Commit 3abbf40

@@ -1,8 +1,11 @@
+using System;
+
 namespace gorilla.migrations.console.infrastructure
 {
     public interface ComponentFactory : ComponentRegistration
     {
         bool is_for<T>();
+        bool is_for(Type type);
         object build();
     }
 }
\ No newline at end of file

@@ -0,0 +1,6 @@
+using System;
+
+namespace gorilla.migrations.console.infrastructure
+{
+    public class ComponentResolutionException<Component> : Exception {}
+}
\ No newline at end of file

@@ -14,6 +14,7 @@ namespace gorilla.migrations.console.infrastructure
         public GenericRegistration(Expression<Func<Implementation>> factory)
         {
             this.factory = factory.Compile();
+            as_an<Implementation>();
         }
 
         public void scoped_as<Scope>() where Scope : infrastructure.Scope, new()
@@ -29,8 +30,12 @@ namespace gorilla.migrations.console.infrastructure
 
         public bool is_for<Contract>()
         {
-            var type = typeof (Contract);
-            return type.Equals(typeof (Implementation)) || contracts.Any(x => x.Equals(type));
+            return is_for(typeof (Contract));
+        }
+
+        public bool is_for(Type type)
+        {
+            return contracts.Any(x => x.Equals(type));
         }
 
         public object build()

@@ -1,6 +1,6 @@
 namespace gorilla.migrations.console.infrastructure
 {
-    static public class ComponentRegistry
+    static public class Ioc
     {
         static Container underlying_container;
 

@@ -14,7 +14,10 @@ namespace gorilla.migrations.console.infrastructure
 
         public T get_a<T>()
         {
-            return (T) registrations.First(x => x.is_for<T>()).build();
+            var type = typeof (T);
+            if (!registrations.Any(x => x.is_for(type))) throw new ComponentResolutionException<T>();
+
+            return (T) registrations.First(x => x.is_for(type)).build();
         }
 
         public IEnumerable<T> get_all<T>()

@@ -50,7 +50,8 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="infrastructure\ComponentFactory.cs" />
-    <Compile Include="infrastructure\ComponentRegistry.cs" />
+    <Compile Include="infrastructure\Ioc.cs" />
+    <Compile Include="infrastructure\ComponentResolutionException.cs" />
     <Compile Include="infrastructure\Container.cs" />
     <Compile Include="infrastructure\Factory.cs" />
     <Compile Include="infrastructure\GenericRegistration.cs" />

@@ -11,7 +11,7 @@ namespace gorilla.migrations.console
                 .then(new RegisterConsoleCommands())
                 .run();
 
-            ComponentRegistry.get_a<Console>().run_against(args);
+            Ioc.get_a<Console>().run_against(args);
         }
     }
 }
\ No newline at end of file

@@ -6,7 +6,7 @@ namespace gorilla.migrations.console
     {
         public void run()
         {
-            ComponentRegistry.get_a<CommandRegistry>().register(ComponentRegistry.get_a<RunMigrationsCommand>());
+            Ioc.get_a<CommandRegistry>().register(Ioc.get_a<RunMigrationsCommand>());
         }
     }
 }
\ No newline at end of file

@@ -1,4 +1,6 @@
 using gorilla.migrations.console.infrastructure;
+using gorilla.migrations.data;
+using gorilla.migrations.io;
 
 namespace gorilla.migrations.console
 {
@@ -7,9 +9,12 @@ namespace gorilla.migrations.console
         public void run()
         {
             var builder = new SimpleContainerBuilder();
-            builder.register(() => new ConsoleApplication(ComponentRegistry.get_a<CommandRegistry>())).as_an<Console>();
+            builder.register(() => new ConsoleApplication(Ioc.get_a<CommandRegistry>())).as_an<Console>();
             builder.register(() => new ConsoleArgumentsCommandRegistry()).as_an<CommandRegistry>().scoped_as<Singleton>();
-            ComponentRegistry.initialize_with(builder.build());
+            builder.register(() => new RunMigrationsCommand(Ioc.get_a<FileSystem>(), Ioc.get_a<DatabaseGatewayFactory>() )).as_an<ConsoleCommand>();
+            builder.register<FileSystem>(() => new WindowsFileSystem());
+            builder.register<DatabaseGatewayFactory>(() => new SqlDatabaseGatewayFactory());
+            Ioc.initialize_with(builder.build());
         }
     }
 }
\ No newline at end of file

@@ -3,6 +3,7 @@ using developwithpassion.bdd.contexts;
 using developwithpassion.bdd.harnesses.mbunit;
 using developwithpassion.bdddoc.core;
 using gorilla.migrations.console.infrastructure;
+using MbUnit.Framework;
 
 namespace tests.console
 {
@@ -66,6 +67,44 @@ namespace tests.console
 
             static IEnumerable<IThingy> results;
         }
+
+        [Concern(typeof (SimpleContainer))]
+        public class when_attempting_to_resolve_an_item_from_the_container_that_has_not_been_registered : concern
+        {
+            because b = () =>
+            {
+                controller.doing(() => controller.sut.get_a<string>());
+            };
+
+            it should_throw_a_meaningful_exception = () =>
+            {
+                controller.exception_thrown_by_the_sut.should_be_an_instance_of<ComponentResolutionException<string>>();
+            };
+        }
+
+        [Concern(typeof (SimpleContainer))]
+        [Ignore]
+        public class when_resolving_an_ienumerable_of_anything : concern
+        {
+            context c = () =>
+            {
+                builder.register(() => new Thingy()).as_an<IThingy>();
+                builder.register(() => new AnotherThingy()).as_an<IThingy>();
+            };
+
+            because b = () =>
+            {
+                results = controller.sut.get_a<IEnumerable<IThingy>>();
+            };
+
+            it should_return_each_registered_implementation = () =>
+            {
+                results.should_contain_item_matching(x => x is Thingy);
+                results.should_contain_item_matching(x => x is AnotherThingy);
+            };
+
+            static IEnumerable<IThingy> results;
+        }
     }