Which version of NUnit ships with Unity? Can't find [TestFixtureSource] attribute.

Where can I find which version of NUnit is shipped by Unity with the Editor Test Tools? I was trying to use the [TestFixtureSource] attribute, but it couldn’t be found in the NUnit namespace, so apparently Unity uses a modified or older version of NUnit (too bad…).

If anyone is googling this with version 2017.3, it looks like its using version 3.5 now.

“The Editor Tests Runner is an implementation of the open source NUnit library - a well-known unit testing library for .Net languages. More information about NUnit can be found on http://www.nunit.org/. The implementaion is based on version 2.6.4.”

I am writing some tests that capture images in “PlayMode” and it works pretty well. I wanted to add them using NUnit TestContext.AddTestAttachment method that is available in 3.8 or something. I tried to replace all nunit.framework.dll and .xml in the Unity installation but tests crash with:
MissingMethodException: Method not found: ‘NUnit.Framework.Internal.Reflect.set_MethodCallWrapper’ at “…/Runtime/Export/Coroutines.cs”. So I guess Unity is doing some work to update the testrunner and match with new NUnit versions.

When can we have NUnit 3.9? I would love to attach actual/diff/expected set of images as attachments to tests: