// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

#nullable disable

using System.Collections;
using System.ComponentModel.Design.Serialization;
using System.Reflection;
using Moq;

namespace System.ComponentModel.Design.Tests;

public class DesignerHostTests
{
    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_CanReloadWithErrors_Set_GetReturnsExpected(bool value)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        host.CanReloadWithErrors = value;
        Assert.Equal(value, host.CanReloadWithErrors);

        // Set same.
        host.CanReloadWithErrors = value;
        Assert.Equal(value, host.CanReloadWithErrors);

        // Set different.
        host.CanReloadWithErrors = !value;
        Assert.Equal(!value, host.CanReloadWithErrors);
    }

    [WinFormsFact]
    public void DesignerHost_Container_Get_ReturnsHost()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Same(host, host.Container);
    }

    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_IgnoreErrorsDuringReload_Set_GetReturnsExpected(bool value)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        host.IgnoreErrorsDuringReload = value;
        Assert.False(host.IgnoreErrorsDuringReload);

        // Set same.
        host.IgnoreErrorsDuringReload = value;
        Assert.False(host.IgnoreErrorsDuringReload);

        // Set different.
        host.IgnoreErrorsDuringReload = !value;
        Assert.False(host.IgnoreErrorsDuringReload);
    }

    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_IgnoreErrorsDuringReload_SetWithCanReloadWithErrors_GetReturnsExpected(bool value)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        host.CanReloadWithErrors = true;

        host.IgnoreErrorsDuringReload = value;
        Assert.Equal(value, host.IgnoreErrorsDuringReload);

        // Set same.
        host.IgnoreErrorsDuringReload = value;
        Assert.Equal(value, host.IgnoreErrorsDuringReload);

        // Set different.
        host.IgnoreErrorsDuringReload = !value;
        Assert.Equal(!value, host.IgnoreErrorsDuringReload);
    }

    [WinFormsFact]
    public void DesignerHost_InTransaction_GetWithoutTransactions_ReturnsFalse()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.False(host.InTransaction);
    }

    [WinFormsFact]
    public void DesignerHost_IsClosingTransaction_GetWithoutTransaction_ReturnsFalse()
    {
        using SubDesignSurface surface = new();
        IDesignerHostTransactionState hostTransactionState = Assert.IsAssignableFrom<IDesignerHostTransactionState>(surface.Host);
        Assert.False(hostTransactionState.IsClosingTransaction);
    }

    [WinFormsFact]
    public void DesignerHost_Loading_GetWithoutComponent_ReturnsFalse()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.False(host.Loading);
    }

    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_Loading_GetWithLoader_ReturnsExpected(bool loading)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Mock<DesignerLoader> mockLoader = new(MockBehavior.Strict);
        mockLoader
            .Setup(l => l.BeginLoad(host));
        mockLoader
            .Setup(l => l.Loading)
            .Returns(loading);
        surface.BeginLoad(mockLoader.Object);
        Assert.True(host.Loading);
        mockLoader.Verify(l => l.Loading, Times.Never());

        host.EndLoad(null, true, null);
        Assert.Equal(loading, host.Loading);
        mockLoader.Verify(l => l.Loading, Times.Once());
    }

    [WinFormsFact]
    public void DesignerHost_RootComponent_GetWithoutComponent_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Null(host.RootComponent);
    }

    [WinFormsFact]
    public void DesignerHost_RootComponentClassName_GetWithoutComponent_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Null(host.RootComponentClassName);
    }

    [WinFormsFact]
    public void DesignerHost_TransactionDescription_GetWithoutTransactions_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        host.TransactionDescription.Should().BeNullOrEmpty();
    }

    [WinFormsFact]
    public void DesignerHost_Activate_Invoke_CallsViewActivated()
    {
        using SubDesignSurface surface = new();
        int viewActivatedCallCount = 0;
        int activatedCallCount = 0;
        surface.ViewActivated += (sender, e) =>
        {
            Assert.Same(surface, sender);
            Assert.Same(EventArgs.Empty, e);
            viewActivatedCallCount++;
        };
        IDesignerLoaderHost2 host = surface.Host;
        host.Activated += (sender, e) => activatedCallCount++;
        host.Activate();
        Assert.Equal(1, viewActivatedCallCount);
        Assert.Equal(0, activatedCallCount);
    }

    [WinFormsFact]
    public void DesignerHost_Activate_InvokeDisposed_Nop()
    {
        using SubDesignSurface surface = new();
        int viewActivatedCallCount = 0;
        int activatedCallCount = 0;
        surface.ViewActivated += (sender, e) =>
        {
            Assert.Same(surface, sender);
            Assert.Same(EventArgs.Empty, e);
            viewActivatedCallCount++;
        };
        IDesignerLoaderHost2 host = surface.Host;
        surface.Dispose();
        host.Activated += (sender, e) => activatedCallCount++;
        host.Activate();
        Assert.Equal(0, viewActivatedCallCount);
        Assert.Equal(0, activatedCallCount);
    }

    public static IEnumerable<object[]> Add_InvalidNameCreationServiceParentProvider_TestData()
    {
        yield return new object[] { null };

        Mock<IServiceProvider> nullMockServiceProvider = new(MockBehavior.Strict);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(DesignerCommandSet)))
            .Returns(new object());
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(IInheritanceService)))
            .Returns(new object());
        yield return new object[] { nullMockServiceProvider.Object };

        Mock<IServiceProvider> invalidMockServiceProvider = new(MockBehavior.Strict);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(new object());
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(DesignerCommandSet)))
            .Returns(new object());
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(IInheritanceService)))
            .Returns(new object());
        yield return new object[] { invalidMockServiceProvider.Object };
    }

    public static IEnumerable<object[]> Add_ComponentParentProvider_TestData()
    {
        foreach (object[] testData in Add_InvalidNameCreationServiceParentProvider_TestData())
        {
            yield return new object[] { testData[0], string.Empty };
        }

        foreach (string name in new string[] { null, string.Empty, "name" })
        {
            Mock<INameCreationService> mockNameCreationService = new(MockBehavior.Strict);
            mockNameCreationService
                .Setup(s => s.CreateName(It.IsAny<IContainer>(), It.IsAny<Type>()))
                .Returns(name);
            Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
            mockServiceProvider
                .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
                .Returns(null);
            mockServiceProvider
                .Setup(p => p.GetService(typeof(ITypeResolutionService)))
                .Returns(null);
            mockServiceProvider
                .Setup(p => p.GetService(typeof(ContainerFilterService)))
                .Returns(null);
            mockServiceProvider
                .Setup(p => p.GetService(typeof(DesignerCommandSet)))
                .Returns(null);
            mockServiceProvider
                .Setup(p => p.GetService(typeof(IInheritanceService)))
                .Returns(null);
            mockServiceProvider
                .Setup(p => p.GetService(typeof(INameCreationService)))
                .Returns(mockNameCreationService.Object);
            yield return new object[] { mockServiceProvider.Object, name };
        }
    }

    [WinFormsTheory]
    [MemberData(nameof(Add_ComponentParentProvider_TestData))]
    public void DesignerHost_Add_ComponentWithRootDesigner_Success(IServiceProvider parentProvider, string expectedName)
    {
        using SubDesignSurface surface = new(parentProvider);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component1 = new();
        using RootDesignerComponent component2 = new();
        using DesignerComponent component3 = new();
        using Component component4 = new();

        host.Container.Add(component1);
        Assert.Same(component1, Assert.Single(host.Container.Components));
        Assert.Same(expectedName, host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(host, component1.Container);
        Assert.Same(component1, component1.Site.Component);
        Assert.Same(host, component1.Site.Container);
        Assert.True(component1.Site.DesignMode);
        Assert.Equal(expectedName, component1.Site.Name);

        // Add different - root designer.
        host.Container.Add(component2);
        Assert.Equal(new IComponent[] { component1, component2 }, host.Container.Components.Cast<IComponent>());
        Assert.Same(expectedName, host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(host, component2.Container);
        Assert.Same(component2, component2.Site.Component);
        Assert.Same(host, component2.Site.Container);
        Assert.True(component2.Site.DesignMode);
        Assert.Equal(expectedName, component2.Site.Name);

        // Add different - non root designer.
        host.Container.Add(component3);
        Assert.Equal(new IComponent[] { component1, component2, component3 }, host.Container.Components.Cast<IComponent>());
        Assert.Same(expectedName, host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(host, component3.Container);
        Assert.Same(component3, component3.Site.Component);
        Assert.Same(host, component3.Site.Container);
        Assert.True(component3.Site.DesignMode);
        Assert.Equal(expectedName, component3.Site.Name);

        // Add different - non designer.
        host.Container.Add(component4);
        Assert.Equal(new IComponent[] { component1, component2, component3, component4 }, host.Container.Components.Cast<IComponent>());
        Assert.Same(expectedName, host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(host, component4.Container);
        Assert.Same(component4, component4.Site.Component);
        Assert.Same(host, component4.Site.Container);
        Assert.True(component4.Site.DesignMode);
        Assert.Equal(expectedName, component4.Site.Name);
    }

    [WinFormsTheory]
    [MemberData(nameof(Add_InvalidNameCreationServiceParentProvider_TestData))]
    public void DesignerHost_Add_ComponentStringWithRootDesigner_Success(IServiceProvider parentProvider)
    {
        using SubDesignSurface surface = new(parentProvider);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component1 = new();
        using RootDesignerComponent component2 = new();
        using DesignerComponent component3 = new();
        using Component component4 = new();

        host.Container.Add(component1, "name1");
        Assert.Same(component1, Assert.Single(host.Container.Components));
        Assert.Equal("name1", host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(host, component1.Container);
        Assert.Same(component1, component1.Site.Component);
        Assert.Same(host, component1.Site.Container);
        Assert.True(component1.Site.DesignMode);
        Assert.Equal("name1", component1.Site.Name);

        // Add different - root designer.
        host.Container.Add(component2, "name2");
        Assert.Equal(new IComponent[] { component1, component2 }, host.Container.Components.Cast<IComponent>());
        Assert.Same(host, component2.Container);
        Assert.Equal("name1", host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(component2, component2.Site.Component);
        Assert.Same(host, component2.Site.Container);
        Assert.True(component2.Site.DesignMode);
        Assert.Equal("name2", component2.Site.Name);

        // Add different - non root designer.
        host.Container.Add(component3, string.Empty);
        Assert.Equal(new IComponent[] { component1, component2, component3 }, host.Container.Components.Cast<IComponent>());
        Assert.Same(host, component3.Container);
        Assert.Equal("name1", host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(component3, component3.Site.Component);
        Assert.Same(host, component3.Site.Container);
        Assert.True(component3.Site.DesignMode);
        Assert.Empty(component3.Site.Name);

        // Add different - non designer.
        host.Container.Add(component4, null);
        Assert.Equal(new IComponent[] { component1, component2, component3, component4 }, host.Container.Components.Cast<IComponent>());
        Assert.Same(host, component4.Container);
        Assert.Equal("name1", host.RootComponentClassName);
        Assert.Same(component1, host.RootComponent);
        Assert.Same(component4, component4.Site.Component);
        Assert.Same(host, component4.Site.Container);
        Assert.True(component4.Site.DesignMode);
        Assert.Empty(component4.Site.Name);
    }

    public static IEnumerable<object[]> Add_IExtenderProviderServiceWithoutDefault_TestData()
    {
        yield return new object[] { new RootDesignerComponent(), 0 };
        yield return new object[] { new RootExtenderProviderDesignerComponent(), 1 };

        RootExtenderProviderDesignerComponent readOnlyComponent = new();
        TypeDescriptor.AddAttributes(readOnlyComponent, new InheritanceAttribute(InheritanceLevel.InheritedReadOnly));
        yield return new object[] { readOnlyComponent, 0 };

        RootExtenderProviderDesignerComponent inheritedComponent = new();
        TypeDescriptor.AddAttributes(inheritedComponent, new InheritanceAttribute(InheritanceLevel.Inherited));
        yield return new object[] { inheritedComponent, 1 };

