MAUI CommunityToolkit MVVM auto instrumentation of async commands

Sentry.sln

@@ -197,6 +197,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sentry.TrimTest", "test\Sen
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sentry.MauiTrimTest", "test\Sentry.MauiTrimTest\Sentry.MauiTrimTest.csproj", "{DF92E098-822C-4B94-B96B-56BFB91FBB54}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sentry.Maui.CommunityToolkitMvvm", "src\Sentry.Maui.CommunityToolkitMvvm\Sentry.Maui.CommunityToolkitMvvm.csproj", "{E898F337-E982-46CC-8DA9-F8556AA7DD72}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -532,6 +534,10 @@ Global
 		{DF92E098-822C-4B94-B96B-56BFB91FBB54}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{DF92E098-822C-4B94-B96B-56BFB91FBB54}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{DF92E098-822C-4B94-B96B-56BFB91FBB54}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E898F337-E982-46CC-8DA9-F8556AA7DD72}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E898F337-E982-46CC-8DA9-F8556AA7DD72}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E898F337-E982-46CC-8DA9-F8556AA7DD72}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E898F337-E982-46CC-8DA9-F8556AA7DD72}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -619,5 +625,6 @@ Global
 		{D7DF0B26-AD43-4F8B-9BFE-C4471CCC9821} = {21B42F60-5802-404E-90F0-AEBCC56760C0}
 		{6030B748-0000-43B5-B8A8-399AA42F5229} = {6987A1CC-608E-4868-A02C-09D30C8B7B2D}
 		{DF92E098-822C-4B94-B96B-56BFB91FBB54} = {6987A1CC-608E-4868-A02C-09D30C8B7B2D}
+		{E898F337-E982-46CC-8DA9-F8556AA7DD72} = {230B9384-90FD-4551-A5DE-1A5C197F25B6}
 	EndGlobalSection
 EndGlobal

SentryMobile.slnf

@@ -11,6 +11,7 @@
       "src\\Sentry.Bindings.Android\\Sentry.Bindings.Android.csproj",
       "src\\Sentry.Bindings.Cocoa\\Sentry.Bindings.Cocoa.csproj",
       "src\\Sentry.Extensions.Logging\\Sentry.Extensions.Logging.csproj",
+      "src\\Sentry.Maui.CommunityToolkitMvvm\\Sentry.Maui.CommunityToolkitMvvm.csproj",
       "src\\Sentry.Maui\\Sentry.Maui.csproj",
       "src\\Sentry\\Sentry.csproj",
       "test\\Sentry.Android.AssemblyReader.Tests\\Sentry.Android.AssemblyReader.Tests.csproj",
@@ -21,4 +22,4 @@
       "test\\Sentry.Tests\\Sentry.Tests.csproj"
     ]
   }
-}
+}

