fix: Read and send unfinished spans (#3533)

Author: bitsandfoxes

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- Unfinished spans are now correctly stored and retrieved by the CachingTransport ([#3533](https://github.com/getsentry/sentry-dotnet/pull/3533))
+
 ## 4.10.0
 
 ### Features

src/Sentry/SentrySpan.cs

@@ -154,7 +154,7 @@ public static SentrySpan FromJson(JsonElement json)
         var parentSpanId = json.GetPropertyOrNull("parent_span_id")?.Pipe(SpanId.FromJson);
         var traceId = json.GetPropertyOrNull("trace_id")?.Pipe(SentryId.FromJson) ?? SentryId.Empty;
         var startTimestamp = json.GetProperty("start_timestamp").GetDateTimeOffset();
-        var endTimestamp = json.GetProperty("timestamp").GetDateTimeOffset();
+        var endTimestamp = json.GetPropertyOrNull("timestamp")?.GetDateTimeOffset();
         var operation = json.GetPropertyOrNull("op")?.GetString() ?? "unknown";
         var description = json.GetPropertyOrNull("description")?.GetString();
         var status = json.GetPropertyOrNull("status")?.GetString()?.Replace("_", "").ParseEnum<SpanStatus>();

test/Sentry.Tests/Protocol/SentryTransactionTests.cs

@@ -246,6 +246,27 @@ public void SerializeObject_AllPropertiesSetToNonDefault_SerializesValidObject()
         });
     }
 
+    [Fact]
+    public void SerializeObject_TransactionContainsUnfinishedSpan_SerializesDeserializesValidObject()
+    {
+        // Arrange
+        SentryTransaction capturedTransaction = null;
+        var hub = Substitute.For<IHub>();
+        hub.CaptureTransaction(Arg.Do<SentryTransaction>(t => capturedTransaction = t));
+
+        var transaction = new TransactionTracer(hub, "test.name", "test.operation");
+        transaction.StartChild("child_op123", "child_desc123");
+        transaction.Finish(SpanStatus.Aborted);
+
+        // Act
+        var actualString = capturedTransaction.ToJsonString(_testOutputLogger);
+        var actualTransaction = Json.Parse(actualString, SentryTransaction.FromJson);
+
+        // Assert
+        Assert.Single(actualTransaction.Spans); // Sanity Check
+        Assert.Null(actualTransaction.Spans.First().EndTimestamp);
+    }
+
     [Fact]
     public void StartChild_LevelOne_Works()
     {