How to capture response error/message in separate route? - node.js

Question

I just want to capture the response error from a middleware function, it works if I write the code as follows:
var express = require('express');
var expressValidator = require('express-validator');
var app = express();
var bodyParser = require('body-parser');
var router = require('./routes');
//monk.mongoList();
app.use(bodyParser.urlencoded({extented:true}));
app.use(bodyParser.json());
app.use(expressValidator([]));
var port = process.env.PORT || 8978;
router.get('/',function(req,res,next) {
var error = Error('Article is not found');
next(error.message);
return res.send("Hello World!");
});
app.use(function(err,req,res,next) {
console.log(err + "TET");
})
app.listen(port);
but I want to separate the following code:
app.use(function(err,req,res,next) {
console.log(err + "TET");
})
and use it as follows:
app.js
var express = require('express');
var expressValidator = require('express-validator');
var app = express();
var bodyParser = require('body-parser');
var router = require('./routes');
//monk.mongoList();
app.use(bodyParser.urlencoded({extented:true}));
app.use(bodyParser.json());
app.use(expressValidator([]));
var port = process.env.PORT || 8978;
var test = require('./util/test')
app.use(test.logger);
app.use('/',router);
app.listen(port);
console.log('test node API ' + port );
util/test.js
module.exports.logger = function (err, req, res, next) {
console.log('LOGGED')
next()
}
/routes/index.js EDIT: I just edited the /routes/index.js file to make it more simple
var express = require('express');
var router = express.Router();
var url = require('url');
router.get('/api', function(req, res, next) {
var err = "this is error";
var error = Error (err)
var data = { data: "Succuss"}
if (err) {
next(error.message)
res.json({message:err})
}else {
res.json(data);
}
});
module.exports = router;
When add the above code, nothing appear in the console.