CODEWITHSUNDEEP
node.jsexpress
punjabi
punjabi

Reputation: 49

Problem returning custom message in the error handling middleware in Express.js

I have the following code. There is the error handling middleware, which does get called when i open localhost:3000 on browser, but the response is never 'system is unavailable for the moment'. Instead i get the error message "my custom error" along with the full stack trace.

Is my understanding incorrect that error middleware is called by express once there is an unhandeled error ?/

CODE

let express = require('express');
let app =  express(); 
let pug = require('pug');
let session = require('express-session');
let passport = require('passport');
require('dotenv').config();


app.listen(3000,"",()=>{
    console.log('server started');
}); 

// set express properties. these properties can be had anywhere in the code
app.set('title','Sample application using Express, Expression session, Pug, Socktet and Passport');

// for pug
app.set('view engine','pug');
app.set('views','./pages'); 

console.log(process.env.ExpressSecret);
console.log(process.env.Port);

// use the express session to se the cookie, 
// use function can take a series of middlewares 
app.use( session({
      secret: process.env.ExpressSecret,
      saveUninitialized:true,
      resave:true
  }),passport.initialize(),passport.session())

app.use((err, req, res,next) => {
    console.error(err.stack);
    res.status(500).json({ error: 'system is unavailable for the moment' });
  });

app.get('/',(request, response)=>{     
    throw new Error('my custom error');               
});

Upvotes: 0

Views: 602

Answers (1)

prosunshining
prosunshining

Reputation: 159

You need to define error-handling middleware last, after other app.use() and routes calls.

app.use( session({
      secret: process.env.ExpressSecret,
      saveUninitialized:true,
      resave:true
  }),passport.initialize(),passport.session())



app.get('/',(request, response)=>{     
    throw new Error('my custom error');               
});

app.use((err, req, res,next) => {
    console.error(err.stack);
    res.status(500).json({ error: 'system is unavailable for the moment' });
  });

https://expressjs.com/en/guide/error-handling.html

Upvotes: 2

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