7.07.2012

Bug Hunting with NDepend


Here's another post about NDepend (one of my favorite tools of the trade)! I've recently installed the new NDepend v4 and here's how I've used it for the first time.
I was going through the logs of the asp.net application I'm developing and found reasons to believe that somewhere in the application an object was being written on the viewstate that wouldn't serialize as supposed and throw an exception.
Now, how do we find and fix this bug easily? Surely we could attempt to find in the solution for all uses of the Viewstate and reading that code, but that would be too much code to read, so I've decided to use NDepend to aid me.
So here's what I've though:
- most of the times we use the viewstate in this application is through a property on a page or user control;
- if it's a serialization error, we can ignore properties whose type is a primitive type as we're likely dealing with a class defined in our application;

Here's how I've done it:

From here I only had 3 source code locations to investigate! Much easier than going through the entire application, isn't it?

The ability to query your code (and now in a syntax much alike the linq queries I write day after day) is something very powerful, and every once in a while we might find a new way of use this power!