children)}</i>`;
 		}

-		const handlers: { [K in mfm.MfmNode['type']]: (node: mfm.NodeType<K>) => any } = {
+		const handlers = {
 			bold: (node) => {
-				const el = doc.createElement('b');
-				appendChildren(node.children, el);
-				return el;
+				return `<b>${toHtml(node.children)}</b>`;
 			},

 			small: (node) => {
-				const el = doc.createElement('small');
-				appendChildren(node.children, el);
-				return el;
+				return `<small>${toHtml(node.children)}</small>`;
 			},

 			strike: (node) => {
-				const el = doc.createElement('del');
-				appendChildren(node.children, el);
-				return el;
+				return `<del>${toHtml(node.children)}</del>`;
 			},

 			italic: (node) => {
-				const el = doc.createElement('i');
-				appendChildren(node.children, el);
-				return el;
+				return `<i>${toHtml(node.children)}</i>`;
 			},

 			fn: (node) => {
@@ -323,10 +307,7 @@ export class MfmService {
 						const text = node.children[0].type === 'text' ? node.children[0].props.text : '';
 						try {
 							const date = new Date(parseInt(text, 10) * 1000);
-							const el = doc.createElement('time');
-							el.setAttribute('datetime', date.toISOString());
-							el.textContent = date.toISOString();
-							return el;
+							return `<time datetime="${escapeHtml(date.toISOString())}">${escapeHtml(date.toISOString())}</time>`;
 						} catch (err) {
 							return fnDefault(node);
 						}
@@ -336,21 +317,9 @@ export class MfmService {
 						if (node.children.length === 1) {
 							const child = node.children[0];
 							const text = child.type === 'text' ? child.props.text : '';
-							const rubyEl = doc.createElement('ruby');
-							const rtEl = doc.createElement('rt');

-							// ruby未対応のHTMLサニタイザーを通したときにルビが「劉備（りゅうび）」となるようにする
-							const rpStartEl = doc.createElement('rp');
-							rpStartEl.appendChild(doc.createTextNode('('));
-							const rpEndEl = doc.createElement('rp');
-							rpEndEl.appendChild(doc.createTextNode(')'));
-
-							rubyEl.appendChild(doc.createTextNode(text.split(' ')[0]));
-							rtEl.appendChild(doc.createTextNode(text.split(' ')[1]));
-							rubyEl.appendChild(rpStartEl);
-							rubyEl.appendChild(rtEl);
-							rubyEl.appendChild(rpEndEl);
-							return rubyEl;
+							// ruby未対応のHTMLサニタイザーを通したときにルビが「対象テキスト（ルビテキスト）」にフォールバックするようにする
+							return `<ruby>${escapeHtml(text.split(' ')[0])}<rp>(</rp><rt>${escapeHtml(text.split(' ')[1])}</rt><rp>)</rp></ruby>`;
 						} else {
 							const rt = node.children.at(-1);

@@ -359,21 +328,9 @@ export class MfmService {
 							}

 							const text = rt.type === 'text' ? rt.props.text : '';
-							const rubyEl = doc.createElement('ruby');
-							const rtEl = doc.createElement('rt');

-							// ruby未対応のHTMLサニタイザーを通したときにルビが「劉備（りゅうび）」となるようにする
-							const rpStartEl = doc.createElement('rp');
-							rpStartEl.appendChild(doc.createTextNode('('));
-							const rpEndEl = doc.createElement('rp');
-							rpEndEl.appendChild(doc.createTextNode(')'));
-
-							appendChildren(node.children.slice(0, node.children.length - 1), rubyEl);
-							rtEl.appendChild(doc.createTextNode(text.trim()));
-							rubyEl.appendChild(rpStartEl);
-							rubyEl.appendChild(rtEl);
-							rubyEl.appendChild(rpEndEl);
-							return rubyEl;
+							// ruby未対応のHTMLサニタイザーを通したときにルビが「対象テキスト（ルビテキスト）」にフォールバックするようにする
+							return `<ruby>${toHtml(node.children.slice(0, node.children.length - 1))}<rp>(</rp><rt>${escapeHtml(text.trim())}</rt><rp>)</rp></ruby>`;
 						}
 					}

