File: System\Windows\Forms\TreeViewImageIndexConverterTests.cs
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Project: src\src\test\unit\System.Windows.Forms\System.Windows.Forms.Tests.csproj (System.Windows.Forms.Tests)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.ComponentModel;
using System.Drawing;
using static System.ComponentModel.TypeConverter;
 
namespace System.Windows.Forms.Tests;
 
// NB: doesn't require thread affinity
public class TreeViewImageIndexConverterTests
{
    [Fact]
    public void TreeViewImageIndexConverter_IncludeNoneAsStandardValue_ReturnsFalse()
    {
        Assert.False(new TreeViewImageIndexConverter().TestAccessor().Dynamic.IncludeNoneAsStandardValue);
    }
 
    [Fact]
    public void TreeViewImageIndexConverter_ConvertTo_destinationType_null_ThrowsArgumentNullException()
    {
        TreeViewImageIndexConverter converter = new();
 
        Assert.Throws<ArgumentNullException>("destinationType", () => converter.ConvertTo(context: null, culture: null, new object(), destinationType: (Type)null!));
    }
 
    public static IEnumerable<object[]> TreeViewImageIndexConverter_ConvertFrom_special_string_to_int_ReturnsExpected_TestData()
    {
        yield return new object[] { SR.toStringDefault, -1, };
        yield return new object[] { SR.toStringDefault, ImageList.Indexer.DefaultIndex };
        yield return new object[] { SR.toStringNone, -2 };
        yield return new object[] { SR.toStringNone, ImageList.Indexer.NoneIndex };
    }
 
    [Theory]
    [MemberData(nameof(TreeViewImageIndexConverter_ConvertFrom_special_string_to_int_ReturnsExpected_TestData))]
    public void TreeViewImageIndexConverter_ConvertFrom_special_string_to_int_ReturnsExpected(object value, object expected)
    {
        TreeViewImageIndexConverter converter = new();
 
        object? result = converter.ConvertFrom(context: null, culture: null, value);
 
        Assert.Equal(expected, result);
    }
 
    public static IEnumerable<object[]> TreeViewImageIndexConverter_ConvertTo_special_int_to_string_ReturnsExpected_TestData()
    {
        yield return new object[] { -1, SR.toStringDefault };
        yield return new object[] { ImageList.Indexer.DefaultIndex, SR.toStringDefault };
        yield return new object[] { -2, SR.toStringNone };
        yield return new object[] { ImageList.Indexer.NoneIndex, SR.toStringNone };
    }
 
    [Theory]
    [MemberData(nameof(TreeViewImageIndexConverter_ConvertTo_special_int_to_string_ReturnsExpected_TestData))]
    public void TreeViewImageIndexConverter_ConvertTo_special_int_to_string_ReturnsExpected(object value, object expected)
    {
        TreeViewImageIndexConverter converter = new();
 
        object? result = converter.ConvertTo(context: null, culture: null, value, destinationType: typeof(string));
 
        Assert.Equal(expected, result);
    }
 
    [Fact]
    public void TreeViewImageIndexConverter_GetStandardValues_Null_Context_ReturnsExpected()
    {
        TreeViewImageIndexConverter converter = new();
 
        StandardValuesCollection result = converter.GetStandardValues(context: null);
 
        Assert.Equal(2, result.Count);
        Assert.Equal(ImageList.Indexer.DefaultIndex, result[0]);
        Assert.Equal(ImageList.Indexer.NoneIndex, result[1]);
    }
 
    [Fact]
    public void TreeViewImageIndexConverter_GetStandardValues_WithContext_ReturnsExpected()
    {
        using ImageList imageList = new();
        using Bitmap image1 = new(10, 10);
        using Bitmap image2 = new(10, 10);
        imageList.Images.Add(image1);
        imageList.Images.Add(image2);
 
        using TreeView treeView = new TreeView { ImageList = imageList };
        PropertyDescriptor? propertyDescriptor = TypeDescriptor.GetProperties(treeView)["ImageList"];
        TypeDescriptorContext context = new(treeView, propertyDescriptor!);
 
        TreeViewImageIndexConverter converter = new();
        var result = converter.GetStandardValues(context);
 
        result.Count.Should().Be(imageList.Images.Count + 2);
        result.Cast<int>().Should().ContainInOrder(0, 1, ImageList.Indexer.DefaultIndex, -2);
    }
 
    private class TypeDescriptorContext : ITypeDescriptorContext
    {
        private readonly object _instance;
        private readonly PropertyDescriptor _propertyDescriptor;
 
        public TypeDescriptorContext(object instance, PropertyDescriptor propertyDescriptor)
        {
            _instance = instance;
            _propertyDescriptor = propertyDescriptor;
        }
 
        public IContainer? Container => null;
        public object Instance => _instance;
        public PropertyDescriptor PropertyDescriptor => _propertyDescriptor;
        public bool OnComponentChanging() => true;
        public void OnComponentChanged() { }
        public object? GetService(Type serviceType) => null;
    }
}