开玩笑：猫鼬和Koa服务器无法关闭连接

Question

当调用afterAll函数时，我调用服务器和猫鼬的close方法，在控制台输出中，Mongodb连接已关闭，但是当我看到连接计数时，mongo cli相同并且测试成功完成，但是节点未关闭脚本，这可能是什么问题？

之前：

关闭猫鼬连接后：

虽然我不暂停ctrl-c脚本的执行

我有猫鼬连接：

import mongoose from 'mongoose'
import { MONGO_URI } from '../config'

mongoose.Promise = Promise

export default {
  connect () {
    return new Promise((resolve, reject) => {
      mongoose.connect(MONGO_URI)

      const connection = mongoose.connection

      connection.on('error', reject)
      connection.on('open', (data) => {
        resolve(connection)
      })
      connection.on('close', () => {
        console.log('Mongodb connection closed')
      })
    })
  }
}

应用程式：

import Koa from 'koa'

const app = new Koa()

...

export default app

测试：

import r from 'supertest'
import mongodb from 'db/mongodb'
import app from 'app'
import CategoryModel from 'modules/categories/models/category'

describe('Categories routes', () => {
  let mongoConnection
  let server

  beforeAll(async () => {
    mongoConnection = await mongodb.connect()
    server = await app.listen()
  })

  afterAll(async () => {
    await mongoConnection.close()
    await server.close()
  })

  afterEach(async () => {
    await mongoConnection.dropDatabase()
  })

  describe('/GET', () => {
    it('records exist', async () => {
      const { body } = await r(server).get('/api/categories')

      expect(body).toHaveProperty('data')
      expect(body.data).toHaveLength(2)
    })
  })
})