关于koa-router和koa-multer结合使用(require,module.exports)，实现图片上传和表单数据提交的请教

问题

我想把下面的koa-router改造成require,module.exports形式

前端vue

<script>
export default {
    data() {
        return {
            userAvator: "../../../static/avator.png",
            userName: "",
            userPhone: "",
            userGender: "",
            userType: ""
        };
    },
    methods: {
        getAvator(event) {
            let avator = event.target.files[0];
            if (avator.size > 100000) {
                //不能大于100kb
                return false;
            }
            console.log(avator);
            let windowURL = window.URL;
            this.userAvator = windowURL.createObjectURL(avator);
        },
        submit(event) {
            if (
                this.userName === "" ||
                this.userPhone === "" ||
                this.userGender === "" ||
                this.userType === ""
            ) {
                return false;
            } else {
                event.preventDefault();
    
                let formData = new FormData();
                let data = {
                    userName: this.userName,
                    userPhone: this.userPhone,
                    userGender: this.userGender,
                    userType: this.userType
                };
                data = JSON.stringify(data);
                formData.append("avator", this.userAvator);
                formData.append("data", data);
                let config = {
                    headers: {
                        "Content-Type": "multipart/form-data"
                    }
                };
                axios
                    
                    .post("http://localhost:3000/userInsertInto", formData, config)
                    .then(response => {
                        console.log(response);
                    })
                    .catch(error => {
                        console.log(error);
                    });
            }
        }
    }
};
</script>

改造前

router.post('/userInsertInto', upload.single('file'), async(ctx, next) => {
	//todo
})

改造后

router.post('/userInsertInto', controller.userInsertInto)

改造前,可以正常实现功能

const router = require('koa-router')();
const controller = require('../controller/user');
const multer = require('koa-multer');

var storage = multer.diskStorage({
        //文件保存路径  
        destination: function(req, file, cb) {
            cb(null, 'static/images/')
        },
        //修改文件名称  
        filename: function(req, file, cb) {
            var fileFormat = (file.originalname).split(".");
            cb(null, Date.now() + "." + fileFormat[fileFormat.length - 1]);
        }
    })
    //加载配置  
var upload = multer({ storage: storage });

router.post('/userInsertInto', upload.single('file'), async(ctx, next) => {
    console.log(ctx.req.body)
    let data = JSON.parse(ctx.req.body.data);
    console.log(data);
    ctx.body = {
        msg: "aa"
    }
})

module.exports = router;

改造后的require,module.exports 模式

require

const router = require('koa-router')();
const controller = require('../controller/user');

router.post('/userInsertInto', controller.userInsertInto)


module.exports = router;

module.exports

const router = require('koa-router')();
const userModel = require('../mysql/mysql');
const multer = require('koa-multer');

var storage = multer.diskStorage({
        //文件保存路径  
        destination: function(req, file, cb) {
            cb(null, 'static/images/')
        },
        //修改文件名称  
        filename: function(req, file, cb) {
            var fileFormat = (file.originalname).split(".");
            cb(null, Date.now() + "." + fileFormat[fileFormat.length - 1]);
        }
    })
    //加载配置  
var upload = multer({ storage: storage });

const userInsertInto = async (ctx) => {
    await upload.single('file');
    console.log(ctx.req.body)
    let data = JSON.parse(ctx.req.body.data);
    ctx.body = {
        msg: "aa"
    }
}

module.exports = {
    userInsertInto: userInsertInto
}

报错