🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 34659

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 34659"

@jfversluis ,
thanks for this addition. Is it possible to also add this on a Microsoft.Maui.Controls.ToolbarItem? I know that is supported on iOS 26 (UIBarButtonItemBadge) and Android (BadgeDrawable).

/azp run maui-pr-uitests

/azp run maui-pr

/azp run maui-pr-uitests

/azp run maui-pr-uitests

/azp run maui-pr

/azp run maui-pr-uitests

/azp run maui-pr

/azp run maui-pr-uitests

/azp run maui-pr

/azp run maui-pr-uitests

Code Review Summary

Shell badge tabs support — Adds BadgeText, BadgeColor, BadgeTextColor to BaseShellItem with platform-specific rendering on Android, iOS/MacCatalyst, and Windows. 28 unit tests, 4 UI screenshot tests, comprehensive gallery sample.

Findings

Overall Assessment

✅ Looks good — well-designed feature with excellent test coverage. The Android index guard (🔴) should be fixed to prevent crashes on section removal during property change propagation. Other findings are non-blocking.

Review performed by Copilot CLI

🧪 PR Test Evaluation

Overall Verdict: ⚠️ Tests need improvement

The PR adds solid unit test coverage for the new badge properties, but the most recent bug fix (index guard in OnShellSectionPropertyChanged) lacks a dedicated test, UI tests have a missing WaitForElement call, and MacCatalyst screenshot coverage is absent.

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🧪 Test evaluation by Evaluate PR Tests

Code Review — PR #34659

Independent Assessment

What this changes: Adds BadgeText, BadgeColor, and BadgeTextColor bindable properties to BaseShellItem, enabling badge notifications on Shell bottom tabs across Android, iOS/MacCatalyst, and Windows. Companion to PR #34669 (ToolbarItem badges) — together they close #8305.

Target branch: net11.0 — correct for new API feature. Milestone .NET 11.0-preview4.

Reconciliation with PR Narrative

Agreement: ✅ Code matches description. Three new properties on BaseShellItem with platform implementations using native badge APIs. Same null/empty/text semantics as the ToolbarItem PR.

Findings

✅ Good — Consistent API design with ToolbarItem badges

Same three properties (BadgeText, BadgeColor, BadgeTextColor) with identical semantics:

• null = hidden, "" = dot indicator, non-empty = text/count
• Properties use BindingMode.OneWay — appropriate for display-only properties set from code/binding
• Comprehensive XML documentation on all three properties

✅ Good — Android: Correct overflow handling

UpdateAllBadges() correctly handles the "More" tab overflow case:

• When items.Count > maxItems, indices 0..maxItems-2 get badges, index maxItems-1 (More tab) is explicitly cleared
• OnShellSectionPropertyChanged has the same guard: !(itemCount > maxItems && index > maxItems - 2)
• UpdateShellSectionBadge uses BottomNavigationView.GetOrCreateBadge()/RemoveBadge() — native Material Design API

✅ Good — iOS: Clean native integration

tabBarItem.BadgeValue = badgeText is null ? null : (badgeText.Length > 0 ? badgeText : "");

Single-line mapping to UITabBarItem.BadgeValue with correct semantics. BadgeColor and SetBadgeTextAttributes for color customization. No version check needed — UITabBarItem.BadgeValue has been available since iOS 2.0. Static helper method keeps code clean.

✅ Good — Windows: Proper MVVM approach

Badge support via ViewModel binding rather than imperative code:

• NavigationViewItemViewModel extended with BadgeText, BadgeBackground, BadgeForeground, computed BadgeValue, BadgeVisibility, HasBadge
• XAML template binds InfoBadge.Value, Background, Foreground, Visibility declaratively
• _badgeTrackedSections HashSet manages PropertyChanged subscriptions with cleanup in DisconnectHandler and SetVirtualView
• Smart BadgeValue computation: int.TryParse → numeric count, else -1 → WinUI dot indicator

✅ Good — Test coverage

• 28 unit tests covering defaults, get/set, clearing, PropertyChanged, binding, edge cases
• 4 UI screenshot tests: initial badge, runtime update, clearing, multiple tabs
• Screenshots for Android, iOS 26, and Windows
• Gallery sample page (ShellBadgeGallery) with interactive controls

✅ Good — All prior review feedback addressed

All 4 review threads resolved:

💡 Observation — Android remove+recreate for default color reset

In UpdateShellSectionBadge, when badgeText is non-null but badgeColor is null:

// Remove and recreate badge when clearing color to reset to platform default
if (badgeColor is null)
{
    _bottomView.RemoveBadge(menuItemId);
}
var badge = _bottomView.GetOrCreateBadge(menuItemId);

This means every badge without a custom color does a remove+recreate cycle. The comment explains the intent (Material BadgeDrawable has no "reset to default" API). This is correct but creates a brief flash on initial badge creation when no custom color is set. If this becomes a visual issue, the badgeColor is null removal could be skipped when the badge doesn't already exist. Not a blocker.

💡 Observation — Windows BadgeValue semantics

BadgeValue returns -1 for non-numeric/empty text, which WinUI InfoBadge renders as a dot. For negative numeric strings (e.g., "-5"), int.TryParse succeeds but the v >= 0 guard catches it, so it shows as a dot. This is correct — negative badge counts don't make sense.

ℹ️ Note — Flyout and top tab badges are out of scope

The PR explicitly notes these are tracked for future iterations in #8305. Bottom tabs only for this iteration.

ℹ️ Note — CI Status

No CI failures detected. Clean build.

Devil's Advocate

• "Should badge be on BaseShellItem or ShellSection?" — BaseShellItem is correct. It's the base for all navigable shell items, and future iterations (flyout badges, top tabs) will need it at this level.
• "Why not use a BadgeMode enum instead of string semantics?" — The string approach matches iOS native (UITabBarItem.BadgeValue is a string) and is more flexible (supports "99+", "New", etc.). An enum would be too restrictive.
• "Could the BottomNavigationView badge flicker on remove+recreate?" — Theoretically, but RemoveBadge + GetOrCreateBadge happens synchronously on the UI thread, so the flicker should be imperceptible. If reports arise, a check for existing badge before removal could be added.
• "Why doesn't iOS need a version check like the ToolbarItem PR?" — UITabBarItem.BadgeValue has been available since iOS 2.0. The ToolbarItem PR uses UIBarButtonItem.badge which is iOS 26+ only.

Verdict: LGTM

Confidence: high
Summary: Well-designed feature with consistent API across Shell and ToolbarItem badge systems. All three platform implementations use the correct native APIs. The Android overflow handling, iOS one-liner mapping, and Windows MVVM binding approach are all clean. 28 unit tests + 4 UI tests provide solid coverage. All prior review feedback addressed. Ready for merge alongside the companion PR #34669.

Review performed by Copilot CLI using the code-review skill

🚨 API change(s) detected @davidortinau FYI