@@ -384,125 +341,98 @@ export class MfmService {
 			},

 			blockCode: (node) => {
-				const pre = doc.createElement('pre');
-				const inner = doc.createElement('code');
-				inner.textContent = node.props.code;
-				pre.appendChild(inner);
-				return pre;
+				return `<pre><code>${escapeHtml(node.props.code)}</code></pre>`;
 			},

 			center: (node) => {
-				const el = doc.createElement('div');
-				appendChildren(node.children, el);
-				return el;
+				return `<div style="text-align: center;">${toHtml(node.children)}</div>`;
 			},

 			emojiCode: (node) => {
-				return doc.createTextNode(`\u200B:${node.props.name}:\u200B`);
+				return `\u200B:${escapeHtml(node.props.name)}:\u200B`;
 			},

 			unicodeEmoji: (node) => {
-				return doc.createTextNode(node.props.emoji);
+				return node.props.emoji;
 			},

 			hashtag: (node) => {
-				const a = doc.createElement('a');
-				a.setAttribute('href', `${this.config.url}/tags/${node.props.hashtag}`);
-				a.textContent = `#${node.props.hashtag}`;
-				a.setAttribute('rel', 'tag');
-				return a;
+				return `<a href="${escapeHtml(`${this.config.url}/tags/${encodeURIComponent(node.props.hashtag)}`)}" rel="tag">#${escapeHtml(node.props.hashtag)}</a>`;
 			},

 			inlineCode: (node) => {
-				const el = doc.createElement('code');
-				el.textContent = node.props.code;
-				return el;
+				return `<code>${escapeHtml(node.props.code)}</code>`;
 			},

 			mathInline: (node) => {
-				const el = doc.createElement('code');
-				el.textContent = node.props.formula;
-				return el;
+				return `<code>${escapeHtml(node.props.formula)}</code>`;
 			},

 			mathBlock: (node) => {
-				const el = doc.createElement('code');
-				el.textContent = node.props.formula;
-				return el;
+				return `<pre><code>${escapeHtml(node.props.formula)}</code></pre>`;
 			},

 			link: (node) => {
-				const a = doc.createElement('a');
-				a.setAttribute('href', node.props.url);
-				appendChildren(node.children, a);
-				return a;
+				try {
+					const url = new URL(node.props.url);
+					return `<a href="${escapeHtml(url.href)}">${toHtml(node.children)}</a>`;
+				} catch (err) {
+					return `[${toHtml(node.children)}](${escapeHtml(node.props.url)})`;
+				}
 			},

 			mention: (node) => {
-				const a = doc.createElement('a');
 				const { username, host, acct } = node.props;
 				const remoteUserInfo = mentionedRemoteUsers.find(remoteUser => remoteUser.username.toLowerCase() === username.toLowerCase() && remoteUser.host?.toLowerCase() === host?.toLowerCase());
-				a.setAttribute('href', remoteUserInfo
+				const href = remoteUserInfo
 					? (remoteUserInfo.url ? remoteUserInfo.url : remoteUserInfo.uri)
-					: `${this.config.url}/${acct.endsWith(`@${this.config.url}`) ? acct.substring(0, acct.length - this.config.url.length - 1) : acct}`);
-				a.className = 'u-url mention';
-				a.textContent = acct;
-				return a;
+					: `${this.config.url}/${acct.endsWith(`@${this.config.url}`) ? acct.substring(0, acct.length - this.config.url.length - 1) : acct}`;
+				try {
+					const url = new URL(href);
+					return `<a href="${escapeHtml(url.href)}" class="u-url mention">${escapeHtml(acct)}</a>`;
+				} catch (err) {
+					return escapeHtml(acct);
+				}
 			},

 			quote: (node) => {
-				const el = doc.createElement('blockquote');
-				appendChildren(node.children, el);
-				return el;
+				return `<blockquote>${toHtml(node.children)}</blockquote>`;
 			},

 			text: (node) => {
 				if (!node.props.text.match(/[\r\n]/)) {
-					return doc.createTextNode(node.props.text);
+					return escapeHtml(node.props.text);
 				}

-				const el = doc.createElement('span');
-				const nodes = node.props.text.split(/\r\n|\r|\n/).map(x => doc.createTextNode(x));
+				let html = '';

-				for (const x of intersperse<FIXME | 'br'>('br', nodes)) {
-					el.appendChild(x === 'br' ? doc.createElement('br') : x);
+				const lines = node.props.text.split(/\r\n|\r|\n/).map(x => escapeHtml(x));
+
+				for (const x of intersperse<FIXME | 'br'>('br', lines)) {
+					html += x === 'br' ? '<br />' : x;
 				}

