Guido van Loon

I needed an easy way to verify if the system under test (sut) was calling the correct methods with the correct parameters as recorded. Rhino Mocks does this by default but my parameters are objects, or even small object trees. Rhino Mocks will compare the pointers of the expected and actual objects instead of comparing the contents of both objects.

I know this can be done with the Property constraint but it works string based and when the object has a lot of properties you must program as many Property constraints as there are poperties.

To overcome this cumbersome task I've created the AllPropertiesMatchConstraint class which can be used through a ReferenceType helper. The syntax looks like this:

Now when HasInventory is called with a different product instance who has the same property values the expectation will still be met. However, if HasInventory is called with a different product who has other property values the constraint will tell you execly which property is different and therefore does not match your expectation.

The way this works it with a pinch of reflection Through reflection all public properties and public fields of the expected object are checked with the properties and fields of the actual object. This works recursive so if a property, in it's self, is an object, that object will also be matched.

Collections are supported through the IEnumerable interface, which means the constraint will check if the actual and expected collection contain the same values in the same order. The values contained by the collection can have properties and fields of their own that will be checked as well because of the recursive nature of the constraint.

Indexed properties are not supported, they will just be skipped.

I have supplied a patch for Rhino Mocks today and I am hoping Ayende will accept it for the next release of Rhino Mocks.

Download code This is a Visual Studio 2005 solution containing the constraint code and unitttests.

A few days after I've pointed my RSS reader to the Rhino.Mocks Google Group There is an announcement form the author of RhinoMocks that a brand new version 3.0 is released yesterday.

On top of this he has been making a screen cast that explains how to use RhinoMocks. The video is almost one hour long but I think is definitely worth watching as it shows you how it all works very well. In order to see the video you must install the Camtasia TSCC codec wich you can download here (it's the first link on the page)

One tip for the author, Ayende: could you please turn off Resharper next time you do a screen cast. Seeing you edit code with that tool is a little hard to follow if you don't use it yourself.

Happy mocking indeed

Scott Guthrie points out that Microsoft is offerring a free online course where you can learn all about ASP.Net AJAX. Click te link below to check it out. You'll need to have a Live ID to sign in though.

Developing Enhanced Web Experiences with Microsoft ASP.NET AJAX Extensions

Here is the discription of the course (taken from the Microsft eLearning web site):

In this 2-hour clinic you will learn about the rich functionality that ASP.NET AJAX Extensions provides for building highly responsive and enhanced web applications. In addition to learning about the different server and client components of ASP.NET AJAX, you will also learn how to build new ASP.NET AJAX applications and how to upgrade existing ASP.NET applications to take advantage of ASP.NET AJAX.

This clinic is appropriate for experienced .NET Web Developers and Software Architects who are looking to incorporate ASP.NET AJAX within their existing and future solutions.

C# has nullable types. This gives us the ability to assign null to value types:

Microsoft writes the following in the C# Programming Guide about nullable types: "The ability to assign null to numeric and Boolean types is particularly useful when dealing with databases and other data types containing elements that may not be assigned a value. For example, a Boolean field in a database can store the values true or false, or it may be undefined."

Then why is it that the Typed DataSet generator in Visual Studio 2005 doesn't use nullable types in it's typed DataRow classes for columns that could be null? Instead we're still stuck with the IsNull() and SetNull() methods. This really is a missed opportunity imho. Perhaps they've had good reasons not to implement nullable types for typed dataset rows but I can't think of any. Leave me a comment if you know why.

At work the other day I had some trouble using the TestDriven.Net 1.0 plugin for Visual Studio 2003. When I ran my tests using TestDriven, no test results where shown in the test output window. Instead I got stuck with a dozen or so test output windows, all of them empty... I tried re-installing the tool and repairing my Visual Studio installation but non of the things I tried really helped.

I was still able to debug my code using te "run with debugger" option but to see some test results I had to use NUnit, which is a separate tool outside the IDE. This was not too big of a deal but it was decreasing productivity and I wanted it fixed.

While I didn't expect too much of it I decided to send an email to the TestDriven.Net support. It didn't take long before I had an anwser from Jamie Cansdale, the creator of TestDriven, with some suggestions of what to try. Unfortunately his suggestions didn't help either but Jamie wouldn't give up. He really cared about the problem at hand and that alone was enough for me. We exchanged quite some emails that day but still without any result. Nonetheless I want everybody to know TestDriven.Net really knows how to give support. After all it's the experience that counts! A positive experience it was!

Unfortunately I was unable to test the newer version of TestDriven because we don't have any licenses for it. It would most likely have solved the problem... With Visual Studio 2005, unit testing is build into the IDE. Running tests and viewing test output is done in a nice way but I miss being able to right click a test method and just run it from there with the debugger. With TestDriven.Net 2.0 comes support for Visual Studio Test projects. When I'm able to fully swith to VS 2005 someday, I will still love to have TestDriven.Net just for running my test directly from the code window.

Today someone showed me WebServiceStudio. A nifty little tool to invoke webservice methods. This tool generates a .Net proxy from a WSDL endpoint and helps you to invoke the methods on the service by creating the request message. All you have to do is give the values for the different element of the request. Once the webmethod is executed you can examine the repsonse message.

This may come in handy when testing or debugging a webservice. WebServiceStudio 2.0 exists for quite some time now, I don't know how I could have missed this one!

Anyway here is the link: WebServiceStudio 2.0 at gotdotnet.

Here is a little Mock super class we've used in one of our projects. It may come in handy when you don't want to bring out the big Mock frameworks... (credits go to TimV for punching up this code)

I got some hands-on experience unit testing with mock objects recently. I must admid I'm very positive about it. The project I'm working on is getting bigger and it is becoming harder to set up the environment in order to test a small piece of functionality. This is a problem that comes with the so called "state testing" that we were using. With mock objects an other way of testing known as "interaction testing" is becoming possible. This way you don't have to set up an entire environment to test a small piece of functionality.