        RootExtenderProviderDesignerComponent notInheritedComponent = new();
        TypeDescriptor.AddAttributes(notInheritedComponent, new InheritanceAttribute(InheritanceLevel.NotInherited));
        yield return new object[] { notInheritedComponent, 1 };
    }

    [WinFormsTheory]
    [MemberData(nameof(Add_IExtenderProviderServiceWithoutDefault_TestData))]
    public void DesignerHost_Add_IExtenderProviderServiceWithoutDefault_Success(Component component, int expectedCallCount)
    {
        Mock<IExtenderProviderService> mockExtenderProviderService = new(MockBehavior.Strict);
        mockExtenderProviderService
            .Setup(s => s.AddExtenderProvider(component as IExtenderProvider))
            .Verifiable();
        mockExtenderProviderService
            .Setup(s => s.RemoveExtenderProvider(component as IExtenderProvider));
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IExtenderProviderService)))
            .Returns(mockExtenderProviderService.Object)
            .Verifiable();

        using SubDesignSurface surface = new(mockServiceProvider.Object);
        surface.ServiceContainer.RemoveService(typeof(IExtenderProviderService));
        IDesignerLoaderHost2 host = surface.Host;

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(expectedCallCount));
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Exactly(expectedCallCount));

        // Add again.
        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(expectedCallCount));
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Exactly(expectedCallCount));

        // Add again with name.
        host.Container.Add(component, "name");
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Equal("name", component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(expectedCallCount));
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Exactly(expectedCallCount));
    }

    public static IEnumerable<object[]> Add_IExtenderProviderServiceWithDefault_TestData()
    {
        yield return new object[] { new RootDesignerComponent() };
        yield return new object[] { new RootExtenderProviderDesignerComponent() };

        RootExtenderProviderDesignerComponent readOnlyComponent = new();
        TypeDescriptor.AddAttributes(readOnlyComponent, new InheritanceAttribute(InheritanceLevel.InheritedReadOnly));
        yield return new object[] { readOnlyComponent };

        RootExtenderProviderDesignerComponent inheritedComponent = new();
        TypeDescriptor.AddAttributes(inheritedComponent, new InheritanceAttribute(InheritanceLevel.Inherited));
        yield return new object[] { inheritedComponent };

        RootExtenderProviderDesignerComponent notInheritedComponent = new();
        TypeDescriptor.AddAttributes(notInheritedComponent, new InheritanceAttribute(InheritanceLevel.NotInherited));
        yield return new object[] { notInheritedComponent };
    }

    [WinFormsTheory]
    [MemberData(nameof(Add_IExtenderProviderServiceWithDefault_TestData))]
    public void DesignerHost_Add_IExtenderProviderServiceWithDefault_DoesNotCallGetService(Component component)
    {
        Mock<IExtenderProviderService> mockExtenderProviderService = new(MockBehavior.Strict);
        mockExtenderProviderService
            .Setup(s => s.AddExtenderProvider(component as IExtenderProvider))
            .Verifiable();
        mockExtenderProviderService
            .Setup(s => s.RemoveExtenderProvider(component as IExtenderProvider));
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IExtenderProviderService)))
            .Returns(mockExtenderProviderService.Object)
            .Verifiable();

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Never());

        // Add again.
        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Never());

        // Add again with name.
        host.Container.Add(component, "name");
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Equal("name", component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Never());
    }

    public static IEnumerable<object[]> InvalidIExtenderProviderService_TestData()
    {
        yield return new object[] { null };

        Mock<IServiceProvider> nullMockServiceProvider = new(MockBehavior.Strict);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        nullMockServiceProvider
            .Setup(p => p.GetService(typeof(IExtenderProviderService)))
            .Returns(null)
            .Verifiable();
        yield return new object[] { nullMockServiceProvider };

        Mock<IServiceProvider> invalidMockServiceProvider = new(MockBehavior.Strict);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        invalidMockServiceProvider
            .Setup(p => p.GetService(typeof(IExtenderProviderService)))
            .Returns(new object())
            .Verifiable();
        yield return new object[] { invalidMockServiceProvider };
    }

    [WinFormsTheory]
    [MemberData(nameof(InvalidIExtenderProviderService_TestData))]
    public void DesignerHost_Add_InvalidIExtenderProviderServiceWithoutDefault_CallsParentGetService(Mock<IServiceProvider> mockParentProvider)
    {
        using SubDesignSurface surface = new(mockParentProvider?.Object);
        surface.ServiceContainer.RemoveService(typeof(IExtenderProviderService));
        IDesignerLoaderHost2 host = surface.Host;
        using RootExtenderProviderDesignerComponent component = new();

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        mockParentProvider?.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Once());
    }

    [WinFormsTheory]
    [MemberData(nameof(InvalidIExtenderProviderService_TestData))]
    public void DesignerHost_Add_InvalidIExtenderProviderServiceWithDefault_DoesNotCallParentGetService(Mock<IServiceProvider> mockParentProvider)
    {
        using SubDesignSurface surface = new(mockParentProvider?.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootExtenderProviderDesignerComponent component = new();

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        mockParentProvider?.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
    }

    [WinFormsFact]
    public void DesignerHost_Add_SameComponent_Success()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);

        // Add again.
        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);

        // Add again with name.
        host.Container.Add(component, "name");
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Equal("name", component.Site.Name);
    }

    [WinFormsFact]
    public void DesignerHost_Add_ComponentWithNameCreationServiceWithoutName_CallsCreateName()
    {
        Mock<INameCreationService> mockNameCreationService = new(MockBehavior.Strict);
        mockNameCreationService
            .Setup(s => s.CreateName(It.IsAny<IContainer>(), It.IsAny<Type>()))
            .Returns("name")
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(mockNameCreationService.Object);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();

        host.Container.Add(component);
        Assert.Equal("name", component.Site.Name);
        mockNameCreationService.Verify(s => s.CreateName(host.Container, typeof(RootDesignerComponent)), Times.Once());

        host.Container.Add(component, null);
        Assert.Equal("name", component.Site.Name);
        mockNameCreationService.Verify(s => s.CreateName(host.Container, typeof(RootDesignerComponent)), Times.Once());
    }

    [WinFormsFact]
    public void DesignerHost_Add_ComponentWithNameCreationServiceWithCustomReflectionType_CallsCreateName()
    {
        using CustomTypeDescriptionProviderComponent component = new();
        Mock<ICustomTypeDescriptor> mockCustomTypeDescriptor = new(MockBehavior.Strict);
        mockCustomTypeDescriptor
            .Setup(d => d.GetAttributes())
            .Returns(TypeDescriptor.GetAttributes(typeof(CustomTypeDescriptionProviderComponent)));
        Mock<TypeDescriptionProvider> mockProvider = new(MockBehavior.Strict);
        mockProvider
            .Setup(p => p.GetReflectionType(typeof(CustomTypeDescriptionProviderComponent), component))
            .Returns(typeof(RootDesignerComponent))
            .Verifiable();
        mockProvider
            .Setup(p => p.GetTypeDescriptor(typeof(CustomTypeDescriptionProviderComponent), component))
            .Returns(mockCustomTypeDescriptor.Object);
        mockProvider
            .Setup(p => p.GetCache(component))
            .CallBase();
        mockProvider
            .Setup(p => p.GetExtendedTypeDescriptor(component))
            .CallBase();
        TypeDescriptor.AddProvider(mockProvider.Object, component);

        Mock<INameCreationService> mockNameCreationService = new(MockBehavior.Strict);
        mockNameCreationService
            .Setup(s => s.CreateName(It.IsAny<IContainer>(), It.IsAny<Type>()))
            .Returns("name")
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(mockNameCreationService.Object);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;

        host.Container.Add(component);
        Assert.Equal("name", component.Site.Name);
        mockNameCreationService.Verify(s => s.CreateName(host.Container, typeof(RootDesignerComponent)), Times.Once());

        host.Container.Add(component, null);
        Assert.Equal("name", component.Site.Name);
        mockNameCreationService.Verify(s => s.CreateName(host.Container, typeof(RootDesignerComponent)), Times.Once());
    }

    [WinFormsTheory]
    [StringData]
    public void DesignerHost_Add_ComponentWithNameCreationServiceWithName_CallsValidateName(string name)
    {
        Mock<INameCreationService> mockNameCreationService = new(MockBehavior.Strict);
        mockNameCreationService
            .Setup(s => s.ValidateName(It.IsAny<string>()))
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(mockNameCreationService.Object)
            .Verifiable();

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component1 = new();
        host.Container.Add(component1, name);
        Assert.Same(name, component1.Site.Name);
        mockNameCreationService.Verify(s => s.ValidateName(name), Times.Once());
        mockServiceProvider.Verify(p => p.GetService(typeof(INameCreationService)), Times.Once());

        // Add another.
        using DesignerComponent component2 = new();
        host.Container.Add(component2, "name2");
        Assert.Equal("name2", component2.Site.Name);
        mockNameCreationService.Verify(s => s.ValidateName("name2"), Times.Once());
        mockServiceProvider.Verify(p => p.GetService(typeof(INameCreationService)), Times.Exactly(2));
    }

    [WinFormsFact]
    public void DesignerHost_Add_ComponentWithTypeDescriptionProviderServiceWithoutProjectTargetFrameworkAttribute_AddsProvider()
    {
        ICustomTypeDescriptor descriptor = TypeDescriptor.GetProvider(typeof(RootDesignerComponent)).GetTypeDescriptor(typeof(RootDesignerComponent));
        Mock<TypeDescriptionProvider> mockTypeDescriptionProvider = new(MockBehavior.Strict);
        mockTypeDescriptionProvider
            .Setup(p => p.IsSupportedType(typeof(int)))
            .Returns(false)
            .Verifiable();
        mockTypeDescriptionProvider
            .Setup(p => p.GetTypeDescriptor(It.IsAny<Type>(), It.IsAny<object>()))
            .Returns(descriptor);
        mockTypeDescriptionProvider
            .Setup(p => p.GetCache(It.IsAny<object>()))
            .CallBase();
        mockTypeDescriptionProvider
            .Setup(p => p.GetExtendedTypeDescriptor(It.IsAny<object>()))
            .CallBase();
        Mock<TypeDescriptionProviderService> mockTypeDescriptionProviderService = new(MockBehavior.Strict);
        mockTypeDescriptionProviderService
            .Setup(s => s.GetProvider(It.IsAny<object>()))
            .Returns(mockTypeDescriptionProvider.Object)
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(mockTypeDescriptionProviderService.Object)
            .Verifiable();
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(DesignerCommandSet)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IInheritanceService)))
            .Returns(null);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component1 = new();
        host.Container.Add(component1, "name1");
        Assert.Equal("name1", component1.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(TypeDescriptionProviderService)), Times.Once());
        mockTypeDescriptionProviderService.Verify(s => s.GetProvider(component1), Times.Once());

        // Make sure we added the TypeDescriptionProvider.
        Assert.False(TypeDescriptor.GetProvider(component1).IsSupportedType(typeof(int)));
        mockTypeDescriptionProvider.Verify(p => p.IsSupportedType(typeof(int)), Times.Once());

        // Add again.
        using DesignerComponent component2 = new();
        host.Container.Add(component2, "name2");
        Assert.Equal("name2", component2.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(TypeDescriptionProviderService)), Times.Once());
        mockTypeDescriptionProviderService.Verify(s => s.GetProvider(component2), Times.Once());

        // Make sure we added the TypeDescriptionProvider.
        Assert.False(TypeDescriptor.GetProvider(component2).IsSupportedType(typeof(int)));
        mockTypeDescriptionProvider.Verify(p => p.IsSupportedType(typeof(int)), Times.Exactly(2));
    }

    [WinFormsFact]
    public void DesignerHost_Add_ComponentWithNullTypeDescriptionProviderService_Success()
    {
        Mock<TypeDescriptionProviderService> mockTypeDescriptionProviderService = new(MockBehavior.Strict);
        mockTypeDescriptionProviderService
            .Setup(s => s.GetProvider(It.IsAny<object>()))
            .Returns<TypeDescriptionProvider>(null)
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(mockTypeDescriptionProviderService.Object)
            .Verifiable();
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component, "name1");
        Assert.Equal("name1", component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(TypeDescriptionProviderService)), Times.Once());
        mockTypeDescriptionProviderService.Verify(s => s.GetProvider(component), Times.Once());
    }

