[DEVEX-155] Account for nullable events

.github/workflows/publish.yml

@@ -76,7 +76,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Generate certificates
       run: |
         mkdir -p certs
@@ -89,7 +89,7 @@ jobs:
         sudo chown -R $USER:$USER certs
         sudo chmod -R 755 certs
     - name: Upload certificates
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: certs
         path: certs
@@ -123,7 +123,7 @@ jobs:
       run: |
         dotnet build --configuration ${{ matrix.configuration }} --framework ${{ matrix.framework }} src/EventStore.Client
     - name: Download certificates
-      uses: actions/download-artifact@v2
+      uses: actions/download-artifact@v4
       with:
         name: certs
         path: certs
@@ -191,7 +191,7 @@ jobs:
           /p:RepositoryUrl=https://github.com/EventStore/EventStore-Client-Dotnet \
           /p:RepositoryType=git
     - name: Publish Artifacts
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v4
       with:
         path: packages
         name: nuget-packages

src/EventStore.Client/Common/Diagnostics/ActivitySourceExtensions.cs

@@ -1,3 +1,5 @@
+// ReSharper disable ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
+
 using System.Diagnostics;
 using EventStore.Diagnostics;
 using EventStore.Diagnostics.Telemetry;
@@ -32,7 +34,7 @@ public static void TraceSubscriptionEvent(
 		EventStoreClientSettings settings,
 		UserCredentials? userCredentials
 	) {
-		if (source.HasNoActiveListeners())
+		if (source.HasNoActiveListeners() || resolvedEvent.Event is null)
 			return;
 
 		var parentContext = resolvedEvent.Event.Metadata.ExtractPropagationContext();

src/EventStore.Client/EventStore.Client.csproj

@@ -14,7 +14,7 @@
         <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>
         <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="8.0.1" />
         <PackageReference Include="System.Linq.Async" Version="6.0.1"/>
-        <PackageReference Include="System.Text.Json" Version="8.0.4"/>
+        <PackageReference Include="System.Text.Json" Version="8.0.5"/>
     </ItemGroup>
 
     <ItemGroup>

test/EventStore.Client.Streams.Tests/Diagnostics/StreamsTracingInstrumentationTests.cs

@@ -1,3 +1,5 @@
+// ReSharper disable ConditionalAccessQualifierIsNonNullableAccordingToAPIContract
+
 using EventStore.Client.Diagnostics;
 using EventStore.Diagnostics.Tracing;
 
@@ -171,4 +173,49 @@ async Task Subscribe(IAsyncEnumerator<StreamMessage> internalEnumerator) {
 			}
 		}
 	}
+
+	[Fact]
+	[Trait("Category", "Special cases")]
+	public async Task should_not_trace_when_event_is_null() {
+		var category   = Guid.NewGuid().ToString("N");
+		var streamName = category + "-123";
+
+		var seedEvents = Fixture.CreateTestEvents(type: $"{category}-{Fixture.GetStreamName()}").ToArray();
+		await Fixture.Streams.AppendToStreamAsync(streamName, StreamState.NoStream, seedEvents);
+
+		await Fixture.Streams.DeleteAsync(streamName, StreamState.StreamExists);
+
+		await using var subscription = Fixture.Streams.SubscribeToStream("$ce-" + category, FromStream.Start, resolveLinkTos: true);
+
+		await using var enumerator = subscription.Messages.GetAsyncEnumerator();
+
+		Assert.True(await enumerator.MoveNextAsync());
+
+		Assert.IsType<StreamMessage.SubscriptionConfirmation>(enumerator.Current);
+
+		await Subscribe().WithTimeout();
+
+		var appendActivities = Fixture
+			.GetActivitiesForOperation(TracingConstants.Operations.Append, streamName)
+			.ShouldNotBeNull();
+
+		var subscribeActivities = Fixture
+			.GetActivitiesForOperation(TracingConstants.Operations.Subscribe, "$ce-" + category)
+			.ToArray();
+
+		appendActivities.ShouldHaveSingleItem();
+		subscribeActivities.ShouldBeEmpty();
+
+		return;
+
+		async Task Subscribe() {
+			while (await enumerator.MoveNextAsync()) {
+				if (enumerator.Current is not StreamMessage.Event(var resolvedEvent))
+					continue;
+
+				if (resolvedEvent.Event?.EventType is "$metadata")
+					return;
+			}
+		}
+	}
 }

test/EventStore.Client.Tests.Common/Fixtures/DiagnosticsFixture.cs

@@ -11,7 +11,7 @@ namespace EventStore.Client.Tests;
 public class DiagnosticsFixture : EventStoreFixture {
 	readonly ConcurrentDictionary<(string Operation, string Stream), List<Activity>> _activities = [];
 
-	public DiagnosticsFixture() {
+	public DiagnosticsFixture() : base(x => x.RunProjections()) {
 		var diagnosticActivityListener = new ActivityListener {
 			ShouldListenTo = source => source.Name == EventStoreClientDiagnostics.InstrumentationName,
 			Sample = (ref ActivityCreationOptions<ActivityContext> _) => ActivitySamplingResult.AllDataAndRecorded,