运行mongoose的populate.js时报错：String不是Schema中name路径的有效类型

项目链接：https://github.com/k4u5hik/node-express-course
我尝试使用populate.js，通过mongoose将products.json中的数据自动导入到我的MongoDB数据库，Schema定义在product.js文件中。

product.js代码 #

const mongoose = require('mongoose')

const productSchema = new mongoose.Schema({
  name: {
    type: String,
    required: [true, 'product price must be provided'],
  },
  price: {
    type: Number,
    required: [true, 'product price must be provided'],
  },
  featured: {
    type: Boolean,
    default: false,
  },
  rating: {
    type: Number,
    default: 4.5,
  },
  createdAt: {
    type: Date,
    default: Date.now(),
  },
  company: {
    type: String,
    enum: {
      values: ['ikea', 'liddy', 'caressa', 'marcos'],
      message: '{VALUE} is not supported',
    },
    // enum: ['ikea', 'liddy', 'caressa', 'marcos'],
  },
})

module.exports = mongoose.model('Product', productSchema)

populate.js代码 #

require ('dotenv').config()

const connectDB = require('./db/connect')
const Product = require('./models/product')

const jsonProducts = require('./products.json')

const start = async () => {
    try {
        await connectDB(process.env.MONGO_URI)
        await Product.deleteMany()
        await Product.create(jsonProducts)
        console.log('Products created or updated on database')
        process.exit(0)
    } catch (error) {
        console.log(error);
    }
}

start()

报错信息 #

kaushik@Madhuras-Air 04 - Practice % node populate
/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/node_modules/mongoose/lib/schema.js:1044
    throw new TypeError(`Invalid schema configuration: \`${name}\` is not ` +
    ^

TypeError: Invalid schema configuration: `String` is not a valid type at path `name`. See bit.ly/mongoose-schematypes for a list of valid schema types.
    at Schema.interpretAsType (/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/node_modules/mongoose/lib/schema.js:1044:11)
    at Schema.path (/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/node_modules/mongoose/lib/schema.js:684:27)
    at Schema.add (/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/node_modules/mongoose/lib/schema.js:536:14)
    at new Schema (/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/node_modules/mongoose/lib/schema.js:132:10)
    at Object.<anonymous> (/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/models/product.js:3:23)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (/Users/kaushik/WebstormProjects/node-express-course/04 - Practice/populate.js:4:17)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)

已有排查情况 #

• 导师本地运行代码无问题，排除代码逻辑错误
• 已确认环境变量配置正确

从报错栈可以判断，错误在加载product.js初始化Schema阶段就已触发，和数据库连接、JSON数据导入逻辑无关，按以下步骤排查即可：

• 排查mongoose版本差异：执行npm list mongoose查看本地安装的mongoose版本，和导师使用的版本做对比。如果版本不一致，卸载本地版本后安装对应稳定版即可，例如执行npm install mongoose@6.10.0安装常用的稳定版本，避免使用测试版/预发布版触发兼容性问题。
• 重装损坏的依赖包：本地依赖安装过程中可能出现文件损坏的情况，先删除node_modules目录和包锁文件：

  rm -rf node_modules package-lock.json yarn.lock
  

  再重新安装所有依赖：

  npm install
  

• 排查代码中的不可见字符：如果是复制粘贴的代码，可能附带了零宽空格等不可见字符，导致Mongoose无法正确识别String等类型关键字。手动重写product.js中所有type: String、type: Number等字段定义行即可。
• 验证mongoose引入有效性：在product.js首行引入mongoose后添加打印逻辑console.log(mongoose.Schema.Types.String)，如果输出为undefined，说明mongoose引入异常，回到重装依赖步骤处理即可。

内容的提问来源于stack exchange，提问作者Kaushik C