    [WinFormsFact]
    public void DesignerHost_Add_ComponentWithTypeDescriptionProviderServiceWithProjectTargetFrameworkAttribute_DoesNotAddProvider()
    {
        using RootDesignerComponent component = new();
        ICustomTypeDescriptor descriptor = TypeDescriptor.GetProvider(typeof(RootDesignerComponent)).GetTypeDescriptor(typeof(RootDesignerComponent));
        Mock<TypeDescriptionProvider> mockTypeDescriptionProvider = new(MockBehavior.Strict);
        mockTypeDescriptionProvider
            .Setup(p => p.GetTypeDescriptor(It.IsAny<Type>(), It.IsAny<object>()))
            .Returns(descriptor);
        mockTypeDescriptionProvider
            .Setup(p => p.GetCache(component))
            .CallBase();
        mockTypeDescriptionProvider
            .Setup(p => p.GetExtendedTypeDescriptor(It.IsAny<object>()))
            .CallBase();
        mockTypeDescriptionProvider
            .Setup(p => p.GetReflectionType(typeof(object), null))
            .Returns(typeof(ClassWithProjectTargetFrameworkAttribute));
        TypeDescriptor.AddProvider(mockTypeDescriptionProvider.Object, component);

        Mock<TypeDescriptionProviderService> mockTypeDescriptionProviderService = new(MockBehavior.Strict);
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(mockTypeDescriptionProviderService.Object)
            .Verifiable();
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        host.Container.Add(component, "name1");
        Assert.Equal("name1", component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(TypeDescriptionProviderService)), Times.Once());
        mockTypeDescriptionProviderService.Verify(s => s.GetProvider(component), Times.Never());
    }

    [WinFormsFact(Skip = "Unstable test, see: https://github.com/dotnet/winforms/issues/1460")]
    public void DesignerHost_Add_DuringUnload_ThrowsException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.BeginLoad(typeof(RootDesignerComponent));

        using DesignerComponent component = new();
        host.Container.Add(component);
        int callCount = 0;
        component.Disposed += (sender, e) =>
        {
            using DesignerComponent newComponent = new();
            Assert.Throws<Exception>(() => host.Container.Add(newComponent));
            callCount++;
        };
        surface.Dispose();
        Assert.Equal(1, callCount);
        Assert.False(surface.IsLoaded);
        Assert.Empty(surface.LoadErrors);
        Assert.False(host.Loading);
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceGetKey_NoDictionary_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);

        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        Assert.Null(service.GetKey(null));
        Assert.Null(service.GetKey(new object()));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceGetKey_NoSuchKeyWithDictionary_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);

        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        object key1 = new();
        object value1 = new();
        service.SetValue(key1, value1);
        Assert.Same(key1, service.GetKey(value1));
        Assert.Same(value1, service.GetValue(key1));

        Assert.Null(service.GetKey(null));
        Assert.Null(service.GetKey(new object()));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceGetValue_NoDictionary_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);

        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        Assert.Null(service.GetValue(new object()));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceGetValue_NoSuchValueWithDictionary_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);

        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        object key1 = new();
        object value1 = new();
        service.SetValue(key1, value1);
        Assert.Same(key1, service.GetKey(value1));
        Assert.Same(value1, service.GetValue(key1));

        Assert.Null(service.GetValue(new object()));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceGetValue_NullValueNoDictionary_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);

        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        Assert.Throws<ArgumentNullException>("key", () => service.GetValue(null));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceGetValue_NullValueWithDictionary_ThrowsArgumentNullException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);

        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        object key1 = new();
        object value1 = new();
        service.SetValue(key1, value1);
        Assert.Same(key1, service.GetKey(value1));
        Assert.Same(value1, service.GetValue(key1));

        Assert.Throws<ArgumentNullException>("key", () => service.GetValue(null));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceSetValue_Invoke_GetKeyValueReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);

        object key1 = new();
        object value1 = new();
        service.SetValue(key1, value1);
        Assert.Same(key1, service.GetKey(value1));
        Assert.Same(value1, service.GetValue(key1));

        // Add another.
        object key2 = new();
        object value2 = new();
        service.SetValue(key2, value2);
        Assert.Same(key2, service.GetKey(value2));
        Assert.Same(value2, service.GetValue(key2));

        // Add same.
        object value3 = new();
        service.SetValue(key1, value3);
        Assert.Same(key1, service.GetKey(value3));
        Assert.Null(service.GetKey(value1));
        Assert.Same(value3, service.GetValue(key1));

        // Add null value.
        service.SetValue(key1, null);
        Assert.Null(service.GetKey(null));
        Assert.Null(service.GetKey(value3));
        Assert.Null(service.GetValue(key1));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIDictionaryServiceSetValue_NullKey_ThrowsArgumentNullException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        Assert.Throws<ArgumentNullException>("key", () => service.SetValue(null, new object()));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIServiceContainerAddService_InvokeObject_ReturnsExpected()
    {
        object service = new();
        object otherService = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(object)))
            .Returns(otherService);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IServiceContainer container = Assert.IsAssignableFrom<IServiceContainer>(component.Site);
        container.AddService(typeof(object), service);
        Assert.Same(service, container.GetService(typeof(object)));
        Assert.Same(otherService, surface.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIServiceContainerAddService_InvokeObjectPromote_ReturnsExpected()
    {
        object service = new();
        object otherService = new();
        ServiceContainer otherContainer = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(object)))
            .Returns(otherService);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IServiceContainer)))
            .Returns(otherContainer);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IServiceContainer container = Assert.IsAssignableFrom<IServiceContainer>(component.Site);
        container.AddService(typeof(object), service, true);
        Assert.Same(otherService, container.GetService(typeof(object)));
        Assert.Same(otherService, surface.GetService(typeof(object)));
        Assert.Same(service, otherContainer.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIServiceContainerAddService_InvokeObjectNoPromote_ReturnsExpected()
    {
        object service = new();
        object otherService = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(object)))
            .Returns(otherService);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IServiceContainer container = Assert.IsAssignableFrom<IServiceContainer>(component.Site);
        container.AddService(typeof(object), service, false);
        Assert.Same(service, container.GetService(typeof(object)));
        Assert.Same(otherService, surface.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIServiceContainerAddService_InvokeServiceCreatorCallback_ReturnsExpected()
    {
        object service = new();
        ServiceCreatorCallback callback = (c, serviceType) =>
        {
            Assert.Same(typeof(object), serviceType);
            return service;
        };
        object otherService = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(object)))
            .Returns(otherService);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IServiceContainer container = Assert.IsAssignableFrom<IServiceContainer>(component.Site);
        container.AddService(typeof(object), callback);
        Assert.Same(service, container.GetService(typeof(object)));
        Assert.Same(otherService, surface.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIServiceContainerAddService_InvokeServiceCreatorCallbackPromote_ReturnsExpected()
    {
        object service = new();
        ServiceCreatorCallback callback = (c, serviceType) =>
        {
            Assert.Same(typeof(object), serviceType);
            return service;
        };
        object otherService = new();
        ServiceContainer otherContainer = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(object)))
            .Returns(otherService);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IServiceContainer)))
            .Returns(otherContainer);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IServiceContainer container = Assert.IsAssignableFrom<IServiceContainer>(component.Site);
        container.AddService(typeof(object), callback, true);
        Assert.Same(otherService, container.GetService(typeof(object)));
        Assert.Same(otherService, surface.GetService(typeof(object)));
        Assert.Same(service, otherContainer.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentIServiceContainerAddService_InvokeServiceCreatorCallbackNoPromote_ReturnsExpected()
    {
        object service = new();
        ServiceCreatorCallback callback = (c, serviceType) =>
        {
            Assert.Same(typeof(object), serviceType);
            return service;
        };
        object otherService = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(object)))
            .Returns(otherService);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IServiceContainer container = Assert.IsAssignableFrom<IServiceContainer>(component.Site);
        container.AddService(typeof(object), callback, false);
        Assert.Same(service, container.GetService(typeof(object)));
        Assert.Same(otherService, surface.GetService(typeof(object)));
    }

    public static IEnumerable<object[]> AddComponentISiteName_Set_TestData()
    {
        foreach (object[] testData in Add_InvalidNameCreationServiceParentProvider_TestData())
        {
            foreach (string oldName in new string[] { null, string.Empty, "oldName" })
            {
                yield return new object[] { testData[0], oldName, null, string.Empty };
                yield return new object[] { testData[0], oldName, string.Empty, string.Empty };
                yield return new object[] { testData[0], oldName, "name", "name" };
                yield return new object[] { testData[0], oldName, "ldName", "ldName" };
                yield return new object[] { testData[0], oldName, "ldName", "ldName" };
            }
        }
    }

    [WinFormsTheory]
    [MemberData(nameof(AddComponentISiteName_Set_TestData))]
    public void DesignerHost_AddComponentISiteName_SetRootComponent_GetReturnsExpected(IServiceProvider parentProvider, string oldName, string value, string expectedName)
    {
        using SubDesignSurface surface = new(parentProvider);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component, oldName);
        component.Site.Name = value;
        Assert.Same(expectedName, component.Site.Name);
        Assert.Same(expectedName, host.RootComponentClassName);

        // Set same.
        component.Site.Name = value;
        Assert.Same(expectedName, component.Site.Name);
        Assert.Same(expectedName, host.RootComponentClassName);
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteName_SetDifferentCase_GetReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component, "name");
        component.Site.Name = "NAME";
        Assert.Equal("NAME", component.Site.Name);

        // Set same.
        component.Site.Name = "NAME";
        Assert.Equal("NAME", component.Site.Name);
    }

    [WinFormsTheory]
    [StringWithNullData]
    public void DesignerHost_AddComponentISiteName_SetWithMultipleComponents_GetReturnsExpected(string value)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component1 = new();
        using RootDesignerComponent component2 = new();
        using RootDesignerComponent component3 = new();
        host.Container.Add(component1);
        host.Container.Add(component2, null);
        host.Container.Add(component3, "name3");

        component1.Site.Name = value;
        Assert.Same(value ?? string.Empty, component1.Site.Name);

        // Set same.
        component1.Site.Name = value;
        Assert.Same(value ?? string.Empty, component1.Site.Name);
    }

    public static IEnumerable<object[]> AddComponentISiteName_SetWithNamespaceInRootComponentClassName_TestData()
    {
        yield return new object[] { string.Empty, "oldName", null, string.Empty, string.Empty };
        yield return new object[] { string.Empty, "oldName", string.Empty, string.Empty, string.Empty };
        yield return new object[] { string.Empty, "oldName", "newName", "newName", "newName" };

        yield return new object[] { "oldName", "oldName", null, string.Empty, string.Empty };
        yield return new object[] { "oldName", "oldName", string.Empty, string.Empty, string.Empty };
        yield return new object[] { "oldName", "oldName", "newName", "newName", "newName" };
        yield return new object[] { "oldName", "oldName", "oldName", "oldName", "oldName" };

        yield return new object[] { "namespace.oldName", "oldName", null, string.Empty, "namespace." };
        yield return new object[] { "namespace.oldName", "oldName", string.Empty, string.Empty, "namespace." };
        yield return new object[] { "namespace.oldName", "oldName", "newName", "newName", "namespace.newName" };
        yield return new object[] { "namespace.oldName", "oldName", "oldName", "oldName", "namespace.oldName" };
        yield return new object[] { "namespace.oldName", "ldName", "ldName", "ldName", "namespace.oldName" };

        yield return new object[] { "namespace.oldName", "namespace.oldName", null, string.Empty, string.Empty };
        yield return new object[] { "namespace.oldName", "namespace.oldName", string.Empty, string.Empty, string.Empty };
        yield return new object[] { "namespace.oldName", "namespace.oldName", "newName", "newName", "newName" };
        yield return new object[] { "namespace.oldName", "namespace.oldName", "oldName", "oldName", "oldName" };
        yield return new object[] { "namespace.oldName", "namespace.oldName", "ldName", "ldName", "ldName" };

        yield return new object[] { "namespace.oldName", "name", null, string.Empty, string.Empty };
        yield return new object[] { "namespace.oldName", "name", string.Empty, string.Empty, string.Empty };
        yield return new object[] { "namespace.oldName", "name", "newName", "newName", "newName" };
        yield return new object[] { "namespace.oldName", "name", "oldName", "oldName", "oldName" };
    }

