感谢@sallyCJ修复我的错误！下面是WP-API主干JS客户端的一些示例。它可以帮助他人：

获取某个作者和类别的帖子：

var filteredPosts = new wp.api.collections.Posts();
authorsPosts.fetch({ data: { author: currentUserId, categories: 42 } }).then( posts => { 
    for(const post of posts){
        //do stuff with each post
    }
} );

var post = new wp.api.models.Post( { 
    id: idOfThePostYouWantToUpdate,
    title: newTitle,
    content: newContent,
    status: newStatus,
    categories: [ 42 ],
    tags: [ 50 ]
    });
post.save();