[Testing] Added a support for the device's theme change

src/Controls/tests/TestCases.HostApp/Issues/ThemeChange.xaml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             Title="ThemeChange"
+             x:Class="Maui.Controls.Sample.Issues.ThemeChange">
+    <VerticalStackLayout>
+        <Label Text="Text visible only in dark mode" AutomationId="labelVisibleOnlyInDarkMode" IsVisible="{AppThemeBinding Dark=True, Light=False}"/>
+        <Label Text="Text visible only in light mode" AutomationId="labelVisibleOnlyInLightMode" IsVisible="{AppThemeBinding Dark=False, Light=True}"/>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/ThemeChange.xaml.cs

@@ -0,0 +1,15 @@
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.None, 2, "UI theme change during the runtime", PlatformAffected.Android | PlatformAffected.iOS)]
+	public partial class ThemeChange : ContentPage
+	{
+		public ThemeChange()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/ThemeChange.cs

@@ -0,0 +1,40 @@
+#if ANDROID || IOS
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class ThemeChange : _IssuesUITest
+	{
+		public override string Issue => "UI theme change during the runtime";
+
+		public ThemeChange(TestDevice device) : base(device)
+		{
+		}
+
+		[Test]
+		[Category(UITestCategories.LifeCycle)]
+		public void AppThemeShouldChange()
+		{
+			try
+			{
+				App.SetLightTheme();
+				_ = App.WaitForElement("labelVisibleOnlyInLightMode");
+
+				App.SetDarkTheme();
+				_ = App.WaitForElement("labelVisibleOnlyInDarkMode");
+				VerifyScreenshot("AppThemeShouldChangeDarkTheme");
+
+				App.SetLightTheme();
+				_ = App.WaitForElement("labelVisibleOnlyInLightMode");
+				VerifyScreenshot("AppThemeShouldChangeLightTheme");
+			}
+			finally
+			{
+				App.SetLightTheme();
+			}
+		}
+	}
+}
+#endif

src/TestUtils/src/UITest.Appium/Actions/AppiumAndroidThemeChangeAction.cs

@@ -0,0 +1,73 @@
+using System.Diagnostics;
+using UITest.Core;
+
+namespace UITest.Appium
+{
+	public class AppiumAndroidThemeChangeAction : ICommandExecutionGroup
+	{
+		const string SetLightTheme = "setLightTheme";
+		const string SetDarkTheme = "setDarkTheme";
+
+		readonly List<string> _commands = new()
+		{
+			SetLightTheme,
+			SetDarkTheme
+		};
+
+		public CommandResponse Execute(string commandName, IDictionary<string, object> parameters)
+		{
+			if (commandName == SetLightTheme)
+			{
+				ExecuteAdbCommand($"adb shell cmd uimode night no");
+				return CommandResponse.SuccessEmptyResponse;
+			}
+			else if (commandName == SetDarkTheme)
+			{
+				ExecuteAdbCommand($"adb shell cmd uimode night yes");
+				return CommandResponse.SuccessEmptyResponse;
+			}
+
+			return CommandResponse.FailedEmptyResponse;
+		}
+
+		public bool IsCommandSupported(string commandName)
+		{
+			return _commands.Contains(commandName, StringComparer.OrdinalIgnoreCase);
+		}
+
+		private static void ExecuteAdbCommand(string command)
+		{
+			var shell = GetShell();
+			var shellArgument = GetShellArgument(shell, command);
+
+			var processInfo = new ProcessStartInfo(shell, shellArgument)
+			{
+				CreateNoWindow = true,
+				UseShellExecute = false,
+				RedirectStandardOutput = true,
+				RedirectStandardError = true
+			};
+
+			var process = new Process { StartInfo = processInfo };
+
+			process.Start();
+			process.WaitForExit();
+		}
+
+		private static string GetShell()
+		{
+			if (Environment.OSVersion.Platform == PlatformID.Win32NT)
+				return "cmd.exe";
+			else
+				return "/bin/bash";
+		}
+
+		private static string GetShellArgument(string shell, string command)
+		{
+			if (shell == "cmd.exe")
+				return $"/C {command}";
+			else
+				return $"-c \"{command}\"";
+		}
+	}
+}

