CODEWITHSUNDEEP
node.js
Lahiru Chandima
Lahiru Chandima

Reputation: 24068

Nodejs uncaughtException event not fired if exception occurred inside express handler

I have caught uncaughtException event in my nodejs app to write a log when an exception occurred.

process.on('uncaughtException', (err) => {
    log.warn('Caught exception. Exiting. error: ' + err + ', stack: ' + err.stack);
    process.exit(1);
});

But, above handler is not called when an exception is thrown inside an express event handler.

someInvalidFunc();    //This causes the uncaughtException handler to get called.

app.all('/ping', function (req, res, next) {
    someInvalidFunc();  //This doesn't cause the uncaughtException handler to get called.
    res.status(200).json({status: 'OK'});
});

Even though the handler is not called, the error is printed to console.

Error: ReferenceError: someInvalidFunc is not defined

What is the reason for this? How can I catch all unhandled exceptions in the app?

Upvotes: 2

Views: 3702

Answers (1)

Javier Uria
Javier Uria

Reputation: 119

If you are using express, the uncaughtException callback won't be even triggered as express provides a default error handler that catches error from the controller and sends 500 as a response.

You can override the error handler. This is explained in the docs: https://expressjs.com/en/guide/error-handling.html

Upvotes: 2

Related Questions