如何在Mongoose模式中设置数组大小的限制

稍微调整一下架构设置，即可添加验证选项：

var peopleSchema = new Schema({  name: {    type: String,    required: true,    default: true  },  friends: {    type: [{      type: Schema.Types.ObjectId,      ref: 'peopleModel'    }],    validate: [arrayLimit, '{PATH} exceeds the limit of 10']  }});function arrayLimit(val) {  return val.length <= 10;}