get all HTML tags that used currnet page

get_html_tags.js

function search_html_tag(tagSet, dom) {
    if (dom.children.length) {
        let i = 0;
        while (i < dom.children.length) {
            if (!tagSet.has(dom.tagName)) {tagSet.add(dom.tagName)}
            get_tags(tagSet, dom.children.item(i))
            i++;
        }       
    } else {
        return ;;
    }
}
const tags = new Set()
const html = document.querySelector('html')
search_html_tag(tags, html)
console.log(tags);