Added a NativeMenu test for macOS.

samples/IntegrationTestApp/MainWindow.axaml

@@ -5,12 +5,20 @@
         mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="IntegrationTestApp.MainWindow"
         Title="IntegrationTestApp">
+  <NativeMenu.Menu>
+    <NativeMenu>
+      <NativeMenuItem Header="File">
+        <NativeMenu>
+          <NativeMenuItem Header="Open..."/>
+        </NativeMenu>
+      </NativeMenuItem>
+      <NativeMenuItem Header="View">
+        <NativeMenu/>
+      </NativeMenuItem>  
+    </NativeMenu>
+  </NativeMenu.Menu>
   <DockPanel>
-    <Menu DockPanel.Dock="Top">
-      <MenuItem Name="FileMenu" Header="_File">
-        <MenuItem Name="OpenMenu" Header="_Open..." InputGesture="Ctrl+O"/>
-      </MenuItem>
-    </Menu>
+    <NativeMenuBar DockPanel.Dock="Top"/>
     <TabControl TabStripPlacement="Left" Name="MainTabs">
       <TabItem Header="Automation">
         <StackPanel>

samples/IntegrationTestApp/MainWindow.axaml.cs

@@ -1,3 +1,4 @@
+using System;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
@@ -9,6 +10,7 @@ namespace IntegrationTestApp
         public MainWindow()
         {
             InitializeComponent();
+            InitializeViewMenu();
             this.AttachDevTools();
         }
 
@@ -16,5 +18,24 @@ namespace IntegrationTestApp
         {
             AvaloniaXamlLoader.Load(this);
         }
+
+        private void InitializeViewMenu()
+        {
+            var mainTabs = this.FindControl<TabControl>("MainTabs");
+            var viewMenu = (NativeMenuItem)NativeMenu.GetMenu(this).Items[1];
+
+            foreach (TabItem tabItem in mainTabs.Items)
+            {
+                var menuItem = new NativeMenuItem
+                {
+                    Header = (string)tabItem.Header!,
+                    IsChecked = tabItem.IsSelected,
+                    ToggleType = NativeMenuItemToggleType.Radio,
+                };
+
+                menuItem.Click += (s, e) => tabItem.IsSelected = true;
+                viewMenu.Menu.Items.Add(menuItem);
+            }
+        }
     }
 }

tests/Avalonia.IntegrationTests.Appium/AutomationTests.cs

@@ -6,7 +6,7 @@ namespace Avalonia.IntegrationTests.Appium
     [Collection("Default")]
     public class AutomationTests
     {
-        private AppiumDriver<AppiumWebElement> _session;
+        private readonly AppiumDriver<AppiumWebElement> _session;
 
         public AutomationTests(TestAppFixture fixture)
         {

tests/Avalonia.IntegrationTests.Appium/ButtonTests.cs

@@ -7,7 +7,7 @@ namespace Avalonia.IntegrationTests.Appium
     [Collection("Default")]
     public class ButtonTests
     {
-        private AppiumDriver<AppiumWebElement> _session;
+        private readonly AppiumDriver<AppiumWebElement> _session;
 
         public ButtonTests(TestAppFixture fixture)
         {

tests/Avalonia.IntegrationTests.Appium/ComboBoxTests.cs

@@ -7,7 +7,7 @@ namespace Avalonia.IntegrationTests.Appium
     [Collection("Default")]
     public class ComboBoxTests
     {
-        private AppiumDriver<AppiumWebElement> _session;
+        private readonly AppiumDriver<AppiumWebElement> _session;
 
         public ComboBoxTests(TestAppFixture fixture)
         {

tests/Avalonia.IntegrationTests.Appium/MenuTests.cs

@@ -6,7 +6,7 @@ namespace Avalonia.IntegrationTests.Appium
     [Collection("Default")]
     public class MenuTests
     {
-        private AppiumDriver<AppiumWebElement> _session;
+        private readonly AppiumDriver<AppiumWebElement> _session;
 
         public MenuTests(TestAppFixture fixture) => _session = fixture.Session;
 
@@ -19,7 +19,7 @@ namespace Avalonia.IntegrationTests.Appium
         }
 
         [PlatformFact(SkipOnOSX = true)]
-        public void Open()
+        public void OpenMenu_AcceleratorKey()
         {
             var fileMenu = _session.FindElementByAccessibilityId("FileMenu");
             fileMenu.Click();

tests/Avalonia.IntegrationTests.Appium/NativeMenuTests.cs

@@ -0,0 +1,37 @@
+using OpenQA.Selenium.Appium;
+using Xunit;
+
+namespace Avalonia.IntegrationTests.Appium
+{
+    [Collection("Default")]
+    public class NativeMenuTests
+    {
+        private readonly AppiumDriver<AppiumWebElement> _session;
+
+        public NativeMenuTests(TestAppFixture fixture)
+        {
+            _session = fixture.Session;
+
+            var tabs = _session.FindElementByAccessibilityId("MainTabs");
+            var tab = tabs.FindElementByName("Automation");
+            tab.Click();
+        }
+
+        [PlatformFact(SkipOnWindows = true)]
+        public void View_Menu_Select_Button_Tab()
+        {
+            var tabs = _session.FindElementByAccessibilityId("MainTabs");
+            var buttonTab = tabs.FindElementByName("Button");
+            var menuBar = _session.FindElementByXPath("/XCUIElementTypeApplication/XCUIElementTypeMenuBar");
+            var viewMenu = menuBar.FindElementByName("View");
+            
+            Assert.False(buttonTab.Selected);
+            
+            viewMenu.Click();
+            var buttonMenu = viewMenu.FindElementByName("Button");
+            buttonMenu.Click();
+
+            Assert.True(buttonTab.Selected);
+        }
+    }
+}