    [WinFormsTheory]
    [MemberData(nameof(AddComponentISiteName_SetWithNamespaceInRootComponentClassName_TestData))]
    public void DesignerHost_AddComponentISiteName_SetWithNamespaceInRootComponentClassName_GetReturnsExpected(string oldRootComponentClassName, string oldName, string value, string expectedName, string expectedRootComponentClassName)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();

        host.EndLoad(oldRootComponentClassName, true, null);
        Assert.Equal(oldRootComponentClassName, host.RootComponentClassName);
        Assert.Null(host.RootComponent);

        host.Container.Add(component, oldName);
        Assert.Equal(oldName, component.Site.Name);
        Assert.Equal(oldRootComponentClassName, host.RootComponentClassName);
        Assert.Same(component, host.RootComponent);

        component.Site.Name = value;
        Assert.Equal(expectedName, component.Site.Name);
        Assert.Equal(expectedRootComponentClassName, host.RootComponentClassName);
        Assert.Same(component, host.RootComponent);
    }

    [WinFormsTheory]
    [StringWithNullData]
    public void DesignerHost_AddComponentISiteName_SetNameWithComponentRename_CallsHandler(string value)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);
        using RootDesignerComponent component = new();

        int callCount = 0;
        ComponentRenameEventHandler handler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component, e.Component);
            Assert.Equal("oldName", e.OldName);
            Assert.Same(value ?? string.Empty, e.NewName);
            callCount++;
        };
        changeService.ComponentRename += handler;
        host.Container.Add(component, "oldName");

        component.Site.Name = value;
        Assert.Same(value ?? string.Empty, component.Site.Name);
        Assert.Equal(1, callCount);

        // Set same.
        component.Site.Name = value;
        Assert.Same(value ?? string.Empty, component.Site.Name);
        Assert.Equal(1, callCount);

        // Remove handler.
        changeService.ComponentRename -= handler;
        component.Site.Name = "name";
        Assert.Equal("name", component.Site.Name);
        Assert.Equal(1, callCount);
    }

    [WinFormsTheory]
    [InlineData(null, "", 1)]
    [InlineData("", "", 1)]
    [InlineData("newName", "newName", 1)]
    [InlineData("OLDNAME", "OLDNAME", 0)]
    public void DesignerHost_AddComponentISite_SetNameWithINameCreateService_CallsValidateName(string value, string expectedName, int expectedCallCount)
    {
        Mock<INameCreationService> mockNameCreationService = new(MockBehavior.Strict);
        mockNameCreationService
            .Setup(s => s.ValidateName("oldName"))
            .Verifiable();
        mockNameCreationService
            .Setup(s => s.ValidateName(expectedName))
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(mockNameCreationService.Object);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component, "oldName");
        Assert.Equal("oldName", component.Site.Name);
        mockNameCreationService.Verify(s => s.ValidateName("oldName"), Times.Once());

        component.Site.Name = value;
        Assert.Equal(expectedName, component.Site.Name);
        mockNameCreationService.Verify(s => s.ValidateName(expectedName), Times.Exactly(expectedCallCount));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteName_SetSameAsOtherComponent_GetReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component1 = new();
        using RootDesignerComponent component2 = new();
        host.Container.Add(component1, "name1");
        host.Container.Add(component2, "name2");
        Assert.Throws<InvalidOperationException>(() => component1.Site.Name = "name2");
        Assert.Throws<InvalidOperationException>(() => component1.Site.Name = "NAME2");
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_Invoke_ReturnsExpected()
    {
        object service = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(int)))
            .Returns(service);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        Assert.Same(service, component.Site.GetService(typeof(int)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_InvokeWithNestedContainer_ReturnsService()
    {
        object service = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(int)))
            .Returns(service);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        INestedContainer nestedContainer = Assert.IsAssignableFrom<INestedContainer>(component.Site.GetService(typeof(INestedContainer)));
        Assert.Same(service, component.Site.GetService(typeof(int)));
        Assert.Same(component.Site, component.Site.GetService(typeof(IDictionaryService)));
        Assert.Same(nestedContainer, component.Site.GetService(typeof(INestedContainer)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_INestedContainer_ReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        INestedContainer container = Assert.IsAssignableFrom<INestedContainer>(component.Site.GetService(typeof(INestedContainer)));
        Assert.Same(container, component.Site.GetService(typeof(INestedContainer)));
        Assert.Empty(container.Components);
        Assert.Same(component, container.Owner);
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetServiceINestedContainerGetService_Invoke_ReturnsExpected()
    {
        object service = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(DesignerCommandSet)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IInheritanceService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(int)))
            .Returns(service);

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        NestedContainer container = Assert.IsAssignableFrom<NestedContainer>(component.Site.GetService(typeof(INestedContainer)));
        using Component nestedComponent = new();
        container.Add(nestedComponent);
        Assert.Same(service, nestedComponent.Site.GetService(typeof(int)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_IDictionaryService_ReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        Assert.Same(component.Site, component.Site.GetService(typeof(IDictionaryService)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_IServiceContainerReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        Assert.Same(surface.ServiceContainer, component.Site.GetService(typeof(IServiceContainer)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_IContainerReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        Assert.Same(host, component.Site.GetService(typeof(IContainer)));
    }

    [WinFormsFact]
    public void DesignerHost_AddComponentISiteGetService_NullServiceType_ThrowsArgumentNullException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        Assert.Throws<ArgumentNullException>("service", () => component.Site.GetService(null));
    }

    [WinFormsFact]
    public void DesignerHost_Add_IComponentWithComponentAddingAndAdded_CallsHandler()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        using RootDesignerComponent component = new();
        int componentAddingCallCount = 0;
        ComponentEventHandler componentAddingHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component, e.Component);
            componentAddingCallCount++;
        };
        changeService.ComponentAdding += componentAddingHandler;
        int componentAddedCallCount = 0;
        ComponentEventHandler componentAddedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component, e.Component);
            Assert.True(componentAddedCallCount < componentAddingCallCount);
            componentAddedCallCount++;
        };
        changeService.ComponentAdded += componentAddedHandler;

        // With handler.
        host.Container.Add(component);
        Assert.Same(host.Container, component.Container);
        Assert.Equal(1, componentAddingCallCount);
        Assert.Equal(1, componentAddedCallCount);

        // Add again.
        host.Container.Add(component);
        Assert.Same(host.Container, component.Container);
        Assert.Equal(1, componentAddingCallCount);
        Assert.Equal(1, componentAddedCallCount);

        // Remove handler.
        changeService.ComponentAdding -= componentAddingHandler;
        changeService.ComponentAdded -= componentAddedHandler;
        host.Container.Add(component);
        Assert.Same(host.Container, component.Container);
        Assert.Equal(1, componentAddingCallCount);
        Assert.Equal(1, componentAddedCallCount);
    }

    public static IEnumerable<object[]> Add_NoRootDesigner_TestData()
    {
        yield return new object[] { new Component() };
        yield return new object[] { new DesignerComponent() };
    }

    [WinFormsTheory]
    [MemberData(nameof(Add_NoRootDesigner_TestData))]
    public void DesignerHost_Add_NoRootDesigner_ThrowsException(IComponent component)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Throws<NotImplementedException>(() => host.Container.Add(component));
        Assert.Throws<NotImplementedException>(() => host.Container.Add(component, "name"));
        Assert.Empty(host.Container.Components);
    }

    [WinFormsFact]
    public void DesignerHost_Add_CyclicRootDesigner_ThrowsException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component, component.GetType().FullName);
        Assert.Equal(component.GetType().FullName, host.RootComponentClassName);
        Assert.Throws<InvalidOperationException>(() => host.Container.Add(component));
        Assert.Throws<InvalidOperationException>(() => host.Container.Add(new RootDesignerComponent(), host.RootComponentClassName));
    }

    [WinFormsFact]
    public void DesignerHost_Add_NonInitializingRootDesigner_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using NonInitializingDesignerComponent component = new();
        Assert.Throws<InvalidOperationException>(() => host.Container.Add(component));
        Assert.Throws<InvalidOperationException>(() => host.Container.Add(component, "name"));
    }

    [WinFormsFact]
    public void DesignerHost_Add_ThrowingInitializingRootDesigner_RethrowsException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using ThrowingInitializingDesignerComponent component = new();
        Assert.Throws<DivideByZeroException>(() => host.Container.Add(component));
        Assert.Null(component.Container);
        Assert.Null(component.Site);

        Assert.Throws<DivideByZeroException>(() => host.Container.Add(component, "name"));
        Assert.Null(component.Container);
        Assert.Null(component.Site);
    }

    [WinFormsFact]
    public void DesignerHost_Add_CheckoutExceptionThrowingInitializingRootDesigner_RethrowsException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        using CheckoutExceptionThrowingInitializingDesignerComponent component = new();
        // CheckoutException does not bubble up in xunit.
        bool threwCheckoutException = false;
        try
        {
            host.Container.Add(component);
        }
        catch (CheckoutException)
        {
            threwCheckoutException = true;
        }

        Assert.True(threwCheckoutException);
        Assert.Same(host.Container, component.Container);
        Assert.Empty(component.Site.Name);

        host.Container.Add(component, "name");
        Assert.Same(host.Container, component.Container);
        Assert.Equal("name", component.Site.Name);
    }

    [WinFormsFact]
    public void DesignerHost_AddService_InvokeObject_GetServiceReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        object service = new();
        host.AddService(typeof(object), service);
        Assert.Same(service, surface.ServiceContainer.GetService(typeof(object)));
        Assert.Same(service, surface.GetService(typeof(object)));
        Assert.Same(service, host.GetService(typeof(object)));
    }

    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_AddService_InvokeObjectBool_GetServiceReturnsExpected(bool promote)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        object service = new();
        host.AddService(typeof(object), service, promote);
        Assert.Same(service, surface.ServiceContainer.GetService(typeof(object)));
        Assert.Same(service, surface.GetService(typeof(object)));
        Assert.Same(service, host.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddService_InvokeCallback_GetServiceReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        object service = new();
        ServiceCreatorCallback callback = (container, serviceType) => service;
        host.AddService(typeof(object), callback);
        Assert.Same(service, surface.ServiceContainer.GetService(typeof(object)));
        Assert.Same(service, surface.GetService(typeof(object)));
        Assert.Same(service, host.GetService(typeof(object)));
    }

    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_AddService_InvokeObjectCallback_GetServiceReturnsExpected(bool promote)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        object service = new();
        ServiceCreatorCallback callback = (container, serviceType) => service;
        host.AddService(typeof(object), callback, promote);
        Assert.Same(service, surface.ServiceContainer.GetService(typeof(object)));
        Assert.Same(service, surface.GetService(typeof(object)));
        Assert.Same(service, host.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_AddService_InvokeDisposed_ThrowsObjectDisposedException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.Dispose();
        ServiceCreatorCallback callback = (container, service) => new object();
        Assert.Throws<ObjectDisposedException>(() => host.AddService(typeof(object), new object()));
        Assert.Throws<ObjectDisposedException>(() => host.AddService(typeof(object), new object(), true));
        Assert.Throws<ObjectDisposedException>(() => host.AddService(typeof(object), new object(), false));
        Assert.Throws<ObjectDisposedException>(() => host.AddService(typeof(object), callback));
        Assert.Throws<ObjectDisposedException>(() => host.AddService(typeof(object), callback, true));
        Assert.Throws<ObjectDisposedException>(() => host.AddService(typeof(object), callback, false));
    }

    [WinFormsFact]
    public void DesignerHost_Dispose_Invoke_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IDisposable disposable = Assert.IsAssignableFrom<IDisposable>(host);
        Assert.Throws<InvalidOperationException>(disposable.Dispose);
    }

