From 62e7dbded926a33415b5c2d636dced2203f4b4aa Mon Sep 17 00:00:00 2001
From: Deadpikle <mbabienco@southern.edu>
Date: Wed, 13 May 2020 11:51:22 -0400
Subject: [PATCH] Add more tests for selection adjustments

---
 .../SelectionModelTests.cs                    | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs b/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs
index 60fe9f3674..9d795f6247 100644
--- a/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs
@@ -1762,6 +1762,18 @@ namespace Avalonia.Controls.UnitTests
             Assert.Empty(target.SelectedIndices);
         }
 
+        [Fact]
+        public void Assigning_Source_With_Less_Items_Than_Previous_Clears_Selection()
+        {
+            var data = new[] { "foo", "bar", "baz", "boo", "hoo" };
+            var smallerData = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { RetainSelectionOnReset = true };
+            target.Source = data;
+            target.SelectedIndex = new IndexPath(4);
+            target.Source = smallerData;
+            Assert.Empty(target.SelectedIndices);
+        }
+
         [Fact]
         public void Assigning_Source_With_Less_Items_Than_Selection_Trims_Selection()
         {
@@ -1772,6 +1784,18 @@ namespace Avalonia.Controls.UnitTests
             Assert.Empty(target.SelectedIndices);
         }
 
+        [Fact]
+        public void Assigning_Source_With_Less_Items_Than_Multiple_Selection_Trims_Selection()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { RetainSelectionOnReset = true };
+            target.Select(4);
+            target.Select(2);
+            target.Source = data;
+            Assert.Equal(1, target.SelectedIndices.Count);
+            Assert.Equal(new IndexPath(2), target.SelectedIndices.First());
+        }
+
         private int GetSubscriberCount(AvaloniaList<object> list)
         {
             return ((INotifyCollectionChangedDebug)list).GetCollectionChangedSubscribers()?.Length ?? 0;