Remove internal hardlink by using MVVM Messenger

Clean-up namespace orderings

Author: michael-hawker

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

@@ -4,6 +4,7 @@
 
 using System;
 using System.Diagnostics;
+using Microsoft.Toolkit.Mvvm.Messaging;
 using UITests.App.Pages;
 using Windows.ApplicationModel.Activation;
 using Windows.ApplicationModel.AppService;
@@ -51,17 +52,14 @@ private async void OnAppServiceRequestReceived(AppServiceConnection sender, AppS
 
                     ValueSet returnMessage = new ValueSet();
 
-                    if (host != null)
+                    // We await the OpenPage method to ensure the navigation has finished.
+                    if (await WeakReferenceMessenger.Default.Send<RequestPageMessage>(new (pageName)))
                     {
-                        // We await the OpenPage method to ensure the navigation has finished.
-                        if (await host.OpenPage(pageName))
-                        {
-                            returnMessage.Add("Status", "OK");
-                        }
-                        else
-                        {
-                            returnMessage.Add("Status", "BAD");
-                        }
+                        returnMessage.Add("Status", "OK");
+                    }
+                    else
+                    {
+                        returnMessage.Add("Status", "BAD");
                     }
 
                     await args.Request.SendResponseAsync(returnMessage);

UITests/UITests.App/App.xaml.cs

@@ -15,11 +15,11 @@
 
 namespace UITests.App
 {
+    /// <summary>
+    /// Application class for hosting UI pages to test.
+    /// </summary>
     public sealed partial class App
     {
-        // TODO: Create a better pattern here to connect these.
-        internal MainTestHost host;
-
         public App()
         {
             this.InitializeComponent();

UITests/UITests.App/MainTestHost.xaml.cs

@@ -2,24 +2,23 @@
 // 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.Uwp.Extensions;
 using System;
-using System.Collections.Generic;
 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.Input;
 using Windows.UI.Xaml.Media.Animation;
 
 namespace UITests.App
 {
     /// <summary>
     /// MainPage hosting all other test pages.
     /// </summary>
-    public sealed partial class MainTestHost
+    public sealed partial class MainTestHost : IRecipient<RequestPageMessage>
     {
         private DispatcherQueue _queue;
 
@@ -30,12 +29,19 @@ public sealed partial class MainTestHost
         public MainTestHost()
         {
             InitializeComponent();
-            ((App)Application.Current).host = this;
+
+            WeakReferenceMessenger.Default.RegisterAll(this);
+
             _queue = DispatcherQueue.GetForCurrentThread();
         }
 
-        // TODO: we should better expose how to control the MainTestHost vs. making this internal.
-        internal async Task<bool> OpenPage(string pageName)
+        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
             {

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 class RequestPageMessage : AsyncRequestMessage<bool>
+    {
+        public string PageName { get; private set; }
+
+        public RequestPageMessage(string name)
+        {
+            PageName = name;
+        }
+    }
+}

UITests/UITests.App/UITests.App.csproj

@@ -10,6 +10,7 @@
     <RootNamespace>UITests.App</RootNamespace>
     <AssemblyName>UITests.App</AssemblyName>
     <DefaultLanguage>en-US</DefaultLanguage>
+    <LangVersion>9.0</LangVersion>
     <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
     <TargetPlatformVersion Condition=" '$(TargetPlatformVersion)' == '' ">10.0.19041.0</TargetPlatformVersion>
     <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
@@ -137,6 +138,7 @@
     <Compile Include="MainTestHost.xaml.cs">
       <DependentUpon>MainTestHost.xaml</DependentUpon>
     </Compile>
+    <Compile Include="RequestPageMessage.cs" />
     <Compile Include="TestInterop.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>

UITests/UITests.Tests.Shared/UITestBase.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -12,7 +13,6 @@
 using Windows.Foundation.Collections;
 using Windows.UI.Xaml.Tests.MUXControls.InteractionTests.Common;
 using Windows.UI.Xaml.Tests.MUXControls.InteractionTests.Infra;
-using System.Diagnostics;
 
 #if USING_TAEF
 using WEX.Logging.Interop;

UnitTests/UnitTests.XamlIslands.UWPApp/XamlIslandsTest_SystemInformation.cs

@@ -3,10 +3,10 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Threading.Tasks;
+using Microsoft.Toolkit.Uwp.Extensions;
 using Microsoft.Toolkit.Uwp.Helpers;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Windows.ApplicationModel.Activation;
-using Microsoft.Toolkit.Uwp.Extensions;
 
 namespace UnitTests.XamlIslands.UWPApp
 {