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c#visual-studiotestingxunit

xUnit tests won't run due to exception during test discovery

I created a new xUnit test project in Visual Studio and add a couple simple tests. But when I try to run any of them, they don't run because, according to the Test output, the discovery is aborted. I see the following stack trace there

Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException: Could not find testhost
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.GetTestHostProcessStartInfo(IEnumerable`1 sources, IDictionary`2 environmentVariables, TestRunnerConnectionInfo connectionInfo)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyOperationManager.SetupChannel(IEnumerable`1 sources, String runSettings)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyDiscoveryManager.InitializeDiscovery(DiscoveryCriteria discoveryCriteria, ITestDiscoveryEventsHandler2 eventHandler, Boolean skipDefaultAdapters)
Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException: Could not find testhost
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.GetTestHostProcessStartInfo(IEnumerable`1 sources, IDictionary`2 environmentVariables, TestRunnerConnectionInfo connectionInfo)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyOperationManager.SetupChannel(IEnumerable`1 sources, String runSettings)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyDiscoveryManager.InitializeDiscovery(DiscoveryCriteria discoveryCriteria, ITestDiscoveryEventsHandler2 eventHandler, Boolean skipDefaultAdapters)
System.InvalidOperationException: The provided manager was not found in any slot.
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ParallelOperationManager`3.ClearCompletedSlot(TManager completedManager)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ParallelOperationManager`3.RunNextWork(TManager completedManager)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.Parallel.ParallelProxyDiscoveryManager.HandlePartialDiscoveryComplete(IProxyDiscoveryManager proxyDiscoveryManager, Int64 totalTests, IEnumerable`1 lastChunk, Boolean isAborted)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.Parallel.ParallelDiscoveryEventsHandler.HandleDiscoveryComplete(DiscoveryCompleteEventArgs discoveryCompleteEventArgs, IEnumerable`1 lastChunk)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyDiscoveryManager.InitializeDiscovery(DiscoveryCriteria discoveryCriteria, ITestDiscoveryEventsHandler2 eventHandler, Boolean skipDefaultAdapters)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyDiscoveryManager.DiscoverTests(DiscoveryCriteria discoveryCriteria, ITestDiscoveryEventsHandler2 eventHandler)

I'm not sure how to proceed.

These tests are meant to test a number of assemblies all of which have a TargetFramework property set to net7.0-windows in the .csproj file. So I had to change the TargetFramework of test project as well. Could that have anything to do with it?

Also I am running Visual Studio 2022 17.6.5

Solution

  • Answering my own question in case someone else hits the same problem. This is embarrassing.

    When I created my test project, I neglected to change the output folder setting so that its binary output would go to the same, shared folder that all my other assembly binaries go to. So I guess it couldn't find many of the dependencies it needed at run time. Once I corrected that, everything went away.

    I literally spent hours on this. So dumb.