Microsoft.Fakes won't run in normal unit test contexts

pattermeister picture pattermeister · Oct 15, 2013 · Viewed 9.6k times · Source

I'm using a simple proof-of-concept Fakes nUnit test:

  [Test]
  public void TestFakes()
  {
      using (var ctx = ShimsContext.Create())
      {
          System.Fakes.ShimDateTime.NowGet = () => { return new DateTime(2000, 1, 1); };

          Assert.That(DateTime.Now.Year, Is.EqualTo(2000));
      }
  }

This test runs in the Visual Studio Test Explorer, but doesn't run in:

  • nUnit GUI
  • nUnit console
  • The JetBrains test runner (dotCover OR Resharper)
  • TestDriven.net test runner

In each of these, I receive the following error:

Microsoft.QualityTools.Testing.Fakes.UnitTestIsolation.UnitTestIsolationException : Failed to resolve profiler path from COR_PROFILER_PATH and COR_PROFILER environment variables

When I reflect into that assembly, it seems like it's looking for Intellitrace, a VS Ultimate-only feature - I only have Premium installed.

Any suggestions on how to work around this (we use the nUnit runner on our build servers, so this is a blocker to using Fakes)

Answer

Jason Evans picture Jason Evans · Oct 15, 2013

I don't think you will be able to execute MS Fakes based tests using anything other then MS Test framework.

I believe that the way MS Fakes works causes problems for test runners such as NUnit. Precisely why this is the case, I don't know, since other mocking frameworks such as TypeMock work fine in NUnit, etc. But there is something specific to MS Fakes which make it harder (if not impossible) to run with anything other than MS Test. That's my theory anyway.

Unless the authors of NUnit, xUnit, etc add support for MS Fakes (or there is a crafty workaround), I think you will have to stick with MS Test.

EDIT:

It looks like the latest version of NCrunch v2.5 does work with MS Fakes. I've tried the beta during it's development, and can confirm that MS Fake tests were executed without fail using NCrunch.