- fix namespaces for generic types

LightweightIocContainer.FactoryGenerator/FactoryGenerator.cs

@@ -179,19 +179,9 @@ public class FactoryGenerator : IIncrementalGenerator
                 continue;
 
             if (!method.ReturnsVoid) 
-            {
+                namespaces.AddRange(GetNamespacesOfType(method.ReturnType));
-                if (method.ReturnType is INamedTypeSymbol { IsGenericType: true } namedTypeSymbol)
-                {
-                    namespaces.AddRange(namedTypeSymbol.TypeArguments.Select(GetNamespaceOfType));
-                    
-                    if (method.ReturnType.Name != "Task")
-                        namespaces.Add(GetNamespaceOfType(method.ReturnType));
-                }
-                else
-                    namespaces.Add(GetNamespaceOfType(method.ReturnType));
-            }
 
-            namespaces.AddRange(method.Parameters.Select(p => GetNamespaceOfType(p.Type)));
+            namespaces.AddRange(method.Parameters.SelectMany(p => GetNamespacesOfType(p.Type)));
         }
 
         foreach (string @namespace in namespaces.Distinct().OfType<string>().OrderBy(n => n)) 
@@ -270,9 +260,25 @@ public class FactoryGenerator : IIncrementalGenerator
     }
 
     private string? GetNamespaceOfType(ITypeSymbol s) => s.ContainingNamespace.IsGlobalNamespace ? null : s.ContainingNamespace.ToString();
+    private List<string?> GetNamespacesOfType(ITypeSymbol typeSymbol)
+    {
+        List<string?> namespaces = [];
+        if (typeSymbol is INamedTypeSymbol { IsGenericType: true } namedTypeSymbol)
+        {
+            namespaces.AddRange(namedTypeSymbol.TypeArguments.SelectMany(GetNamespacesOfType));
+                    
+            if (typeSymbol.Name != "Task")
+                namespaces.Add(GetNamespaceOfType(typeSymbol));
+        }
+        else
+            namespaces.Add(GetNamespaceOfType(typeSymbol));
+
+        return namespaces;
+    }
+    
     private IEnumerable<string> GetNamespacesOfTypes(ImmutableArray<ITypeSymbol?> types) =>
         types.OfType<ITypeSymbol>()
-            .Select(GetNamespaceOfType)
+            .SelectMany(GetNamespacesOfType)
             .OfType<string>()
             .Distinct();