AvaloniaDictionary accept IDictionary as init collection

Author: IoannTerrible

src/Avalonia.Base/Collections/AvaloniaDictionary.cs

@@ -35,18 +35,20 @@ public AvaloniaDictionary(int capacity)
         }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="AvaloniaDictionary{TKey, TValue}"/> class.
+        /// Initializes a new instance of the <see cref="AvaloniaDictionary{TKey, TValue}"/> class using an IDictionary.
         /// </summary>
-        public AvaloniaDictionary(Dictionary<TKey, TValue> initialDictionary)
+        public AvaloniaDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey>? comparer = null)
         {
-            if (initialDictionary == null)
+            if (dictionary != null)
             {
-                throw new ArgumentNullException(nameof(initialDictionary));
+                _inner = new Dictionary<TKey, TValue>(dictionary, comparer ?? EqualityComparer<TKey>.Default);
+            }
+            else
+            {
+                throw new ArgumentNullException(nameof(dictionary));
             }
-            _inner = new Dictionary<TKey, TValue>(initialDictionary);
         }
 
-
         /// <summary>
         /// Occurs when the collection changes.
         /// </summary>

tests/Avalonia.Base.UnitTests/Collections/AvaloniaDictionaryTests.cs

@@ -1,8 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+
 using Avalonia.Collections;
 using Avalonia.Data.Core;
+
 using Xunit;
 
 namespace Avalonia.Base.UnitTests.Collections
@@ -158,29 +160,32 @@ public void Clearing_Collection_Should_Raise_PropertyChanged()
         }
 
         [Fact]
-        public void Constructor_Should_Throw_ArgumentNullException_When_Dictionary_Is_Null()
+        public void Constructor_Should_Throw_ArgumentNullException_When_Collection_Is_Null()
         {
             Assert.Throws<ArgumentNullException>(() =>
             {
-                var target = new AvaloniaDictionary<string, string>(null);
+                var target = new AvaloniaDictionary<string, string>(null, null);
             });
         }
 
+
         [Fact]
-        public void Constructor_Should_Initialize_With_Provided_Dictionary()
+        public void Constructor_Should_Initialize_With_Provided_Collection()
         {
-            var initialDictionary = new Dictionary<string, string>
+            var initialCollection = new Dictionary<string, string>
             {
                 { "key1", "value1" },
                 { "key2", "value2" }
             };
 
-            var target = new AvaloniaDictionary<string, string>(initialDictionary);
+            var target = new AvaloniaDictionary<string, string>(initialCollection, null);
 
             Assert.Equal(2, target.Count);
             Assert.Equal("value1", target["key1"]);
             Assert.Equal("value2", target["key2"]);
         }
 
+
+
     }
 }