Add unit tests for EditorServiceContext (#13273)

* Add unit tests for EditorServiceContext
Related #10773
---------

Co-authored-by: Tanya Solyanik <[email protected]>

Author: MelonWang1

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

@@ -0,0 +1,214 @@
+// 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.ComponentModel.Design;
+using System.Drawing.Design;
+using Moq;
+
+namespace System.Windows.Forms.Design.Tests;
+
+public class EditorServiceContextTests : IDisposable
+{
+    private readonly TestComponent _component;
+    private readonly TestComponentDesigner _designer;
+    private readonly Mock<PropertyDescriptor> _mockPropertyDescriptor;
+    private readonly Mock<UITypeEditor> _mockEditor;
+    private readonly Mock<IContainer> _mockContainer;
+    private readonly Mock<ISite> _mockSite;
+    private readonly Mock<IComponentChangeService> _mockChangeService;
+    private readonly Mock<IUIService> _mockUIService;
+    private readonly Mock<Form> _mockDialog;
+
+    public EditorServiceContextTests()
+    {
+        _component = new();
+        _designer = new(_component);
+        _mockPropertyDescriptor = new("Items", Array.Empty<Attribute>());
+        _mockEditor = new();
+        _mockContainer = new();
+        _mockSite = new();
+        _mockChangeService = new();
+        _mockUIService = new();
+        _mockDialog = new();
+    }
+
+    public void Dispose()
+    {
+        _designer.Dispose();
+        _component.Dispose();
+        _mockDialog.Object.Dispose();
+    }
+
+    [Fact]
+    public void EditValue_ShouldUpdatePropertyValue_WhenEditorReturnsNewValue()
+    {
+        List<string> oldValue = new() { "Old" };
+        List<string> newValue = new() { "New" };
+
+        _mockPropertyDescriptor.Setup(p => p.GetValue(_component)).Returns(oldValue);
+        _mockPropertyDescriptor.Setup(p => p.SetValue(_component, newValue));
+        _mockPropertyDescriptor.Setup(p => p.PropertyType).Returns(typeof(List<string>));
+        _mockPropertyDescriptor.Setup(p => p.Name).Returns("Items");
+        _mockPropertyDescriptor.Setup(p => p.Attributes).Returns(new AttributeCollection(null));
+
+        _mockEditor
+            .Setup(e => e.EditValue(It.IsAny<ITypeDescriptorContext>(), It.IsAny<IServiceProvider>(), oldValue))
+            .Returns(newValue);
+
+        _mockPropertyDescriptor
+            .Setup(p => p.GetEditor(typeof(UITypeEditor)))
+            .Returns(_mockEditor.Object);
+
+        TypeDescriptor.AddProvider(new TypeDescriptionProviderMock(_mockPropertyDescriptor.Object), _component);
+
+        object? result = EditorServiceContext.EditValue(_designer, _component, "Items");
+
+        result.Should().BeEquivalentTo(newValue);
+        _mockPropertyDescriptor.Verify(p => p.SetValue(_component, newValue), Times.Once);
+    }
+
+    [Fact]
+    public void EditValue_ShouldNotUpdatePropertyValue_WhenEditorReturnsSameValue()
+    {
+        List<string> list = new() { "Same" };
+        _component.Items = list;
+
+        _mockPropertyDescriptor.Setup(p => p.GetValue(_component)).Returns(list);
+        _mockPropertyDescriptor.Setup(p => p.PropertyType).Returns(typeof(List<string>));
+        _mockPropertyDescriptor.Setup(p => p.Name).Returns("Items");
+        _mockPropertyDescriptor.Setup(p => p.Attributes).Returns(new AttributeCollection(null));
+
+        _mockEditor
+            .Setup(e => e.EditValue(It.IsAny<ITypeDescriptorContext>(), It.IsAny<IServiceProvider>(), list))
+            .Returns(list);
+
+        _mockPropertyDescriptor
+            .Setup(p => p.GetEditor(typeof(UITypeEditor)))
+            .Returns(_mockEditor.Object);
+
+        TypeDescriptor.AddProvider(new TypeDescriptionProviderMock(_mockPropertyDescriptor.Object), _component);
+
+        object? result = EditorServiceContext.EditValue(_designer, _component, "Items");
+
+        result.Should().BeSameAs(list);
+        _mockPropertyDescriptor.Verify(p => p.SetValue(It.IsAny<object>(), It.IsAny<object>()), Times.Never);
+    }
+
+    [Fact]
+    public void Container_ShouldReturnNull_WhenComponentSiteIsNull()
+    {
+        EditorServiceContext context = new(_designer, _mockPropertyDescriptor.Object);
+
+        using IContainer? container = ((ITypeDescriptorContext)context).Container;
+
+        container.Should().BeNull();
+    }
