Unit tests are inconclusive when adding xUnit project to Unity project

Question

I create a new Unity project and make sure the Assembly-CSharp.csproj file exists by creating a script in the Assets folder. I open that script and edit it to

public class AScript : MonoBehaviour {}

I close the IDE and Unity after that. The Assembly-CSharp.csproj file exists now in the root directory of the project.

I start my IDE again (without Unity) and open the project from the .sln file. I add a new xUnit project to the solution and modify the first test to

[Fact]
public void Test1()
{
    Assert.True(true);
}

Just for the sake of completeness I reference the Unity project in my test project. When running the test (which should be fine) the tests didn't run because they are inconclusive. I found this information in the test output

Last runner error: No such file or directory

Below I will post the whole test output. Does someone know how to add a unit test project to a Unity project? Please let me know if you need more information.

I don't want to use the Unity test framework because I'm using Entitas and don't want to rely on the engine. I just want to test my pure C# code outside.

I'm also curious why Rider comes up with this when adding the test project to the solution

I got it working but I don't like the solution, so please explain if this is the only way or if this is wrong (as I think)

When creating a completely new solution with only that test project the unit tests will run correctly. Now I can add the existing Unity project via "Add existing project". Referencing the Unity project works fine too.

So yeah this works but now I have two solutions in my repository? Why do I have to separate the test project? Why can't I just add the unit test project to Unity's solution file?

---

This is the whole test output

TestProject1.UnitTest1.Test1

Test not run

Last runner error: No such file or directory

--- EXCEPTION #1/2 [Win32Exception] Message = “No such file or directory” ExceptionPath = Root.InnerException ClassName = System.ComponentModel.Win32Exception HResult = E_FAIL=EFail=80004005 Source = System.Diagnostics.Process NativeErrorCode = 2 StackTraceString = “ at System.Diagnostics.Process.ForkAndExecProcess(String filename, String[] argv, String[] envp, String cwd, Boolean redirectStdin, Boolean redirectStdout, Boolean redirectStderr, Boolean setCredentials, UInt32 userId, UInt32 groupId, UInt32[] groups, Int32& stdinFd, Int32& stdoutFd, Int32& stderrFd, Boolean usesTerminal, Boolean throwOnNoExec) at System.Diagnostics.Process.StartCore(ProcessStartInfo startInfo) at System.Diagnostics.Process.Start() at JetBrains.ReSharper.UnitTestFramework.Processes.PreparedProcess.Start() at JetBrains.ReSharper.UnitTestFramework.TestRunner.TestRunnerRunStrategy.<>c.b__19_1(IPreparedProcess p) at JetBrains.Util.Special.GeneralUtil.With[T](T control, Action1 action) at JetBrains.ReSharper.UnitTestFramework.TestRunner.TestRunnerRunStrategy.StartTestRunner(IUnitTestRun run, ITestRunnerEnvironmentSpecifier environmentSpecifier, IUnitTestAgentCommunicationChannel channel) at JetBrains.ReSharper.UnitTestFramework.TestRunner.TestRunnerRunStrategy.Run(IUnitTestRun run) --- End of stack trace from previous location where exception was thrown --- at JetBrains.ReSharper.UnitTestFramework.Launch.UnitTestRun.StartCore(CancellationToken onCancel, CancellationToken onAbort) at JetBrains.ReSharper.UnitTestFramework.Launch.UnitTestRun.<>c.<StartCore>b__29_0(ExceptionDispatchInfo e) at JetBrains.Util.Special.GeneralUtil.WithNotNull[T](T item, Action1 F) at JetBrains.ReSharper.UnitTestFramework.Launch.UnitTestRun.StartCore(CancellationToken onCancel, CancellationToken onAbort) at JetBrains.ReSharper.UnitTestFramework.Launch.UnitTestRun.Start(CancellationToken onCancel, CancellationToken onAbort) ”

--- Outer ---

--- EXCEPTION #2/2 [LoggerException] Message = “No such file or directory” ExceptionPath = Root ClassName = JetBrains.Util.LoggerException InnerException = “Exception #1 at Root.InnerException” HResult = COR_E_APPLICATION=80131600 StackTraceString = “ at JetBrains.Util.ILoggerEx.LogException(ILogger this, LoggingLevel level, Exception exception, ExceptionOrigin exceptionOrigin, String comment) at JetBrains.Util.ILoggerEx.Error(ILogger this, Exception exception, ExceptionOrigin origin, String comment) at JetBrains.ReSharper.UnitTestFramework.Launch.UnitTestRun.Start(CancellationToken onCancel, CancellationToken onAbort) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at JetBrains.ReSharper.UnitTestFramework.Launch.UnitTestRun.Start(CancellationToken onCancel, CancellationToken onAbort) at JetBrains.ReSharper.UnitTestFramework.Launch.Stages.RunTestsStage.<>c__DisplayClass5_0.b__0() at System.Threading.Tasks.Task`1.InnerInvoke() at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread) at System.Threading.Tasks.Task.ExecuteFromThreadPool(Thread threadPoolThread) at System.Threading.ThreadPoolWorkQueue.Dispatch() ”