-				return el;
+				return html;
 			},

 			url: (node) => {
-				const a = doc.createElement('a');
-				a.setAttribute('href', node.props.url);
-				a.textContent = node.props.url;
-				return a;
+				try {
+					const url = new URL(node.props.url);
+					return `<a href="${escapeHtml(url.href)}">${escapeHtml(node.props.url)}</a>`;
+				} catch (err) {
+					return escapeHtml(node.props.url);
+				}
 			},

 			search: (node) => {
-				const a = doc.createElement('a');
-				a.setAttribute('href', `https://www.google.com/search?q=${node.props.query}`);
-				a.textContent = node.props.content;
-				return a;
+				return `<a href="${escapeHtml(`https://www.google.com/search?q=${encodeURIComponent(node.props.query)}`)}">${escapeHtml(node.props.content)}</a>`;
 			},

 			plain: (node) => {
-				const el = doc.createElement('span');
-				appendChildren(node.children, el);
-				return el;
+				return `<span>${toHtml(node.children)}</span>`;
 			},
-		};
+		} satisfies { [K in mfm.MfmNode['type']]: (node: mfm.NodeType<K>) => string } as { [K in mfm.MfmNode['type']]: (node: mfm.MfmNode) => string };

-		appendChildren(nodes, body);
-
-		for (const additionalAppender of additionalAppenders) {
-			additionalAppender(doc, body);
-		}
-
-		// Remove the unnecessary namespace
-		const serialized = new XMLSerializer().serializeToString(body).replace(/^\s*<p xmlns=\"http:\/\/www.w3.org\/1999\/xhtml\">/, '<p>');
-
-		happyDOM.close().catch(err => {});
-
-		return serialized;
+		return `${toHtml(nodes)}${extraHtml ?? ''}`;
 	}
 }
--- a/packages/backend/src/core/activitypub/ApMfmService.ts
+++ b/packages/backend/src/core/activitypub/ApMfmService.ts
@@ -5,7 +5,7 @@

 import { Injectable } from '@nestjs/common';
 import * as mfm from 'mfm-js';
-import { MfmService, Appender } from '@/core/MfmService.js';
+import { MfmService } from '@/core/MfmService.js';
 import type { MiNote } from '@/models/Note.js';
 import { bindThis } from '@/decorators.js';
 import { extractApHashtagObjects } from './models/tag.js';
@@ -25,17 +25,17 @@ export class ApMfmService {
 	}

 	@bindThis
-	public getNoteHtml(note: Pick<MiNote, 'text' | 'mentionedRemoteUsers'>, additionalAppender: Appender[] = []) {
+	public getNoteHtml(note: Pick<MiNote, 'text' | 'mentionedRemoteUsers'>, extraHtml: string | null = null) {
 		let noMisskeyContent = false;
 		const srcMfm = (note.text ?? '');

 		const parsed = mfm.parse(srcMfm);

-		if (!additionalAppender.length && parsed.every(n => ['text', 'unicodeEmoji', 'emojiCode', 'mention', 'hashtag', 'url'].includes(n.type))) {
+		if (extraHtml == null && parsed.every(n => ['text', 'unicodeEmoji', 'emojiCode', 'mention', 'hashtag', 'url'].includes(n.type))) {
 			noMisskeyContent = true;
 		}

-		const content = this.mfmService.toHtml(parsed, JSON.parse(note.mentionedRemoteUsers), additionalAppender);
+		const content = this.mfmService.toHtml(parsed, JSON.parse(note.mentionedRemoteUsers), extraHtml);

 		return {
 			content,
--- a/packages/backend/src/core/activitypub/ApRendererService.ts
+++ b/packages/backend/src/core/activitypub/ApRendererService.ts
@@ -19,7 +19,7 @@ import type { MiEmoji } from '@/models/Emoji.js';
 import type { MiPoll } from '@/models/Poll.js';
 import type { MiPollVote } from '@/models/PollVote.js';
 import { UserKeypairService } from '@/core/UserKeypairService.js';
-import { MfmService, type Appender } from '@/core/MfmService.js';
+import { MfmService } from '@/core/MfmService.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
 import { DriveFileEntityService } from '@/core/entities/DriveFileEntityService.js';
 import type { MiUserKeypair } from '@/models/UserKeypair.js';
@@ -28,6 +28,7 @@ import { bindThis } from '@/decorators.js';
 import { CustomEmojiService } from '@/core/CustomEmojiService.js';
 import { IdService } from '@/core/IdService.js';
 import { UtilityService } from '@/core/UtilityService.js';
+import { escapeHtml } from '@/misc/escape-html.js';
 import { JsonLdService } from './JsonLdService.js';
 import { ApMfmService } from './ApMfmService.js';
 import { CONTEXT } from './misc/contexts.js';
@@ -384,7 +385,7 @@ export class ApRendererService {
 			inReplyTo = null;
 		}

