wp-use-mutationobserver-to-spy-on-the-dom-14.js

let observer = new MutationObserver((mutationsList) => {
    console.log(`${mutationsList.length} change(s) detected`);

    for (let mutation of mutationsList) {
        console.log(mutation);
    }
});

observer.observe(div, {
    subtree: true,
    childList: true
});

div.innerText = "Hello";

observer.disconnect();