Fixed duplicate SentryMauiEventProcessors (#3905)

Author: jamescrosswell

CHANGELOG.md

@@ -11,6 +11,10 @@
 - .NET on iOS: Add experimental EnableAppHangTrackingV2 configuration flag to the options binding SDK ([#3877](https://github.com/getsentry/sentry-dotnet/pull/3877))
 - Added `SentryOptions.DisableSentryHttpMessageHandler`. Useful if you're using `OpenTelemetry.Instrumentation.Http` and ending up with duplicate spans. ([#3879](https://github.com/getsentry/sentry-dotnet/pull/3879))
 
+### Fixes
+
+- Fixed duplicate SentryMauiEventProcessors ([#3905](https://github.com/getsentry/sentry-dotnet/pull/3905))
+
 ### Dependencies
 
 - Bump Native SDK from v0.7.17 to v0.7.19 ([#3891](https://github.com/getsentry/sentry-dotnet/pull/3891), [#3908](https://github.com/getsentry/sentry-dotnet/pull/3908))

src/Sentry.Maui/Internal/SentryMauiOptionsSetup.cs

@@ -15,7 +15,7 @@ internal class SentryMauiOptionsSetup : IConfigureOptions<SentryMauiOptions>
     public SentryMauiOptionsSetup(IConfiguration config)
     {
         ArgumentNullException.ThrowIfNull(config);
-        _config = config;
+        _config = config.GetSection("Sentry");
     }
 
     public void Configure(SentryMauiOptions options)

src/Sentry.Maui/SentryMauiAppBuilderExtensions.cs

@@ -44,9 +44,6 @@ public static MauiAppBuilder UseSentry(this MauiAppBuilder builder,
     {
         var services = builder.Services;
 
-        var section = builder.Configuration.GetSection("Sentry");
-        services.AddSingleton<IConfigureOptions<SentryMauiOptions>>(_ => new SentryMauiOptionsSetup(section));
-
         if (configureOptions != null)
         {
             services.Configure(configureOptions);

test/Sentry.Maui.Tests/SentryMauiAppBuilderExtensionsTests.cs

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.Options;
 using Sentry.Internal.Http;
+using Sentry.Maui.Internal;
 using MauiConstants = Sentry.Maui.Internal.Constants;
 
 namespace Sentry.Maui.Tests;
@@ -29,6 +30,24 @@ public Fixture()
 
     private readonly Fixture _fixture = new();
 
+    [Fact]
+    public void UseSentry_RegistersEventProcessorOnlyOnce()
+    {
+        // Arrange
+        var builder = _fixture.Builder;
+        builder.Services.Configure<SentryMauiOptions>(options =>
+        {
+            options.Dsn = ValidDsn;
+        });
+
+        // Act
+        using var app = builder.UseSentry().Build();
+
+        // Assert
+        var options = app.Services.GetRequiredService<IOptions<SentryMauiOptions>>().Value;
+        options.EventProcessors.Should().ContainSingle(t => t.Type == typeof(SentryMauiEventProcessor));
+    }
+
     [Fact]
     public void CanUseSentry_WithConfigurationOnly()
     {