Add unit test for image list action list (#11766)

Add unit test for ImageListActionList

src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/ImageListActionListTests.cs

@@ -0,0 +1,88 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable enable
+
+using System.ComponentModel.Design;
+using System.Drawing;
+
+namespace System.Windows.Forms.Design.Tests;
+
+public sealed class ImageListActionListTests : IDisposable
+{
+    private readonly ImageListDesigner _imageListDesigner;
+    private readonly ImageList _imageList;
+    private readonly ImageListActionList _actionList;
+    public ImageListActionListTests()
+    {
+        _imageListDesigner = new();
+        _imageList = new();
+        _imageListDesigner.Initialize(_imageList);
+        _actionList = new(_imageListDesigner);
+    }
+
+    public void Dispose()
+    {
+        _imageListDesigner.Dispose();
+        _imageList.Dispose();
+    }
+
+    [Fact]
+    public void Constructor_ShouldInitializeDesigner()
+    {
+        _actionList.Should().NotBeNull();
+        _actionList.Should().BeOfType<ImageListActionList>();
+        _actionList.Component.Should().Be(_imageListDesigner.Component);
+    }
+
+    [Fact]
+    public void ColorDepth_Get_ShouldReturnColorDepth()
+    {
+        _actionList.ColorDepth.Should().Be(ColorDepth.Depth32Bit);
+    }
+
+    [Fact]
+    public void ColorDepth_Set_ShouldUpdateColorDepth()
+    {
+        _actionList.ColorDepth = ColorDepth.Depth16Bit;
+        _actionList.ColorDepth.Should().Be(ColorDepth.Depth16Bit);
+    }
+
+    [Fact]
+    public void ImageSize_Get_ShouldReturnImageSize()
+    {
+        Size size = new(16, 16);
+        _actionList.ImageSize.Should().Be(size);
+    }
+
+    [Fact]
+    public void ImageSize_Set_ShouldUpdateImageSize()
+    {
+        Size size = new(32, 32);
+        _actionList.ImageSize = size;
+        _actionList.ImageSize.Should().Be(size);
+    }
+
+    [Fact]
+    public void GetSortedActionItems_ShouldReturnExpectedItems()
+    {
+        DesignerActionItemCollection items = _actionList.GetSortedActionItems();
+        items.Should().NotBeNull();
+        items.Should().BeOfType<DesignerActionItemCollection>();
+
+        items[0].Should().BeOfType<DesignerActionPropertyItem>();
+        items[0].DisplayName.Should().Be(SR.ImageListActionList_ImageSizeDisplayName);
+        items[0].Category.Should().Be(SR.PropertiesCategoryName);
+        items[0].Description.Should().Be(SR.ImageListActionList_ImageSizeDescription);
+
+        items[1].Should().BeOfType<DesignerActionPropertyItem>();
+        items[1].DisplayName.Should().Be(SR.ImageListActionList_ColorDepthDisplayName);
+        items[1].Category.Should().Be(SR.PropertiesCategoryName);
+        items[1].Description.Should().Be(SR.ImageListActionList_ColorDepthDescription);
+
+        items[2].Should().BeOfType<DesignerActionMethodItem>();
+        items[2].DisplayName.Should().Be(SR.ImageListActionList_ChooseImagesDisplayName);
+        items[2].Category.Should().Be(SR.LinksCategoryName);
+        items[2].Description.Should().Be(SR.ImageListActionList_ChooseImagesDescription);
+    }
+}