Question

Sorry for the long post…

While being introduced to a brown field project, I’m having doubts regarding certain sets of unit tests and what to think. Say you had a repostory class, wrapping a stored procedure and in the developer guide book, a certain set guidelines (rules), describe how this class should be constructured. The class could look like the following:

public class PersonRepository
{
public PersonCollection FindPersonsByNameAndCity(string personName, string cityName)
{
    using (new SomeProfiler("someKey"))
    {
        var sp = Ioc.Resolve<IPersonStoredProcedure>();

        sp.addNameArguement(personName);
        sp.addCityArguement(cityName);

        return sp.invoke();
    }
} }

Now, I would of course write some integration tests, testing that the SP can be invoked, and that the behavior is as expected. However, would I write unit tests that assert that:

• Constructor for SomeProfiler with the input parameter “someKey” is called
• The Constructor of PersonStoredProcedure is called
• The addNameArgument method on the stored procedure is called with parameter personName
• The addCityArgument method on the stored procedure is called with parameter cityName
• The invoke method is called on the stored procedure –

If so, I would potentially be testing the whole structure of a method, besides the behavior. My initial thought is that it is overkill. However, in regards to the coding practices enforced by the team, these test ensure a uniform and ‘correct’ structure and that the next layer is called correctly (from DAL to DB, BLL to DAL etc).

In my case these type of tests, are performed for each layer of the application.

Follow up question – the use of the SomeProfiler class smells a little like a convention to me – Instead creating explicit tests for this, could one create convention styled test by using static code analysis or unittest + reflection?

Thanks in advance.

Answer 1

I think that your initial thought was right – this is an overkill. Although you can use reflection to make sure that the class has the methods you expect I’m not sure you want to test it that way.

Perhaps instead of unit testing you should use some tool such as FxCop/StyleCop or nDepend to make sure all of the classes in a specific assembly/dll has these properties.

Having said that I’m a believer of “only code what you need” why test that a method exist, either you use it somewhere in your code and in that can you can test the specific case or you don’t – and so it’s irrelevant.