feat: Auto-create traces for MAUI navigation events

samples/Sentry.Samples.Maui/MauiProgram.cs

@@ -42,6 +42,9 @@ public static MauiApp CreateMauiApp()
                 // capture a certain percentage)
                 options.TracesSampleRate = 1.0F;
 
+                // Automatically create traces for navigation events
+                options.EnableNavigationTransactions = true;
+
                 // Automatically create traces for async relay commands in the MVVM Community Toolkit
                 options.AddCommunityToolkitIntegration();
 

src/Sentry.Maui/BindableSentryMauiOptions.cs

@@ -10,6 +10,8 @@ internal class BindableSentryMauiOptions : BindableSentryLoggingOptions
     public bool? IncludeBackgroundingStateInBreadcrumbs { get; set; }
     public bool? CreateElementEventsBreadcrumbs { get; set; } = false;
     public bool? AttachScreenshot { get; set; }
+    public bool? EnableNavigationTransactions { get; set; }
+    public TimeSpan? NavigationTransactionIdleTimeout { get; set; }
 
     public void ApplyTo(SentryMauiOptions options)
     {
@@ -19,5 +21,7 @@ public void ApplyTo(SentryMauiOptions options)
         options.IncludeBackgroundingStateInBreadcrumbs = IncludeBackgroundingStateInBreadcrumbs ?? options.IncludeBackgroundingStateInBreadcrumbs;
         options.CreateElementEventsBreadcrumbs = CreateElementEventsBreadcrumbs ?? options.CreateElementEventsBreadcrumbs;
         options.AttachScreenshot = AttachScreenshot ?? options.AttachScreenshot;
+        options.EnableNavigationTransactions = EnableNavigationTransactions ?? options.EnableNavigationTransactions;
+        options.NavigationTransactionIdleTimeout = NavigationTransactionIdleTimeout ?? options.NavigationTransactionIdleTimeout;
     }
 }

src/Sentry.Maui/Internal/MauiEventsBinder.cs

@@ -1,4 +1,5 @@
 using Microsoft.Extensions.Options;
+using Sentry.Internal;
 
 namespace Sentry.Maui.Internal;
 
@@ -13,6 +14,10 @@ internal class MauiEventsBinder : IMauiEventsBinder
     private readonly SentryMauiOptions _options;
     internal readonly IEnumerable<IMauiElementEventBinder> _elementEventBinders;
 
+    // Tracks the active auto-finishing navigation transaction so we can explicitly finish it early
+    // (e.g. when the next navigation begins) before the idle timeout would fire.
+    private ITransactionTracer? _currentTransaction;
+
     // https://develop.sentry.dev/sdk/event-payloads/breadcrumbs/#breadcrumb-types
     // https://github.com/getsentry/sentry/blob/master/static/app/types/breadcrumbs.tsx
     internal const string NavigationType = "navigation";
@@ -319,16 +324,72 @@ internal void HandlePageEvents(Page page, bool bind = true)
         }
     }
 
+    private ITransactionTracer? StartNavigationTransaction(string name)
+    {
+        // Reset the idle timeout instead of creating a new transaction if the destination is the same
+        if (_currentTransaction is { IsFinished: false } current && current.Name == name)
+        {
+            current.ResetIdleTimeout();
+            return current;
+        }
+
+        // Finish any previous SDK-owned navigation transaction before starting a new one.
+        _currentTransaction?.Finish(SpanStatus.Ok);
+
+        var context = new TransactionContext(name, "ui.load")
+        {
+            NameSource = TransactionNameSource.Route
+        };
+
+        var transaction = _hub is IHubInternal internalHub
+            ? internalHub.StartTransaction(context, _options.NavigationTransactionIdleTimeout)
+            : _hub.StartTransaction(context);
+
+        // Only bind to scope if there is no user-created transaction already there.
+        // Re-evaluated on each navigation so a user transaction that finishes later is handled correctly.
+        var hasUserTransaction = false;
+        _hub.ConfigureScope(scope =>
+        {
+            if (scope.Transaction is { } existing && !ReferenceEquals(existing, _currentTransaction))
+            {
+                hasUserTransaction = true;
+            }
+        });
+
+        if (!hasUserTransaction)
+        {
+            _hub.ConfigureScope(static (scope, t) => scope.Transaction = t, transaction);
+        }
+
+        _currentTransaction = transaction;
+        return transaction;
+    }
+
     // Application Events
 
