Action delete, moveUp and moveDown

arrAction.js

playListAction({action, index}) {
    switch (action) {
        case 'delete':
            this.playList.splice(index, 1);
            break;
        case 'moveUp':
            this.playList.splice((index - 1 + this.playList.length) % this.playList.length, 0, this.playList.splice(index, 0));
            break;
        case 'moveDown':
            this.playList.splice((index + 1) % this.playList.length, 0, this.playList.splice(index, 0));
            break;
    }
}