src/TestUtils/src/UITest.Appium/Actions/AppiumIOSThemeChangeAction.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Diagnostics;
+using UITest.Core;
+
+namespace UITest.Appium
+{
+	public class AppiumIOSThemeChangeAction : ICommandExecutionGroup
+	{
+		const string SetLightTheme = "setLightTheme";
+		const string SetDarkTheme = "setDarkTheme";
+
+		protected readonly AppiumApp _app;
+
+		public AppiumIOSThemeChangeAction(AppiumApp app)
+		{
+			_app = app;
+		}
+
+		readonly List<string> _commands = new()
+		{
+			SetLightTheme,
+			SetDarkTheme
+		};
+
+		public CommandResponse Execute(string commandName, IDictionary<string, object> parameters)
+		{
+			if (commandName == SetLightTheme)
+			{
+				var args = new Dictionary<string, string> { { "style", "light" } };
+				_app.Driver.ExecuteScript("mobile: setAppearance", args);
+				return CommandResponse.SuccessEmptyResponse;
+			}
+			else if(commandName == SetDarkTheme)
+			{
+				var args = new Dictionary<string, string> { { "style", "dark" } };
+				_app.Driver.ExecuteScript("mobile: setAppearance", args);
+				return CommandResponse.SuccessEmptyResponse;
+			}
+
+			return CommandResponse.FailedEmptyResponse;
+		}
+
+		public bool IsCommandSupported(string commandName)
+		{
+			return _commands.Contains(commandName, StringComparer.OrdinalIgnoreCase);
+		}
+	}
+}
+

src/TestUtils/src/UITest.Appium/AppiumAndroidApp.cs

@@ -10,6 +10,7 @@ public class AppiumAndroidApp : AppiumApp, IAndroidApp
 		private AppiumAndroidApp(Uri remoteAddress, IConfig config)
 			: base(new AndroidDriver(remoteAddress, GetOptions(config)), config)
 		{
+			_commandExecutor.AddCommandGroup(new AppiumAndroidThemeChangeAction());
 			_commandExecutor.AddCommandGroup(new AppiumAndroidVirtualKeyboardActions(this));
 			_commandExecutor.AddCommandGroup(new AppiumAndroidAlertActions(this));
 		}

src/TestUtils/src/UITest.Appium/AppiumIOSApp.cs

@@ -14,7 +14,9 @@ public AppiumIOSApp(Uri remoteAddress, IConfig config)
 			_commandExecutor.AddCommandGroup(new AppiumIOSMouseActions(this));
 			_commandExecutor.AddCommandGroup(new AppiumIOSTouchActions(this));
 			_commandExecutor.AddCommandGroup(new AppiumIOSVirtualKeyboardActions(this));
+			_commandExecutor.AddCommandGroup(new AppiumIOSThemeChangeAction(this));
 			_commandExecutor.AddCommandGroup(new AppiumIOSAlertActions(this));
+			_commandExecutor.AddCommandGroup(new AppiumIOSThemeChangeAction(this));
 		}
 
 		public override ApplicationState AppState

src/TestUtils/src/UITest.Appium/HelperExtensions.cs

@@ -831,6 +831,34 @@ public static TestDevice GetTestDevice(this IApp app)
 			return aaa.Config.GetProperty<TestDevice>("TestDevice");
 		}
 
+		/// <summary>
+		/// Sets light device's theme
+		/// </summary>
+		/// <param name="app">Represents the main gateway to interact with an app.</param>
+		public static void SetLightTheme(this IApp app)
+		{
+			if (app is not AppiumAndroidApp && app is not AppiumIOSApp)
+			{
+				throw new InvalidOperationException($"SetLightTheme is not supported");
+			}
+
+			app.CommandExecutor.Execute("setLightTheme", ImmutableDictionary<string, object>.Empty);
+		}
+
+		/// <summary>
+		/// Sets dark device's theme
+		/// </summary>
+		/// <param name="app">Represents the main gateway to interact with an app.</param>
+		public static void SetDarkTheme(this IApp app)
+		{
+			if (app is not AppiumAndroidApp && app is not AppiumIOSApp)
+			{
+				throw new InvalidOperationException($"SetDarkTheme is not supported");
+			}
+
+			app.CommandExecutor.Execute("setDarkTheme", ImmutableDictionary<string, object>.Empty);
+		}
+
 		/// <summary>
 		/// Check if element has focused
 		/// </summary>