Make node.js not exit on error

Question

I am working on a websocket oriented node.js server using Socket.IO. I noticed a bug where certain browsers aren't following the correct connect procedure to the server, and the code isn't written to gracefully handle it, and in short, it calls a method to an object that was never set up, thus killing the server due to an error.

My concern isn't with the bug in particular, but the fact that when such errors occur, the entire server goes down. Is there anything I can do on a global level in node to make it so if an error occurs it will simply log a message, perhaps kill the event, but the server process will keep on running?

I don't want other users' connections to go down due to one clever user exploiting an uncaught error in a large included codebase.

Answer 1

You can attach a listener to the uncaughtException event of the process object.

Code taken from the actual Node.js API reference (it's the second item under "process"):

process.on('uncaughtException', function (err) {
  console.log('Caught exception: ', err);
});

setTimeout(function () {
  console.log('This will still run.');
}, 500);

// Intentionally cause an exception, but don't catch it.
nonexistentFunc();
console.log('This will not run.');

All you've got to do now is to log it or do something with it, in case you know under what circumstances the bug occurs, you should file a bug over at Socket.IO's GitHub page:
https://github.com/LearnBoost/Socket.IO-node/issues