Programming against an enum in a switch statement, is this your way to do?

Question

Look at the code snippet:

This is what I normally do when coding against an enum. I have a default escape with an InvalidOperationException (I do not use ArgumentExc

Answer 1

I don't like this approach because the default case is untestable. This leads to reduced coverage in your unit tests, which while isn't necessarily the end of the world, annoys obsessive-compulsive me.

I would prefer to simply unit test each case and have an additional assertion that there are only four possible cases. If anyone ever added new enum values, a unit test would break.

Something like

[Test]
public void ShouldOnlyHaveFourStates()
{
    Assert.That(Enum.GetValues( typeof( DrivingState) ).Length == 4, "Update unit tests for your new DrivingState!!!");
}