1 files changed, 24 insertions, 0 deletions
diff --git a/test/Microsoft.TestCommon/PreserveSyncContextAttribute.cs b/test/Microsoft.TestCommon/PreserveSyncContextAttribute.cs
new file mode 100644
index 00000000..f47e9b62
--- /dev/null
+++ b/test/Microsoft.TestCommon/PreserveSyncContextAttribute.cs
@@ -0,0 +1,24 @@
+using System.Threading;
+using Xunit;
+
+namespace Microsoft.TestCommon
+{
+    /// <summary>
+    /// Preserves the current <see cref="SynchronizationContext"/>. Use this attribute on
+    /// tests which modify the current <see cref="SynchronizationContext"/>.
+    /// </summary>
+    public class PreserveSyncContextAttribute : BeforeAfterTestAttribute
+    {
+        private SynchronizationContext _syncContext;
+
+        public override void Before(System.Reflection.MethodInfo methodUnderTest)
+        {
+            _syncContext = SynchronizationContext.Current;
+        }
+
+        public override void After(System.Reflection.MethodInfo methodUnderTest)
+        {
+            SynchronizationContext.SetSynchronizationContext(_syncContext);
+        }
+    }
+}