Merge pull request #78 from snakefoot/dev

Skip TraceId when when default value

src/NLog.Targets.Seq/ActivityExtensions.cs

@@ -0,0 +1,66 @@
+// Seq Target for NLog - Copyright 2014-2020 Datalust and contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.Diagnostics;
+
+namespace NLog.Targets.Seq
+{
+    /// <summary>
+    /// Formats elements of <see cref="Activity.Current"/> for inclusion in log events. Non-W3C-format activities are
+    /// ignored (Seq does not support the older Microsoft-proprietary hierarchical activity id format).
+    /// </summary>
+    internal static class ActivityExtensions
+    {
+        private static readonly System.Diagnostics.ActivitySpanId EmptySpanId = default(System.Diagnostics.ActivitySpanId);
+        private static readonly System.Diagnostics.ActivityTraceId EmptyTraceId = default(System.Diagnostics.ActivityTraceId);
+
+        public static string GetSpanId(this Activity activity)
+        {
+            return activity.IdFormat == ActivityIdFormat.W3C ?
+                SpanIdToHexString(activity.SpanId) :
+                string.Empty;
+        }
+
+        public static string GetTraceId(this Activity activity)
+        {
+            return activity.IdFormat == ActivityIdFormat.W3C ?
+                TraceIdToHexString(activity.TraceId) :
+                string.Empty;
+        }
+
+        private static string SpanIdToHexString(ActivitySpanId spanId)
+        {
+            if (EmptySpanId.Equals(spanId))
+                return string.Empty;
+
+            var spanHexString = spanId.ToHexString();
+            if (ReferenceEquals(spanHexString, EmptySpanId.ToHexString()))
+                return string.Empty;
+
+            return spanHexString;
+        }
+
+        private static string TraceIdToHexString(ActivityTraceId traceId)
+        {
+            if (EmptyTraceId.Equals(traceId))
+                return string.Empty;
+
+            var traceHexString = traceId.ToHexString();
+            if (ReferenceEquals(traceHexString, EmptyTraceId.ToHexString()))
+                return string.Empty;
+
+            return traceHexString;
+        }
+    }
+}

src/NLog.Targets.Seq/Layouts/CompactJsonLayout.cs

@@ -27,8 +27,8 @@ readonly JsonAttribute
             _exceptionAttribute = new("@x", new SimpleLayout("${exception:format=toString}")),
             _messageAttribute = new("@m", new FormattedMessageLayout()),
             _messageTemplateAttribute = new("@mt", new SimpleLayout("${onhasproperties:${message:raw=true}}")),
-            _traceIdAttribute = new("@tr", new CurrentW3CActivityLayout(a => a.TraceId.ToHexString())),
-            _spanIdAttribute = new("@sp", new CurrentW3CActivityLayout(a => a.SpanId.ToHexString()));
+            _traceIdAttribute = new("@tr", Layout.FromMethod(evt => System.Diagnostics.Activity.Current?.GetTraceId())),
+            _spanIdAttribute = new("@sp", Layout.FromMethod(evt => System.Diagnostics.Activity.Current?.GetSpanId()));
 
         public Layout LogLevel { get => _levelAttribute.Layout; set => _levelAttribute.Layout = value; }
 

test/NLog.Targets.Seq.Tests/SeqTargetTests.cs

@@ -204,17 +204,23 @@ public void TraceAndSpanIdAreIgnoredWhenMissing()
             Assert.False(evt.ContainsKey("@tr"));
             Assert.False(evt.ContainsKey("@sp"));
         }
-        
+
         [Fact]
-        public void TraceAndSpanIdAreCollectedWhenPresent()
+        public void TraceAndSpanIdAreIgnoredWhenEmpty()
         {
-            using var listener = new ActivityListener();
-            listener.ShouldListenTo = _ => true;
-            listener.Sample = delegate { return ActivitySamplingResult.AllData; };
-            ActivitySource.AddActivityListener(listener);
+            using var activity = new Activity("child").SetParentId(default, default).Start();    // TraceId comes from the Parent-Activity
+            Assert.NotNull(Activity.Current);
+
+            var evt = AssertValidJson(log => log.Info("Hello"));
+            Assert.False(evt.ContainsKey("@tr"));
+            Assert.Equal(activity.SpanId.ToHexString(), (string)evt["@sp"]);
+        }
 
-            var source = new ActivitySource("Example");
-            using var activity = source.StartActivity()!;
+        [Fact]
+        public void TraceAndSpanIdAreCollectedWhenPresent()
+        {
+            using var activity = new Activity("Example").Start();
+            Assert.NotNull(Activity.Current);
 
             dynamic evt = AssertValidJson(log => log.Info("Hello"));