-		let quote;
+		let quote: string | undefined;

 		if (note.renoteId) {
 			const renote = await this.notesRepository.findOneBy({ id: note.renoteId });
@@ -430,29 +431,18 @@ export class ApRendererService {
 			poll = await this.pollsRepository.findOneBy({ noteId: note.id });
 		}

-		const apAppend: Appender[] = [];
+		let extraHtml: string | null = null;

-		if (quote) {
+		if (quote != null) {
 			// Append quote link as `<br><br><span class="quote-inline">RE: <a href="...">...</a></span>`
-			// the claas name `quote-inline` is used in non-misskey clients for styling quote notes.
+			// the class name `quote-inline` is used in non-misskey clients for styling quote notes.
 			// For compatibility, the span part should be kept as possible.
-			apAppend.push((doc, body) => {
-				body.appendChild(doc.createElement('br'));
-				body.appendChild(doc.createElement('br'));
-				const span = doc.createElement('span');
-				span.className = 'quote-inline';
-				span.appendChild(doc.createTextNode('RE: '));
-				const link = doc.createElement('a');
-				link.setAttribute('href', quote);
-				link.textContent = quote;
-				span.appendChild(link);
-				body.appendChild(span);
-			});
+			extraHtml = `<br><br><span class="quote-inline">RE: <a href="${escapeHtml(quote)}">${escapeHtml(quote)}</a></span>`;
 		}

 		const summary = note.cw === '' ? String.fromCharCode(0x200B) : note.cw;

-		const { content, noMisskeyContent } = this.apMfmService.getNoteHtml(note, apAppend);
+		const { content, noMisskeyContent } = this.apMfmService.getNoteHtml(note, extraHtml);

 		const emojis = await this.getEmojis(note.emojis);
 		const apemojis = emojis.filter(emoji => !emoji.localOnly).map(emoji => this.renderEmoji(emoji));
--- a/packages/backend/src/core/activitypub/ApRequestService.ts
+++ b/packages/backend/src/core/activitypub/ApRequestService.ts
@@ -6,7 +6,7 @@
 import * as crypto from 'node:crypto';
 import { URL } from 'node:url';
 import { Inject, Injectable } from '@nestjs/common';
-import { Window } from 'happy-dom';
+import * as htmlParser from 'node-html-parser';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
 import type { MiUser } from '@/models/User.js';
@@ -215,29 +215,9 @@ export class ApRequestService {
 			_followAlternate === true
 		) {
 			const html = await res.text();
-			const { window, happyDOM } = new Window({
-				settings: {
-					disableJavaScriptEvaluation: true,
-					disableJavaScriptFileLoading: true,
-					disableCSSFileLoading: true,
-					disableComputedStyleRendering: true,
-					handleDisabledFileLoadingAsSuccess: true,
-					navigation: {
-						disableMainFrameNavigation: true,
-						disableChildFrameNavigation: true,
-						disableChildPageNavigation: true,
-						disableFallbackToSetURL: true,
-					},
-					timer: {
-						maxTimeout: 0,
-						maxIntervalTime: 0,
-						maxIntervalIterations: 0,
-					},
-				},
-			});
-			const document = window.document;
+
 			try {
-				document.documentElement.innerHTML = html;
+				const document = htmlParser.parse(html);

 				const alternate = document.querySelector('head > link[rel="alternate"][type="application/activity+json"]');
 				if (alternate) {
@@ -248,8 +228,6 @@ export class ApRequestService {
 				}
 			} catch (e) {
 				// something went wrong parsing the HTML, ignore the whole thing
-			} finally {
-				happyDOM.close().catch(err => {});
 			}
 		}
 		//#endregion
--- a/packages/backend/src/misc/escape-html.ts
+++ b/packages/backend/src/misc/escape-html.ts
@@ -0,0 +1,13 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export function escapeHtml(text: string): string {
+	return text
+		.replace(/&/g, '&amp;')
+		.replace(/</g, '&lt;')
+		.replace(/>/g, '&gt;')
+		.replace(/"/g, '&quot;')
+		.replace(/'/g, '&#039;');
+}
--- a/packages/backend/src/server/api/endpoints/i/update.ts
+++ b/packages/backend/src/server/api/endpoints/i/update.ts
@@ -7,7 +7,7 @@ import RE2 from 're2';
 import * as mfm from 'mfm-js';
 import { Inject, Injectable } from '@nestjs/common';
 import ms from 'ms';
-import { JSDOM } from 'jsdom';
+import * as htmlParser from 'node-html-parser';
 import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm.js';
 import { extractHashtags } from '@/misc/extract-hashtags.js';
 import * as Acct from '@/misc/acct.js';
@@ -569,16 +569,15 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 		try {
 			const html = await this.httpRequestService.getHtml(url);

