The latest Resharper (v5) version is based on native NUnit code and allows NUnit addins.
I have a NUnit addin that works fine in NUnit GUI but I can not make it work with Resharper. Based on R# indication I have put my addins library in %ResharperPath%\Bin\addins but I doesn't work, my tests are marked as Ignored.
Question: How to use NUnit addins with ReSharper?
Unfortunately, ReSharper's test runner doesn't support NUnit add-ins. It's been requested, but hasn't been added, not even to the forthcoming ReSharper 6. (Feel free to vote for the feature request to let them know there's interest -- I just did.)
We use an NUnit add-in for some of our tests, and those tests don't show up in ReSharper at all -- no gutter icons, nothing in the Unit Tests window, nothing. Our only option is, when we want to run those tests, to fire up the NUnit GUI. It's a pain.
Now ReSharper supports NUnit addins. Try this link: http://blogs.sourceallies.com/2013/06/nunit-addins-that-works-with-resharper/
Also you need to change default settings in resharper:
http://i.imgur.com/2qT0y2U.png
Options -> Tools -> Unit Testing -> NUnit
Load NUnit Addins -> Always
and copy dll with Addin to C:\Users...\AppData\Local\JetBrains\Installations\ReSharperPlatformVs12\addins
Also your dll with tests (not with addin) must not contain NUnit.AddinsDependencies package
