NUnit Error: Not a test assembly
asp.net, asp.net-mvc, c#, nunit, unit-testing
Solution
This may or may not be the issue that you are facing, but I had exactly the same issue and I found that the dll I was loading was an old file.
Rebuild the project and then actually go into the directory that the dll is in and check that it has a creation/modification time that is current.
It's very easy, for example, to create:
my_project/
my_project/domain/
my_project/unit-tests/ (removed but not deleted on the HD, not visible in studio)
my_project/domain/unit-tests/ (visible as MyProject.UnitTests)
If you then load the dll in my_project/unit-tests/ you may not be loading the dll you just built.
Try also file -> save as while editing a test class, and see what actual directory it is being saved into, and check that the dll you are loading is from the same path.
Problem
I have a solution with 3 projects in it (one is a C# class-library for unit tests, another is a MVC 2 web application) I have included all the necessary references for NUnit, and I have correctly decorated the classes and methods with `[TestFixture]` and `[Test]` respectively. It compiles with no errors. I am using Visual Studio 2010 Pro When I try to open UnitTests.dll in NUnit, I get the following error: Not a test assembly. This assembly was not built with any known testing framework.