Add the NUnit test adapter NuGet package to your test projects
- 2.* (https://www.nuget.org/packages/NUnitTestAdapter/)
- 3.* (https://www.nuget.org/packages/NUnit3TestAdapter/)
Or install the Test Adapter Visual Studio extension. There is one for
- 2.* (https://marketplace.visualstudio.com/items?itemName=NUnitDevelopers.NUnitTestAdapter)
- 3.* (https://marketplace.visualstudio.com/items?itemName=NUnitDevelopers.NUnit3TestAdapter).
I prefer the NuGet package, because it will be in sync with the NUnit version used by your project and will thus automatically match the version used in any build server.