fix: connect exception to transaction (#1043)

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## Unreleased
+
+
+### Fixes
+
+- Connect middleware exceptions to transactions ([#1043](https://github.com/getsentry/sentry-dotnet/pull/1043))
+
 ## 3.4.0
 
 ### Features

src/Sentry.AspNetCore/SentryTracingMiddleware.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Runtime.ExceptionServices;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
@@ -122,10 +123,15 @@ public async Task InvokeAsync(HttpContext context)
                 scope.OnEvaluating += (_, _) => scope.Populate(context, _options);
             });
 
+            Exception? exception = null;
             try
             {
                 await _next(context).ConfigureAwait(false);
             }
+            catch (Exception e)
+            {
+                exception = e;
+            }
             finally
             {
                 if (transaction is not null)
@@ -146,9 +152,20 @@ public async Task InvokeAsync(HttpContext context)
                         transaction.Name = transactionName;
                     }
 
-                    transaction.Finish(
-                        SpanStatusConverter.FromHttpStatusCode(context.Response.StatusCode)
-                    );
+                    var status = SpanStatusConverter.FromHttpStatusCode(context.Response.StatusCode);
+                    if (exception is null)
+                    {
+                        transaction.Finish(status);
+                    }
+                    else
+                    {
+                        transaction.Finish(exception, status);
+                    }
+                }
+
+                if (exception is not null)
+                {
+                    ExceptionDispatchInfo.Capture(exception).Throw();
                 }
             }
         }

src/Sentry/Internal/Hub.cs

@@ -16,7 +16,8 @@ internal class Hub : IHub, IDisposable
         private readonly IDisposable _rootScope;
         private readonly Enricher _enricher;
 
-        private readonly ConditionalWeakTable<Exception, ISpan> _exceptionToSpanMap = new();
+        // Internal for testability
+        internal ConditionalWeakTable<Exception, ISpan> ExceptionToSpanMap { get; } = new();
 
         internal SentryScopeManager ScopeManager { get; }
 
@@ -144,7 +145,7 @@ public void BindException(Exception exception, ISpan span)
             }
 
             // Don't overwrite existing pair in the unlikely event that it already exists
-            _ = _exceptionToSpanMap.GetValue(exception, _ => span);
+            _ = ExceptionToSpanMap.GetValue(exception, _ => span);
         }
 
         public ISpan? GetSpan()
@@ -159,7 +160,7 @@ public void BindException(Exception exception, ISpan span)
         {
             // Find the span which is bound to the same exception
             if (evt.Exception is { } exception &&
-                _exceptionToSpanMap.TryGetValue(exception, out var spanBoundToException))
+                ExceptionToSpanMap.TryGetValue(exception, out var spanBoundToException))
             {
                 return spanBoundToException;
             }

test/Sentry.AspNetCore.Tests/SentryTracingMiddlewareTests.cs

@@ -284,6 +284,67 @@ public async Task Transaction_sampling_context_contains_HTTP_context_data()
             samplingContext.TryGetHttpRoute().Should().Be("/person/{id}");
             samplingContext.TryGetHttpPath().Should().Be("/person/13");
         }
+
+        [Fact]
+        public async Task Transaction_binds_exception_thrown()
+        {
+            // Arrange
+            TransactionSamplingContext samplingContext = null;
+
+            var sentryClient = Substitute.For<ISentryClient>();
+
+            var hub = new Internal.Hub(sentryClient, new SentryOptions
+            {
+                Dsn = DsnSamples.ValidDsnWithoutSecret,
+                TracesSampler = ctx =>
+                {
+                    samplingContext = ctx;
+                    return 1;
+                }
+            });
+            var exception = new Exception();
+
+            var server = new TestServer(new WebHostBuilder()
+                .UseDefaultServiceProvider(di => di.EnableValidation())
+                .UseSentry()
+                .ConfigureServices(services =>
+                {
+                    services.AddRouting();
+
+                    services.RemoveAll(typeof(Func<IHub>));
+                    services.AddSingleton<Func<IHub>>(() => hub);
+                })
+                .Configure(app =>
+                {
+                    app.UseRouting();
+                    app.Use(async (r, c) =>
+                    {
+                        try
+                        {
+                            await c().ConfigureAwait(false);
+                        }
+                        catch
+                        {
+                            // We just want to know if it got into Sentry's Hub
+                        }
+                    });
+                    app.UseSentryTracing();
+
+                    app.UseEndpoints(routes =>
+                    {
+                        routes.Map("/person/{id}", _ => throw exception);
+                    });
+                })
+            );
+
+            var client = server.CreateClient();
+
+            // Act
+            await client.GetAsync("/person/13");
+
+            // Assert
+            Assert.True(hub.ExceptionToSpanMap.TryGetValue(exception, out _));
+        }
     }
 }
 #endif