Test app service in CI (#3580)

Quick prototype to test out an app service on top of #3552.

Working locally with MSTest, though some oddities when trying to shore-up timing guards, unknown unhandled exception... Went back to looser code and working well. Not sure if this resolves the TAEF error we're seeing in #3552 yet, but wanted to see if this provided different info.

Lots to do here to clean this work up, as I just hacked things together to see if it would work, but looking very promising. This should allow us to optimize the start-up performance of the app more easily as well as have a bi-directional communication pipe between our two processes for logging messages from the host within the harness/CI logs. 🎉

FYI @RosarioPulella

UITests/UITests.App/App.AppService.xaml.cs

@@ -0,0 +1,103 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Diagnostics;
+using Microsoft.Toolkit.Mvvm.Messaging;
+using UITests.App.Pages;
+using Windows.ApplicationModel.Activation;
+using Windows.ApplicationModel.AppService;
+using Windows.ApplicationModel.Background;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+
+namespace UITests.App
+{
+    /// <summary>
+    /// This file contains part of the app related to the AppService for communication between this test host and the test harness processes.
+    /// </summary>
+    public sealed partial class App
+    {
+        private AppServiceConnection _appServiceConnection;
+        private BackgroundTaskDeferral _appServiceDeferral;
+
+        protected override void OnBackgroundActivated(BackgroundActivatedEventArgs args)
+        {
+            base.OnBackgroundActivated(args);
+            IBackgroundTaskInstance taskInstance = args.TaskInstance;
+            AppServiceTriggerDetails appService = taskInstance.TriggerDetails as AppServiceTriggerDetails;
+            _appServiceDeferral = taskInstance.GetDeferral();
+            taskInstance.Canceled += OnAppServicesCanceled;
+            _appServiceConnection = appService.AppServiceConnection;
+            _appServiceConnection.RequestReceived += OnAppServiceRequestReceived;
+            _appServiceConnection.ServiceClosed += AppServiceConnection_ServiceClosed;
+        }
+
+        private async void OnAppServiceRequestReceived(AppServiceConnection sender, AppServiceRequestReceivedEventArgs args)
+        {
+            AppServiceDeferral messageDeferral = args.GetDeferral();
+            ValueSet message = args.Request.Message;
+            string cmd = message["Command"] as string;
+
+            try
+            {
+                // Return the data to the caller.
+                if (cmd == "Start")
+                {
+                    var pageName = message["Page"] as string;
+
+                    Log.Comment("Received request for Page: {0}", pageName);
+
+                    ValueSet returnMessage = new ValueSet();
+
+                    // We await the OpenPage method to ensure the navigation has finished.
+                    if (await WeakReferenceMessenger.Default.Send(new RequestPageMessage(pageName)))
+                    {
+                        returnMessage.Add("Status", "OK");
+                    }
+                    else
+                    {
+                        returnMessage.Add("Status", "BAD");
+                    }
+
+                    await args.Request.SendResponseAsync(returnMessage);
+                }
+            }
+            catch (Exception e)
+            {
+                // Your exception handling code here.
+                Log.Error("Exception processing request: {0}", e.Message);
+            }
+            finally
+            {
+                // Complete the deferral so that the platform knows that we're done responding to the app service call.
+                // Note: for error handling: this must be called even if SendResponseAsync() throws an exception.
+                messageDeferral.Complete();
+            }
+        }
+
+        private void OnAppServicesCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
+        {
+            _appServiceDeferral.Complete();
+        }
+
+        private void AppServiceConnection_ServiceClosed(AppServiceConnection sender, AppServiceClosedEventArgs args)
+        {
+            _appServiceDeferral.Complete();
+        }
+
+        public async void SendLogMessage(string level, string msg)
+        {
+            var message = new ValueSet();
+            message.Add("Command", "Log");
+            message.Add("Level", level);
+            message.Add("Message", msg);
+
+            await _appServiceConnection.SendMessageAsync(message);
+
+            // TODO: do we care if we have a problem here?
+        }
+    }
+}

UITests/UITests.App/App.xaml

@@ -1,7 +1,4 @@
-<Application
-    x:Class="UITests.App.App"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:local="using:UITests.App">
-
-</Application>
+<Application x:Class="UITests.App.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="using:UITests.App" />

UITests/UITests.App/App.xaml.cs

@@ -3,6 +3,10 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using UITests.App.Pages;
 using Windows.ApplicationModel;
 using Windows.ApplicationModel.Activation;
 using Windows.UI.Xaml;
@@ -11,12 +15,22 @@
 
 namespace UITests.App
 {
+    /// <summary>
+    /// Application class for hosting UI pages to test.
+    /// </summary>
     public sealed partial class App
     {
         public App()
         {
             this.InitializeComponent();
             this.Suspending += OnSuspending;
+            this.UnhandledException += this.App_UnhandledException;
+        }
+
+        private void App_UnhandledException(object sender, Windows.UI.Xaml.UnhandledExceptionEventArgs e)
+        {
+            // TODO: Also Log to a file?
+            Log.Error("Unhandled Exception: " + e.Message);
         }
 
         /// <summary>
@@ -53,7 +67,7 @@ protected override void OnLaunched(LaunchActivatedEventArgs e)
                     // When the navigation stack isn't restored navigate to the first page,
                     // configuring the new page by passing required information as a navigation
                     // parameter
-                    rootFrame.Navigate(typeof(MainPage), e.Arguments);
+                    rootFrame.Navigate(typeof(MainTestHost), e.Arguments);
                 }
 