src/Sentry.Maui.CommunityToolkitMvvm/CtMvvmMauiElementEventBinder.cs

@@ -0,0 +1,151 @@
+using System.Windows.Input;
+using CommunityToolkit.Mvvm.Input;
+
+namespace Sentry.Maui.CommunityToolkitMvvm;
+
+/// <summary>
+/// Scans all elements for known commands that are implement
+/// </summary>
+public class CtMvvmMauiElementEventBinder : IMauiElementEventBinder
+{
+    /// <summary>
+    /// Binds to the element
+    /// </summary>
+    /// <param name="element"></param>
+    /// <param name="addBreadcrumb"></param>
+    public void Bind(VisualElement element, Action<BreadcrumbEvent> addBreadcrumb) => Iterate(element, true);
+
+    /// <summary>
+    /// Unbinds from the element
+    /// </summary>
+    /// <param name="element"></param>
+    /// <exception cref="NotImplementedException"></exception>
+    public void UnBind(VisualElement element) => Iterate(element, false);
+
+
+    private static void Iterate(VisualElement element, bool bind)
+    {
+        switch (element)
+        {
+            case Button button:
+                TryBindTo(button.Command, bind);
+                break;
+
+            case ImageButton imageButton:
+                TryBindTo(imageButton.Command, bind);
+                break;
+
+            case CarouselView carousel:
+                TryBindTo(carousel.CurrentItemChangedCommand, bind);
+                TryBindTo(carousel.RemainingItemsThresholdReachedCommand, bind);
+                TryBindTo(carousel.PositionChangedCommand, bind);
+                break;
+
+            case CollectionView collectionView:
+                TryBindTo(collectionView.RemainingItemsThresholdReachedCommand, bind);
+                TryBindTo(collectionView.SelectionChangedCommand, bind);
+                break;
+
+            case Entry entry:
+                TryBindTo(entry.ReturnCommand, bind);
+                break;
+
+            case RefreshView refresh:
+                TryBindTo(refresh.Command, bind);
+                break;
+
+            case SearchBar searchBar:
+                TryBindTo(searchBar.SearchCommand, bind);
+                break;
+
+            default:
+                TryGestureBinding(element, bind);
+                break;
+        }
+    }
+
+    private static void TryGestureBinding(VisualElement element, bool bind)
+    {
+        if (element is IGestureRecognizers gestureRecognizers)
+        {
+            foreach (var gestureRecognizer in gestureRecognizers.GestureRecognizers)
+            {
+                TryBindTo(gestureRecognizer, bind);
+            }
+        }
+    }
+
+    private static void TryBindTo(IGestureRecognizer recognizer, bool bind)
+    {
+        switch (recognizer)
+        {
+            case TapGestureRecognizer tap:
+                TryBindTo(tap.Command, bind);
+                break;
+
+            case SwipeGestureRecognizer swipe:
+                TryBindTo(swipe.Command, bind);
+                break;
+
+            // no commands
+            //case PinchGestureRecognizer pinch
+            //case PanGestureRecognizer pan
+            case DragGestureRecognizer drag:
+                TryBindTo(drag.DragStartingCommand, bind); // unlikely to ever be async
+                TryBindTo(drag.DropCompletedCommand, bind);
+                break;
+
+            case PointerGestureRecognizer pointer:
+                TryBindTo(pointer.PointerPressedCommand, bind);
+                TryBindTo(pointer.PointerReleasedCommand, bind);
+                TryBindTo(pointer.PointerEnteredCommand, bind); // unlikely to ever be async
+                TryBindTo(pointer.PointerExitedCommand, bind);
+                break;
+        }
+    }
+
+    private static List<IAsyncRelayCommand> _refs = [];
+    private static void TryBindTo(ICommand? command, bool bind)
+    {
+        if (command is IAsyncRelayCommand relayCommand)
+        {
+            if (bind)
+            {
+                // necessary for collectionview buttons
+                if (!_refs.Contains(relayCommand))
+                {
+                    _refs.Add(relayCommand);
+                    relayCommand.PropertyChanged += RelayCommandOnPropertyChanged;
+                }
+            }
+            else
+            {
+                _refs.Remove(relayCommand);
+                relayCommand.PropertyChanged -= RelayCommandOnPropertyChanged;
+            }
+        }
+    }
+
+    private static ConcurrentDictionary<IAsyncRelayCommand, (ITransactionTracer Transaction, ISpan Span)> _contexts = new();
+
+    private static void RelayCommandOnPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName == nameof(IAsyncRelayCommand.IsRunning))
+        {
+            var relay = (IAsyncRelayCommand)sender!;
+
+            if (relay.IsRunning)
+            {
+                var transaction = SentrySdk.StartTransaction("ctmvvm", "asynccommand");
+                var span = transaction.StartChild("run");
+                _contexts.TryAdd(relay, (transaction, span));
+            }
+            else if (_contexts.TryGetValue(relay, out var value))
+            {
+                value.Span.Finish();
+                value.Transaction.Finish();
+                _contexts.TryRemove(relay, out _);
+            }
+        }
+    }
+}

src/Sentry.Maui.CommunityToolkitMvvm/MauiAppBuilderExtensions.cs

@@ -0,0 +1,32 @@
+using Sentry.Maui.CommunityToolkitMvvm;
+
+namespace Sentry.Maui;
+
+/// <summary>
+/// Methods to hook into MAUI & CommunityToolkit.Mvvm
+/// </summary>
+public static class MauiAppBuilderExtensions
+{
+    /// <summary>
+    /// Installs necessary services to auto-instrument CommunityToolkit.Mvvm commands
+    /// </summary>
+    /// <param name="builder">The MauiAppBuilder</param>
+    /// <returns>The MauiAppBuilder</returns>
+    public static MauiAppBuilder UseSentryCommunityToolkitIntegration(this MauiAppBuilder builder)
+    {
+        builder.Services.UseSentryCommunityToolkitIntegration();
+        return builder;
+    }
+
+
+    /// <summary>
+    /// Installs necessary services to auto-instrument CommunityToolkit.Mvvm commands
+    /// </summary>
+    /// <param name="services">The Service Collection</param>
+    /// <returns>The Service Collection</returns>
+    public static IServiceCollection UseSentryCommunityToolkitIntegration(this IServiceCollection services)
+    {
+        services.AddSingleton<IMauiElementEventBinder, CtMvvmMauiElementEventBinder>();
+        return services;
+    }
+}

src/Sentry.Maui.CommunityToolkitMvvm/Sentry.Maui.CommunityToolkitMvvm.csproj

@@ -0,0 +1,26 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <Description>MAUI and Community Toolkit integration for Sentry - Open-source error tracking that helps developers monitor and fix crashes in real time.</Description>
+    <TargetFrameworks>net9.0;net8.0</TargetFrameworks>
+
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <UseMaui>true</UseMaui>
+
+    <!-- Skip warnings about including Microsoft.Maui.Controls... that should be done from the application -->
+    <SkipValidateMauiImplicitPackageReferences>true</SkipValidateMauiImplicitPackageReferences>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.4.0"/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Sentry.Maui\Sentry.Maui.csproj"/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="Sentry.Maui.Tests" PublicKey="$(SentryPublicKey)" />
+  </ItemGroup>
+</Project>