nested-error

NestedError
===========

NestedError is an Error class useful for wrapping another Error to get a
better stack trace associated with it.

This can be very helpful, especially when the original Error is created
close to node's internal event loop.

Usage
-----

First, install NestedError: npm install nested-error

Then make use of it like in this illustrative example:

var net = require('net');
var NestedError = require('nested-error');

// This function is our program:
function listen(callback) {
// Connect to a nonexistent UNIX domain socket to
// cause an error in the net module:
var server = net.connect({ "path": "nonexistent" });

server.on('error', function (err) {
// Wrap the error message we get in a NestedError
// to attach a stack trace that goes here
callback(new NestedError(err));
});
}

// This should give an error callback
listen(function (err) {
if (err) {
// Write out both stack traces for comparison:
console.error(err.stack);
console.error("\nCompare to inner exception:");
console.error(err.innerException.stack);
console.error("\nConclude that NestedError lets you debug easier :)");
}
});

This program will output the stack traces for both the error object we got
from node's net module and the NestedError we created. The NestedError
gives a much better context to be able to debug the problem.