// Cause an error and then log it.
try {

	var foo = bar;

} catch ( error ) {

	// NOTE: Unlike the core Error properties, this one will be iterable.
	error.customProperty = "Injected custom property.";

	logError(
		{
			message: "Something went wrong when trying to set Foo!"
		},
		error
	);

}


// ----------------------------------------------------------------------------------- //
// ----------------------------------------------------------------------------------- //


// Create a log-entry and log it to the console (for demo).
function logError( entry, error ) {

	// Create a log-entry with the error data as a key off the entry.
	var data = extend(
		{
			_id: ( process.pid + "-" + Date.now() ),
			_timestamp: ( new Date() ).toUTCString(),
		},
		entry,
		{
			error: extend( {}, error )
		}
	);

	// None of the native error objects properties are iterable. As such, we have to
	// explicitly check for error-specific properties that we want to track for future
	// debugging purposes.
	// --
	// NOTE: If the Error object is a custom error object, it might have other
	// properties, but those will be handled implicitly by the extend() call above.
	[ "name", "message", "stack" ].forEach(
		function iterator( key ) {

			if ( error[ key ] && ! data.error[ key ] ) {

				data.error[ key ] = error[ key ];

			}

		}
	);

	// For demo, log to console.
	console.error( data );

}


// I collapse the given argument list down into the destination object and return it.
function extend( destination, source ) {

	for ( var i = 1, length = arguments.length ; i < length ; i++ ) {

		var source = arguments[ i ];

		for ( var key in source ) {

			if ( source.hasOwnProperty( key ) ) {

				destination[ key ] = source[ key ];

			}

		}

	}

	return( destination );

}