nested-error-stacks

Nested stacktraces for Node.js!

With this module, you can wrap a caught exception with extra context for better debugging. For example, a network error's stack would normally look like this:

Error: connect ECONNREFUSED
    at errnoException (net.js:904:11)
    at Object.afterConnect [as oncomplete] (net.js:895:19)

Using this module, you can wrap the Error with more context to get a stack that looks like this:

NestedError: Failed to communicate with localhost:8080
    at Socket.<anonymous> (/Users/mattlavin/Projects/nested-stacks/demo.js:6:18)
    at Socket.EventEmitter.emit (events.js:95:17)
    at net.js:440:14
    at process._tickCallback (node.js:415:13)
Caused By: Error: connect ECONNREFUSED
    at errnoException (net.js:904:11)
    at Object.afterConnect [as oncomplete] (net.js:895:19)

How to wrap errors

Here is an example program that uses this module to add more context to errors:

var NestedError = require('nested-error-stacks');
var net = require('net');
    
var client = net.connect({port: 8080});
client.on('error', function (err) {
    var newErr = new NestedError("Failed to communicate with localhost:8080", err);
    console.log(newErr.stack);
});

How to inherit

It is recommended to use explicit names for Error classes. You can do it like this:

var util = require('util');
var NestedError = require('nested-error-stacks');

function MyError(message, nested) {
    NestedError.call(this, message, nested);
}

util.inherits(MyError, NestedError);
MyError.prototype.name = 'MyError';