The type or namespace name 'NUnit' cannot be found.,Type or namespace 'NUnit' could not be found.

Questions & Answers
1

I am facing a new problem with one of my projects. The solution gives me compilation errors when I try to build it in Unity complaining about NUnit missing as a reference. However, it compiles correctly on Monodevelop and NUnit.Core and NUnit.Framework are added as references.
Any idea on how to solve this issue and compile it correctly on Unity as well?

3

NUnit is only available within Editor scope of unity and thus all unit test have to be under a Editor folder.

All scripts that are placed in a
folder called Editor (or a sub-folder
within it) will be treated as editor
scripts rather than runtime scripts.
Such scripts are designed to add
functionality to Unity itself during
development and are not available to
the finished game at runtime.
(Unity - Manual: Special folder names)

2

I had the same problem. I do not fully understand the issue, but here is what I deduced:

Your test scripts need to follow the same path names as the path that leads to the nunit dll files. On my system these files were at:

C:\Users\MyName\Documents\GameSourceCode\Assets\UnityTestTools\UnitTesting\Editor\NUnit\Libs

I tried to place my test script in:

C:\Users\MyName\Documents\GameSourceCode\Assets\Tests

This produces the error. So, I moved them to:

C:\Users\MyName\Documents\GameSourceCode\Assets\Tests\Editor

Now I can run tests, and I do not have errors reported. I am certain that there is a more elegant solution, but I am a newbie.