Removing all video inside of the youtubes watch later playlist.

clearWatchLater.js

var clearTimer;
function clearWatchList(interval) {clearTimer = setInterval(clearWatchLater, interval);}
function getButtonAttr() {
    var menuName = ["Aktionsmenü", "Action menu"]
    var buttons = document.querySelectorAll("#button");

    for (var i = 0; i < buttons.length; i++) {
        var context = buttons[i].getAttribute("aria-label");
        if (menuName.includes(context))
            return buttons[i].getAttribute("aria-label");
    }
}

function getPlaylistName() {
    var playlistElem_watchLater = document.querySelectorAll("#title > yt-formatted-string > a")[0].innerHTML;
    var playlistElem = document.getElementById("text-displayed");
    
    if (playlistElem) {
        return playlistElem.innerHTML;
    } else {
        return playlistElem_watchLater;
    }
}

function getVideoCount() {
    var elem = document.querySelectorAll("#stats > yt-formatted-string:nth-child(1) > span:nth-child(1)");
    if (!elem) return 0;

    var count = elem[0].innerHTML;
    return ((count - 1));
}

function evaluate(playlistName) {
    return document.evaluate(`//span[contains(text(),"${playlistName}")]`,document,null,XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,null);
}

function killSwitch() {
    clearInterval(clearTimer);
}

function clearWatchLater() {
    var selectorLabel = getButtonAttr();
    var playlistName = getPlaylistName();
    var videos = getVideoCount();

    document.querySelector(`#primary button[aria-label="${selectorLabel}"]`).click();
    var things = evaluate(playlistName);

    for (var i = 0; i < videos; i++) {
        things.snapshotItem(i).click();
        if (i == videos) {
            killSwitch();
        }
        console.log(getVideoCount());
    }
    
}