From 2336f85d02b2b8909d0b7a0ebe3b740c6239eb88 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Wed, 29 Jan 2020 21:48:14 +0100
Subject: [PATCH] Added some failing tests.

That demonstrate some problems with the `SelectionModel` change notifications found so far.
---
 .../SelectionModelTests.cs                    | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs b/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs
index 3e908681e6..b9149bf42b 100644
--- a/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs
@@ -1360,6 +1360,38 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(3, target.SelectedItems.Count);
         }
 
+        [Fact]
+        public void Not_Enumerating_Changes_Does_Not_Prevent_Further_Operations()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { Source = data };
+
+            target.SelectionChanged += (s, e) => { };
+
+            target.SelectAll();
+            target.ClearSelection();
+        }
+
+        [Fact]
+        public void Can_Change_Selection_From_SelectionChanged()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { Source = data };
+            var raised = 0;
+
+            target.SelectionChanged += (s, e) => 
+            {
+                if (raised++ == 0)
+                {
+                    target.ClearSelection();
+                }
+            };
+
+            target.SelectAll();
+
+            Assert.Equal(2, raised);
+        }
+
         private int GetSubscriberCount(AvaloniaList<object> list)
         {
             return ((INotifyCollectionChangedDebug)list).GetCollectionChangedSubscribers()?.Length ?? 0;