There have been some issues filed recently about exceptions being thrown when running NUnit tests under the VS test window. In many cases, they result in trying to install two different versions of the NUnit Engine into the same project directory. I'll try to explain how the problem arises and what to do about it. The table at the end of this post will also be useful to anyone wanting to know which version of the engine is being used by the adapter version they have installed.
NUnit 2.0 through 2.7 was delivered as an all-inclusive package: test framework, console runner and GUI runner. With NUnit 3 that changed. The framework and console runner became separate packages and the GUI was no longer developed.
I'm in the process of moving many of my old posts to a new website - this one - and that involves thinking about some things I have not thought of in years.
A while back I began to have some concern about the future of NUnit. I was entering my 70s and I knew I wanted to spend more time on other things. NUnit had been very much my project for a few years and I didn't want it to die when I was no longer maintaining it.
In a recent online discussion, one of our users talked about needing to re-run the NUnit console runner, executing just the failed tests from the previous run. This isn't a feature in NUnit but it could be useful to some people. So... can we do this by creating an Engine Extension? Let's give it a try!
As I've worked on NUnit 2.4 and its follow-ups, I have begun to feel that it's time for a much more significant update to NUnit, a rethinking of what it's all about and how it should work. Of course, at the same time, I don't want to lose all the work that has gone into NUnit up to now. Puzzling over this, and helped by a group of dedicated NUnit users and contributors, I think I now have a direction to go.