     private void OnApplicationOnPageAppearing(object? sender, Page page) =>
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Application.PageAppearing), NavigationType, NavigationCategory, data => data.AddElementInfo(_options, page, nameof(Page)));
     private void OnApplicationOnPageDisappearing(object? sender, Page page) =>
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Application.PageDisappearing), NavigationType, NavigationCategory, data => data.AddElementInfo(_options, page, nameof(Page)));
-    private void OnApplicationOnModalPushed(object? sender, ModalPushedEventArgs e) =>
+
+    private void OnApplicationOnModalPushed(object? sender, ModalPushedEventArgs e)
+    {
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Application.ModalPushed), NavigationType, NavigationCategory, data => data.AddElementInfo(_options, e.Modal, nameof(e.Modal)));
-    private void OnApplicationOnModalPopped(object? sender, ModalPoppedEventArgs e) =>
+        if (_options.EnableNavigationTransactions)
+        {
+            StartNavigationTransaction(e.Modal.GetType().Name);
+        }
+    }
+
+    private void OnApplicationOnModalPopped(object? sender, ModalPoppedEventArgs e)
+    {
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Application.ModalPopped), NavigationType, NavigationCategory, data => data.AddElementInfo(_options, e.Modal, nameof(e.Modal)));
+        if (_options.EnableNavigationTransactions)
+        {
+            _currentTransaction?.Finish(SpanStatus.Ok);
+            _currentTransaction = null;
+        }
+    }
     private void OnApplicationOnRequestedThemeChanged(object? sender, AppThemeChangedEventArgs e) =>
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Application.RequestedThemeChanged), SystemType, RenderingCategory, data => data.Add(nameof(e.RequestedTheme), e.RequestedTheme.ToString()));
 
@@ -340,8 +401,15 @@ private void OnWindowOnActivated(object? sender, EventArgs _) =>
     private void OnWindowOnDeactivated(object? sender, EventArgs _) =>
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Window.Deactivated), SystemType, LifecycleCategory);
 
-    private void OnWindowOnStopped(object? sender, EventArgs _) =>
+    private void OnWindowOnStopped(object? sender, EventArgs _)
+    {
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Window.Stopped), SystemType, LifecycleCategory);
+        if (_options.EnableNavigationTransactions)
+        {
+            _currentTransaction?.Finish(SpanStatus.Ok);
+            _currentTransaction = null;
+        }
+    }
 
     private void OnWindowOnResumed(object? sender, EventArgs _) =>
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Window.Resumed), SystemType, LifecycleCategory);
@@ -419,22 +487,37 @@ private void OnElementOnUnfocused(object? sender, FocusEventArgs _) =>
 
     // Shell Events
 
-    private void OnShellOnNavigating(object? sender, ShellNavigatingEventArgs e) =>
+    private void OnShellOnNavigating(object? sender, ShellNavigatingEventArgs e)
+    {
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Shell.Navigating), NavigationType, NavigationCategory, data =>
         {
             data.Add("from", e.Current?.Location.ToString() ?? "");
             data.Add("to", e.Target?.Location.ToString() ?? "");
             data.Add(nameof(e.Source), e.Source.ToString());
         });
 
-    private void OnShellOnNavigated(object? sender, ShellNavigatedEventArgs e) =>
+        if (_options.EnableNavigationTransactions)
+        {
+            StartNavigationTransaction(e.Target?.Location.ToString() ?? "Unknown");
+        }
+    }
+
+    private void OnShellOnNavigated(object? sender, ShellNavigatedEventArgs e)
+    {
         _hub.AddBreadcrumbForEvent(_options, sender, nameof(Shell.Navigated), NavigationType, NavigationCategory, data =>
         {
             data.Add("from", e.Previous?.Location.ToString() ?? "");
             data.Add("to", e.Current?.Location.ToString() ?? "");
             data.Add(nameof(e.Source), e.Source.ToString());
         });
 
+        // Update the transaction name to the final resolved route now that navigation is confirmed
+        if (_options.EnableNavigationTransactions && _currentTransaction != null)
+        {
+            _currentTransaction.Name = e.Current?.Location.ToString() ?? _currentTransaction.Name;
+        }
+    }
+
     // Page Events
 
     private void OnPageOnAppearing(object? sender, EventArgs _) =>

src/Sentry.Maui/SentryMauiOptions.cs

@@ -76,6 +76,23 @@ public SentryMauiOptions()
     /// </remarks>
     public bool AttachScreenshot { get; set; }
 
