signal-desktop/ts/hooks/usePortal.ts

// Copyright 2019 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

import { useEffect, useState } from 'react';

export function usePortal(): HTMLDivElement | null {
  const [root, setRoot] = useState<HTMLDivElement | null>(null);

  useEffect(() => {
    const div = document.createElement('div');
    document.body.appendChild(div);
    setRoot(div);

    return () => {
      document.body.removeChild(div);
      setRoot(null);
    };
  }, []);

  return root;
}