Remove unused go_router imports

lib/screens/brewery_screen.dart

@@ -1,6 +1,5 @@
 import 'dart:async';
 import 'package:flutter/material.dart';
-import 'package:go_router/go_router.dart';
 import 'package:provider/provider.dart';
 import '../providers/providers.dart';
 import '../models/models.dart';
@@ -39,25 +38,13 @@ class _BreweryScreenState extends State<BreweryScreen> {
     });
   }
 
-  /// Safely check if we can pop (handles test contexts without GoRouter)
-  bool _canPop(BuildContext context) {
-    try {
-      return GoRouter.of(context).canPop();
-    } catch (e) {
-      return false;
-    }
-  }
-
   @override
   Widget build(BuildContext context) {
     final provider = context.watch<BeerProvider>();
 
     // Show loading state while drinks are being fetched
     if (provider.isLoading) {
-      return Scaffold(
-        appBar: AppBar(title: const Text('Loading...')),
-        body: const Center(child: CircularProgressIndicator()),
-      );
+      return buildLoadingScaffold();
     }
 
     // Get all drinks from this brewery
@@ -80,19 +67,7 @@ class _BreweryScreenState extends State<BreweryScreen> {
     return Scaffold(
       appBar: AppBar(
         title: _buildAppBarTitle(context, provider, producer),
-        leading: _canPop(context)
-            ? null
-            : Semantics(
-                label: 'Go to home screen',
-                hint: 'Double tap to return to drinks list',
-                button: true,
-                child: IconButton(
-                  icon: const Icon(Icons.home),
-                  onPressed: () =>
-                      context.go(buildFestivalHome(widget.festivalId)),
-                  tooltip: 'Home',
-                ),
-              ),
+        leading: buildHomeLeadingButton(context, widget.festivalId),
       ),
       body: CustomScrollView(
         slivers: [
@@ -122,25 +97,10 @@ class _BreweryScreenState extends State<BreweryScreen> {
     BeerProvider provider,
     Producer producer,
   ) {
-    final festivalName = provider.currentFestival.name;
-
-    return Column(
-      mainAxisSize: MainAxisSize.min,
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: [
-        Text(
-          producer.name,
-          style: Theme.of(context).textTheme.titleLarge,
-          overflow: TextOverflow.ellipsis,
-        ),
-        Text(
-          festivalName,
-          style: Theme.of(context).textTheme.bodySmall?.copyWith(
-                color: Theme.of(context).colorScheme.onSurfaceVariant,
-              ),
-          overflow: TextOverflow.ellipsis,
-        ),
-      ],
+    return buildBreadcrumbTitle(
+      context,
+      title: producer.name,
+      festivalName: provider.currentFestival.name,
     );
   }
 

lib/screens/drink_detail_screen.dart

@@ -46,10 +46,7 @@ class _DrinkDetailScreenState extends State<DrinkDetailScreen> {
 
     // Show loading state while drinks are being fetched
     if (provider.isLoading) {
-      return Scaffold(
-        appBar: AppBar(title: const Text('Loading...')),
-        body: const Center(child: CircularProgressIndicator()),
-      );
+      return buildLoadingScaffold();
     }
 
     final drink = provider.getDrinkById(widget.drinkId);
@@ -66,18 +63,7 @@ class _DrinkDetailScreenState extends State<DrinkDetailScreen> {
     return Scaffold(
       appBar: AppBar(
         title: _buildAppBarTitle(context, provider, drink),
-        leading: _canPop(context)
-            ? null
-            : Semantics(
-                label: 'Go to home screen',
-                hint: 'Double tap to return to drinks list',
-                button: true,
-                child: IconButton(
-                  icon: const Icon(Icons.home),
-                  onPressed: () => context.go(buildFestivalHome(widget.festivalId)),
-                  tooltip: 'Home',
-                ),
-              ),
+        leading: buildHomeLeadingButton(context, widget.festivalId),
       ),
       body: Column(
         children: [
@@ -475,13 +461,4 @@ class _DrinkDetailScreenState extends State<DrinkDetailScreen> {
     final provider = context.read<BeerProvider>();
     unawaited(provider.analyticsService.logDrinkShared(drink));
   }
-
-  bool _canPop(BuildContext context) {
-    try {
-      GoRouter.of(context);
-      return context.canPop();
-    } catch (e) {
-      return true;
-    }
-  }
 }

lib/screens/style_screen.dart

@@ -1,6 +1,5 @@
 import 'dart:async';
 import 'package:flutter/material.dart';
-import 'package:go_router/go_router.dart';
 import 'package:provider/provider.dart';
 import '../providers/providers.dart';
 import '../models/models.dart';
@@ -33,25 +32,13 @@ class _StyleScreenState extends State<StyleScreen> {
     });
   }
 
-  /// Safely check if we can pop (handles test contexts without GoRouter)
-  bool _canPop(BuildContext context) {
-    try {
-      return GoRouter.of(context).canPop();
-    } catch (e) {
-      return false;
-    }
-  }
-
   @override
   Widget build(BuildContext context) {
     final provider = context.watch<BeerProvider>();
 
