dotnet-maui-testing（dotnet 毛伊岛测试）

dotnet-maui-testing

Testing.NET MAUI applications using Appium for UI automation and XHarness for cross-platform test execution. Covers device and emulator testing, platform-specific behavior validation, element location strategies for MAUI controls, and test infrastructure for mobile/desktop apps.

Version assumptions:.NET 8.0+ baseline, Appium 2.x with UIAutomator2 (Android) and XCUITest (iOS) drivers, XHarness 1.x. Examples use the latest Appium.NET client (5.x+).

Out of scope: Shared UI testing patterns (page object model, wait strategies) are in [skill:dotnet-ui-testing-core]. Browser-based testing is covered by [skill:dotnet-playwright]. Test project scaffolding is owned by [skill:dotnet-add-testing].

Prerequisites: MAUI test project scaffolded via [skill:dotnet-add-testing]. Appium server installed (npm install -g appium). For Android: Android SDK with emulator configured. For iOS: Xcode with simulator (macOS only). For Windows: WinAppDriver installed.

Cross-references: [skill:dotnet-ui-testing-core] for page object model, test selectors, and async wait patterns, [skill:dotnet-xunit] for xUnit fixtures and test organization, [skill:dotnet-maui-development] for MAUI project structure, XAML/MVVM patterns, and platform services, [skill:dotnet-maui-aot] for Native AOT on iOS/Mac Catalyst and AOT build testing considerations.

Appium Setup for MAUI

Packages

<PackageReference Include="Appium.WebDriver" Version="5.*" />
<PackageReference Include="xunit.v3" Version="3.2.2" />
<PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />

Driver Initialization

public class AppiumFixture : IAsyncLifetime
{
    public AppiumDriver Driver { get; private set; } = null!;

    public ValueTask InitializeAsync()
    {
        var options = new AppiumOptions();

        if (OperatingSystem.IsAndroid() || TestConfig.TargetPlatform == "Android")
        {
            options.PlatformName = "Android";
            options.AutomationName = "UiAutomator2";
            options.App = TestConfig.AndroidApkPath;
            options.AddAdditionalAppiumOption("deviceName", "Pixel_7_API_34");
            options.AddAdditionalAppiumOption("avd", "Pixel_7_API_34");
        }
        else if (OperatingSystem.IsIOS() || TestConfig.TargetPlatform == "iOS")
        {
            options.PlatformName = "iOS";
            options.AutomationName = "XCUITest";
            options.App = TestConfig.iOSAppPath;
            options.AddAdditionalAppiumOption("deviceName", "iPhone 15");
            options.AddAdditionalAppiumOption("platformVersion", "17.2");
        }
        else if (OperatingSystem.IsWindows() || TestConfig.TargetPlatform == "Windows")
        {
            options.PlatformName = "Windows";
            options.AutomationName = "Windows";
            options.App = TestConfig.WindowsAppPath;
        }

        Driver = new AppiumDriver(
            new Uri("http://localhost:4723"), options);

        // Explicit waits only -- do not set ImplicitWait (it causes
        // additive timeout behavior when combined with WebDriverWait)
        Driver.Manage().Timeouts().ImplicitWait = TimeSpan.Zero;

        return ValueTask.CompletedTask;
    }

    public ValueTask DisposeAsync()
    {
        Driver?.Quit();
        return ValueTask.CompletedTask;
    }
}

Test Configuration

public static class TestConfig
{
    // Set via environment variables or test runsettings
    public static string TargetPlatform =>
        Environment.GetEnvironmentVariable("TEST_PLATFORM") ?? "Android";

    public static string AndroidApkPath =>
        Environment.GetEnvironmentVariable("ANDROID_APK_PATH")
        ?? Path.Combine(SolutionDir, "bin", "Release", "net8.0-android", "com.myapp-Signed.apk");

    public static string iOSAppPath =>
        Environment.GetEnvironmentVariable("IOS_APP_PATH")
        ?? Path.Combine(SolutionDir, "bin", "Release", "net8.0-ios", "MyApp.app");

    public static string WindowsAppPath =>
        Environment.GetEnvironmentVariable("WINDOWS_APP_PATH")
        ?? "com.mycompany.myapp_1.0.0.0_x64__9a0dh7ch11qe4!App";

    private static string SolutionDir =>
        Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..", "..", "..", ".."));
}

Element Location with AutomationId

MAUI's AutomationId property maps to the platform-native accessibility identifier. This is the most reliable selector for cross-platform tests.

