First time when I familiarized with unit testing was 5 or 6 years ago. It was start of my developing career. I remember that somebody told me about code coverage. At that time I didn’t write any Unit tests. Guy, who was my team lead, told me “Do you see operator if with three conditions? You should check all of these conditions”. So, after that I had written some code, I should go to interface and try to invoke all code which I wrote from user interface. Nice? At current time I know little more about tests and unit testing. I have not participated in projects, designed by Test Driven Development (TDD). Basics of my knowledge are a spying code of my colleagues, some articles and screencasts. I had decide that I should know much more, and became a real professional of unit testing, this is why I had start to read book The art of Unit Testing with Examples in .NET. More than, in my current job place looks like I’m just one who writing unit tests for my code. I should show good examples of my tests.

I had read about Code Contracts long time ago, but I didn’t see a reason to use contract instead of simple tests and argument's check with Exception's throws. Only now I’m trying to use them at real project. I didn’t see why I need to write:

Contract.Requires<ArgumentNullException>(argument == null); 

Instead of like I did it before:

if (argument == null) 

    throw new ArgumentNullException(“argument”)

Couple of weeks ago I had reinstall my Windows 7 on my laptop (I bought SSD for my laptop). After I install ReSharper with Visual Studio 2010 after run I accidental choosed “Go to the metadata” instead of like usual “Go to Object Explorer” by Ctrl and Mouse Click. So when I clicked on some class of System.xxx (basic classes of .NET) I looked at source code of these classes and found that they are using Code Contracts. I thought this is why I need to understand why I need to use contracts in my code, so I started to use them in some small applications and tried to find some interesting case.

Couple days ago I got a question about how to register hotkey in Windows for WPF application. I remembered that one year ago I was solving the same problem in WinForms application, I was registering hot keys for my application, it was Vista Keys Extender project. I knew that my project worked, so I suggested author of question to use code of my project to solve his problem. But as we learned later in WPF message handle mechanism different from WinForms. So I started to find solution for WPF application. I copied my old code from my old project and started to rewrite it step-by-step.

Couple of weeks ago I wrote about my small utility Config Transformation Tool, which I wrote with base of web.config transformation task. In those moments I was thinking about opportunity to pass parameters to transform file, to tool can replaces parameters in transformation file with special values. Yesterday I resolved this issue. From now I use class Microsoft.Web.Publishing.Tasks.XmlTransformation which works with strings and XmlDocuments instead of files. I had two tasks: (a) I need method which will replace parameters on values, (b) I need method which will be parse command line and create dictionary of parameters.

Couple of weeks ago I got a paper copy of book Pablo Cibraro, Kurt Claeys, Fabio Cozzolino, Johann Grabner - Professional WCF 4: Windows Communication Foundation with .NET 4. This book has not a lot of pages, just about 400. Really, I don’t remember when I saw so thin book about some technology. But maybe this book has not a lot pages, but a lot of interesting themes.

First chapter is patterns and principles of SOA applications. This is the best chapter in this book. When I was reading this chapter I saw that authors have a lot experience of creating applications with Service-oriented architecture. Authors described all possible architecture principles, with which you can create SOA applications. And they did not limit themselves to the principles that are possible with WCF. I think that this chapter is “must read” for all developers, it is doesn’t matter what technologies you are using: php, java or .net. And this is good luck that Wrox published this chapter online: Design Principles and Patterns. It is about 30 pages, so read it right now.

Passing array/list/set to stored procedure is fairly common task when you are working with Databases. You can meet this when you want to filter some collection. Other case – it can be an import into database from extern sources. I will consider few solutions: creation of sql-query at server code, put set of parameters to sql stored procedure’s parameter with next variants: parameters separated by comma, bulk insert, and at last table-valued parameters (it is most interesting approach, which we can use from MS SQL Server 2008).

At our product we have a client Silverlight part and server-code part, which contains a lot of WCF methods. We don’t use ASP.NET Compatible mode, because we want to leave an opportunity to deploy server part to server without web-server role (without IIS). Really, I don’t know why we chose this way, because all of our installations at current moment are on IIS. But we have what we have, so we haven’t ASP.NET Compatible mode, and as an expected result we can’t get HttpContext.Current instance at server WCF methods. One of WCF Service is a RESTful service, which at his methods returns report files, so it can handle GET-queries from browsers.

Just became a lucky owner of this book C# IN A NUTSHELL 4th edition. This is a fourth edition of this book’s series. I saw previous third edition of this book, we presented it on one of our events at Yaroslavl State University, but that book was a Russian translated version and published in Russia, this is was bad side of that book – all books at Russia printed on really bad paper. I should say that I didn’t read this book by end, but already I was surprised. Why? Why I heard a lot about Richter CLR via C# (English version of 3rd edition of this book I already have, and this book are waiting my attention), and just a few words about C# IN A NUTSHELL, at least in my sphere. I just listen once about this book at one of the podcast of Alt.Net group, and this words was Richter it is really good book, and C# IN A NUTSHELL it is a good handbook. My opinion is - you should read Richter if you want to develop with .NET. But if you want to develop on .NET with C# you should read C# IN A NUTSHELL too.

In Windows 7, I really liked an opportunity to change the position of the windows by pressing hotkeys Win + (Left | Right | Up | Bottom):

• Win + Left - window attached to the left side
• Win + Right - window attached to the right side
• Win + Up - window is maximized
• Win + Bottom - window in the normal state

So I spent my time and wrote this tool for Vista/XP users.

Recently I read good Russian post with many interesting extensions methods after then I remembered that I too have one good extension method “Safely type convert”. Idea of this method I got at last job.

We often write code like this:

int intValue;

if (obj == null || !int.TryParse(obj.ToString(), out intValue))

    intValue = 0;

This is method how to safely parse object to int. Of course will be good if we will create some unify method for safely casting.

I found that better way is to create extension methods and use them then follows:

int i;

i = "1".To<int>();

// i == 1

i = "1a".To<int>();

// i == 0 (default value of int)

i = "1a".To(10);

// i == 10 (set as default value 10)

i = "1".To(10);

// i == 1

// ********** Nullable sample **************

int? j;

j = "1".To<int?>();

// j == 1

j = "1a".To<int?>();

// j == null

j = "1a".To<int?>(10);

// j == 10

j = "1".To<int?>(10);

// j == 1