From f530cc1301f1330a8145ebf93edd1fc665ba02ef Mon Sep 17 00:00:00 2001
From: "Simon G." <simon.gockner@gmail.com>
Date: Wed, 18 Dec 2024 14:50:15 +0100
Subject: [PATCH] - fix invalidOperationException when trying to resolve a
 type, that is registered as an open generic, as a parameter

---
 LightweightIocContainer/IocContainer.cs       | 16 ++++++++++----
 .../OpenGenericRegistrationTest.cs            | 22 +++++++++++++++++++
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/LightweightIocContainer/IocContainer.cs b/LightweightIocContainer/IocContainer.cs
index a3fa7de..f31230a 100644
--- a/LightweightIocContainer/IocContainer.cs
+++ b/LightweightIocContainer/IocContainer.cs
@@ -231,10 +231,18 @@ public class IocContainer : IIocContainer, IIocResolver
             parametersToResolve ??= [];
             parametersToResolve.Insert(0, multitonScopeArgument); //insert scope at first place, won't be passed to ctor when creating multiton
         }
-            
-        if (result) 
-            return (true, new InternalToBeResolvedPlaceholder(registeredType, registration, parametersToResolve), null);
-            
+
+        switch (result)
+        {
+            case true when registration is IOpenGenericRegistration openGenericRegistration:
+            {
+                Type genericImplementationType = openGenericRegistration.ImplementationType.MakeGenericType(typeof(T).GenericTypeArguments);
+                return (true, new InternalToBeResolvedPlaceholder(genericImplementationType, registration, parametersToResolve), null);
+            }
+            case true:
+                return (true, new InternalToBeResolvedPlaceholder(registeredType, registration, parametersToResolve), null);
+        }
+
         if (exception != null)
             return (false, new object(), exception);
 
diff --git a/Test.LightweightIocContainer/OpenGenericRegistrationTest.cs b/Test.LightweightIocContainer/OpenGenericRegistrationTest.cs
index 3985b61..8f09b3e 100644
--- a/Test.LightweightIocContainer/OpenGenericRegistrationTest.cs
+++ b/Test.LightweightIocContainer/OpenGenericRegistrationTest.cs
@@ -49,6 +49,18 @@ public class OpenGenericRegistrationTest
         ITest<T> Create<T>(T item) where T : IConstraint, new();
     }
 
+    [UsedImplicitly]
+    public interface IA;
+    
+    [UsedImplicitly]
+    public class A : IA
+    {
+        public A(ITest<Constraint> test)
+        {
+            
+        }
+    }
+
     [SetUp]
     public void SetUp() => _iocContainer = new IocContainer();
 
@@ -104,4 +116,14 @@ public class OpenGenericRegistrationTest
         ITest<Constraint> test = testFactory.Create(new Constraint());
         Assert.That(test, Is.InstanceOf<CtorTest<Constraint>>());
     }
+
+    [Test]
+    public void TestOpenGenericTypeAsParameter()
+    {
+        _iocContainer.Register(r => r.Add<IA, A>());
+        _iocContainer.Register(r => r.AddOpenGenerics(typeof(ITest<>), typeof(Test<>), Lifestyle.Singleton));
+        
+        IA a = _iocContainer.Resolve<IA>();
+        Assert.That(a, Is.TypeOf<A>());
+    }
 }
\ No newline at end of file