hotfix(backend): MfmServiceでメモリリークが発生する

[taiyme]

What

MfmService内のtoHtml関数のwindowが解放できずにメモリリークを引き起こしている

misskey/packages/backend/src/core/MfmService.ts

Lines 241 to 465 in 2b21c19

	public toHtml(nodes: mfm.MfmNode[] | null, mentionedRemoteUsers: IMentionedRemoteUsers = []) {
	if (nodes == null) {
	return null;
	}
	const { 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 fnDefault(node: mfm.MfmFn) {
	const el = doc.createElement('i');
	appendChildren(node.children, el);
	return el;
	}
	const handlers: { [K in mfm.MfmNode['type']]: (node: mfm.NodeType<K>) => any } = {
	bold: (node) => {
	const el = doc.createElement('b');
	appendChildren(node.children, el);
	return el;
	},
	small: (node) => {
	const el = doc.createElement('small');
	appendChildren(node.children, el);
	return el;
	},
	strike: (node) => {
	const el = doc.createElement('del');
	appendChildren(node.children, el);
	return el;
	},
	italic: (node) => {
	const el = doc.createElement('i');
	appendChildren(node.children, el);
	return el;
	},
	fn: (node) => {
	switch (node.props.name) {
	case 'unixtime': {
	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;
	} catch (err) {
	return fnDefault(node);
	}
	}
	case 'ruby': {
	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;
	} else {
	const rt = node.children.at(-1);
	if (!rt) {
	return fnDefault(node);
	}
	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;
	}
	}
	default: {
	return fnDefault(node);
	}
	}
	},
	blockCode: (node) => {
	const pre = doc.createElement('pre');
	const inner = doc.createElement('code');
	inner.textContent = node.props.code;
	pre.appendChild(inner);
	return pre;
	},
	center: (node) => {
	const el = doc.createElement('div');
	appendChildren(node.children, el);
	return el;
	},
	emojiCode: (node) => {
	return doc.createTextNode(`\u200B:${node.props.name}:\u200B`);
	},
	unicodeEmoji: (node) => {
	return doc.createTextNode(node.props.emoji);
	},
	hashtag: (node) => {
	const a = doc.createElement('a');
	a.setAttribute('href', `${this.config.url}/tags/${node.props.hashtag}`);
	a.textContent = `#${node.props.hashtag}`;
	a.setAttribute('rel', 'tag');
	return a;
	},
	inlineCode: (node) => {
	const el = doc.createElement('code');
	el.textContent = node.props.code;
	return el;
	},
	mathInline: (node) => {
	const el = doc.createElement('code');
	el.textContent = node.props.formula;
	return el;
	},
	mathBlock: (node) => {
	const el = doc.createElement('code');
	el.textContent = node.props.formula;
	return el;
	},
	link: (node) => {
	const a = doc.createElement('a');
	a.setAttribute('href', node.props.url);
	appendChildren(node.children, a);
	return a;
	},
	mention: (node) => {
	const a = doc.createElement('a');
	const { username, host, acct } = node.props;
	const remoteUserInfo = mentionedRemoteUsers.find(remoteUser => remoteUser.username === username && remoteUser.host === host);
	a.setAttribute('href', remoteUserInfo ? (remoteUserInfo.url ? remoteUserInfo.url : remoteUserInfo.uri) : `${this.config.url}/${acct}`);
	a.className = 'u-url mention';
	a.textContent = acct;
	return a;
	},
	quote: (node) => {
	const el = doc.createElement('blockquote');
	appendChildren(node.children, el);
	return el;
	},
	text: (node) => {
	if (!node.props.text.match(/[\r\n]/)) {
	return doc.createTextNode(node.props.text);
	}
	const el = doc.createElement('span');
	const nodes = node.props.text.split(/\r\n|\r|\n/).map(x => doc.createTextNode(x));
	for (const x of intersperse<FIXME | 'br'>('br', nodes)) {
	el.appendChild(x === 'br' ? doc.createElement('br') : x);
	}
	return el;
	},
	url: (node) => {
	const a = doc.createElement('a');
	a.setAttribute('href', node.props.url);
	a.textContent = node.props.url;
	return a;
	},
	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;
	},
	plain: (node) => {
	const el = doc.createElement('span');
	appendChildren(node.children, el);
	return el;
	},
	};
	appendChildren(nodes, body);
	return new XMLSerializer().serializeToString(body);
	}

happy-domをv10.0.3からv14.7.1に更新したことで、挙動が変わっている？

• 関連PR: update deps misskey-dev/misskey#13624
• commit: 2b21c19

Why

Additional info (optional)

Checklist

• Test working in a local environment
• (If needed) Add story of storybook
• (If possible) Add tests