Typescript: Access window object with type check

"typescript": "3.7.2"

interface iConfig extends Window {
  config: {
    username: string,
    server: string,
    port: number,
  }
}

declare var window: iConfig;

export const windowConfig = window;

import { windowConfig } from './windowConfig';

/* use windowConfig as 'window' */

import { useEffect } from 'react';

/* Add declaration for window.AMap */
declare let AMap;

export default function Map() {
  let map;

  useEffect(() => {
    /* Directly use AMap */
    map = new AMap.Map(`container`, {
      zoom: 10,
    });
  }, []);

  return (
    /* ... */
  );
}