From 493b6ab29e7993ccd0b7f4c0c9ec2f1959e351b3 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Wed, 29 Jul 2020 14:28:08 -0300
Subject: [PATCH] add failing unit test.

---
 .../ToolTipTests.cs                           | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs b/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs
index 9d7bc6af74..67df6343af 100644
--- a/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs
@@ -64,6 +64,40 @@ namespace Avalonia.Controls.UnitTests
                 Assert.False(ToolTip.GetIsOpen(target));
             }
         }
+        
+        [Fact]
+        public void Should_Close_When_Tip_Is_Changed()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var window = new Window();
+
+                var panel = new Panel();
+                
+                var target = new Decorator()
+                {
+                    [ToolTip.TipProperty] = "Tip",
+                    [ToolTip.ShowDelayProperty] = 0
+                };
+                
+                panel.Children.Add(target);
+
+                window.Content = panel;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                Assert.True((target as IVisual).IsAttachedToVisualTree);                               
+
+                _mouseHelper.Enter(target);
+
+                Assert.True(ToolTip.GetIsOpen(target));
+                
+                ToolTip.SetTip(target, "");
+                
+                Assert.False(ToolTip.GetIsOpen(target));
+            }
+        }
 
         [Fact]
         public void Should_Open_On_Pointer_Enter()