类型错误：无法读取未定义的属性"apply"？

Question

设置路由器文件时。我得到

TypeError: Cannot read property 'apply' of undefined at /Users/evibreukers/Desktop/NODEJS/beginnerguide/node_modules/express/lib/router/index.js:635:15 
at next (/Users/evibreukers/Desktop/NODEJS/beginnerguide/node_modules/express/lib/router/index.js:210:14) 
at Function.handle (/Users/evibreukers/Desktop/NODEJS/beginnerguide/node_modules/express/lib/router/index.js:174:3) 
at router (/Users/evibreukers/Desktop/NODEJS/beginnerguide/node_modules/express/lib/router/index.js:47:12) 
at Object. (/Users/evibreukers/Desktop/NODEJS/beginnerguide/server.js:20:20) 
at Module._compile (internal/modules/cjs/loader.js:1158:30) 
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1178:10) 
at Module.load (internal/modules/cjs/loader.js:1002:32) 
at Function.Module._load (internal/modules/cjs/loader.js:901:14) 
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12)

问题出在express库中。

我不确定代码中的问题在哪里，因为我自己没有使用apply方法。

/路由器/index.js

const express = require('express');
const router = express.Router();
router.get('/',function(req,res){
res.render('index.html')
});
router.get('/about',function(req,res){
res.render('about.html');
});
router.get('/all', function (req, res) {
res.send(projectData);
// console.log(req);       
});
module.exports.data = data = []
router.post('/addName', function (req, res) {
data.push(req.body);
console.log(data);      
});
module.exports = router;

server.js

projectData = {};
// --> npm init (set up package.json)
// --> npm install express
const express    =    require('express');
const app        =    express();
app.use(express.static(__dirname + '/static')); 
// --> npm install cors 
const cors = require('cors');
app.use(cors());
// --> npm install ejs
require('./routes')(app); 
app.set('views',__dirname + '/views'); 
app.set('view engine', 'ejs'); 
app.engine('html', require('ejs').renderFile); 
// --> npm install body-parser 
const bodyParser = require('body-parser');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
// connect with routes file
app.use(require('./routes'));
// set up PORT
const port     =    3000;
const server   =    app.listen(port,function(){
console.log(`We have started our server on port ${port}`);
});

/static/app.js

const postData = async ( url = '', data = {})=>{                 
console.log(data);                                           
const response = await fetch(url, {                        
method: 'POST', 
credentials: 'same-origin',
headers: {'Content-Type': 'application/json',},
// Body data type must match "Content-Type" header        
body: JSON.stringify(data),                               
}); // end of respnose
try {
const newData = await response.json();                  
console.log(newData);
return newData;                                         
} 
catch(error) {
console.log("error", error);
}
} // end of postData
postData('/addName', {answer: 'evi'});                                  

Answer 1

回溯指向线require('./routes')(app);(如果我正确计算了行号(。

我认为你可以删除它，因为你稍后要做app.use(require('./routes'));。

Answer 2

因为您需要带有require('./routes')(app);的模块，所以在您的模块中，您需要导出一个以应用程序为参数的函数：

module.exports = app => {
...
return router;
}

所以，错误可能是因为你把一个参数传递给了一个不需要参数的东西。