Fixes error where empty Transaction has throws exception when no Spans.

ContribSentry/.Transaction/SentryTracing.cs

@@ -39,9 +39,7 @@ public SentryTracing(string name, int trackerId)
         }
 
         public ISpanBase GetSpan(string op)
-        {
-            return Spans.FirstOrDefault(s => s.Op == op);
-        }
+            => Spans.FirstOrDefault(s => s.Op == op) ?? DisabledSpan.Instance;
 
         public ISpanBase GetCurrentSpan()
         {
@@ -68,7 +66,7 @@ public void Finish()
             if (ContribSentrySdk.IsTracingSdkEnabled && new Random().NextDouble() <= ContribSentrySdk.Options.TracesSampleRate)
             {
                 var hasError = Spans.Any(p => p.Error);
-                Trace.SetStatus(Spans.Last().Status);
+                Trace.SetStatus(Spans.LastOrDefault()?.Status);
 
                 var @event = new SentryTracingEvent(this, hasError);
                 if (ContribSentrySdk.Options.RegisterTracingBreadcrumb)

ContribSentry/ContribSentry.csproj

@@ -14,7 +14,7 @@
     <PackageId>ContribSentry</PackageId>
     <Product>ContribSentry.SessionSdk</Product>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <Version>3.1.6</Version>
+    <Version>3.1.7</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">

Testing/SentryTracingTests.cs

@@ -0,0 +1,122 @@
+using ContribSentry.Extensibility;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Xunit;
+
+namespace ContribSentry.TracingTest
+{
+    public class SentryTracingTests
+    {
+        [Fact]
+        public void Ctor_ValidSentryTracing()
+        {
+            //Act
+            var sentryTracing = new SentryTracing(null, 0);
+
+            //Assert
+            Assert.True(sentryTracing != null);
+        }
+
+        [Fact]
+        public void StartChild_AddsChild()
+        {
+            //Arrange
+            var sentryTracing = new SentryTracing(null, 0);
+
+            //Act
+            var span = sentryTracing.StartChild("name","name");
+
+            //Assert
+            Assert.Contains(span, sentryTracing.Spans);
+
+        }
+
+        [Fact]
+        public void GetSpan_EmptySpan_DisabledSpan()
+        {
+            //Arrange
+            var sentryTracing = new SentryTracing(null, 0);
+
+            //Act
+            var span = sentryTracing.GetSpan("name");
+
+            //Assert
+            Assert.IsType<DisabledSpan>(span);
+        }
+
+        [Fact]
+        public void GetSpan_OpExist_SpanWithOp()
+        {
+            //Arrange
+            var sentryTracing = new SentryTracing(null, 0);
+            sentryTracing.StartChild("name", "name");
+
+            //Act
+            var span = sentryTracing.GetSpan("name");
+
+            //Assert
+            Assert.IsType<Span>(span);
+            Assert.Equal("name", span.Op);
+        }
+
+        [Fact]
+        public void GetCurrentSpan_NoSpan_DisabledSpan()
+        {
+            //Arrange
+            var sentryTracing = new SentryTracing(null, 0);
+
+            //Act
+            var span = sentryTracing.GetCurrentSpan();
+
+            //Assert
+            Assert.IsType<DisabledSpan>(span);
+        }
+
+        [Fact]
+        public void GetCurrentSpan_FirstSpanOpen_FirstSpan()
+        {
+            //Arrange
+            var sentryTracing = new SentryTracing(null, 0);
+            sentryTracing.StartChild("name", "name");
+
+            //Act
+            var span = sentryTracing.GetCurrentSpan();
+
+            //Assert
+            Assert.IsType<Span>(span);
+            Assert.Equal("name", span.Op);
+        }
+
+        [Fact]
+        public void GetCurrentSpan_FirstSpanOpenAndSecondIsChildofChild_FirstSpan()
+        {
+            //Arrange
+            var sentryTracing = new SentryTracing(null, 0);
+            var parent = sentryTracing.StartChild("name", "name");
+            parent.StartChild("aaa");
+
+            //Act
+            var span = sentryTracing.GetCurrentSpan();
+
+            //Assert
+            Assert.IsType<Span>(span);
+            Assert.Equal("name", span.Op);
+        }
+
+        [Fact]
+        public void Finish_NoSpan_CapturesEvent()
+        {
+            //Arrange
+            ContribSentrySdk.Init(new ContribSentryOptions());
+            ContribSentrySdk.Options.TracesSampleRate = 1.0;
+
+            var sentryTracing = new SentryTracing(null, 0);
+
+            //Act
+            sentryTracing.Finish();
+
+            ContribSentrySdk.Close();
+        }
+    }
+}