From fe377e3955aac1a73e8db015e888bb2a982889e3 Mon Sep 17 00:00:00 2001
From: Antony Male <antony.male@gmail.com>
Date: Wed, 7 May 2014 16:22:01 +0100
Subject: [PATCH] Provide a decent error if unbound generic type used as an
 abstract factory, and fill in more coverage

---
 Stylet/StyletIoC/StyletIoCBuilder.cs          |  8 +++++--
 .../StyletIoC/StyletIoCBindingChecksTests.cs  |  7 ++++++
 .../StyletIoC/StyletIoCFactoryTests.cs        | 23 +++++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/Stylet/StyletIoC/StyletIoCBuilder.cs b/Stylet/StyletIoC/StyletIoCBuilder.cs
index 27fc418..d2b1d45 100644
--- a/Stylet/StyletIoC/StyletIoCBuilder.cs
+++ b/Stylet/StyletIoC/StyletIoCBuilder.cs
@@ -229,9 +229,9 @@ namespace StyletIoC
 
         public BuilderFactoryBinding(Type serviceType, Func<IContainer, TImplementation> factory) : base(serviceType)
         {
-            this.EnsureType(typeof(TImplementation));
             if (this.serviceType.IsGenericTypeDefinition)
                 throw new StyletIoCRegistrationException(String.Format("A factory cannot be used to implement unbound generic type {0}", this.serviceType.Description()));
+            this.EnsureType(typeof(TImplementation));
             this.factory = factory;
         }
 
@@ -277,7 +277,11 @@ namespace StyletIoC
 
     internal class AbstractFactoryBinding : BuilderBindingBase
     {
-        public AbstractFactoryBinding(Type serviceType) : base(serviceType) { }
+        public AbstractFactoryBinding(Type serviceType) : base(serviceType)
+        {
+            if (serviceType.IsGenericTypeDefinition)
+                throw new StyletIoCRegistrationException(String.Format("Unbound generic type {0} can't be used as an abstract factory", serviceType.Description()));
+        }
 
         public override void Build(StyletIoCContainer container)
         {
diff --git a/StyletUnitTests/StyletIoC/StyletIoCBindingChecksTests.cs b/StyletUnitTests/StyletIoC/StyletIoCBindingChecksTests.cs
index e27ffbd..94a2698 100644
--- a/StyletUnitTests/StyletIoC/StyletIoCBindingChecksTests.cs
+++ b/StyletUnitTests/StyletIoC/StyletIoCBindingChecksTests.cs
@@ -66,5 +66,12 @@ namespace StyletUnitTests
             Assert.Throws<StyletIoCRegistrationException>(() => builder.Bind(typeof(I6<>)).To(typeof(C7<,>)));
             Assert.Throws<StyletIoCRegistrationException>(() => builder.Bind(typeof(I7<,>)).To(typeof(C6<>)));
         }
+
+        [Test]
+        public void ThrowsIfFactoryBoundToUnboundGeneric()
+        {
+            var builder = new StyletIoCBuilder();
+            Assert.Throws<StyletIoCRegistrationException>(() => builder.Bind(typeof(I6<>)).ToFactory(x => new C6<int>()));
+        }
     }
 }
diff --git a/StyletUnitTests/StyletIoC/StyletIoCFactoryTests.cs b/StyletUnitTests/StyletIoC/StyletIoCFactoryTests.cs
index 36dee98..d018dfb 100644
--- a/StyletUnitTests/StyletIoC/StyletIoCFactoryTests.cs
+++ b/StyletUnitTests/StyletIoC/StyletIoCFactoryTests.cs
@@ -53,6 +53,11 @@ namespace StyletUnitTests
             void Method();
         }
 
+        public interface IGenericFactory<T>
+        {
+            T GetI1();
+        }
+
         [Test]
         public void CreatesImplementationWithoutKey()
         {
@@ -172,5 +177,23 @@ namespace StyletUnitTests
             Assert.Throws<StyletIoCRegistrationException>(() => ioc.Get<I1Factory>());
             Assert.NotNull(ioc.Get<I1Factory>("hello"));
         }
+
+        [Test]
+        public void ThrowsIfFactoryTypeIsUnboundGeneric()
+        {
+            var builder = new StyletIoCBuilder();
+            Assert.Throws<StyletIoCRegistrationException>(() => builder.Bind(typeof(IGenericFactory<>)).ToAbstractFactory());
+        }
+
+        [Test]
+        public void BoundGenericFactoriesWork()
+        {
+            var builder = new StyletIoCBuilder();
+            builder.Bind<I1>().To<C1>();
+            builder.Bind<IGenericFactory<I1>>().ToAbstractFactory();
+            var ioc = builder.BuildContainer();
+            var factory = ioc.Get<IGenericFactory<I1>>();
+            Assert.IsInstanceOf<C1>(factory.GetI1());
+        }
     }
 }