    [WinFormsFact(Skip = "Unstable test, see: https://github.com/dotnet/winforms/issues/1460")]
    public void DesignerHost_Add_DesignerDisposeThrowsDuringUnloadingDispose_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.BeginLoad(typeof(RootDesignerComponent));

        using ThrowingDesignerDisposeComponent component = new();
        host.Container.Add(component);
        Assert.Throws<InvalidOperationException>(surface.Dispose);
        Assert.False(surface.IsLoaded);
        Assert.Empty(surface.LoadErrors);
        Assert.False(host.Loading);
    }

    [WinFormsFact(Skip = "Unstable test, see: https://github.com/dotnet/winforms/issues/1151")]
    public void DesignerHost_Add_ComponentDisposeThrowsDuringUnloadingDispose_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.BeginLoad(typeof(RootDesignerComponent));

        using ThrowingDisposeDesignerComponent component = new();
        host.Container.Add(component);
        Assert.Throws<InvalidOperationException>(surface.Dispose);
        Assert.False(surface.IsLoaded);
        Assert.Empty(surface.LoadErrors);
        Assert.False(host.Loading);
    }

    [WinFormsFact(Skip = "Unstable test, see: https://github.com/dotnet/winforms/issues/1460")]
    public void DesignerHost_Add_RootDesignerDisposeThrowsDuringUnloadingDispose_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.BeginLoad(typeof(ThrowingRootDesignerDisposeComponent));

        Assert.Throws<InvalidOperationException>(surface.Dispose);
        Assert.False(surface.IsLoaded);
        Assert.Empty(surface.LoadErrors);
        Assert.False(host.Loading);
    }

    [WinFormsFact(Skip = "Unstable test, see: https://github.com/dotnet/winforms/issues/1460")]
    public void DesignerHost_Add_RootComponentDisposeThrowsDuringUnloadingDispose_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.BeginLoad(typeof(ThrowingDisposeRootDesignerComponent));
        Assert.Throws<InvalidOperationException>(surface.Dispose);
        Assert.False(surface.IsLoaded);
        Assert.Empty(surface.LoadErrors);
        Assert.False(host.Loading);
    }

    [WinFormsFact]
    public void DesignerHost_CreateComponent_NullComponentType_ThrowsArgumentNullException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Throws<ArgumentNullException>("componentType", () => host.CreateComponent(null));
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_Invoke_ReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction();
        Assert.False(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal("No Description Available", transaction1.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("No Description Available", host.TransactionDescription);

        DesignerTransaction transaction2 = host.CreateTransaction();
        Assert.False(transaction2.Canceled);
        Assert.False(transaction2.Committed);
        Assert.Equal("No Description Available", transaction2.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("No Description Available", host.TransactionDescription);

        transaction2.Cancel();
    }

    [WinFormsTheory]
    [InlineData(null, "No Description Available")]
    [InlineData("", "")]
    [InlineData("Description", "Description")]
    public void DesignerHost_CreateTransaction_InvokeWithDescription_ReturnsExpected(string description, string expectedDescription)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction(description);
        Assert.False(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal(expectedDescription, transaction1.Description);
        Assert.True(host.InTransaction);
        Assert.Equal(expectedDescription, host.TransactionDescription);

        DesignerTransaction transaction2 = host.CreateTransaction("CustomDescription");
        Assert.False(transaction2.Canceled);
        Assert.False(transaction2.Committed);
        Assert.Equal("CustomDescription", transaction2.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("CustomDescription", host.TransactionDescription);

        transaction2.Cancel();
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_InvokeWithTransactionOpeningAndTransactionOpened_CallsHandlers()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        int openingCallCount = 0;
        EventHandler openingHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(EventArgs.Empty, e);
            openingCallCount++;
        };
        int openedCallCount = 0;
        EventHandler openedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(EventArgs.Empty, e);
            Assert.True(openedCallCount < openingCallCount);
            openedCallCount++;
        };
        host.TransactionOpening += openingHandler;
        host.TransactionOpened += openedHandler;

        // With handler.
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        Assert.Equal(1, openingCallCount);
        Assert.Equal(1, openedCallCount);

        // Create again.
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");
        Assert.Equal(2, openingCallCount);
        Assert.Equal(2, openedCallCount);

        // Remove handler.
        host.TransactionOpening -= openingHandler;
        host.TransactionOpened -= openedHandler;
        DesignerTransaction transaction3 = host.CreateTransaction("Description2");
        Assert.Equal(2, openingCallCount);
        Assert.Equal(2, openedCallCount);

        transaction3.Cancel();
        transaction2.Cancel();
        transaction1.Cancel();
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_Cancel_Success()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");

        // Cancel first.
        transaction2.Cancel();
        Assert.False(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal("Description1", transaction1.Description);
        Assert.True(transaction2.Canceled);
        Assert.False(transaction2.Committed);
        Assert.Equal("Description2", transaction2.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("Description1", host.TransactionDescription);

        // Cancel again.
        transaction2.Cancel();
        Assert.False(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal("Description1", transaction1.Description);
        Assert.True(transaction2.Canceled);
        Assert.False(transaction2.Committed);
        Assert.Equal("Description2", transaction2.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("Description1", host.TransactionDescription);

        // Cancel second.
        transaction1.Cancel();
        Assert.True(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal("Description1", transaction1.Description);
        Assert.True(transaction2.Canceled);
        Assert.False(transaction2.Committed);
        Assert.Equal("Description2", transaction2.Description);
        Assert.False(host.InTransaction);
        host.TransactionDescription.Should().BeNullOrEmpty();
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_CancelWithTransactionClosingAndTransactionClosed_CallsHandlers()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");

        bool expectedLastTransaction = false;
        int closingCallCount = 0;
        DesignerTransactionCloseEventHandler closingHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.False(e.TransactionCommitted);
            Assert.Equal(expectedLastTransaction, e.LastTransaction);
            closingCallCount++;
        };
        int closedCallCount = 0;
        DesignerTransactionCloseEventHandler closedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.False(e.TransactionCommitted);
            Assert.Equal(expectedLastTransaction, e.LastTransaction);
            Assert.True(closedCallCount < closingCallCount);
            closedCallCount++;
        };
        host.TransactionClosing += closingHandler;
        host.TransactionClosed += closedHandler;

        // With handler.
        transaction2.Cancel();
        Assert.False(transaction1.Canceled);
        Assert.True(transaction2.Canceled);
        Assert.Equal(1, closingCallCount);
        Assert.Equal(1, closedCallCount);

        // Cancel again.
        transaction2.Cancel();
        Assert.False(transaction1.Canceled);
        Assert.True(transaction2.Canceled);
        Assert.Equal(1, closingCallCount);
        Assert.Equal(1, closedCallCount);

        // Cancel second.
        expectedLastTransaction = true;
        transaction1.Cancel();
        Assert.True(transaction1.Canceled);
        Assert.True(transaction2.Canceled);
        Assert.Equal(2, closingCallCount);
        Assert.Equal(2, closedCallCount);

        // Remove handler.
        host.TransactionClosing -= closingHandler;
        host.TransactionClosed -= closedHandler;
        DesignerTransaction transaction3 = host.CreateTransaction("Description1");
        transaction3.Cancel();
        Assert.True(transaction3.Canceled);
        Assert.Equal(2, closingCallCount);
        Assert.Equal(2, closedCallCount);
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_CancelNested_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");
        Assert.Throws<InvalidOperationException>(transaction1.Cancel);
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_Commit_Success()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");

        // Commit first.
        transaction2.Commit();
        Assert.False(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal("Description1", transaction1.Description);
        Assert.False(transaction2.Canceled);
        Assert.True(transaction2.Committed);
        Assert.Equal("Description2", transaction2.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("Description1", host.TransactionDescription);

        // Commit again.
        transaction2.Commit();
        Assert.False(transaction1.Canceled);
        Assert.False(transaction1.Committed);
        Assert.Equal("Description1", transaction1.Description);
        Assert.False(transaction2.Canceled);
        Assert.True(transaction2.Committed);
        Assert.Equal("Description2", transaction2.Description);
        Assert.True(host.InTransaction);
        Assert.Equal("Description1", host.TransactionDescription);

        // Commit second.
        transaction1.Commit();
        Assert.False(transaction1.Canceled);
        Assert.True(transaction1.Committed);
        Assert.Equal("Description1", transaction1.Description);
        Assert.False(transaction2.Canceled);
        Assert.True(transaction2.Committed);
        Assert.Equal("Description2", transaction2.Description);
        Assert.False(host.InTransaction);
        host.TransactionDescription.Should().BeNullOrEmpty();
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_CommitWithTransactionClosingAndTransactionClosed_CallsHandlers()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");

        bool expectedLastTransaction = false;
        int closingCallCount = 0;
        DesignerTransactionCloseEventHandler closingHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.True(e.TransactionCommitted);
            Assert.Equal(expectedLastTransaction, e.LastTransaction);
            closingCallCount++;
        };
        int closedCallCount = 0;
        DesignerTransactionCloseEventHandler closedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.True(e.TransactionCommitted);
            Assert.Equal(expectedLastTransaction, e.LastTransaction);
            Assert.True(closedCallCount < closingCallCount);
            closedCallCount++;
        };
        host.TransactionClosing += closingHandler;
        host.TransactionClosed += closedHandler;

        // With handler.
        transaction2.Commit();
        Assert.False(transaction1.Committed);
        Assert.True(transaction2.Committed);
        Assert.Equal(1, closingCallCount);
        Assert.Equal(1, closedCallCount);

        // Commit again.
        transaction2.Commit();
        Assert.False(transaction1.Committed);
        Assert.True(transaction2.Committed);
        Assert.Equal(1, closingCallCount);
        Assert.Equal(1, closedCallCount);

        // Commit second.
        expectedLastTransaction = true;
        transaction1.Commit();
        Assert.True(transaction1.Committed);
        Assert.True(transaction2.Committed);
        Assert.Equal(2, closingCallCount);
        Assert.Equal(2, closedCallCount);

        // Remove handler.
        host.TransactionClosing -= closingHandler;
        host.TransactionClosed -= closedHandler;
        DesignerTransaction transaction3 = host.CreateTransaction("Description1");
        transaction3.Commit();
        Assert.True(transaction3.Committed);
        Assert.Equal(2, closingCallCount);
        Assert.Equal(2, closedCallCount);
    }

    [WinFormsFact]
    public void DesignerHost_CreateTransaction_CommitNested_ThrowsInvalidOperationException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        DesignerTransaction transaction1 = host.CreateTransaction("Description1");
        DesignerTransaction transaction2 = host.CreateTransaction("Description2");
        Assert.Throws<InvalidOperationException>(transaction1.Commit);
    }

    public static IEnumerable<object[]> DesignerHost_EndLoad_TestData()
    {
        yield return new object[] { null, true, null };
        yield return new object[] { null, true, Array.Empty<object>() };
        yield return new object[] { null, true, new object[] { new InvalidOperationException() } };
        yield return new object[] { null, true, new object[] { "abc" } };
        yield return new object[] { null, true, new object[] { null } };
        yield return new object[] { null, false, null };
        yield return new object[] { null, false, Array.Empty<object>() };
        yield return new object[] { null, false, new object[] { new InvalidOperationException() } };
        yield return new object[] { null, false, new object[] { "abc" } };
        yield return new object[] { null, false, new object[] { null } };
        yield return new object[] { string.Empty, true, null };
        yield return new object[] { string.Empty, true, Array.Empty<object>() };
        yield return new object[] { string.Empty, true, new object[] { new InvalidOperationException() } };
        yield return new object[] { string.Empty, true, new object[] { "abc" } };
        yield return new object[] { string.Empty, true, new object[] { null } };
        yield return new object[] { string.Empty, false, null };
        yield return new object[] { string.Empty, false, Array.Empty<object>() };
        yield return new object[] { string.Empty, false, new object[] { new InvalidOperationException() } };
        yield return new object[] { string.Empty, false, new object[] { "abc" } };
        yield return new object[] { string.Empty, false, new object[] { null } };
        yield return new object[] { "baseClassName", true, null };
        yield return new object[] { "baseClassName", true, new object[] { new InvalidOperationException() } };
        yield return new object[] { "baseClassName", true, new object[] { "abc" } };
        yield return new object[] { "baseClassName", true, new object[] { null } };
        yield return new object[] { "baseClassName", false, null };
        yield return new object[] { "baseClassName", false, new object[] { new InvalidOperationException() } };
        yield return new object[] { "baseClassName", false, new object[] { "abc" } };
        yield return new object[] { "baseClassName", false, new object[] { null } };
    }

