added failing test for ClrNamespace leaks in AvaloniaNamespaceRegistry

tests/Avalonia.Markup.Xaml.UnitTests/Avalonia.Markup.Xaml.UnitTests.csproj

@@ -92,6 +92,7 @@
     <Otherwise />
   </Choose>
   <ItemGroup>
+    <Compile Include="Context\AvaloniaNamespaceRegistryTest.cs" />
     <Compile Include="Data\BindingTests_Source.cs" />
     <Compile Include="Data\BindingTests_ElementName.cs" />
     <Compile Include="Data\BindingTests_Validation.cs" />

tests/Avalonia.Markup.Xaml.UnitTests/Context/AvaloniaNamespaceRegistryTest.cs

@@ -0,0 +1,37 @@
+// Copyright (c) The Avalonia Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using Avalonia.Collections;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml.Context;
+using Avalonia.Markup.Xaml.Converters;
+using Avalonia.Styling;
+using Moq;
+using OmniXaml;
+using OmniXaml.ObjectAssembler.Commands;
+using OmniXaml.TypeConversion;
+using OmniXaml.Typing;
+using System;
+using System.Reactive;
+using Xunit;
+
+namespace Avalonia.Markup.Xaml.UnitTests.Context
+{
+    public class AvaloniaNamespaceRegistryTest
+    {
+        [Fact]
+        public void Should_Return_Same_ClrNameSpace()
+        {
+            string name = "clr-namespace:Avalonia.Markup.Xaml.UnitTests.Context;assembly=Avalonia.Markup.Xaml.UnitTests";
+
+            var target = new AvaloniaNamespaceRegistry();
+
+            var ns1 = target.GetNamespace(name);
+            var ns2 = target.GetNamespace(name);
+
+            //AvaloniaNamespaceRegistry should not create new CreateClrNamespace
+            //for the same namespace
+            Assert.Same(ns1, ns2);
+        }
+    }
+}