Setting AutomationId in XAML

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml">

    <VerticalStackLayout>
        <Entry AutomationId="username-input"
               Placeholder="Username" />

        <Entry AutomationId="password-input"
               Placeholder="Password"
               IsPassword="True" />

        <Button AutomationId="login-button"
                Text="Log In"
                Clicked="OnLoginClicked" />

        <Label AutomationId="error-message"
               TextColor="Red" />
    </VerticalStackLayout>
</ContentPage>

Finding Elements in Tests

public class LoginTests : IClassFixture<AppiumFixture>
{
    private readonly AppiumDriver _driver;

    public LoginTests(AppiumFixture fixture)
    {
        _driver = fixture.Driver;
    }

    [Fact]
    public void Login_ValidCredentials_NavigatesToHome()
    {
        // Find by AutomationId (maps to accessibility ID on each platform)
        var usernameField = _driver.FindElement(MobileBy.AccessibilityId("username-input"));
        var passwordField = _driver.FindElement(MobileBy.AccessibilityId("password-input"));
        var loginButton = _driver.FindElement(MobileBy.AccessibilityId("login-button"));

        usernameField.Clear();
        usernameField.SendKeys("testuser");
        passwordField.Clear();
        passwordField.SendKeys("P@ssw0rd!");
        loginButton.Click();

        // Wait for navigation
        var wait = new WebDriverWait(_driver, TimeSpan.FromSeconds(10));
        var homeTitle = wait.Until(d =>
            d.FindElement(MobileBy.AccessibilityId("home-title")));

        Assert.Equal("Welcome", homeTitle.Text);
    }

    [Fact]
    public void Login_InvalidCredentials_ShowsError()
    {
        var usernameField = _driver.FindElement(MobileBy.AccessibilityId("username-input"));
        var passwordField = _driver.FindElement(MobileBy.AccessibilityId("password-input"));
        var loginButton = _driver.FindElement(MobileBy.AccessibilityId("login-button"));

        usernameField.Clear();
        usernameField.SendKeys("wrong");
        passwordField.Clear();
        passwordField.SendKeys("wrong");
        loginButton.Click();

        var wait = new WebDriverWait(_driver, TimeSpan.FromSeconds(5));
        var errorLabel = wait.Until(d =>
            d.FindElement(MobileBy.AccessibilityId("error-message")));

        Assert.Contains("Invalid", errorLabel.Text);
    }
}

Page Object Model for MAUI

Apply the page object model pattern (see [skill:dotnet-ui-testing-core]) with Appium's driver:

public class LoginPage
{
    private readonly AppiumDriver _driver;
    private readonly WebDriverWait _wait;

    public LoginPage(AppiumDriver driver)
    {
        _driver = driver;
        _wait = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
        WaitForPageLoaded();
    }

    private AppiumElement UsernameField =>
        _driver.FindElement(MobileBy.AccessibilityId("username-input"));
    private AppiumElement PasswordField =>
        _driver.FindElement(MobileBy.AccessibilityId("password-input"));
    private AppiumElement LoginButton =>
        _driver.FindElement(MobileBy.AccessibilityId("login-button"));
    private AppiumElement ErrorMessage =>
        _driver.FindElement(MobileBy.AccessibilityId("error-message"));

    public HomePage Login(string username, string password)
    {
        UsernameField.Clear();
        UsernameField.SendKeys(username);
        PasswordField.Clear();
        PasswordField.SendKeys(password);
        LoginButton.Click();

        return new HomePage(_driver);
    }

    public string GetErrorText()
    {
        _wait.Until(d =>
        {
            var el = d.FindElement(MobileBy.AccessibilityId("error-message"));
            return !string.IsNullOrEmpty(el.Text);
        });
        return ErrorMessage.Text;
    }

    private void WaitForPageLoaded()
    {
        _wait.Until(d => d.FindElement(MobileBy.AccessibilityId("login-button")));
    }
}

// Usage
[Fact]
public void Login_ValidUser_ReachesHomePage()
{
    var loginPage = new LoginPage(_driver);
    var homePage = loginPage.Login("alice", "P@ssw0rd!");

    Assert.True(homePage.IsLoaded);
}

Platform-Specific Behavior Testing

Conditional Tests by Platform

public class PlatformTests : IClassFixture<AppiumFixture>
{
    private readonly AppiumDriver _driver;

    public PlatformTests(AppiumFixture fixture)
    {
        _driver = fixture.Driver;
    }

    [Fact]
    [Trait("Platform", "Android")]
    public void BackButton_Android_NavigatesBack()
    {
        // xUnit v3 native skip support (no SkippableFact package needed)
        Assert.SkipWhen(TestConfig.TargetPlatform != "Android",
            "Android-only: hardware back button");

        // Navigate to details page
        _driver.FindElement(MobileBy.AccessibilityId("item-1")).Click();

        // Press Android back button
        _driver.Navigate().Back();

        // Verify we returned to the list
        var wait = new WebDriverWait(_driver, TimeSpan.FromSeconds(5));
        wait.Until(d => d.FindElement(MobileBy.AccessibilityId("item-list")));
    }

    [Fact]
    [Trait("Platform", "iOS")]
    public void SwipeToDelete_iOS_RemovesItem()
    {
        // xUnit v3 native skip support
        Assert.SkipWhen(TestConfig.TargetPlatform != "iOS",
            "iOS-only: swipe gesture");

        var item = _driver.FindElement(MobileBy.AccessibilityId("item-1"));

