feat(telemetry.serilog): TraceContextEnricher for trace<->log correlation

2026-06-01 07:38:54 -04:00
parent 1344f249d0
commit 70f91a855a
3 changed files with 111 additions and 0 deletions
@@ -0,0 +1,66 @@
+using System.Diagnostics;
+using Serilog;
+using Serilog.Core;
+using Serilog.Events;
+using Serilog.Sinks.InMemory;
+using ZB.MOM.WW.Telemetry;
+using ZB.MOM.WW.Telemetry.Serilog;
+
+namespace ZB.MOM.WW.Telemetry.Serilog.Tests;
+
+public sealed class TraceContextEnricherTests
+{
+    private const string SourceName = "ZB.MOM.WW.Telemetry.Serilog.Tests.TraceContext";
+
+    private static Logger BuildLogger(InMemorySink sink) =>
+        new LoggerConfiguration()
+            .Enrich.With(new TraceContextEnricher())
+            .WriteTo.Sink(sink)
+            .CreateLogger();
+
+    private static string? ScalarOrNull(LogEvent logEvent, string propertyName) =>
+        logEvent.Properties.TryGetValue(propertyName, out var value) && value is ScalarValue scalar
+            ? scalar.Value?.ToString()
+            : null;
+
+    [Fact]
+    public void Active_activity_stamps_trace_id_and_span_id()
+    {
+        using var listener = new ActivityListener
+        {
+            ShouldListenTo = source => source.Name == SourceName,
+            Sample = (ref ActivityCreationOptions<ActivityContext> _) =>
+                ActivitySamplingResult.AllDataAndRecorded,
+        };
+        ActivitySource.AddActivityListener(listener);
+
+        using var activitySource = new ActivitySource(SourceName);
+        var sink = new InMemorySink();
+        using var logger = BuildLogger(sink);
+
+        using var activity = activitySource.StartActivity("unit-test");
+        Assert.NotNull(activity);
+        Assert.NotNull(Activity.Current);
+
+        logger.Information("traced");
+
+        var logEvent = Assert.Single(sink.LogEvents);
+        Assert.Equal(Activity.Current!.TraceId.ToString(), ScalarOrNull(logEvent, "trace_id"));
+        Assert.Equal(Activity.Current!.SpanId.ToString(), ScalarOrNull(logEvent, "span_id"));
+    }
+
+    [Fact]
+    public void No_active_activity_omits_trace_id_and_span_id()
+    {
+        Assert.Null(Activity.Current);
+
+        var sink = new InMemorySink();
+        using var logger = BuildLogger(sink);
+
+        logger.Information("untraced");
+
+        var logEvent = Assert.Single(sink.LogEvents);
+        Assert.False(logEvent.Properties.ContainsKey("trace_id"));
+        Assert.False(logEvent.Properties.ContainsKey("span_id"));
+    }
+}