Question

I have a class that I need to Unit Test.

For background I’m developing in c# and using NUnit, but my question is more theoretical:

I don’t know if I’ve written enough test methods and if I checked all the scenarios.
Is there a known working method/best practices/collection of rules for that?

Something like

• “check every method in your class …bla bla “
• “check all the inserts to DB …bla bla “

(this is a silly example of possible rules but if I had something not silly on my mind I wouldn’t ask this question)

Answer 1

There are several available metrics for unit testing. Have a look into both code coverage and orthogonal testing.

However, I would say that this is not the best way of addressing the problem. While 100% code coverage is an admirable goal it can become the sort of metric which obscures that actual quality of the tests.

Personally I think you would get better results from investigating test driven development – using this approach you know you have good coverage (both in terms of lines of code and in terms of functionality of your class) because you have been writing the tests to exercise your class before you wrote the class methods themselves.