From 50d6d0b5709ae8631672d7dcea20c3ad6a1a231d Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Fri, 30 Jan 2026 14:56:12 -0800
Subject: [PATCH] Fix XunitLoggerProvider crash when background work logs after
 test disposal (#1229)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
---
 tests/Common/Utils/XunitLoggerProvider.cs | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/tests/Common/Utils/XunitLoggerProvider.cs b/tests/Common/Utils/XunitLoggerProvider.cs
index 9e77c1f..2fb76fc 100644
--- a/tests/Common/Utils/XunitLoggerProvider.cs
+++ b/tests/Common/Utils/XunitLoggerProvider.cs
@@ -34,7 +34,20 @@ public class XunitLoggerProvider(ITestOutputHelper output) : ILoggerProvider
                 sb.Append(exception.ToString());
             }
 
-            output.WriteLine(sb.ToString());
+            try
+            {
+                output.WriteLine(sb.ToString());
+            }
+            catch (InvalidOperationException)
+            {
+                // Ignore exceptions from xUnit's TestOutputHelper when the test has already completed.
+                // Background work may continue logging after xUnit has disposed the test context.
+            }
+            catch (NullReferenceException)
+            {
+                // xUnit v3 may throw NullReferenceException in TestOutputHelper.QueueTestOutput()
+                // when the internal queue has been torn down after test completion.
+            }
         }
 
         public bool IsEnabled(LogLevel logLevel) => true;