(maint) fixed resolving of multiple registrations

Author: nils-a

src/Spectre.Console.Registrars.SimpleInjector.Tests/RegistrarTests.cs

@@ -72,6 +72,33 @@ public void Resolver_Should_Not_Call_Lazy_Factory_If_Not_Needed()
             factoryCalled.ShouldBeFalse();
         }
 
+        [Fact]
+        public void Resolver_Registering_Multiple_Does_Not_Throw()
+        {
+            var fixture = new RegistrarFixture();
+            fixture.GivenMultiRegistrationTypes(typeof(ISomeInterface));
+            fixture.GivenOnRegistrar(r => r.Register(typeof(ISomeInterface), typeof(SomeDependency)));
+            fixture.GivenOnRegistrar(r => r.Register(typeof(ISomeInterface), typeof(SomeOtherDependency)));
+
+            var actual = fixture.GetResolver().Resolve(typeof(ISomeInterface));
+
+            actual.ShouldNotBeNull();
+        }
+
+        [Fact]
+        public void Resolver_Resolving_From_Multiple_Returns_The_Last_Registration()
+        {
+            var fixture = new RegistrarFixture();
+            fixture.GivenMultiRegistrationTypes(typeof(ISomeInterface));
+            fixture.GivenOnRegistrar(r => r.Register(typeof(ISomeInterface), typeof(SomeDependency)));
+            fixture.GivenOnRegistrar(r => r.Register(typeof(ISomeInterface), typeof(SomeOtherDependency)));
+
+            var actual = fixture.GetResolver().Resolve(typeof(ISomeInterface));
+
+            actual.ShouldNotBeNull();
+            actual.ShouldBeOfType<SomeOtherDependency>();
+        }
+
         private interface ISomeInterface
         {
         }

src/Spectre.Console.Registrars.SimpleInjector/SimlpeInjectorRegistrar.cs

@@ -84,16 +84,18 @@ public void RegisterLazy(Type service, Func<object> factory)
         public ITypeResolver Build()
         {
             container.Verify();
-            return new SimpleInjectorTypeResolver(container);
+            return new SimpleInjectorTypeResolver(container, multiRegistrationTypes);
         }
 
         private class SimpleInjectorTypeResolver : ITypeResolver
         {
             private readonly Container container;
+            private readonly Type[] multiRegistrationTypes;
 
-            public SimpleInjectorTypeResolver(Container container)
+            public SimpleInjectorTypeResolver(Container container, Type[] multiRegistrationTypes)
             {
                 this.container = container;
+                this.multiRegistrationTypes = multiRegistrationTypes;
             }
 
             public object Resolve(Type type)
@@ -103,6 +105,11 @@ public object Resolve(Type type)
                     throw new ArgumentNullException(nameof(type));
                 }
 
+                if (multiRegistrationTypes.Contains(type))
+                {
+                    return container.GetAllInstances(type).LastOrDefault();
+                }
+
                 return container.GetInstance(type);
             }
         }