XUnit in Visual Studio 2015 RC1 Update 1 doesn't find tests

Question

I created an ASP.NET 5 project in Visual Studio 2015, using the Preview Templates. I installed XUnit via NuGet, and I added an "xUnit Test Project (DNX)" to my solution.

But my Test Explorer shows nothing, even though I have a public "Fact" test method in Class1.cs. When I "Run All Tests", the "Tests" output window is blank. My "Build" output window shows that 2 project build succeeds. (My ASP.NET 5 project, and my xUnit project.)

When I either build or clean my solution, however, I get the following message in the "Tests" output window:

------ Discover test started ------
------ Test started: Project: MyProjectTest ------
Starting  Microsoft.Dnx.TestHost [C:\Users\xxxxxx\.dnx\runtimes\dnx-clr-win-x86.1.0.0-rc1-update1\bin\dnx.exe --appbase "C:\Users\xxxxxx\Documents\GitForWindows\Repositories\MySolution\MyProjectTest" Microsoft.Dnx.ApplicationHost --port 8424 Microsoft.Dnx.TestHost --port 8458 --parentProcessId 17312]

System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.Dnx.TestHost.Program.<>c__DisplayClass2_0.<<Main>b__0>d.MoveNext()
Unable to start Microsoft.Dnx.TestHost
========== Discover test finished: 0 found (0:00:01.057196) ==========

My solution DNX SDK version, according to both projects' properties window, is 1.0.0-rc1-update1. I also set that as the "active" runtime via dnvm, with no change in the above behavior. I don't understand the instructions about running DNX from the command line, though, so perhaps that's a starting point?

When I try switching DNX SDK to 1.0.0-beta5, instead, and clean solution, I get:

------ Discover test started ------
------ Test started: Project: MyProjectTest ------
Starting  Microsoft.Framework.TestHost [C:\Users\xxxxx\.dnx\runtimes\dnx-clr-win-x86.1.0.0-beta5\bin\dnx.exe --appbase "C:\Users\xxxxxx\Documents\GitForWindows\Repositories\MySolution\MyProjectTest" Microsoft.Framework.ApplicationHost --port 9737 Microsoft.Framework.TestHost --port 9770 --parentProcessId 16732]

System.InvalidOperationException: Failed to resolve the following dependencies for target framework 'DNX,Version=v4.5.1':
   xunit 2.1.0
   xunit.runner.dnx 2.1.0-beta6-build191

Searched Locations:
  C:\Users\xxxxx\Documents\GitForWindows\Repositories\MySolution\{name}\project.json
  C:\Users\xxxxx\Documents\GitForWindows\Repositories\MySolution\src\{name}\project.json
  C:\Users\xxxxx\Documents\GitForWindows\Repositories\MySolution\test\{name}\project.json
  C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\{name}.dll
  C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\Facades\{name}.dll
  C:\Windows\Microsoft.NET\assembly\GAC_32\{name}\{version}\{name}.dll
  C:\Windows\Microsoft.NET\assembly\GAC_64\{name}\{version}\{name}.dll
  C:\Windows\Microsoft.NET\assembly\GAC_MSIL\{name}\{version}\{name}.dll

Try running 'dnu restore'.

   at Microsoft.Framework.Runtime.DefaultHost.GetEntryPoint(String applicationName)
   at Microsoft.Framework.ApplicationHost.Program.ExecuteMain(DefaultHost host, String applicationName, String[] args)
   at Microsoft.Framework.ApplicationHost.Program.Main(String[] args)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.Framework.Runtime.Common.EntryPointExecutor.Execute(Assembly assembly, String[] args, IServiceProvider serviceProvider)
   at dnx.host.Bootstrapper.RunAsync(List`1 args, IRuntimeEnvironment env)
   at dnx.host.RuntimeBootstrapper.ExecuteAsync(String[] args)
   at dnx.host.RuntimeBootstrapper.Execute(String[] args)
Unable to start Microsoft.Framework.TestHost
========== Discover test finished: 0 found (0:00:01.4699978) ==========

Running DNU restore doesn't resolve anything.

EDIT: Here's the project.json as requested:

{
  "version": "1.0.0-*",
  "description": "",
  "authors": [ "" ],
  "tags": [ "" ],
  "projectUrl": "",
  "licenseUrl": "",

  "dependencies": {
    "xunit": "2.1.0",
    "xunit.runner.dnx": "2.1.0-beta6-build191"
  },
  "commands": {
    "test": "xunit.runner.dnx"
  },

  "frameworks" : {
    "dnx451": { },
    "dnxcore50" : {
      "dependencies": {
        "System.Collections": "4.0.11-beta-23225",
        "System.Linq": "4.0.1-beta-23225",
        "System.Threading": "4.0.11-beta-23225",
        "Microsoft.CSharp": "4.0.1-beta-23225"
      }
    }
  }
}

Answer 1

You need to use a version of xUnit runner that matches dnx. For dxn RC1 you need to use the version 2.1.0-rc1-build204 of xunit.runner.dnx