Express Error Handling isn't working correctly

Question

I've tried all the ways to handle my errors but error handling middleware is never been called.

I tried many ways to handle the error but it seems that code instantly breaks when I throw an error.

-- App.js --
const app = express();
app.set('trust proxy', true); 
app.use(json());

app.use(
  cookieSession({
    signed: false, 
    secure: process.env.NODE_ENV !== 'test',
  })
);

// routes
app.use(CurrentUserRoute);
app.use(SignInRoute);
app.use(SignUpRoute);
app.use(SignOutRoute);

app.all('*', async (req, res) => {
  console.log('This is a global error handler at route level....');
  throw new Error('Error');
});

app.use(errorHandler);  // this is the error middleware

Error handling middleware:

import { Request, Response, NextFunction } from 'express';

export const errorHandler = (
  err: Error,
  req: Request,
  res: Response,
  next: NextFunction
) => {
  console.log('Something went wrong!!!!!!!!!!!!!!!!!!!!!!!!!!!!: ', err);

  res.status(400).send({
    message: 'Something Went Wrong',
  });
};

In my routes, whenever I throw an error, the middleware is never called and it instantly shows its own error like

[auth] Error: "email" length must be at least 5 characters long
[auth] at /app/src/routes/signUp.ts:17:11
[auth] at step (/app/src/routes/signUp.ts:33:23)
[auth] at Object.next (/app/src/routes/signUp.ts:14:53)
[auth] at /app/src/routes/signUp.ts:8:71
[auth] at new Promise ()
[auth] at __awaiter (/app/src/routes/signUp.ts:4:12)
[auth] at /app/src/routes/signUp.ts:11:68
[auth] at Layer.handle [as handle_request] (/app/node_modules/express/lib/router/layer.js:95:5)
[auth] at next (/app/node_modules/express/lib/router/route.js:137:13)
[auth] at Route.dispatch (/app/node_modules/express/lib/router/route.js:112:3)
[auth] at Layer.handle [as handle_request] (/app/node_modules/express/lib/router/layer.js:95:5)
[auth] at /app/node_modules/express/lib/router/index.js:281:22
[auth] at Function.process_params (/app/node_modules/express/lib/router/index.js:335:12)
[auth] at next (/app/node_modules/express/lib/router/index.js:275:10)
[auth] at Function.handle (/app/node_modules/express/lib/router/index.js:174:3)
[auth] at router (/app/node_modules/express/lib/router/index.js:47:12)
[auth] [ERROR] 12:13:25 Error: "email" length must be at least 5 characters long

P.S I'm using Docker and Kubernetes Environment with ingress-nginx service but I don't think it could have any problem with error handling.

https://stackoverflow.com/questions/51391080/handling-errors-in-express-async-middleware — hoangdv, Jan 30 '21 at 14:20

score 0 · Accepted Answer · answered Jan 30 '21 at 17:55

One of the ways to fix this problem is to make middleware directly in your app.js file. so instead of this :

app.use(errorHandler);

use this :

app.use(async (error, req, res, next)=>{

     res.status(400).send({
          message: 'Something Went Wrong',
     });

});

score 0 · Answer 2 · answered Feb 04 '21 at 17:46

if Error handling middleware don't have any error you can use like this in controller

use return next() after that error middleware should run

const MyFunction = async (req, res, next) => {
    const error = new Error("Error Message in controller")
    return next(error);
}

my error middleware handling (errorMiddleware.js)

const errorHandler = (err, req, res, next) => {
  console.log("Something went wrong!!!!!!!!!!!!!!!!!!!!!!!!!!!!: ", err);

  res.status(400).send({
    message: "Something Went Wrong",
  });
};

exports.errorHandler = errorHandler

in app.js

const {errorHandler} = require('./errorMiddleware');
app.use(errorHandler);

Express Error Handling isn't working correctly

2 Answers2