astro/packages/renderers/renderer-react/static-html.js

import { createElement as h } from 'react';

/**
 * Astro passes `children` as a string of HTML, so we need
 * a wrapper `div` to render that content as VNodes.
 *
 * As a bonus, we can signal to React that this subtree is
 * entirely static and will never change via `shouldComponentUpdate`.
 */
const StaticHtml = ({ value }) => {
  if (!value) return null;
  return h('astro-fragment', { suppressHydrationWarning: true, dangerouslySetInnerHTML: { __html: value } });
};

/**
 * This tells React to opt-out of re-rendering this subtree,
 * In addition to being a performance optimization,
 * this also allows other frameworks to attach to `children`.
 *
 * See https://preactjs.com/guide/v8/external-dom-mutations
 */
StaticHtml.shouldComponentUpdate = () => false;

export default StaticHtml;