Vue can not import jsonwebtoken ,it shows there denpendencies were not found: net dns

this is my code auth.js(koa)

const auth=require('../function/auth');
const jwt = require('jsonwebtoken');
const bcrypt = require('bcryptjs');

var log = async (ctx,next)=>{

     var Account=ctx.request.body.account,
            Password=ctx.request.body.password,
            query={
                account:Account,
            }
        var data=await auth.log(query);

        if(data.length>0){
            if(bcrypt.compareSync(Password,data[0].password)){
                const userToken={
                    account:data[0].account,
                    id:data[0]._id
                }
                const secret = 'vue-koa-demo';
                const token =jwt.sign(userToken,secret);
                ctx.response.type='application/json'
                ctx.response.body={
                    sta:true,
                    token:token}
            }
            else if(!bcrypt.compareSync(Password,data[0].password)){
                ctx.response.type='application/json'
                ctx.response.body={
                    sta:false,
                    info:'密码错了'}


            }

        }if(data.length==0){
                ctx.response.type='application/json'
                ctx.response.body={
                    sta:false,
                    info:'账号不存在'}
        }

}

and this is my TodoList.vue (vue)

...
<script>
import jws from 'jsonwebtoken'
export default {
  created () { // 组件创建时调用
    const userInfo = this.getUserInfo()
    if (userInfo !== null) {
      this.id = userInfo.id
      this.name = userInfo.name
    } else {
      this.id = ''
      this.name = ''
    }
  },
  data () {
    return {
      name: 'Molunerfinn',
      todos: '',
      activeName: 'first',
      list: [],
      count: 0
    }
  },
  computed: { // 计算属性用于计算是否已经完成了所有任务
    Done () {
      let count = 0
      let length = this.list.length
      for (let i in this.list) {
        this.list[i].status === true ? count += 1 : ''
      }
      this.count = count
      if (count === length || length === 0) {
        return true
      } else {
        return false
      }
    }
  },
  methods: {
    addTodos () {
      if (this.todos === '') {
        return
      }
      let obj = {
        status: false,
        content: this.todos
      }
      this.list.push(obj)
      this.todos = ''
    },
    finished (index) {
      this.$set(this.list[index], 'status', true)
      this.$message({
        type: 'success',
        message: '任务完成'
      })
    },
    remove (index) {
      this.list.splice(index, 1)
      this.$message({
        type: 'info',
        message: '任务删除'
      })
    },
    restore (index) {
      this.$set(this.list[index], 'status', false)
      this.$message({
        type: 'info',
        message: '任务还原'
      })
    },
    getUserInfo () {
      const token = sessionStorage.getItem('my-token')
      if (token !== null) {
        let decode = jwt.verify(token, 'vue-koa-demo')
        return decode
      } else {
        return null
      }
    }
  }
}
</script>
...

then in vsCODE npm run dev ,

hese dependencies were not found:

• net in ./~/joi/lib/string.js
• dns in ./~/isemail/lib/isemail.js

To install them, you can run: npm install --save net dns

and i try , but now the problem is

These dependencies were not found:

• fs in ./~/native-dns/lib/platform.js
• dgram in ./~/native-dns/lib/server.js, ./~/native-dns/lib/utils.js and 1 other

To install them, you can run: npm install --save fs dgram

via ZZ huang