Learning to write good tests can be hard. There are a lot of things to learn technologies to master and if you have been programming for some time then there are some bad habits to undo.

I train a lot of people to do TDD and have learnt from this that there a few small tricks that will significantly help you write a good test.

This blog assumes that you are familiar with the Red, Green Refactor process of test driven development and have some exposure to a unit testing framework such as NUnit.

I also assume you are familiar with the concept that TDD is not a testing activity but is in fact a design and development activity.

In this blog I go through the parts of what I consider to be a good test.

So, we are starting to develop a project in an Agile, TDD manner and we don’t really want to be concerned with too much other than this object has this property and relates to some other object... because my test that I’m currently writing needs it. I don’t really care how this fits into the whole scheme of things at this stage. The fact that my “Invoice Line” object can only ever exist on an “Invoice” and that the invoice must be associated to a “Customer” in order to be valid doesn’t really concern me at this stage. Although all those other facts are true, they have no relevance to my SUT (system under test)...

For part 2 in this series (which I've renamed slightly), we add some new domain classes to the nascent Bob's Pizza Place domain model with relationships between them. We also add a bit of logic to some of the classes to enrich the domain model with business logic.

You can download the article in PDF format here: DomainModellingWithHabanero01-02.zip. This zip contains part 1 and part 2, as well as the final source for both.

I'm putting together a series of articles for people new to Habanero to get basic idea of domain concepts and how to implement them in Habanero as simply as possible. They won't include any of the UI stuff, and won't use FireStarter, so it's first principles stuff, all manual. The core of Habanero is it's powerful Business Object layer, so this is what I'm focussing on here.

I've attached the first in the series to this blog post below, and I'll put it up on the tutorial section of the site soon (which will be revamped too).

I'd really appreciate any feedback, good or bad.

Building and using a Domain Model with Habanero: Part 1- A Beginner's Guide.zip