fix(blazor): Skip duplicate navigation breadcrumbs in WASM (#4922)

* fix(blazor): Skip duplicate navigation breadcrumbs in WASM

When Blazor apps use both @OnClick+NavigateTo and href on links,
LocationChanged fires twice for the same URL. Skip creating a
breadcrumb when the new location matches the previous one.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add changelog entry for duplicate breadcrumb fix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Remove changelog entry

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: bruno-garcia

src/Sentry.AspNetCore.Blazor.WebAssembly/Internal/BlazorWasmOptionsSetup.cs

@@ -42,6 +42,12 @@ public void Configure(SentryBlazorOptions options)
 
         _navigationManager.LocationChanged += (_, args) =>
         {
+            // Skip duplicate navigations (e.g. when both @onclick+NavigateTo and href fire)
+            if (string.Equals(args.Location, previousUrl, StringComparison.Ordinal))
+            {
+                return;
+            }
+
             var from = ToRelativePath(previousUrl);
             var to = ToRelativePath(args.Location);
 

test/Sentry.AspNetCore.Blazor.WebAssembly.Tests/BlazorWasmOptionsSetupTests.cs

@@ -147,4 +147,18 @@ public void Navigation_FromInitialPath_TracksCorrectFrom()
         crumb.Data.Should().ContainKey("from").WhoseValue.Should().Be("/login");
         crumb.Data.Should().ContainKey("to").WhoseValue.Should().Be("/home");
     }
+
+    [Fact]
+    public void DuplicateNavigation_SkipsBreadcrumb()
+    {
+        // Arrange
+        _sut.Configure(new SentryBlazorOptions());
+
+        // Act — navigate to /page1, then fire LocationChanged again for the same URL
+        _navigationManager.NavigateTo("/page1");
+        _navigationManager.NavigateTo("/page1");
+
+        // Assert — only one breadcrumb should be created
+        _scope.Breadcrumbs.Should().ContainSingle();
+    }
 }