gistfile1.js

if(req.body.action == 'unlike') {

    //using find a
    db.Like.findAll({
        where: db.Sequelize.and(
            {Post_postId: req.body.postId},
            {User_userId: req.user.userId}
        )
    }).then(function(likes) {
        if(likes.length > 0) {
            return db.Promise.map(likes, function (like) {
                        return like.destroy();
            }).then(function () {
                        return eventEmitter.emit('addRemoveLikeDone', true);
            });
        } else {

            console.log('attempt to unlike a post has not been liked');
            return eventEmitter.emit('addRemoveLikeDone', false);

        }
            

    }).catch(function(err) {
        console.log('caught error:');
        console.log(err); 
        return eventEmitter.emit('addRemoveLikeDone', false);
    });

}