Added failing tests for #2350.

tests/Avalonia.Controls.UnitTests/StackPanelTests.cs

@@ -1,7 +1,8 @@
 // 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.Controls;
+using System.Linq;
+using Avalonia.Layout;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
@@ -147,6 +148,151 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(new Rect(50, 0, 50, 120), target.Children[2].Bounds);
         }
 
+        [Fact]
+        public void Arranges_Vertical_Children_With_Correct_Bounds()
+        {
+            var target = new StackPanel
+            {
+                Orientation = Orientation.Vertical,
+                Children =
+                {
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Left,
+                        MeasureSize = new Size(50, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Left,
+                        MeasureSize = new Size(150, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Center,
+                        MeasureSize = new Size(50, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Center,
+                        MeasureSize = new Size(150, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Right,
+                        MeasureSize = new Size(50, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Right,
+                        MeasureSize = new Size(150, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Stretch,
+                        MeasureSize = new Size(50, 10),
+                    },
+                    new TestControl
+                    {
+                        HorizontalAlignment = HorizontalAlignment.Stretch,
+                        MeasureSize = new Size(150, 10),
+                    },
+                }
+            };
+
+            target.Measure(new Size(100, 150));
+            Assert.Equal(new Size(100, 80), target.DesiredSize);
+
+            target.Arrange(new Rect(target.DesiredSize));
+
+            var bounds = target.Children.Select(x => x.Bounds).ToArray();
+
+            Assert.Equal(
+                new[]
+                {
+                    new Rect(0, 0, 50, 10),
+                    new Rect(0, 10, 150, 10),
+                    new Rect(25, 20, 50, 10),
+                    new Rect(-25, 30, 150, 10),
+                    new Rect(50, 40, 50, 10),
+                    new Rect(-50, 50, 150, 10),
+                    new Rect(0, 60, 100, 10),
+                    new Rect(0, 70, 150, 10),
+
+                }, bounds);
+        }
+
+        [Fact]
+        public void Arranges_Horizontal_Children_With_Correct_Bounds()
+        {
+            var target = new StackPanel
+            {
+                Orientation = Orientation.Horizontal,
+                Children =
+                {
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Top,
+                        MeasureSize = new Size(10, 50),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Top,
+                        MeasureSize = new Size(10, 150),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Center,
+                        MeasureSize = new Size(10, 50),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Center,
+                        MeasureSize = new Size(10, 150),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Bottom,
+                        MeasureSize = new Size(10, 50),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Bottom,
+                        MeasureSize = new Size(10, 150),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Stretch,
+                        MeasureSize = new Size(10, 50),
+                    },
+                    new TestControl
+                    {
+                        VerticalAlignment = VerticalAlignment.Stretch,
+                        MeasureSize = new Size(10, 150),
+                    },
+                }
+            };
+
+            target.Measure(new Size(150, 100));
+            Assert.Equal(new Size(80, 100), target.DesiredSize);
+
+            target.Arrange(new Rect(target.DesiredSize));
+
+            var bounds = target.Children.Select(x => x.Bounds).ToArray();
+
+            Assert.Equal(
+                new[]
+                {
+                    new Rect(0, 0, 10, 50),
+                    new Rect(10, 0, 10, 150),
+                    new Rect(20, 25, 10, 50),
+                    new Rect(30, -25, 10, 150),
+                    new Rect(40, 50, 10, 50),
+                    new Rect(50, -50, 10, 150),
+                    new Rect(60, 0, 10, 100),
+                    new Rect(70, 0, 10, 150),
+                }, bounds);
+        }
+
         [Theory]
         [InlineData(Orientation.Horizontal)]
         [InlineData(Orientation.Vertical)]
@@ -185,5 +331,17 @@ namespace Avalonia.Controls.UnitTests
 
             Assert.Equal(sizeWithTwoChildren, sizeWithThreeChildren);
         }
+
+        private class TestControl : Control
+        {
+            public Size MeasureConstraint { get; private set; }
+            public Size MeasureSize { get; set; }
+
+            protected override Size MeasureOverride(Size availableSize)
+            {
+                MeasureConstraint = availableSize;
+                return MeasureSize;
+            }
+        }
     }
 }