+    /// <summary>
+    /// Automatically starts a Sentry transaction when the user navigates to a new page and sets it on the scope,
+    /// allowing child spans (e.g. HTTP requests, database calls) to be attached during page load.
+    /// The transaction finishes automatically after <see cref="NavigationTransactionIdleTimeout"/> if not
+    /// finished explicitly first (e.g. by a subsequent navigation).
+    /// Requires <see cref="SentryOptions.TracesSampleRate"/> or <see cref="SentryOptions.TracesSampler"/> to
+    /// be configured.
+    /// The default is <c>true</c>.
+    /// </summary>
+    public bool EnableNavigationTransactions { get; set; } = true;
+
+    /// <summary>
+    /// Controls how long an automatic navigation transaction waits before finishing itself when not explicitly
+    /// finished. Defaults to 3 seconds.
+    /// </summary>
+    public TimeSpan NavigationTransactionIdleTimeout { get; set; } = TimeSpan.FromSeconds(3);
+
     private Func<SentryEvent, SentryHint, bool>? _beforeCapture;
     /// <summary>
     /// Action performed before attaching a screenshot

src/Sentry/Extensibility/DisabledHub.cs

@@ -6,7 +6,7 @@ namespace Sentry.Extensibility;
 /// <summary>
 /// Disabled Hub.
 /// </summary>
-public class DisabledHub : IHub, IDisposable
+public class DisabledHub : IHub, IHubInternal, IDisposable
 {
     /// <summary>
     /// The singleton instance.
@@ -81,6 +81,12 @@ public void UnsetTag(string key)
     public ITransactionTracer StartTransaction(ITransactionContext context,
         IReadOnlyDictionary<string, object?> customSamplingContext) => NoOpTransaction.Instance;
 
+    /// <summary>
+    /// Returns a dummy transaction.
+    /// </summary>
+    public ITransactionTracer StartTransaction(ITransactionContext context, TimeSpan? idleTimeout)
+        => NoOpTransaction.Instance;
+
     /// <summary>
     /// No-Op.
     /// </summary>

src/Sentry/Extensibility/HubAdapter.cs

@@ -1,4 +1,5 @@
 using Sentry.Infrastructure;
+using Sentry.Internal;
 using Sentry.Protocol.Envelopes;
 
 namespace Sentry.Extensibility;
@@ -12,7 +13,7 @@ namespace Sentry.Extensibility;
 /// </remarks>
 /// <inheritdoc cref="IHub" />
 [DebuggerStepThrough]
-public sealed class HubAdapter : IHub
+public sealed class HubAdapter : IHub, IHubInternal
 {
     /// <summary>
     /// The single instance which forwards all calls to <see cref="SentrySdk"/>
@@ -121,6 +122,13 @@ internal ITransactionTracer StartTransaction(
         DynamicSamplingContext? dynamicSamplingContext)
         => SentrySdk.StartTransaction(context, customSamplingContext, dynamicSamplingContext);
 
+    /// <summary>
+    /// Forwards the call to <see cref="SentrySdk"/>.
+    /// </summary>
+    [DebuggerStepThrough]
+    ITransactionTracer IHubInternal.StartTransaction(ITransactionContext context, TimeSpan? idleTimeout)
+        => SentrySdk.StartTransaction(context, idleTimeout);
+
     /// <summary>
     /// Forwards the call to <see cref="SentrySdk"/>.
     /// </summary>

src/Sentry/ITransactionTracer.cs

@@ -26,4 +26,9 @@ public interface ITransactionTracer : ITransactionData, ISpan
     /// Gets the last active (not finished) span in this transaction.
     /// </summary>
     public ISpan? GetLastActiveSpan();
+
+    /// <summary>
+    /// Resets the idle timeout for auto-finishing transactions. No-op for transactions without an idle timeout.
+    /// </summary>
+    public void ResetIdleTimeout();
 }

src/Sentry/Infrastructure/ITimer.cs

@@ -0,0 +1,17 @@
+namespace Sentry.Infrastructure;
+
+/// <summary>
+/// Abstraction over a one-shot timer, to allow deterministic testing.
+/// </summary>
+internal interface ISentryTimer : IDisposable
+{
+    /// <summary>
+    /// Starts (or restarts) the timer to fire after <paramref name="timeout"/>.
+    /// </summary>
+    public void Start(TimeSpan timeout);
+
+    /// <summary>
+    /// Cancels any pending fire. Has no effect if the timer is already cancelled.
+    /// </summary>
+    public void Cancel();
+}

src/Sentry/Infrastructure/SystemTimer.cs

@@ -0,0 +1,22 @@
+namespace Sentry.Infrastructure;
+
+/// <summary>
+/// Production <see cref="ISentryTimer"/> backed by <see cref="System.Threading.Timer"/>.
+/// </summary>
+internal sealed class SystemTimer : ISentryTimer
+{
+    private readonly Timer _timer;
+
+    public SystemTimer(Action callback)
+    {
+        _timer = new Timer(_ => callback(), null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+    }
+
+    public void Start(TimeSpan timeout) =>
+        _timer.Change(timeout, Timeout.InfiniteTimeSpan);
+
+    public void Cancel() =>
+        _timer.Change(Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+
+    public void Dispose() => _timer.Dispose();
+}

src/Sentry/Internal/Hub.cs

@@ -6,7 +6,7 @@
 
 namespace Sentry.Internal;
 
