sendou.ink/app/hooks/useWindowSize.ts

import * as React from "react";

interface WindowSize {
	width: number;
	height: number;
}

function subscribe(listener: () => void) {
	window.addEventListener("resize", listener);
	return () => window.removeEventListener("resize", listener);
}

/**
 * Returns the current window dimensions, re-rendering on resize. Both
 * dimensions are `0` during server-side rendering and the initial hydration
 * render.
 */
export function useWindowSize(): WindowSize {
	const width = React.useSyncExternalStore(
		subscribe,
		() => window.innerWidth,
		() => 0,
	);
	const height = React.useSyncExternalStore(
		subscribe,
		() => window.innerHeight,
		() => 0,
	);

	return { width, height };
}