    [WinFormsTheory]
    [MemberData(nameof(DesignerHost_EndLoad_TestData))]
    public void DesignerHost_EndLoad_NotCalledBeginLoad_Success(string baseClassName, bool successful, ICollection errorCollection)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        host.EndLoad(baseClassName, successful, errorCollection);
        Assert.False(surface.IsLoaded);
        Assert.False(host.Loading);
        Assert.Empty(surface.LoadErrors);
        Assert.Null(host.RootComponent);
        Assert.Same(baseClassName, host.RootComponentClassName);
    }

    [WinFormsFact]
    public void DesignerHost_GetComponents_Invoke_ReturnsFiltered()
    {
        ComponentCollection collection = new(new Component[] { new() });
        Mock<ContainerFilterService> mockFilterService = new(MockBehavior.Strict);
        mockFilterService
            .Setup(f => f.FilterComponents(new ComponentCollection(Array.Empty<IComponent>())))
            .Returns(collection);
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(mockFilterService.Object);
        using SubDesignSurface surface = new(mockServiceProvider.Object);
        Assert.Same(collection, surface.ComponentContainer.Components);
    }

    [WinFormsFact]
    public void DesignerHost_GetDesigner_InvokeNonEmpty_ReturnsExpected()
    {
        using SubDesignSurface surface = new();
        IDesignerHost host = surface.Host;
        using RootDesignerComponent component = new();
        host.Container.Add(component);
        Assert.IsType<RootDesigner>(host.GetDesigner(component));
        Assert.Null(host.GetDesigner(new Component()));
        Assert.Null(host.GetDesigner(new RootDesignerComponent()));
    }

    [WinFormsFact]
    public void DesignerHost_GetDesigner_InvokeEmpty_ReturnsExpected()
    {
        using SubDesignSurface surface = new();
        IDesignerHost host = surface.Host;
        Assert.Null(host.GetDesigner(new Component()));
        Assert.Null(host.GetDesigner(new RootDesignerComponent()));
    }

    [WinFormsFact]
    public void DesignerHost_GetDesigner_NullComponent_ThrowsArgumentNullException()
    {
        using SubDesignSurface surface = new();
        IDesignerHost host = surface.Host;
        Assert.Throws<ArgumentNullException>("component", () => host.GetDesigner(null));
    }

    public static IEnumerable<object[]> GetService_InvalidLoader_TestData()
    {
        Mock<DesignerLoader> mockLoader = new(MockBehavior.Strict);
        mockLoader
            .Setup(l => l.BeginLoad(It.IsAny<IDesignerLoaderHost>()));
        yield return new object[] { mockLoader.Object, null };

        Mock<DesignerLoader> mockNullServiceProviderLoader = new(MockBehavior.Strict);
        mockNullServiceProviderLoader
            .Setup(l => l.BeginLoad(It.IsAny<IDesignerLoaderHost>()));
        mockNullServiceProviderLoader
            .As<IServiceProvider>()
            .Setup(p => p.GetService(typeof(IMultitargetHelperService)))
            .Returns(null);
        yield return new object[] { mockNullServiceProviderLoader.Object, null };

        object o = new();
        Mock<DesignerLoader> mockInvalidServiceProviderLoader = new(MockBehavior.Strict);
        mockInvalidServiceProviderLoader
            .Setup(l => l.BeginLoad(It.IsAny<IDesignerLoaderHost>()));
        mockInvalidServiceProviderLoader
            .As<IServiceProvider>()
            .Setup(p => p.GetService(typeof(IMultitargetHelperService)))
            .Returns(o);
        yield return new object[] { mockInvalidServiceProviderLoader.Object, o };
    }

    [WinFormsTheory]
    [MemberData(nameof(GetService_InvalidLoader_TestData))]
    public void DesignerHost_GetService_IMultitargetHelperServiceWithLoader_ReturnsExpected(DesignerLoader loader, object expected)
    {
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IDesignerEventService)))
            .Returns(null);
        SubDesignSurface surface = new(mockServiceProvider.Object);
        surface.BeginLoad(loader);

        IDesignerLoaderHost2 host = surface.Host;
        Assert.Same(expected, host.GetService(typeof(IMultitargetHelperService)));
    }

    [WinFormsFact]
    public void DesignerHost_GetServiceIMultitargetHelperServiceWithoutLoader_ReturnsNull()
    {
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Null(host.GetService(typeof(IMultitargetHelperService)));
    }

    [WinFormsFact]
    public void DesignerHost_GetService_InvokeWithServiceProvider_ReturnsExpected()
    {
        object service = new();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(int)))
            .Returns(service)
            .Verifiable();
        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Same(service, host.GetService(typeof(int)));
        mockServiceProvider.Verify(p => p.GetService(typeof(int)), Times.Once());
    }

    [WinFormsFact]
    public void DesignerHost_GetService_InvokeWithoutServiceProvider_ReturnsNull()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Null(host.GetService(typeof(int)));
    }

    [WinFormsFact]
    public void DesignerHost_GetService_IContainer_ReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Same(host, host.GetService(typeof(IContainer)));
    }

    [WinFormsTheory]
    [InlineData(typeof(IServiceContainer))]
    [InlineData(typeof(ServiceContainer))]
    public void DesignerHost_GetService_IServiceContainer_ReturnsExpected(Type serviceType)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Same(surface.ServiceContainer, host.GetService(serviceType));
    }

    [WinFormsFact]
    public void DesignerHost_GetService_NullType_ThrowsArgumentNullException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        Assert.Throws<ArgumentNullException>("service", () => host.GetService(null));
    }

    [WinFormsTheory]
    [InlineData("", null)]
    [InlineData("", typeof(int))]
    [InlineData("typeName", null)]
    [InlineData("typeName", typeof(int))]
    [InlineData("System.Object", null)]
    [InlineData("System.Object", typeof(int))]
    public void DesignerHost_GetType_InvokeWithTypeResolutionService_ReturnsExpected(string typeName, Type expected)
    {
        Mock<ITypeResolutionService> mockTypeResolutionService = new(MockBehavior.Strict);
        mockTypeResolutionService
            .Setup(s => s.GetType(typeName))
            .Returns(expected)
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(mockTypeResolutionService.Object)
            .Verifiable();
        using SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerHost host = surface.Host;
        Assert.Equal(expected, host.GetType(typeName));
        mockServiceProvider.Verify(p => p.GetService(typeof(ITypeResolutionService)), Times.Once());
        mockTypeResolutionService.Verify(s => s.GetType(typeName), Times.Once());
    }

    public static IEnumerable<object[]> GetType_InvalidTypeResolutionService_TestData()
    {
        yield return new object[] { null };
        yield return new object[] { new() };
    }

    [WinFormsTheory]
    [MemberData(nameof(GetType_InvalidTypeResolutionService_TestData))]
    public void DesignerHost_GetType_InvokeWithInvalidTypeResolutionService_ReturnsExpected(object service)
    {
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(service)
            .Verifiable();
        using SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerHost host = surface.Host;
        Assert.Equal(typeof(int), host.GetType(typeof(int).FullName));
        mockServiceProvider.Verify(p => p.GetService(typeof(ITypeResolutionService)), Times.Once());
    }

    [WinFormsFact]
    public void DesignerHost_GetType_NullTypeName_ThrowsArgumentNullException()
    {
        using SubDesignSurface surface = new();
        IDesignerHost host = surface.Host;
        Assert.Throws<ArgumentNullException>("typeName", () => host.GetType(null));
    }

    private static readonly IDesignerHost s_placeholderHost = new Mock<IDesignerHost>(MockBehavior.Strict).Object;

    public static IEnumerable<object[]> ChangeActiveDesigner_TestData()
    {
        IDesignerLoaderHost2 otherHost = new SubDesignSurface().Host;

        yield return new object[] { null, 0, 0, 0 };

        yield return new object[] { new ActiveDesignerEventArgs(s_placeholderHost, s_placeholderHost), 0, 1, 1 };
        yield return new object[] { new ActiveDesignerEventArgs(s_placeholderHost, otherHost), 0, 1, 1 };
        yield return new object[] { new ActiveDesignerEventArgs(s_placeholderHost, null), 0, 1, 1 };

        yield return new object[] { new ActiveDesignerEventArgs(otherHost, s_placeholderHost), 1, 0, 0 };
        yield return new object[] { new ActiveDesignerEventArgs(otherHost, otherHost), 0, 0, 0 };
        yield return new object[] { new ActiveDesignerEventArgs(otherHost, null), 0, 0, 0 };

        yield return new object[] { new ActiveDesignerEventArgs(null, s_placeholderHost), 1, 0, 0 };
        yield return new object[] { new ActiveDesignerEventArgs(null, otherHost), 0, 0, 0 };
        yield return new object[] { new ActiveDesignerEventArgs(null, null), 0, 0, 0 };
    }

    [WinFormsTheory]
    [MemberData(nameof(ChangeActiveDesigner_TestData))]
    public void DesignerHost_ChangeActiveDesigner_Invoke_Success(ActiveDesignerEventArgs eventArgs, int expectedActivatedCallCount, int expectedDeactivatedCallCount, int expectedFlushCount)
    {
        Mock<IDesignerEventService> mockDesignerEventService = new(MockBehavior.Strict);
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IDesignerEventService)))
            .Returns(mockDesignerEventService.Object);
        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;

        int activatedCallCount = 0;
        EventHandler activatedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(EventArgs.Empty, e);
            activatedCallCount++;
        };
        host.Activated += activatedHandler;
        int deactivatedCallCount = 0;
        EventHandler deactivatedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(EventArgs.Empty, e);
            deactivatedCallCount++;
        };
        host.Deactivated += deactivatedHandler;
        int flushCallCount = 0;
        EventHandler flushedHandler = (sender, e) =>
        {
            Assert.Same(surface, sender);
            Assert.Same(EventArgs.Empty, e);
            flushCallCount++;
        };
        surface.Flushed += flushedHandler;

        Mock<DesignerLoader> mockLoader = new(MockBehavior.Strict);
        mockLoader
            .Setup(l => l.BeginLoad((IDesignerLoaderHost)surface.ComponentContainer));
        mockLoader
            .Setup(l => l.Flush());
        surface.BeginLoad(mockLoader.Object);
        Assert.Equal(0, activatedCallCount);
        Assert.Equal(0, deactivatedCallCount);
        Assert.Equal(0, flushCallCount);

        // Replace placeholders for "this"
        ActiveDesignerEventArgs actualEventArgs = null;
        if (eventArgs is not null)
        {
            IDesignerHost newDesigner = eventArgs.NewDesigner == s_placeholderHost ? host : eventArgs.NewDesigner;
            IDesignerHost oldDesigner = eventArgs.OldDesigner == s_placeholderHost ? host : eventArgs.OldDesigner;
            actualEventArgs = new ActiveDesignerEventArgs(oldDesigner, newDesigner);
        }

        mockDesignerEventService.Raise(s => s.ActiveDesignerChanged += null, actualEventArgs);
        Assert.Equal(expectedActivatedCallCount, activatedCallCount);
        Assert.Equal(expectedDeactivatedCallCount, deactivatedCallCount);
        Assert.Equal(expectedFlushCount, flushCallCount);

        // Should not invoke if removed.
        host.Activated -= activatedHandler;
        host.Deactivated -= deactivatedHandler;
        surface.Flushed -= flushedHandler;
        mockDesignerEventService.Raise(s => s.ActiveDesignerChanged += null, actualEventArgs);
        Assert.Equal(expectedActivatedCallCount, activatedCallCount);
        Assert.Equal(expectedDeactivatedCallCount, deactivatedCallCount);
        Assert.Equal(expectedFlushCount, flushCallCount);
    }