-internal class Hub : IHub, IDisposable
+internal class Hub : IHub, IHubInternal, IDisposable
 {
     private readonly Lock _sessionPauseLock = new();
 
@@ -173,10 +173,14 @@ public ITransactionTracer StartTransaction(
         IReadOnlyDictionary<string, object?> customSamplingContext)
         => StartTransaction(context, customSamplingContext, null);
 
+    public ITransactionTracer StartTransaction(ITransactionContext context, TimeSpan? idleTimeout)
+        => StartTransaction(context, new Dictionary<string, object?>(), null, idleTimeout);
+
     internal ITransactionTracer StartTransaction(
         ITransactionContext context,
         IReadOnlyDictionary<string, object?> customSamplingContext,
-        DynamicSamplingContext? dynamicSamplingContext)
+        DynamicSamplingContext? dynamicSamplingContext,
+        TimeSpan? idleTimeout = null)
     {
         // If the hub is disabled, we will always sample out.  In other words, starting a transaction
         // after disposing the hub will result in that transaction not being sent to Sentry.
@@ -255,7 +259,7 @@ internal ITransactionTracer StartTransaction(
             return unsampledTransaction;
         }
 
-        var transaction = new TransactionTracer(this, context)
+        var transaction = new TransactionTracer(this, context, idleTimeout)
         {
             SampleRate = sampleRate,
             SampleRand = sampleRand,

src/Sentry/Internal/IHubInternal.cs

@@ -0,0 +1,15 @@
+namespace Sentry.Internal;
+
+/// <summary>
+/// Internal hub interface exposing additional overloads not part of the public <see cref="IHub"/> contract.
+/// Implemented by <see cref="Hub"/>, <see cref="Extensibility.DisabledHub"/>, and
+/// <see cref="Extensibility.HubAdapter"/>.
+/// </summary>
+internal interface IHubInternal : IHub
+{
+    /// <summary>
+    /// Starts a transaction that will automatically finish after <paramref name="idleTimeout"/> if not
+    /// finished explicitly first.
+    /// </summary>
+    public ITransactionTracer StartTransaction(ITransactionContext context, TimeSpan? idleTimeout);
+}

src/Sentry/Internal/NoOpTransaction.cs

@@ -93,5 +93,7 @@ public IReadOnlyList<string> Fingerprint
 
     public ISpan? GetLastActiveSpan() => default;
 
+    public void ResetIdleTimeout() { }
+
     public void AddBreadcrumb(Breadcrumb breadcrumb) { }
 }

src/Sentry/SentrySdk.cs

@@ -210,6 +210,11 @@ public static IDisposable Init(Action<SentryOptions>? configureOptions)
 
     internal static IDisposable UseHub(IHub hub)
     {
+        if (hub is HubAdapter)
+        {
+            hub.GetSentryOptions()?.LogError("Attempting to initianise the SentrySdk with a HubAdapter can lead to infinite recursion. Initialisation cancelled.");
+            return DisabledHub.Instance;
+        }
         var oldHub = Interlocked.Exchange(ref CurrentHub, hub);
         (oldHub as IDisposable)?.Dispose();
         return new DisposeHandle(hub);
@@ -663,6 +668,16 @@ internal static ITransactionTracer StartTransaction(
         DynamicSamplingContext? dynamicSamplingContext)
         => CurrentHub.StartTransaction(context, customSamplingContext, dynamicSamplingContext);
 
+    /// <summary>
+    /// Starts a transaction that will automatically finish after <paramref name="idleTimeout"/> if not
+    /// finished explicitly first.
+    /// </summary>
+    [DebuggerStepThrough]
+    internal static ITransactionTracer StartTransaction(ITransactionContext context, TimeSpan? idleTimeout)
+        => CurrentHub is IHubInternal internalHub
+            ? internalHub.StartTransaction(context, idleTimeout)
+            : CurrentHub.StartTransaction(context);
+
     /// <summary>
     /// Starts a transaction.
     /// </summary>

src/Sentry/SpanTracer.cs

@@ -156,6 +156,7 @@ public void Finish()
     {
         Status ??= SpanStatus.Ok;
         EndTimestamp ??= _stopwatch.CurrentDateTimeOffset;
+        Transaction?.ChildSpanFinished();
     }
 
     /// <inheritdoc />