Dispose container when an IStartable throws during Build (#1392)

src/Autofac/ContainerBuilder.cs

@@ -175,13 +175,21 @@ public IContainer Build(ContainerBuildOptions options = ContainerBuildOptions.No
         var componentRegistry = ComponentRegistryBuilder.Build();
 
         var result = new Container(componentRegistry);
-        if ((options & ContainerBuildOptions.IgnoreStartableComponents) == ContainerBuildOptions.None)
+        try
         {
-            StartableManager.StartStartableComponents(Properties, result);
-        }
+            if ((options & ContainerBuildOptions.IgnoreStartableComponents) == ContainerBuildOptions.None)
+            {
+                StartableManager.StartStartableComponents(Properties, result);
+            }
 
-        // Run any build callbacks.
-        BuildCallbackManager.RunBuildCallbacks(result);
+            // Run any build callbacks.
+            BuildCallbackManager.RunBuildCallbacks(result);
+        }
+        catch
+        {
+            result.Dispose();
+            throw;
+        }
 
         // Allow the reflection cache to empty any registration-time caches to save memory.
         ReflectionCacheSet.Shared.OnContainerBuildClearCaches(_clearRegistrationCaches);

test/Autofac.Specification.Test/Features/StartableTests.cs

@@ -120,6 +120,22 @@ public void Startable_WhenStartableCreatesChildScope_NoExceptionIsThrown()
         Assert.NotNull(container);
     }
 
+    [Fact]
+    [SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope", Justification = "Disposal is part of the test.")]
+    public void Startable_WhenStartableThrows_DependenciesAreDisposed()
+    {
+        // Issue #1392 - disposable instances resolved to satisfy a startable should be
+        // disposed when the startable's Start() method throws.
+        var dependency = new DisposableDependency();
+        var builder = new ContainerBuilder();
+        builder.RegisterInstance(dependency);
+        builder.RegisterType<ThrowingStartable>().As<IStartable>().SingleInstance();
+
+        Assert.Throws<DependencyResolutionException>(() => builder.Build());
+
+        Assert.True(dependency.IsDisposed);
+    }
+
     [Fact]
     public void Startable_WhenStartIsSpecified_StartableComponentsAreStarted()
     {
@@ -285,4 +301,29 @@ public void Start()
             WasStarted = true;
         }
     }
+
+    private class DisposableDependency : IDisposable
+    {
+        public bool IsDisposed
+        {
+            get; private set;
+        }
+
+        public void Dispose()
+        {
+            IsDisposed = true;
+        }
+    }
+
+    private class ThrowingStartable : IStartable
+    {
+        public ThrowingStartable(DisposableDependency dependency)
+        {
+        }
+
+        public void Start()
+        {
+            throw new InvalidOperationException("Startable failed.");
+        }
+    }
 }