+
+    [Fact]
+    public void Container_ShouldReturnContainer_WhenComponentSiteHasContainer()
+    {
+        _mockSite.Setup(s => s.Container).Returns(_mockContainer.Object);
+        _component.Site = _mockSite.Object;
+
+        EditorServiceContext context = new(_designer, _mockPropertyDescriptor.Object);
+
+        using IContainer? container = ((ITypeDescriptorContext)context).Container;
+
+        container.Should().BeSameAs(_mockContainer.Object);
+    }
+
+    [Fact]
+    public void OnComponentChanging_ShouldReturnTrue_WhenChangeServiceDoesNotThrow()
+    {
+        _mockSite.Setup(s => s.GetService(typeof(IComponentChangeService))).Returns(_mockChangeService.Object);
+        _component.Site = _mockSite.Object;
+
+        EditorServiceContext context = new(_designer, _mockPropertyDescriptor.Object);
+
+        bool result = ((ITypeDescriptorContext)context).OnComponentChanging();
+
+        result.Should().BeTrue();
+        _mockChangeService.Verify(cs => cs.OnComponentChanging(_component, _mockPropertyDescriptor.Object), Times.Once);
+    }
+
+    [Fact]
+    public void OnComponentChanging_ShouldReturnFalse_WhenChangeServiceThrowsCheckoutExceptionCanceled()
+    {
+        _mockChangeService
+            .Setup(cs => cs.OnComponentChanging(It.IsAny<object>(), It.IsAny<PropertyDescriptor>()))
+            .Throws(CheckoutException.Canceled);
+
+        _mockSite.Setup(s => s.GetService(typeof(IComponentChangeService))).Returns(_mockChangeService.Object);
+        _component.Site = _mockSite.Object;
+
+        EditorServiceContext context = new(_designer, _mockPropertyDescriptor.Object);
+
+        bool result = ((ITypeDescriptorContext)context).OnComponentChanging();
+
+        result.Should().BeFalse();
+        _mockChangeService.Verify(cs => cs.OnComponentChanging(_component, _mockPropertyDescriptor.Object), Times.Once);
+    }
+
+    [Fact]
+    public void ShowDialog_ShouldUseIUIService_WhenAvailable()
+    {
+        _mockSite.Setup(s => s.GetService(typeof(IUIService))).Returns(_mockUIService.Object);
+        _component.Site = _mockSite.Object;
+
+        EditorServiceContext context = new(_designer, _mockPropertyDescriptor.Object);
+
+        _mockUIService.Setup(s => s.ShowDialog(_mockDialog.Object)).Returns(DialogResult.OK);
+
+        DialogResult result = ((IWindowsFormsEditorService)context).ShowDialog(_mockDialog.Object);
+
+        result.Should().Be(DialogResult.OK);
+        _mockUIService.Verify(s => s.ShowDialog(_mockDialog.Object), Times.Once);
+    }
+
+    [Fact]
+    public void ShowDialog_ShouldFallbackToFormShowDialog_WhenIUIServiceNotAvailable()
+    {
+        _mockSite.Setup(s => s.GetService(typeof(IUIService))).Returns((object?)null);
+        _component.Site = _mockSite.Object;
+
+        EditorServiceContext context = new(_designer, _mockPropertyDescriptor.Object);
+
+        Mock<IWindowsFormsEditorService> mockEditorService = new();
+        mockEditorService.Setup(es => es.ShowDialog(It.IsAny<Form>())).Returns(DialogResult.Cancel);
+
+        DialogResult result = mockEditorService.Object.ShowDialog(new Form());
+
+        result.Should().Be(DialogResult.Cancel);
+    }
+
+    private class TestComponent : Component
+    {
+        public List<string> Items { get; set; } = new();
+    }
+
+    private class TestComponentDesigner : ComponentDesigner
+    {
+        public TestComponentDesigner(IComponent component) => Initialize(component);
+    }
+
+    private class TypeDescriptionProviderMock : TypeDescriptionProvider
+    {
+        private readonly PropertyDescriptor _property;
+
+        public TypeDescriptionProviderMock(PropertyDescriptor property) => _property = property;
+
+        public override ICustomTypeDescriptor? GetTypeDescriptor(Type objectType, object? instance) => new TypeDescriptorStub(_property);
+
+        private class TypeDescriptorStub : CustomTypeDescriptor
+        {
+            private readonly PropertyDescriptor _property;
+
+            public TypeDescriptorStub(PropertyDescriptor property) => _property = property;
+
+            public override PropertyDescriptorCollection GetProperties() => new PropertyDescriptorCollection([_property]);
+
+            public override PropertyDescriptorCollection GetProperties(Attribute[]? attributes) => GetProperties();
+        }
+    }
+}