Mongoose -解决依赖于其他模型的复杂验证

const mongoose = require('mongoose');

// 定义模型之间的关联关系
const UserSchema = new mongoose.Schema({
  name: String,
  email: String,
});

const PostSchema = new mongoose.Schema({
  title: String,
  content: String,
  author: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
  },
});

// 定义验证器函数
PostSchema.path('author').validate(async function(value) {
  const User = mongoose.model('User');
  const user = await User.findById(value);
  return user !== null;
}, 'Invalid author');

const User = mongoose.model('User', UserSchema);
const Post = mongoose.model('Post', PostSchema);

// 创建用户和文章
const user = new User({
  name: 'John',
  email: 'john@example.com',
});

const post = new Post({
  title: 'Hello World',
  content: 'This is a test post',
  author: user._id,
});

// 保存用户和文章
user.save();
post.save();