-			const { window } = new JSDOM(html);
-			const doc: Document = window.document;
+			const doc = htmlParser.parse(html);

 			const myLink = `${this.config.url}/@${user.username}`;

 			const aEls = Array.from(doc.getElementsByTagName('a'));
 			const linkEls = Array.from(doc.getElementsByTagName('link'));

-			const includesMyLink = aEls.some(a => a.href === myLink);
-			const includesRelMeLinks = [...aEls, ...linkEls].some(link => link.rel === 'me' && link.href === myLink);
+			const includesMyLink = aEls.some(a => a.attributes.href === myLink);
+			const includesRelMeLinks = [...aEls, ...linkEls].some(link => link.attributes.rel?.split(/\s+/).includes('me') && link.attributes.href === myLink);

 			if (includesMyLink || includesRelMeLinks) {
 				await this.userProfilesRepository.createQueryBuilder('profile').update()
@@ -588,8 +587,6 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					})
 					.execute();
 			}
-
-			window.close();
 		} catch (err) {
 			// なにもしない
 		}
--- a/packages/backend/src/server/oauth/OAuth2ProviderService.ts
+++ b/packages/backend/src/server/oauth/OAuth2ProviderService.ts
@@ -6,7 +6,7 @@
 import dns from 'node:dns/promises';
 import { fileURLToPath } from 'node:url';
 import { Inject, Injectable } from '@nestjs/common';
-import { JSDOM } from 'jsdom';
+import * as htmlParser from 'node-html-parser';
 import httpLinkHeader from 'http-link-header';
 import ipaddr from 'ipaddr.js';
 import oauth2orize, { type OAuth2, AuthorizationError, ValidateFunctionArity2, OAuth2Req, MiddlewareRequest } from 'oauth2orize';
@@ -120,9 +120,9 @@ async function discoverClientInformation(logger: Logger, httpRequestService: Htt
 		}

 		const text = await res.text();
-		const fragment = JSDOM.fragment(text);
+		const fragment = htmlParser.parse(`<div>${text}</div>`);

-		redirectUris.push(...[...fragment.querySelectorAll<HTMLLinkElement>('link[rel=redirect_uri][href]')].map(el => el.href));
+		redirectUris.push(...[...fragment.querySelectorAll('link[rel=redirect_uri][href]')].map(el => el.attributes.href));

 		let name = id;
 		let logo: string | null = null;
--- a/packages/backend/src/server/web/ClientServerService.ts
+++ b/packages/backend/src/server/web/ClientServerService.ts
@@ -15,7 +15,6 @@ import fastifyStatic from '@fastify/static';
 import fastifyView from '@fastify/view';
 import fastifyProxy from '@fastify/http-proxy';
 import vary from 'vary';
-import htmlSafeJsonStringify from 'htmlescape';
 import type { Config } from '@/config.js';
 import { getNoteSummary } from '@/misc/get-note-summary.js';
 import { DI } from '@/di-symbols.js';
@@ -63,6 +62,20 @@ const frontendViteOut = `${_dirname}/../../../../../built/_frontend_vite_/`;
 const frontendEmbedViteOut = `${_dirname}/../../../../../built/_frontend_embed_vite_/`;
 const tarball = `${_dirname}/../../../../../built/tarball/`;

+const ESCAPE_LOOKUP = {
+	'&': '\\u0026',
+	'>': '\\u003e',
+	'<': '\\u003c',
+	'\u2028': '\\u2028',
+	'\u2029': '\\u2029',
+} as Record<string, string>;
+
+const ESCAPE_REGEX = /[&><\u2028\u2029]/g;
+
+function htmlSafeJsonStringify(obj: any): string {
+	return JSON.stringify(obj).replace(ESCAPE_REGEX, x => ESCAPE_LOOKUP[x]);
+}
+
@Injectable()
 export class ClientServerService {
 	private logger: Logger;