在nodejs中使用express routes方法时出错

我试图以不同的方式构造nodejs api,但在尝试导入路由时出现以下错误:

/users/pato/documents/node js-bp-api/node-modules/express/lib/router/index.js:139 调试('dispatching%s%s',req.method,req.url); ^

类型错误:无法读取未定义的属性“method”

express.js文件

.
.
app.use(cors());
app.use(config.api.prefix, apiRoutes());

API路由/索引.js

const todo = require('../api/routes/todo');
const express = require('express');   
const apiRoutes = () => {
   const app = express.Router();
   todo(app);
   return app();
};

    module.exports = apiRoutes;

TOdo.js路线

const todo = router => {
  router.get('/', function(req, res, next) {
    res.json({ msg: 'This is CORS-enabled for all origins!' });
  });
};