    [WinFormsFact]
    public void DesignerHost_Remove_Invoke_Success()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        using RootDesignerComponent rootComponent = new();
        using DesignerComponent component = new();
        host.Container.Add(rootComponent);
        host.Container.Add(component);
        host.Container.Remove(rootComponent);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Null(host.RootComponent);
        Assert.Null(host.RootComponentClassName);
        Assert.Null(host.GetDesigner(rootComponent));
        Assert.NotNull(host.GetDesigner(component));
        Assert.Null(rootComponent.Container);
        Assert.Null(rootComponent.Site);
        Assert.Same(host.Container, component.Container);
        Assert.NotNull(component.Site);

        // Remove again.
        host.Container.Remove(rootComponent);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Null(host.RootComponent);
        Assert.Null(host.RootComponentClassName);
        Assert.Null(host.GetDesigner(rootComponent));
        Assert.NotNull(host.GetDesigner(component));
        Assert.Null(rootComponent.Container);
        Assert.Null(rootComponent.Site);
        Assert.Same(host.Container, component.Container);
        Assert.NotNull(component.Site);

        // Remove other.
        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        Assert.Null(host.RootComponent);
        Assert.Null(host.RootComponentClassName);
        Assert.Null(host.GetDesigner(rootComponent));
        Assert.Null(host.GetDesigner(component));
        Assert.Null(rootComponent.Container);
        Assert.Null(rootComponent.Site);
        Assert.Null(component.Container);
        Assert.Null(component.Site);
    }

    public static IEnumerable<object[]> Remove_IExtenderProviderServiceWithoutDefault_TestData()
    {
        yield return new object[] { new RootDesignerComponent(), 0, 0 };
        yield return new object[] { new RootExtenderProviderDesignerComponent(), 1, 1 };

        RootExtenderProviderDesignerComponent readOnlyComponent = new();
        TypeDescriptor.AddAttributes(readOnlyComponent, new InheritanceAttribute(InheritanceLevel.InheritedReadOnly));
        yield return new object[] { readOnlyComponent, 0, 1 };

        RootExtenderProviderDesignerComponent inheritedComponent = new();
        TypeDescriptor.AddAttributes(inheritedComponent, new InheritanceAttribute(InheritanceLevel.Inherited));
        yield return new object[] { inheritedComponent, 1, 1 };

        RootExtenderProviderDesignerComponent notInheritedComponent = new();
        TypeDescriptor.AddAttributes(notInheritedComponent, new InheritanceAttribute(InheritanceLevel.NotInherited));
        yield return new object[] { notInheritedComponent, 1, 1 };
    }

    [WinFormsTheory]
    [MemberData(nameof(Remove_IExtenderProviderServiceWithoutDefault_TestData))]
    public void DesignerHost_Remove_IExtenderProviderServiceWithoutDefault_Success(Component component, int expectedAddCallCount, int expectedRemoveCallCount)
    {
        Mock<IExtenderProviderService> mockExtenderProviderService = new(MockBehavior.Strict);
        mockExtenderProviderService
            .Setup(s => s.AddExtenderProvider(component as IExtenderProvider));
        mockExtenderProviderService
            .Setup(s => s.RemoveExtenderProvider(component as IExtenderProvider))
            .Verifiable();
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IExtenderProviderService)))
            .Returns(mockExtenderProviderService.Object)
            .Verifiable();

        using SubDesignSurface surface = new(mockServiceProvider.Object);
        surface.ServiceContainer.RemoveService(typeof(IExtenderProviderService));
        IDesignerLoaderHost2 host = surface.Host;

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Same(host, component.Container);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(expectedAddCallCount));

        // Remove.
        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        Assert.Null(component.Container);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(expectedAddCallCount + expectedRemoveCallCount));
        mockExtenderProviderService.Verify(s => s.RemoveExtenderProvider(component as IExtenderProvider), Times.Exactly(expectedRemoveCallCount));

        // Remove again.
        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        Assert.Null(component.Container);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(expectedAddCallCount + expectedRemoveCallCount));
        mockExtenderProviderService.Verify(s => s.RemoveExtenderProvider(component as IExtenderProvider), Times.Exactly(expectedRemoveCallCount));
    }

    public static IEnumerable<object[]> Remove_IExtenderProviderServiceWithDefault_TestData()
    {
        yield return new object[] { new RootDesignerComponent() };
        yield return new object[] { new RootExtenderProviderDesignerComponent() };

        RootExtenderProviderDesignerComponent readOnlyComponent = new();
        TypeDescriptor.AddAttributes(readOnlyComponent, new InheritanceAttribute(InheritanceLevel.InheritedReadOnly));
        yield return new object[] { readOnlyComponent };

        RootExtenderProviderDesignerComponent inheritedComponent = new();
        TypeDescriptor.AddAttributes(inheritedComponent, new InheritanceAttribute(InheritanceLevel.Inherited));
        yield return new object[] { inheritedComponent };

        RootExtenderProviderDesignerComponent notInheritedComponent = new();
        TypeDescriptor.AddAttributes(notInheritedComponent, new InheritanceAttribute(InheritanceLevel.NotInherited));
        yield return new object[] { notInheritedComponent };
    }

    [WinFormsTheory]
    [MemberData(nameof(Remove_IExtenderProviderServiceWithDefault_TestData))]
    public void DesignerHost_Remove_IExtenderProviderServiceWithDefault_Success(Component component)
    {
        Mock<IExtenderProviderService> mockExtenderProviderService = new(MockBehavior.Strict);
        mockExtenderProviderService
            .Setup(s => s.AddExtenderProvider(component as IExtenderProvider))
            .Verifiable();
        mockExtenderProviderService
            .Setup(s => s.RemoveExtenderProvider(component as IExtenderProvider));
        Mock<IServiceProvider> mockServiceProvider = new(MockBehavior.Strict);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ITypeResolutionService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(TypeDescriptionProviderService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(INameCreationService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(ContainerFilterService)))
            .Returns(null);
        mockServiceProvider
            .Setup(p => p.GetService(typeof(IExtenderProviderService)))
            .Returns(mockExtenderProviderService.Object)
            .Verifiable();

        SubDesignSurface surface = new(mockServiceProvider.Object);
        IDesignerLoaderHost2 host = surface.Host;

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        Assert.Empty(component.Site.Name);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
        mockExtenderProviderService.Verify(s => s.AddExtenderProvider(component as IExtenderProvider), Times.Never());

        // Remove.
        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        Assert.Null(component.Container);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
        mockExtenderProviderService.Verify(s => s.RemoveExtenderProvider(component as IExtenderProvider), Times.Never());

        // Remove again.
        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        Assert.Null(component.Container);
        mockServiceProvider.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
        mockExtenderProviderService.Verify(s => s.RemoveExtenderProvider(component as IExtenderProvider), Times.Never());
    }

    [WinFormsTheory]
    [MemberData(nameof(InvalidIExtenderProviderService_TestData))]
    public void DesignerHost_Remove_InvalidIExtenderProviderServiceWithoutDefault_CallsParentGetService(Mock<IServiceProvider> mockParentProvider)
    {
        using SubDesignSurface surface = new(mockParentProvider?.Object);
        surface.ServiceContainer.RemoveService(typeof(IExtenderProviderService));
        IDesignerLoaderHost2 host = surface.Host;
        using RootExtenderProviderDesignerComponent component = new();

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        mockParentProvider?.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Once());

        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        mockParentProvider?.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Exactly(2));
    }

    [WinFormsTheory]
    [MemberData(nameof(InvalidIExtenderProviderService_TestData))]
    public void DesignerHost_Remove_InvalidIExtenderProviderServiceWithDefault_DoesNotCallParentGetService(Mock<IServiceProvider> mockParentProvider)
    {
        using SubDesignSurface surface = new(mockParentProvider?.Object);
        IDesignerLoaderHost2 host = surface.Host;
        using RootExtenderProviderDesignerComponent component = new();

        host.Container.Add(component);
        Assert.Same(component, Assert.Single(host.Container.Components));
        mockParentProvider?.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());

        host.Container.Remove(component);
        Assert.Empty(host.Container.Components);
        mockParentProvider?.Verify(p => p.GetService(typeof(IExtenderProviderService)), Times.Never());
    }

    [WinFormsFact]
    public void Remove_ComponentNotInContainerNonEmpty_Nop()
    {
        using SubDesignSurface surface1 = new();
        using SubDesignSurface surface2 = new();
        IDesignerLoaderHost2 host1 = surface1.Host;
        IDesignerLoaderHost2 host2 = surface2.Host;

        RootDesignerComponent otherComponent = new();
        using RootDesignerComponent component = new();
        host1.Container.Add(otherComponent);
        host2.Container.Add(component);
        host2.Container.Remove(otherComponent);
        host2.Container.Remove(new Component());
        Assert.Same(otherComponent, Assert.Single(host1.Container.Components));
        Assert.Same(component, Assert.Single(host2.Container.Components));
    }

    [WinFormsFact]
    public void Remove_ComponentNotInContainerEmpty_Nop()
    {
        using SubDesignSurface surface1 = new();
        using SubDesignSurface surface2 = new();
        IDesignerLoaderHost2 host1 = surface1.Host;
        IDesignerLoaderHost2 host2 = surface2.Host;

        using RootDesignerComponent otherComponent = new();
        host1.Container.Add(otherComponent);
        host2.Container.Remove(otherComponent);
        host2.Container.Remove(new Component());
        Assert.Same(otherComponent, Assert.Single(host1.Container.Components));
        Assert.Empty(host2.Container.Components);
    }

    [WinFormsFact]
    public void Remove_InvokeWithComponentRemoved_CallsHandler()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        using RootDesignerComponent component1 = new();
        using DesignerComponent component2 = new();
        int componentRemovingCallCount = 0;
        ComponentEventHandler componentRemovingHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component1, e.Component);
            Assert.NotNull(e.Component.Site);
            componentRemovingCallCount++;
        };
        changeService.ComponentRemoving += componentRemovingHandler;

        int componentRemovedCallCount = 0;
        ComponentEventHandler componentRemovedHandler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component1, e.Component);
            Assert.NotNull(e.Component.Site);
            Assert.True(componentRemovedCallCount < componentRemovingCallCount);
            componentRemovedCallCount++;
        };
        changeService.ComponentRemoved += componentRemovedHandler;

        host.Container.Add(component1);
        host.Container.Add(component2);

        // With handler.
        host.Container.Remove(component1);
        Assert.Null(component1.Container);
        Assert.Null(component1.Site);
        Assert.Same(host.Container, component2.Container);
        Assert.NotNull(component2.Site);
        Assert.Same(component2, Assert.Single(host.Container.Components));
        Assert.Equal(1, componentRemovingCallCount);
        Assert.Equal(1, componentRemovedCallCount);

        // Remove again.
        host.Container.Remove(component1);
        Assert.Null(component1.Container);
        Assert.Null(component1.Site);
        Assert.Same(host.Container, component2.Container);
        Assert.NotNull(component2.Site);
        Assert.Same(component2, Assert.Single(host.Container.Components));
        Assert.Equal(1, componentRemovingCallCount);
        Assert.Equal(1, componentRemovedCallCount);

        // Remove handler.
        changeService.ComponentRemoving -= componentRemovingHandler;
        changeService.ComponentRemoved -= componentRemovedHandler;
        host.Container.Remove(component2);
        Assert.Null(component1.Container);
        Assert.Null(component1.Site);
        Assert.Null(component2.Container);
        Assert.Null(component2.Site);
        Assert.Empty(host.Container.Components);
        Assert.Equal(1, componentRemovingCallCount);
        Assert.Equal(1, componentRemovedCallCount);
    }

    [WinFormsFact]
    public void DesignerHost_Remove_SetSiteToNullInComponentRemoving_Success()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        using RootDesignerComponent component = new();
        int componentRemovingCallCount = 0;
        ComponentEventHandler componentRemovingHandler = (sender, e) =>
        {
            component.Site = null;
            componentRemovingCallCount++;
        };
        changeService.ComponentRemoving += componentRemovingHandler;

        host.Container.Add(component);
        host.Container.Remove(component);
        Assert.Null(component.Container);
        Assert.Null(component.Site);
    }

