From 9f887e65f31270427796d792bd6a1709283c6c7d Mon Sep 17 00:00:00 2001
From: Sergio Pedri <sergio0694@live.com>
Date: Sun, 12 Sep 2021 20:26:40 +0200
Subject: [PATCH] Fixed [AlsoNotifyChangeFor] attribute definition

---
 .../Attributes/AlsoNotifyChangeForAttribute.cs             | 6 +++---
 .../Mvvm/Test_ObservablePropertyAttribute.cs               | 7 +++++--
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/Microsoft.Toolkit.Mvvm/ComponentModel/Attributes/AlsoNotifyChangeForAttribute.cs b/Microsoft.Toolkit.Mvvm/ComponentModel/Attributes/AlsoNotifyChangeForAttribute.cs
index ae5a66feaf3..0eb967a4c32 100644
--- a/Microsoft.Toolkit.Mvvm/ComponentModel/Attributes/AlsoNotifyChangeForAttribute.cs
+++ b/Microsoft.Toolkit.Mvvm/ComponentModel/Attributes/AlsoNotifyChangeForAttribute.cs
@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -67,7 +67,7 @@ namespace Microsoft.Toolkit.Mvvm.ComponentModel
     /// }
     /// </code>
     /// </summary>
-    [AttributeUsage(AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
+    [AttributeUsage(AttributeTargets.Field, AllowMultiple = true, Inherited = false)]
     public sealed class AlsoNotifyChangeForAttribute : Attribute
     {
         /// <summary>
@@ -87,7 +87,7 @@ public AlsoNotifyChangeForAttribute(string propertyName)
         /// The other property names to also notify when the annotated property changes. This parameter can optionally
         /// be used to indicate a series of dependent properties from the same attribute, to keep the code more compact.
         /// </param>
-        public AlsoNotifyChangeForAttribute(string propertyName, string[] otherPropertyNames)
+        public AlsoNotifyChangeForAttribute(string propertyName, params string[] otherPropertyNames)
         {
             PropertyNames = new[] { propertyName }.Concat(otherPropertyNames).ToArray();
         }
diff --git a/UnitTests/UnitTests.NetCore/Mvvm/Test_ObservablePropertyAttribute.cs b/UnitTests/UnitTests.NetCore/Mvvm/Test_ObservablePropertyAttribute.cs
index f7c596ba438..280a0d82e48 100644
--- a/UnitTests/UnitTests.NetCore/Mvvm/Test_ObservablePropertyAttribute.cs
+++ b/UnitTests/UnitTests.NetCore/Mvvm/Test_ObservablePropertyAttribute.cs
@@ -71,7 +71,7 @@ public void Test_AlsoNotifyChangeForAttribute_Events()
             model.Name = "Bob";
             model.Surname = "Ross";
 
-            CollectionAssert.AreEqual(new[] { nameof(model.Name), nameof(model.FullName), nameof(model.Surname), nameof(model.FullName) }, propertyNames);
+            CollectionAssert.AreEqual(new[] { nameof(model.Name), nameof(model.FullName), nameof(model.Alias), nameof(model.Surname), nameof(model.FullName), nameof(model.Alias) }, propertyNames);
         }
 
         [TestCategory("Mvvm")]
@@ -169,13 +169,16 @@ public sealed partial class DependentPropertyModel
         {
             [ObservableProperty]
             [AlsoNotifyChangeFor(nameof(FullName))]
+            [AlsoNotifyChangeFor(nameof(Alias))]
             private string? name;
 
             [ObservableProperty]
-            [AlsoNotifyChangeFor(nameof(FullName))]
+            [AlsoNotifyChangeFor(nameof(FullName), nameof(Alias))]
             private string? surname;
 
             public string FullName => $"{Name} {Surname}";
+
+            public string Alias => $"{Name?.ToLower()}{Surname?.ToLower()}";
         }
 
         public partial class MyFormViewModel : ObservableValidator