[Bug Fix] ASP.NET pipeline hangs when function execution throws an unhandled exception (#2527)

Author: satvu

extensions/Worker.Extensions.Http.AspNetCore/release_notes.md

@@ -4,6 +4,6 @@
 - My change description (#PR/#issue)
 -->
 
-### Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore <version>
+### Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore 1.3.2
 
-- <entry>
+- Fixes a bug where the invocation hangs when the function has an unhandled exception (#2527).

extensions/Worker.Extensions.Http.AspNetCore/src/FunctionsMiddleware/FunctionsHttpProxyingMiddleware.cs

@@ -49,19 +49,24 @@ public async Task Invoke(FunctionContext context, FunctionExecutionDelegate next
             // Register additional context features
             context.Features.Set<IFromBodyConversionFeature>(FromBodyConversionFeature.Instance);
 
-            await next(context);
+            try
+            {
+                await next(context);
+
+                var responseHandled = await TryHandleHttpResult(context.GetInvocationResult().Value, context, httpContext, true)
+                    || await TryHandleOutputBindingsHttpResult(context, httpContext);
 
-            var responseHandled = await TryHandleHttpResult(context.GetInvocationResult().Value, context, httpContext, true)
-                || await TryHandleOutputBindingsHttpResult(context, httpContext);
-            
-            if (!responseHandled)
+                if (!responseHandled)
+                {
+                    var logger = context.InstanceServices.GetRequiredService<ExtensionTrace>();
+                    logger.NoHttpResponseReturned(context.FunctionDefinition.Name, context.InvocationId);
+                }
+            }
+            finally
             {
-                var logger = context.InstanceServices.GetRequiredService<ExtensionTrace>();
-                logger.NoHttpResponseReturned(context.FunctionDefinition.Name, context.InvocationId);
+                // Allow ASP.NET Core middleware to continue
+                _coordinator.CompleteFunctionInvocation(invocationId);
             }
-
-            // Allow ASP.NET Core middleware to continue
-            _coordinator.CompleteFunctionInvocation(invocationId);
         }
 
         private static async Task<bool> TryHandleHttpResult(object? result, FunctionContext context, HttpContext httpContext, bool isInvocationResult = false)

extensions/Worker.Extensions.Http.AspNetCore/src/Worker.Extensions.Http.AspNetCore.csproj

@@ -6,7 +6,7 @@
     <Description>ASP.NET Core extensions for .NET isolated functions</Description>
 
     <!--Version information-->
-    <VersionPrefix>1.3.1</VersionPrefix>
+    <VersionPrefix>1.3.2</VersionPrefix>
     <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
 

test/DotNetWorkerTests/AspNetCore/FunctionsHttpProxyingMiddlewareTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -259,5 +260,21 @@ private Mock<IResult> GetMockIResult()
 
             return mockResult;
         }
+
+        [Fact]
+        public async Task CompleteFunctionInvocation_RunsWhen_FunctionThrowsException()
+        {
+            var test = SetupTest("httpTrigger");
+            var mockDelegate = new Mock<FunctionExecutionDelegate>();
+            mockDelegate.Setup(d => d.Invoke(It.IsAny<FunctionContext>()))
+                .Throws(new Exception("Custom exception message"));
+
+            var funcMiddleware = new FunctionsHttpProxyingMiddleware(test.MockCoordinator.Object);
+
+            await Assert.ThrowsAsync<Exception>(async () => await funcMiddleware.Invoke(test.FunctionContext, mockDelegate.Object));
+
+            mockDelegate.Verify(p => p.Invoke(test.FunctionContext), Times.Once());
+            test.MockCoordinator.Verify(p => p.CompleteFunctionInvocation(It.IsAny<string>()), Times.Once());
+        }
     }
 }