testing an internal class

Question

how to write unit tests to internal classes ???

Answer 1

We have used a helper class which uses reflection to load and call methods on internal classes. It is also possible to change the accessibility at compile time using the DEBUG symbol eg

#if DEBUG
public
#else
internal
#endif
    class MyInternalClass
{
    ...
}

However Esko Luontola's answer is more correct as it is the functionality or business requirements which are most important. It is easy to get too focused on code coverage rather than testing the important risk areas.