Window object - JSON.stringify replacer - vue.js

Question

I am attempting to persist a Window object in Local Storage in my Vue project via JSON.stringify with a replacer.
Since Window has a circular structure, I can't use JSON.stringify by itself.
So I've researched the usage of the replacer.
I came across this implementation:
const getCircularReplacer = () => {
console.log("replacer called...");
const seen = new WeakSet();
return (key, value) => {
if (typeof value === window && value !== null) {
if (seen.has(value)) {
return;
}
seen.add(value);
}
return value;
};
};
The following replacer implementations didn't work for me....meaning that the getCircularReplacer() method doesn't get called.
const winClean = JSON.stringify(win, getCircularReplacer());
but wrapping the replacer in a function seems to do the trick and it calls the getCircularReplacer method
const winClean = JSON.stringify(win, function () { getCircularReplacer(); });
Another issue is that the winClean returns 'undefined'.
I tested the getCircularReplacer with the following modifications:
if (typeof value === 'object' && value !== null)
and
if (typeof value === window && value !== null) {
and
if (typeof value === Window && value !== null) {
to no avail.
Here's the full code in HellowWorld.vue
<template>
<div class="hello">
<h1>{{ msg }}</h1>
<div>
Google |
Bing |
Yahoo |
BBC
</div>
</div>
</template>
<script>
export default {
name: "HelloWorld",
props: {
msg: String,
},
methods: {
openWindow(url, name) {
console.log(url + " | " + name);
const win = window.open(url, name);
console.log("window name: " + win.name);
console.log(win);
const getCircularReplacer = () => {
console.log("replacer called...");
const seen = new WeakSet();
return (key, value) => {
if (typeof value === window && value !== null) {
if (seen.has(value)) {
return;
}
seen.add(value);
}
return value;
};
};
const winClean = JSON.stringify(win, function () {
getCircularReplacer();
});
console.log(winClean);
},
},
};
</script>
Could anybody please clarify why my winClean is undefined and how to correctly stringify my window object to avoid the "Converting circular structure to JSON" error.
Thank you!