As noted here: https://docs.microsoft.com/en-us/azure/devops/pipelines/test/review-continuous-test-results-after-build?view=azure-devops#tests-tab
If you use the Visual Studio Test task to run tests, diagnostic output logged from tests (using any of Console.WriteLine, Trace.WriteLine or TestContext.WriteLine methods), will appear as an attachment for a failed test.
How can I enforce Azure Devops pipelines to publish attachments for successful tests?
Update
riQQ pointed to the another stackoverflow question:Azure DevOps: Console output for green tests is missing Proposed solution doesn't help me, because they solved using TestContext. We are using xUnit, and there is no TestContext for xUnit.