    [WinFormsFact]
    public void DesignerHost_Remove_SiteHasDictionary_ClearsDictionary()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        using RootDesignerComponent component = new();
        host.Container.Add(component);
        IDictionaryService service = Assert.IsAssignableFrom<IDictionaryService>(component.Site);
        service.SetValue("key", "value");
        Assert.Equal("value", service.GetValue("key"));

        host.Container.Remove(component);
        Assert.Null(service.GetValue("key"));
    }

    [WinFormsFact]
    public void DesignerHost_RemoveService_Invoke_GetServiceReturnsExpected()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        host.AddService(typeof(object), new object());
        host.RemoveService(typeof(object));
        Assert.Null(surface.ServiceContainer.GetService(typeof(object)));
        Assert.Null(surface.GetService(typeof(object)));
        Assert.Null(host.GetService(typeof(object)));
    }

    [WinFormsTheory]
    [BoolData]
    public void DesignerHost_RemoveService_InvokeBool_GetServiceReturnsExpected(bool promote)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;

        host.AddService(typeof(object), new object());
        host.RemoveService(typeof(object), promote);
        Assert.Null(surface.ServiceContainer.GetService(typeof(object)));
        Assert.Null(surface.GetService(typeof(object)));
        Assert.Null(host.GetService(typeof(object)));
    }

    [WinFormsFact]
    public void DesignerHost_RemoveService_InvokeDisposed_ThrowsObjectDisposedException()
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        surface.Dispose();
        ServiceCreatorCallback callback = (container, service) => new object();
        Assert.Throws<ObjectDisposedException>(() => host.RemoveService(typeof(object)));
        Assert.Throws<ObjectDisposedException>(() => host.RemoveService(typeof(object), true));
        Assert.Throws<ObjectDisposedException>(() => host.RemoveService(typeof(object), false));
    }

    public static IEnumerable<object[]> OnComponentChanging_TestData()
    {
        yield return new object[] { null, null };
        yield return new object[] { new(), TypeDescriptor.GetProperties(typeof(string))[0] };
    }

    [WinFormsTheory]
    [MemberData(nameof(OnComponentChanging_TestData))]
    public void DesignerHost_IComponentChangeServiceOnComponentChanging_Invoke_CallsComponentChanging(object component, MemberDescriptor member)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        int callCount = 0;
        ComponentChangingEventHandler handler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component, e.Component);
            Assert.Same(member, e.Member);
            callCount++;
        };
        changeService.ComponentChanging += handler;
        Assert.False(host.Loading);

        // With handler.
        changeService.OnComponentChanging(component, member);
        Assert.Equal(1, callCount);

        // Call again.
        changeService.OnComponentChanging(component, member);
        Assert.Equal(2, callCount);

        // Remove handler.
        changeService.ComponentChanging -= handler;
        changeService.OnComponentChanging(component, member);
        Assert.Equal(2, callCount);
    }

    [WinFormsTheory]
    [MemberData(nameof(OnComponentChanging_TestData))]
    public void DesignerHost_IComponentChangeServiceOnComponentChanging_InvokeLoading_DoesNotCallHandler(object component, MemberDescriptor member)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        int callCount = 0;
        ComponentChangingEventHandler handler = (sender, e) => callCount++;
        changeService.ComponentChanging += handler;
        Mock<DesignerLoader> mockLoader = new(MockBehavior.Strict);
        mockLoader
            .Setup(l => l.BeginLoad(host));
        surface.BeginLoad(mockLoader.Object);
        Assert.True(host.Loading);

        // With handler.
        changeService.OnComponentChanging(component, member);
        Assert.Equal(0, callCount);

        // Call again.
        changeService.OnComponentChanging(component, member);
        Assert.Equal(0, callCount);

        // Remove handler.
        changeService.ComponentChanging -= handler;
        changeService.OnComponentChanging(component, member);
        Assert.Equal(0, callCount);
    }

    public static IEnumerable<object[]> OnComponentChanged_TestData()
    {
        yield return new object[] { null, null, null, null };
        yield return new object[] { new(), TypeDescriptor.GetProperties(typeof(string))[0], new(), new() };
    }

    [WinFormsTheory]
    [MemberData(nameof(OnComponentChanged_TestData))]
    public void DesignerHost_IComponentChangeServiceOnComponentChanged_Invoke_CallsComponentChanged(object component, MemberDescriptor member, object oldValue, object newValue)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        int callCount = 0;
        ComponentChangedEventHandler handler = (sender, e) =>
        {
            Assert.Same(host, sender);
            Assert.Same(component, e.Component);
            Assert.Same(member, e.Member);
            Assert.Same(oldValue, e.OldValue);
            Assert.Same(newValue, e.NewValue);
            callCount++;
        };
        changeService.ComponentChanged += handler;
        Assert.False(host.Loading);

        // With handler.
        changeService.OnComponentChanged(component, member, oldValue, newValue);
        Assert.Equal(1, callCount);

        // Call again.
        changeService.OnComponentChanged(component, member, oldValue, newValue);
        Assert.Equal(2, callCount);

        // Remove handler.
        changeService.ComponentChanged -= handler;
        changeService.OnComponentChanged(component, member, oldValue, newValue);
        Assert.Equal(2, callCount);
    }

    [WinFormsTheory]
    [MemberData(nameof(OnComponentChanged_TestData))]
    public void DesignerHost_IComponentChangeServiceOnComponentChanged_InvokeLoading_DoesNotCallHandler(object component, MemberDescriptor member, object oldValue, object newValue)
    {
        SubDesignSurface surface = new();
        IDesignerLoaderHost2 host = surface.Host;
        IComponentChangeService changeService = Assert.IsAssignableFrom<IComponentChangeService>(host);

        int callCount = 0;
        ComponentChangedEventHandler handler = (sender, e) => callCount++;
        changeService.ComponentChanged += handler;
        Mock<DesignerLoader> mockLoader = new(MockBehavior.Strict);
        mockLoader
            .Setup(l => l.BeginLoad(host));
        surface.BeginLoad(mockLoader.Object);
        Assert.True(host.Loading);

        // With handler.
        changeService.OnComponentChanged(component, member, oldValue, newValue);
        Assert.Equal(0, callCount);

        // Call again.
        changeService.OnComponentChanged(component, member, oldValue, newValue);
        Assert.Equal(0, callCount);

        // Remove handler.
        changeService.ComponentChanged -= handler;
        changeService.OnComponentChanged(component, member, oldValue, newValue);
        Assert.Equal(0, callCount);
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_UnderlyingSystemType_ReturnsExpected()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost), reflect.UnderlyingSystemType);
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetField_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetField(nameof(IDesignerHost.Activate)), reflect.GetField(nameof(IDesignerHost.Activate), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetFields_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetFields(), reflect.GetFields(BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetMember_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetMember(nameof(IDesignerHost.Container)), reflect.GetMember(nameof(IDesignerHost.Container), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetMembers_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetMembers(), reflect.GetMembers(BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetMethod_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetMethod(nameof(IDesignerHost.Activate)), reflect.GetMethod(nameof(IDesignerHost.Activate), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
        Assert.Equal(typeof(IDesignerHost).GetMethod(nameof(IDesignerHost.Activate)), reflect.GetMethod(nameof(IDesignerHost.Activate), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public, null, Array.Empty<Type>(), Array.Empty<ParameterModifier>()));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetMethods_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetMethods(), reflect.GetMethods(BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetProperty_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetProperty(nameof(IDesignerHost.Container)), reflect.GetProperty(nameof(IDesignerHost.Container), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
        Assert.Equal(typeof(IDesignerHost).GetProperty(nameof(IDesignerHost.Container)), reflect.GetProperty(nameof(IDesignerHost.Container), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public, null, typeof(IContainer), Array.Empty<Type>(), Array.Empty<ParameterModifier>()));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_GetProperties_Success()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(typeof(IDesignerHost).GetProperties(), reflect.GetProperties(BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public));
    }

    [WinFormsFact]
    public void DesignerHost_IReflect_InvokeMember_ReturnsExpected()
    {
        using SubDesignSurface surface = new();
        IReflect reflect = Assert.IsAssignableFrom<IReflect>(surface.Host);
        Assert.Equal(surface.Host.Container, reflect.InvokeMember(nameof(IDesignerHost.Container), BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.GetProperty, null, surface.Host, Array.Empty<object>(), Array.Empty<ParameterModifier>(), null, Array.Empty<string>()));
    }

    private class SubDesignSurface : DesignSurface
    {
        public SubDesignSurface() : base()
        {
        }

        public SubDesignSurface(IServiceProvider parentProvider) : base(parentProvider)
        {
        }

        public IDesignerLoaderHost2 Host => Assert.IsAssignableFrom<IDesignerLoaderHost2>(ComponentContainer);

        public new ServiceContainer ServiceContainer => base.ServiceContainer;
    }

    private abstract class CustomDesigner : IDesigner
    {
        protected IComponent _initializedComponent;

        public IComponent Component => _initializedComponent;

        public DesignerVerbCollection Verbs { get; }

        public void DoDefaultAction()
        {
        }

        public void Dispose() => Dispose(true);

        protected virtual void Dispose(bool disposing)
        {
        }

        public abstract void Initialize(IComponent component);
    }

    private class Designer : CustomDesigner
    {
        public override void Initialize(IComponent component) => _initializedComponent = component;
    }

    [Designer(typeof(Designer))]
    private class DesignerComponent : Component
    {
    }

    private class RootDesigner : Designer, IRootDesigner
    {
        public ViewTechnology[] SupportedTechnologies { get; }

        public object GetView(ViewTechnology technology) => throw new NotImplementedException();
    }

    [Designer(typeof(RootDesigner), typeof(IRootDesigner))]
    private class RootDesignerComponent : Component
    {
    }

    [ProjectTargetFramework("ProjectTargetFramework")]
    private class ClassWithProjectTargetFrameworkAttribute
    {
    }

    [Designer(typeof(RootDesigner), typeof(IRootDesigner))]
    private class RootExtenderProviderDesignerComponent : Component, IExtenderProvider
    {
        public bool CanExtend(object extendee) => throw new NotImplementedException();
    }

    private class NonInitializingDesigner : RootDesigner
    {
        public override void Initialize(IComponent component)
        {
        }
    }

    [Designer(typeof(NonInitializingDesigner), typeof(IRootDesigner))]
    private class NonInitializingDesignerComponent : Component
    {
    }

    private class ThrowingInitializingDesigner : RootDesigner
    {
        public override void Initialize(IComponent component)
        {
            throw new DivideByZeroException();
        }
    }

    [Designer(typeof(ThrowingInitializingDesigner), typeof(IRootDesigner))]
    private class ThrowingInitializingDesignerComponent : Component
    {
    }

    private class CheckoutExceptionThrowingInitializingDesigner : RootDesigner
    {
        public override void Initialize(IComponent component)
        {
            throw CheckoutException.Canceled;
        }
    }

    [Designer(typeof(CheckoutExceptionThrowingInitializingDesigner), typeof(IRootDesigner))]
    private class CheckoutExceptionThrowingInitializingDesignerComponent : Component
    {
    }

    private class ThrowingDisposeComponentDesigner : Designer
    {
        protected override void Dispose(bool disposing)
        {
            throw new NotImplementedException();
        }
    }

    [Designer(typeof(ThrowingDisposeComponentDesigner))]
    private class ThrowingDesignerDisposeComponent : Component
    {
    }

    [Designer(typeof(Designer))]
    private class ThrowingDisposeDesignerComponent : Component
    {
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                throw new NotImplementedException();
            }
        }
    }

    private class ThrowingDisposeRootComponentDesigner : RootDesigner
    {
        protected override void Dispose(bool disposing)
        {
            throw new NotImplementedException();
        }
    }

    [Designer(typeof(ThrowingDisposeRootComponentDesigner), typeof(IRootDesigner))]
    private class ThrowingRootDesignerDisposeComponent : Component
    {
    }

    [Designer(typeof(RootDesigner), typeof(IRootDesigner))]
    private class ThrowingDisposeRootDesignerComponent : Component
    {
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                throw new NotImplementedException();
            }
        }
    }

    [Designer(typeof(RootDesigner), typeof(IRootDesigner))]
    private class CustomTypeDescriptionProviderComponent : Component
    {
    }
}