        // Swipe left to reveal delete action
        var swipe = new PointerInputDevice(PointerKind.Touch, "finger");
        var sequence = new ActionSequence(swipe);
        var itemLocation = item.Location;
        var itemSize = item.Size;

        sequence.AddAction(swipe.CreatePointerMove(
            item, itemSize.Width - 10, itemSize.Height / 2,
            TimeSpan.FromMilliseconds(0)));
        sequence.AddAction(swipe.CreatePointerDown(MouseButton.Left));
        sequence.AddAction(swipe.CreatePointerMove(
            item, 10, itemSize.Height / 2,
            TimeSpan.FromMilliseconds(300)));
        sequence.AddAction(swipe.CreatePointerUp(MouseButton.Left));

        _driver.PerformActions([sequence]);

        // Tap the delete button
        var deleteBtn = _driver.FindElement(MobileBy.AccessibilityId("delete-action"));
        deleteBtn.Click();

        // Verify item removed
        var wait = new WebDriverWait(_driver, TimeSpan.FromSeconds(5));
        wait.Until(d =>
        {
            var items = d.FindElements(MobileBy.AccessibilityId("item-1"));
            return items.Count == 0;
        });
    }
}

Screen Size and Orientation

[Fact]
public void Dashboard_LandscapeMode_ShowsSidePanel()
{
    // Rotate to landscape
    _driver.Orientation = ScreenOrientation.Landscape;

    try
    {
        var wait = new WebDriverWait(_driver, TimeSpan.FromSeconds(5));
        var sidePanel = wait.Until(d =>
            d.FindElement(MobileBy.AccessibilityId("side-panel")));

        Assert.True(sidePanel.Displayed);
    }
    finally
    {
        // Restore portrait
        _driver.Orientation = ScreenOrientation.Portrait;
    }
}

XHarness Test Execution

XHarness is a command-line tool for running tests on devices and emulators across platforms. It handles app installation, test execution, and result collection.

Running Tests with XHarness

# Install XHarness
dotnet tool install --global Microsoft.DotNet.XHarness.CLI

# Run on Android emulator
xharness android test \
    --app bin/Release/net8.0-android/com.myapp-Signed.apk \
    --package-name com.myapp \
    --instrumentation devicerunner.AndroidInstrumentation \
    --output-directory test-results/android

# Run on iOS simulator
xharness apple test \
    --app bin/Release/net8.0-ios/MyApp.app \
    --target ios-simulator-64 \
    --output-directory test-results/ios

# Run with specific device
xharness android test \
    --app app.apk \
    --package-name com.myapp \
    --device-id emulator-5554 \
    --output-directory test-results

XHarness with Device Runner

For xUnit tests running directly on device, add the device runner NuGet package:

<PackageReference Include="Microsoft.DotNet.XHarness.TestRunners.Xunit" Version="1.*" />

// In the MAUI test app's MauiProgram.cs
public static MauiApp CreateMauiApp()
{
    var builder = MauiApp.CreateBuilder();
    builder.UseVisualRunner(); // XHarness visual test runner
    return builder.Build();
}

Key Principles

• Use AutomationId for all testable elements. It is the cross-platform equivalent of data-testid and maps to the native accessibility identifier on every platform.
• Run tests against real emulators/simulators, not just unit tests. MAUI rendering, navigation, and platform services behave differently than in-memory tests.
• Use explicit waits, never implicit waits or delays. WebDriverWait with a condition is reliable; Thread.Sleep and implicit waits hide timing issues.
• Tag platform-specific tests with [Trait] and Assert.SkipWhen. xUnit v3's native skip support allows running the correct tests per platform in CI without failures from unsupported features.
• Apply the page object model for maintainability. MAUI apps have complex navigation flows; page objects keep tests readable as the app grows.

Agent Gotchas

1. Do not use FindElement without a wait strategy. Elements may not be available immediately after navigation. Always use WebDriverWait for elements that appear after async operations or page transitions.
2. Do not hardcode emulator/simulator names. Use environment variables or test configuration so CI can specify the available device. Different CI environments have different emulators installed.
3. Do not forget to set AutomationId on MAUI controls. Without it, Appium falls back to platform-specific selectors (XPath, class name) that differ across Android, iOS, and Windows -- breaking cross-platform tests.
4. Do not run iOS tests on non-macOS machines. iOS simulators require Xcode, which is macOS-only. Use platform-conditional test skipping or separate CI pipelines per platform.
5. Do not leave the Appium server unmanaged. Start Appium as a fixture or CI service, not manually. Forgotten Appium processes cause port conflicts and test hangs.

References

• Appium Documentation
• Appium.NET Client
• .NET MAUI Testing
• XHarness
• UIAutomator2 Driver
• XCUITest Driver