Fix generated members accessibility for sealed types

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/TransitiveMembersGenerator.Execute.cs

@@ -86,6 +86,13 @@ public static void ProcessMemberDeclarations(
             // If the target class is sealed, make protected members private and remove the virtual modifier
             sealedMemberDeclarations = annotatedMemberDeclarations.Select(static member =>
             {
+                // Constructors become public for sealed types
+                if (member is ConstructorDeclarationSyntax)
+                {
+                    return member.ReplaceModifier(SyntaxKind.ProtectedKeyword, SyntaxKind.PublicKeyword);
+                }
+
+                // Other members become private
                 return
                     member
                     .ReplaceModifier(SyntaxKind.ProtectedKeyword, SyntaxKind.PrivateKeyword)

tests/CommunityToolkit.Mvvm.UnitTests/Test_ObservableRecipientAttribute.cs

@@ -228,4 +228,36 @@ protected virtual partial void OnDeactivated()
             OnDeactivatedResult = true;
         }
     }
+
+    [TestMethod]
+    public void Test_ObservableRecipientAttribute_SealedPersonWithCustomOnActivatedAndOnDeactivated()
+    {
+        SealedPersonWithCustomOnActivatedAndOnDeactivated model = new();
+
+        model.IsActive = true;
+
+        Assert.IsTrue(model.OnActivatedResult);
+
+        model.IsActive = false;
+
+        Assert.IsTrue(model.OnDeactivatedResult);
+    }
+
+    [ObservableRecipient]
+    public sealed partial class SealedPersonWithCustomOnActivatedAndOnDeactivated : ObservableObject
+    {
+        public bool OnActivatedResult { get; private set; }
+
+        public bool OnDeactivatedResult { get; private set; }
+
+        private partial void OnActivated()
+        {
+            OnActivatedResult = true;
+        }
+
+        private partial void OnDeactivated()
+        {
+            OnDeactivatedResult = true;
+        }
+    }
 }