QUnit - Unit testing javascript

Started using QUnit for unit testing javascript/jquery code. Using the likes of Watin with NUnit, we can write a unit test that browses to a .htm page that contains the QUnit tests. By checking the actual html rendered by by the QUnit test runner (using Watin of course) we can verify if all the tests passed or failed.

Will update this post with technical examples soon...

Managed Entity Framework (MEF)

Started looking at this today. Its main aim is to make application extensible - in my opinion from first impressions it is just a glorified IOC container.

Will see over the coming days if this is the case...

DDD + NHibernate dosen't fit 100%

Before I start, I think NHibernate is a classy open source piece of software and in my opinion is by far the best ORM out there! I am just outlining some of the problems I have encounterd with it when trying to integrate it into a DDD codebase.

One of the most major domain driven design principles is the concept of "persistence ignorance".
If you have entities in your domain that you want to persist through NHibernate, you must include a default constructor in the entity (although it can be private) - a small price to pay to use the power of NHibernate but persistence ignorance is broken (see following entity example):

public class SampleEntity
{
      // Persistence ignorance broken...
      private SampleEntity() { }
      

      public void Method1()
      {
            . . .
      }
}

When trying to convince the development team in my company to adopt NHibernate into the codebase, the default constructor requirement was a major stumbling block - as the domain was completely persistence ignorant!


Also, if you are developing a system where multiple threads of execution are in play regularly, making sure that all your value types are "immutable" avoids many concurrency issues. The problems working with immutable types and NHibernate are as follows:

1. Immutable types only work at a field level, not at a property level
2. Even if your types class is immutable (guard checks are performed via constructor), an invalid type can be retrieved back from the database (as the default constructor is called by NHibernate through reflection). There are ways around this using PostLoadEventListener to call the constructor with the guard checks is one solution - there are others

Has anyone else experienced the same proplems as described?

New blog

Ok, I have decided to start blogging, mainly because I have a major interest in software patterns, best practices, interest in open source software etc...

Also I would like to use this blog to get some of my own ideas out there...

Anyway we will give it a shot anyway...