                 // Ensure the current window is active
@@ -68,6 +82,7 @@ protected override void OnLaunched(LaunchActivatedEventArgs e)
         /// <param name="e">Details about the navigation failure</param>
         private void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
         {
+            Log.Error("Failed to load root page: " + e.SourcePageType.FullName);
             throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
         }
 

UITests/UITests.App/MainTestHost.xaml

@@ -0,0 +1,17 @@
+<Page x:Class="UITests.App.MainTestHost"
+      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+      xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+      xmlns:testhelpers="using:AppTestAutomationHelpers"
+      Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
+      mc:Ignorable="d">
+
+    <Grid>
+        <testhelpers:TestAutomationHelpersPanel />
+
+        <Frame x:Name="navigationFrame"
+               Navigated="NavigationFrame_Navigated"
+               NavigationFailed="NavigationFrame_NavigationFailed" />
+    </Grid>
+</Page>

UITests/UITests.App/MainTestHost.xaml.cs

@@ -0,0 +1,118 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Reflection;
+using System.Threading.Tasks;
+using Microsoft.Toolkit.Mvvm.Messaging;
+using Microsoft.Toolkit.Uwp.Extensions;
+using UITests.App.Pages;
+using Windows.System;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Media.Animation;
+
+namespace UITests.App
+{
+    /// <summary>
+    /// MainPage hosting all other test pages.
+    /// </summary>
+    public sealed partial class MainTestHost : IRecipient<RequestPageMessage>
+    {
+        private DispatcherQueue _queue;
+
+        private Assembly _executingAssembly = Assembly.GetExecutingAssembly();
+
+        private TaskCompletionSource<bool> _loadingStateTask;
+
+        public MainTestHost()
+        {
+            InitializeComponent();
+
+            WeakReferenceMessenger.Default.Register<RequestPageMessage>(this);
+
+            _queue = DispatcherQueue.GetForCurrentThread();
+        }
+
+        public void Receive(RequestPageMessage message)
+        {
+            // Reply with task back to so it can be properly awaited link:App.AppService.xaml.cs#L56
+            message.Reply(OpenPage(message.PageName));
+        }
+
+        private async Task<bool> OpenPage(string pageName)
+        {
+            try
+            {
+                Log.Comment("Trying to Load Page: " + pageName);
+
+                _loadingStateTask = new TaskCompletionSource<bool>();
+
+                // Ensure we're on the UI thread as we'll be called from the AppService now.
+                _ = _queue.EnqueueAsync(() =>
+                {
+                    // Navigate without extra animations
+                    navigationFrame.Navigate(FindPageType(pageName), new SuppressNavigationTransitionInfo());
+                });
+
+                // Wait for load to complete
+                await _loadingStateTask.Task;
+            }
+            catch (Exception e)
+            {
+                Log.Error("Exception Loading Page {0}: {1} ", pageName, e.Message);
+                return false;
+            }
+
+            return true;
+        }
+
+        private Type FindPageType(string pageName)
+        {
+            try
+            {
+                return _executingAssembly.GetType("UITests.App.Pages." + pageName);
+            }
+            catch (Exception e)
+            {
+                Log.Error("Exception Finding Page {0}: {1} ", pageName, e.Message);
+            }
+
+            return null;
+        }
+
+        private void NavigationFrame_Navigated(object sender, Windows.UI.Xaml.Navigation.NavigationEventArgs e)
+        {
+            Log.Comment("Navigated to Page {0}", e.SourcePageType.FullName);
+            if (e.Content is Page page)
+            {
+                if (page.IsLoaded)
+                {
+                    Log.Comment("Loaded Page {0}", e.SourcePageType.FullName);
+                    _loadingStateTask.SetResult(true);
+                }
+                else
+                {
+                    page.Loaded += this.Page_Loaded;
+                }
+            }
+        }
+
+        private void Page_Loaded(object sender, RoutedEventArgs e)
+        {
+            var page = sender as Page;
+
+            page.Loaded -= Page_Loaded;
+
+            Log.Comment("Loaded Page (E) {0}", page.GetType().FullName);
+            _loadingStateTask.SetResult(true);
+        }
+
+        private void NavigationFrame_NavigationFailed(object sender, Windows.UI.Xaml.Navigation.NavigationFailedEventArgs e)
+        {
+            Log.Error("Failed to navigate to page {0}", e.SourcePageType.FullName);
+            _loadingStateTask.SetResult(false);
+        }
+    }
+}

UITests/UITests.App/Package.appxmanifest

@@ -40,6 +40,11 @@
         <uap:DefaultTile Wide310x150Logo="Assets\Wide310x150Logo.png"/>
         <uap:SplashScreen Image="Assets\SplashScreen.png" />
       </uap:VisualElements>
+      <Extensions>
+        <uap:Extension Category="windows.appService">
+          <uap:AppService Name="TestHarnessCommunicationService"/>
+        </uap:Extension>
+      </Extensions>
     </Application>
   </Applications>
 

UITests/UITests.App/RequestPageMessage.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.Toolkit.Mvvm.Messaging.Messages;
+
+namespace UITests.App
+{
+    public sealed class RequestPageMessage : AsyncRequestMessage<bool>
+    {
+        public RequestPageMessage(string name)
+        {
+            PageName = name;
+        }
+
+        public string PageName { get; }
+    }
+}