Avalonia/tests/Perspex.LeakTests/ControlTests.cs

// Copyright (c) The Perspex Project. All rights reserved.
// Licensed under the MIT license. See licence.md file in the project root for full license information.

using System;
using System.Collections.Generic;
using System.Linq;
using JetBrains.dotMemoryUnit;
using Perspex.Controls;
using Perspex.Controls.Primitives;
using Perspex.Controls.Templates;
using Perspex.VisualTree;
using Xunit;
using Xunit.Abstractions;

namespace Perspex.LeakTests
{
    [DotMemoryUnit(FailIfRunWithoutSupport = false)]
    public class ControlTests
    {
        public ControlTests(ITestOutputHelper atr)
        {
            TestApp.Initialize();
            DotMemoryUnitTestOutput.SetOutputMethod(atr.WriteLine);
        }

        [Fact]
        public void Canvas_Is_Freed()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    Content = new Canvas()
                };

                // Do a layout and make sure that Canvas gets added to visual tree.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<Canvas>(window.Presenter.Child);

                // Clear the content and ensure the Canvas is removed.
                window.Content = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Null(window.Presenter.Child);

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<Canvas>()).ObjectsCount));
        }

        [Fact]
        public void Named_Canvas_Is_Freed()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    Content = new Canvas
                    {
                        Name = "foo"
                    }
                };

                // Do a layout and make sure that Canvas gets added to visual tree.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<Canvas>(window.Find<Canvas>("foo"));
                Assert.IsType<Canvas>(window.Presenter.Child);

                // Clear the content and ensure the Canvas is removed.
                window.Content = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Null(window.Presenter.Child);

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<Canvas>()).ObjectsCount));
        }

        [Fact]
        public void Templated_Child_Is_Freed_When_Template_Cleared()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    Content = new TestTemplatedControl()
                };

                // Do a layout and make sure that the control gets added to visual tree and its
                // template applied.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<TestTemplatedControl>(window.Presenter.Child);
                Assert.IsType<Canvas>(window.Presenter.Child.GetVisualChildren().SingleOrDefault());

                // Clear the template and ensure the control template gets removed
                ((TestTemplatedControl)window.Content).Template = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Equal(0, window.Presenter.Child.GetVisualChildren().Count());

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<Canvas>()).ObjectsCount));
        }

        [Fact]
        public void ScrollViewer_With_Content_Is_Freed()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    Content = new ScrollViewer
                    {
                        Content = new Canvas()
                    }
                };

                // Do a layout and make sure that ScrollViewer gets added to visual tree and its 
                // template applied.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<ScrollViewer>(window.Presenter.Child);
                Assert.IsType<Canvas>(((ScrollViewer)window.Presenter.Child).Presenter.Child);

                // Clear the content and ensure the ScrollViewer is removed.
                window.Content = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Null(window.Presenter.Child);

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<TextBox>()).ObjectsCount));
            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<Canvas>()).ObjectsCount));
        }

        [Fact]
        public void TextBox_Is_Freed()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    Content = new TextBox()
                };

                // Do a layout and make sure that TextBox gets added to visual tree and its 
                // template applied.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<TextBox>(window.Presenter.Child);
                Assert.NotEqual(0, window.Presenter.Child.GetVisualChildren().Count());

                // Clear the content and ensure the TextBox is removed.
                window.Content = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Null(window.Presenter.Child);

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<TextBox>()).ObjectsCount));
        }

        [Fact]
        public void TextBox_With_Xaml_Binding_Is_Freed()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    DataContext = new Node { Name = "foo" },
                    Content = new TextBox()
                };

                var binding = new Perspex.Markup.Xaml.Data.Binding
                {
                    Path = "Name"
                };

                var textBox = (TextBox)window.Content;
                textBox.Bind(TextBox.TextProperty, binding);

                // Do a layout and make sure that TextBox gets added to visual tree and its 
                // Text property set.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<TextBox>(window.Presenter.Child);
                Assert.Equal("foo", ((TextBox)window.Presenter.Child).Text);

                // Clear the content and DataContext and ensure the TextBox is removed.
                window.Content = null;
                window.DataContext = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Null(window.Presenter.Child);

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<TextBox>()).ObjectsCount));
            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<Node>()).ObjectsCount));
        }

        [Fact]
        public void TextBox_ScrollViewer_Is_Freed_When_Template_Cleared()
        {
            Func<Window> run = () =>
            {
                var window = new Window
                {
                    Content = new TextBox()
                };

                // Do a layout and make sure that TextBox gets added to visual tree and its 
                // template applied.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.IsType<TextBox>(window.Presenter.Child);
                Assert.NotEqual(0, window.Presenter.Child.GetVisualChildren().Count());

                // Clear the template and ensure the TextBox template gets removed
                ((TextBox)window.Content).Template = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Equal(0, window.Presenter.Child.GetVisualChildren().Count());

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<ScrollViewer>()).ObjectsCount));
        }

        [Fact]
        public void TreeView_Is_Freed()
        {
            Func<Window> run = () =>
            {
                var nodes = new[]
                {
                    new Node
                    {
                        Children = new[] { new Node() },
                    }
                };

                TreeView target;

                var window = new Window
                {
                    Content = target = new TreeView
                    {
                        DataTemplates = new DataTemplates
                        {
                            new FuncTreeDataTemplate<Node>(
                                x => new TextBlock { Text = x.Name },
                                x => x.Children)
                        },
                        Items = nodes
                    }
                };

                // Do a layout and make sure that TreeViewItems get realized.
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Equal(1, target.ItemContainerGenerator.Containers.Count());

                // Clear the content and ensure the TreeView is removed.
                window.Content = null;
                window.LayoutManager.ExecuteLayoutPass();
                Assert.Null(window.Presenter.Child);

                return window;
            };

            var result = run();

            dotMemory.Check(memory =>
                Assert.Equal(0, memory.GetObjects(where => where.Type.Is<TreeView>()).ObjectsCount));
        }

        private class TestTemplatedControl : TemplatedControl
        {
            public static readonly StyledProperty<int> IsCanvasVisibleProperty =
                PerspexProperty.Register<TestTemplatedControl, int>("IsCanvasVisible");

            public TestTemplatedControl()
            {
                Template = new FuncControlTemplate<TestTemplatedControl>(parent =>
                    new Canvas
                    {
                        [~IsVisibleProperty] = parent[~IsCanvasVisibleProperty]
                    });
            }
        }

        private class Node
        {
            public string Name { get; set; }
            public IEnumerable<Node> Children { get; set; }
        }
    }
}