Error in useSize: Cannot read property 'contentWindow' of null

[ManojBahuguna]

Problem

When we redirect in a component using useSize in the first render, we get this error:
Cannot read property 'contentWindow' of null

Reproduction link

https://codesandbox.io/s/react-use-usesize-error-xo3q4

Cause

This seems to be causing the issue:

react-use/src/useSize.tsx

Lines 48 to 51 in cf68e36

	const iframe: HTMLIFrameElement = ref.current!;
	if (iframe.contentWindow) {
	window = iframe.contentWindow!;
	onWindow(window);

Possible solution

We can check if iframe is defined before accessing it's property

...
useEffect(() => {
    const iframe: HTMLIFrameElement = ref.current!;
    
   if(!iframe) {
    // this will happen if component is already unmounted
    return;
   }

    if (iframe.contentWindow) {
...