带有打字稿的猫鼬，来自猫鼬的错误“连接”

Question

当我启动服务器时，出现这个错误：

this.mongo.connect('mongodb://localhost:27017/tsnode', { ^ 类型错误：无法读取未定义的属性“连接”

import express from 'express';
import mongoose from 'mongoose';
import cors from 'cors';

class App {
  public express: express.Application;

  public mongo: mongoose.Mongoose;

  constructor() {
    this.express = express();
    this.database();
    this.middlewares();
    this.routes();
  }

  private middlewares(): void {
    this.express.use(express.json());
    this.express.use(cors());
  }

  private database(): void {
    this.mongo.connect('mongodb://localhost:27017/tsnode', {
      useUnifiedTopology: true,
    });
  }

  private routes(): void {
    this.express.get('/', (req, res) => res.send('Hello World!'));
  }
}

export default new App().express;

Answer 1

你还没有启动 mongo 变量，你应该在构造函数中做。 喜欢：

  constructor() {
    this.express = express();
    this.mongo= mongoose;  // initialize mongo variable
    this.database();
    this.middlewares();
    this.routes();
  }