如何从Mongoose推送到对象中的数组？

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const postSchema = new Schema({
  title: String,
  content: String
});

const userSchema = new Schema({
  name: String,
  posts: [postSchema]
});

const User = mongoose.model('User', userSchema);

const newPost = {
  title: 'My New Post',
  content: 'This is the content of my new post.'
};

User.findByIdAndUpdate(
  userId, // 这里是用户的ID
  { $push: { posts: newPost } },
  { new: true, useFindAndModify: false },
  (err, updatedUser) => {
    if (err) {
      console.error('Error updating user:', err);
    } else {
      console.log('User updated:', updatedUser);
    }
  }
);

try {
  const updatedUser = await User.findByIdAndUpdate(
    userId,
    { $push: { posts: newPost } },
    { new: true, useFindAndModify: false }
  );
  console.log('User updated:', updatedUser);
} catch (err) {
  console.error('Error updating user:', err);
}