3.10.1: An unhandled exception was thrown by the 'Execute' method.

[JohnYoungers]

Describe the bug

We're seeing the same issue that was reported in #6246

  Error Message:
   An unhandled exception was thrown by the 'Execute' method. Please report this error to the author of the attribute 'Microsoft.VisualStudio.TestTools.UnitTesting.TestMethodAttribute'.
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than or equal to the size of the collection. (Parameter 'chunkLength')
   at System.Text.StringBuilder.ToString()
   at Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.TestContextImplementation.GetDiagnosticMessages() in /_/src/Adapter/MSTestAdapter.PlatformServices/Services/TestContextImplementation.cs:line 338
   at Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter.Extensions.TestContextExtensions.GetAndClearDiagnosticMessages(ITestContext testContext) in /_/src/Adapter/MSTestAdapter.PlatformServices/Extensions/TestContextExtensions.cs:line 17
   at Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter.Execution.TestMethodInfo.InvokeAsync(Object[] arguments) in /_/src/Adapter/MSTestAdapter.PlatformServices/Execution/TestMethodInfo.cs:line 169
   at Microsoft.VisualStudio.TestTools.UnitTesting.TestMethodAttribute.ExecuteAsync(ITestMethod testMethod) in /_/src/TestFramework/TestFramework/Attributes/TestMethod/TestMethodAttribute.cs:line 71
   at Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter.Execution.TestMethodRunner.<>c__DisplayClass11_0.<<ExecuteTestAsync>b__0>d.MoveNext() in /_/src/Adapter/MSTestAdapter.PlatformServices/Execution/TestMethodRunner.cs:line 472
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter.Execution.TestMethodRunner.ExecuteTestAsync(TestMethodInfo testMethodInfo) in /_/src/Adapter/MSTestAdapter.PlatformServices/Execution/TestMethodRunner.cs:line 481

Steps To Reproduce

We upgraded 30+ applications without issue, but we have one where the tests hang, sometimes reporting this error. I'm sure it's not coincidence, but this is the only application we have that makes extensive use of Trace opposed to ILogger.

It sounds like the primary issue was resolved in #6246, but are there any other potential reasons this could fail on that line?

Expected behavior

Actual behavior

Additional context

[Youssef1313]

It's likely you are using TestContext incorrectly and are writing to it outside of the boundary of a test.

Meanwhile, we can workaround that on our side for backward compatibility, but I'd strongly encourage you to investigate the race condition on your tests where you could be calling TestContext.Write/WriteLine after the test has already finished.

[JohnYoungers]

Thank you! I didn't think of TestContext; I'll check to see if they're wiring up something there that isn't happening in the other applications