app.use("/",middlwarre) shows an error code example

Example 1: how to handle all error of all router in express

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function (err, req, res, next) {
        res.status(err.status || 500);
        res.render('error.ejs', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function (err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});

Example 2: how to handle all error of all router in express

var router = express.Router();

router.get('/req1', handleErrorAsync(async (req, res, next) => {
   let result = await someAsyncFunction1();
   if(result){
       // res.send whatever
   }
}));
router.post('/req2', handleErrorAsync(async (req, res, next) => {
    let result = await someAsyncFunction2(req.body.param1);
    if(result){
        // res.send whatever
    }
}));
router.post('/req3', handleErrorAsync(async (req, res, next) => {
    let result = await someAsyncFunction3(req.body.param1, req.body.param2);
    if(result){
        // res.send whatever
    }
}));

module.exports = router;