No tests discovered using xUnit on ASP.Net Core 1.0 project with build on Visual Studio Team Services Hosted agent
<p>I have a problem where my xUnit tests in my ASP.Net Core 1.0 application are not discovered when building on Visual Studio Team Services.</p>

<p>The test project is being built successfully, but no test results are given. I find the following messages regarding the Visual Studio Test step in the log:</p>

<pre><code>******************************************************************************
Starting task: Test Assemblies **\*test*.dll;-:**\xunit.runner.visualstudio.testadapter.dll
******************************************************************************
Executing the powershell script: C:\LR\MMS\Services\Mms\TaskAgentProvisioner\Tools\agents\default\tasks\VSTest\1.0.29\VSTest.ps1
Working folder: C:\a\1
Executing C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\CommonExtensions\Microsoft\TestWindow\vstest.console.exe "C:\a\1\s\artifacts\bin\project.test\Debug\dnx451\project.test.dll"  /EnableCodeCoverage /InIsolation /logger:trx
Microsoft (R) Test Execution Command Line Tool Version 14.0.24720.0
Copyright (c) Microsoft Corporation.  All rights reserved.
Starting test execution, please wait...
Warning: No test is available in C:\a\1\s\artifacts\bin\project.test\Debug\dnx451\project.test.dll. Make sure that installed test discoverers &amp; executors, platform &amp; framework version settings are appropriate and try again.
Attachments:
  C:\a\1\TestResults\0ad44b11-4dd4-41ba-a0bf-66d9cd487a3c\buildguest_TASKAGENT5-0007 2016-03-01 07_33_04.coverage
Information: Additionally, you can try specifying '/UseVsixExtensions' command if the test discoverer &amp; executor is installed on the machine as vsix extensions and your installation supports vsix extensions. Example: vstest.console.exe myTests.dll /UseVsixExtensions:true
No results found to publish.
</code></pre>

<p>The tests are written like this:</p>

<pre><code>using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using Xunit;

namespace project.tests
{
    public class ProjectTests
    {
        [Fact]
        public void PassingTest()
        {
            Assert.Equal(4, Add(2, 2));
        }

        [Fact]
        public void FailingTest()
        {
            Assert.Equal(5, Add(2, 2));
        }

        int Add(int x, int y)
        {
            return x + y;
        }
    }
}
</code></pre>

<p>The tests run just fine locally, but not on Visual Studio Team Services.</p>

<p>For reference, this is my project.json</p>

<pre><code>{
  "authors": [ "Tom Reiertsen" ],
  "commands": {
    "test": "xunit.runner.dnx"
  },
  "dependencies": {
    "project": "1.0.0-rc1-update1",
    "Microsoft.AspNet.Hosting": "1.0.0-rc1-final",
    "Microsoft.AspNet.TestHost": "1.0.0-rc1-final",
    "Microsoft.AspNet.WebApi.Client": "5.2.3",
    "Microsoft.CSharp": "4.0.1-beta-23516",
    "System.Collections": "4.0.11-beta-23516",
    "System.Linq": "4.0.1-beta-23516",
    "System.Runtime": "4.0.21-beta-23516",
    "System.Threading": "4.0.11-beta-23516",
    "xunit": "2.1.0",
    "xunit.runner.dnx": "2.1.0-rc1-build204",
    "xunit.runner.visualstudio": "2.1.0"
  },
  "description": "project.test Class Library",
  "frameworks": {
    "dnx451": { }
  },
  "licenseUrl": "",
  "projectUrl": "",
  "tags": [ "" ],
  "version": "1.0.0-rc1-update1"
}
</code></pre>