astro/examples/astro-markdown/src/components/PreactCounter.tsx

import { h, Fragment } from 'preact';
import { useState } from 'preact/hooks';

/** a counter written in Preact */
export default function PreactCounter({ children }) {
  const [count, setCount] = useState(0);
  const add = () => setCount((i) => i + 1);
  const subtract = () => setCount((i) => i - 1);

  return (
    <>
      <div className="counter">
        <button onClick={subtract}>-</button>
        <pre>{count}</pre>
        <button onClick={add}>+</button>
      </div>
      <div className="children">{children}</div>
    </>
  );
}