code-server/lib/vscode/extensions/notebook-markdown-extensions/notebook/katex.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
import type * as markdownIt from 'markdown-it';

const styleHref = import.meta.url.replace(/katex.js$/, 'katex.min.css');

export async function activate(ctx: {
	getRenderer: (id: string) => Promise<any | undefined>
}) {
	const markdownItRenderer = await ctx.getRenderer('markdownItRenderer');
	if (!markdownItRenderer) {
		throw new Error('Could not load markdownItRenderer');
	}

	const link = document.createElement('link');
	link.rel = 'stylesheet';
	link.classList.add('markdown-style');
	link.href = styleHref;
	document.head.append(link);

	const style = document.createElement('style');
	style.classList.add('markdown-style');
	style.textContent = `
		.katex-error {
			color: var(--vscode-editorError-foreground);
		}
	`;
	document.head.append(style);

	const katex = require('@iktakahiro/markdown-it-katex');
	markdownItRenderer.extendMarkdownIt((md: markdownIt.MarkdownIt) => {
		return md.use(katex);
	});
}