mongoose通过用户和他的追随者获取帖子

// 定义用户模型
const userSchema = new mongoose.Schema({
  username: String,
  email: String,
  followers: [{ type: mongoose.Schema.Types.ObjectId, ref: 'User' }]
});

// 定义帖子模型
const postSchema = new mongoose.Schema({
  title: String,
  content: String,
  author: { type: mongoose.Schema.Types.ObjectId, ref: 'User' }
});

// 获取用户的帖子
const getUserPosts = async (userId) => {
  try {
    // 查询用户的追随者列表
    const user = await User.findById(userId).populate('followers');

    // 遍历追随者列表，查询每个追随者的帖子
    const posts = [];
    for (const follower of user.followers) {
      const followerPosts = await Post.find({ author: follower._id });
      posts.push(...followerPosts);
    }

    return posts;
  } catch (error) {
    console.error(error);
    throw new Error('Failed to get user posts');
  }
};