Merge branch 'main' into nullableattributes

Author: Timothy Mothra

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+* Added support to set `TraceState` when converting the
+  System.Diagnostics.Activity object to its corresponding
+  OpenTelemetry.Proto.Trace.V1.Span object.
+  ([#4331](https://github.com/open-telemetry/opentelemetry-dotnet/pull/4331))
+
 ## 1.5.0-alpha.1
 
 Released 2023-Mar-07

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/ActivityExtensions.cs

@@ -143,6 +143,7 @@ internal static Span ToOtlpSpan(this Activity activity, SdkLimitOptions sdkLimit
                 TraceId = UnsafeByteOperations.UnsafeWrap(traceIdBytes),
                 SpanId = UnsafeByteOperations.UnsafeWrap(spanIdBytes),
                 ParentSpanId = parentSpanIdString,
+                TraceState = activity.TraceStateString ?? string.Empty,
 
                 StartTimeUnixNano = (ulong)startTimeUnixNano,
                 EndTimeUnixNano = (ulong)(startTimeUnixNano + activity.Duration.ToNanoseconds()),

test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/OtlpTraceExporterTests.cs

@@ -551,6 +551,32 @@ public void ToOtlpSpanActivityStatusTakesPrecedenceOverStatusTagsWhenActivitySta
             Assert.Equal(StatusDescriptionOnError, otlpSpan.Status.Message);
         }
 
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void ToOtlpSpanTraceStateTest(bool traceStateWasSet)
+        {
+            using var activitySource = new ActivitySource(nameof(this.ToOtlpSpanTest));
+            using var activity = activitySource.StartActivity("Name");
+            string tracestate = "a=b;c=d";
+            if (traceStateWasSet)
+            {
+                activity.TraceStateString = tracestate;
+            }
+
+            var otlpSpan = activity.ToOtlpSpan(DefaultSdkLimitOptions);
+
+            if (traceStateWasSet)
+            {
+                Assert.NotNull(otlpSpan.TraceState);
+                Assert.Equal(tracestate, otlpSpan.TraceState);
+            }
+            else
+            {
+                Assert.Equal(string.Empty, otlpSpan.TraceState);
+            }
+        }
+
         [Fact]
         public void ToOtlpSpanPeerServiceTest()
         {