     // Show loading state while drinks are being fetched
     if (provider.isLoading) {
-      return Scaffold(
-        appBar: AppBar(title: const Text('Loading...')),
-        body: const Center(child: CircularProgressIndicator()),
-      );
+      return buildLoadingScaffold();
     }
 
     // Get all drinks with this style
@@ -73,19 +60,7 @@ class _StyleScreenState extends State<StyleScreen> {
     return Scaffold(
       appBar: AppBar(
         title: _buildAppBarTitle(context, provider),
-        leading: _canPop(context)
-            ? null
-            : Semantics(
-                label: 'Go to home screen',
-                hint: 'Double tap to return to drinks list',
-                button: true,
-                child: IconButton(
-                  icon: const Icon(Icons.home),
-                  onPressed: () =>
-                      context.go(buildFestivalHome(widget.festivalId)),
-                  tooltip: 'Home',
-                ),
-              ),
+        leading: buildHomeLeadingButton(context, widget.festivalId),
       ),
       body: CustomScrollView(
         slivers: [
@@ -123,25 +98,10 @@ class _StyleScreenState extends State<StyleScreen> {
 
   /// Build the app bar title with breadcrumb navigation
   Widget _buildAppBarTitle(BuildContext context, BeerProvider provider) {
-    final festivalName = provider.currentFestival.name;
-
-    return Column(
-      mainAxisSize: MainAxisSize.min,
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: [
-        Text(
-          widget.style,
-          style: Theme.of(context).textTheme.titleLarge,
-          overflow: TextOverflow.ellipsis,
-        ),
-        Text(
-          festivalName,
-          style: Theme.of(context).textTheme.bodySmall?.copyWith(
-                color: Theme.of(context).colorScheme.onSurfaceVariant,
-              ),
-          overflow: TextOverflow.ellipsis,
-        ),
-      ],
+    return buildBreadcrumbTitle(
+      context,
+      title: widget.style,
+      festivalName: provider.currentFestival.name,
     );
   }
 

lib/utils/navigation_helpers.dart

@@ -7,6 +7,9 @@
 /// characters safely.
 library;
 
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
 /// Builds a festival-scoped URL path.
 ///
 /// The [festivalId] and [path] must not be empty.
@@ -191,3 +194,25 @@ String? extractFestivalId(String path) {
 bool isFestivalPath(String path) {
   return extractFestivalId(path) != null;
 }
+
+/// Checks if navigation can pop in the current context.
+///
+/// Safely handles contexts where GoRouter may not be available (e.g., in tests).
+/// Returns `true` if the router can navigate back, `false` otherwise.
+///
+/// This is useful for determining whether to show a back button or a home button
+/// in the app bar.
+///
+/// Example:
+/// ```dart
+/// final canPop = canPopNavigation(context);
+/// leading: canPop ? null : IconButton(icon: Icon(Icons.home), ...)
+/// ```
+bool canPopNavigation(BuildContext context) {
+  try {
+    return GoRouter.of(context).canPop();
+  } catch (e) {
+    // GoRouter not available (e.g., in tests)
+    return false;
+  }
+}

lib/utils/utils.dart

@@ -6,3 +6,4 @@ export 'string_comparison_helper.dart';
 export 'string_formatting_helper.dart';
 export 'style_description_helper.dart';
 export 'url_launcher_helper.dart';
+export 'widget_builders.dart';

lib/utils/widget_builders.dart

@@ -0,0 +1,102 @@
+/// Common widget builders for reducing duplication across screens.
+///
+/// This file contains reusable widget builders that are used across multiple
+/// screens to maintain consistency and reduce code duplication.
+library;
+
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'navigation_helpers.dart';
+
+/// Builds a loading scaffold with standard appearance.
+///
+/// Used when data is being fetched to show a consistent loading state
+/// across all screens.
+///
+/// Example:
+/// ```dart
+/// if (provider.isLoading) {
+///   return buildLoadingScaffold();
+/// }
+/// ```
+Widget buildLoadingScaffold() {
+  return Scaffold(
+    appBar: AppBar(title: const Text('Loading...')),
+    body: const Center(child: CircularProgressIndicator()),
+  );
+}
+
+/// Builds a home button for the AppBar leading position.
+///
+/// Shows a home button instead of the back button when navigation cannot pop.
+/// This ensures users can always navigate back to the festival home.
+///
+/// The [festivalId] is used to navigate to the correct festival home page.
+///
+/// Example:
+/// ```dart
+/// AppBar(
+///   leading: buildHomeLeadingButton(context, festivalId),
+/// )
+/// ```
+Widget? buildHomeLeadingButton(BuildContext context, String festivalId) {
+  if (canPopNavigation(context)) {
+    return null; // Use default back button
+  }
+
+  return Semantics(
+    label: 'Go to home screen',
+    hint: 'Double tap to return to drinks list',
+    button: true,
+    child: IconButton(
+      icon: const Icon(Icons.home),
+      onPressed: () => context.go(buildFestivalHome(festivalId)),
+      tooltip: 'Home',
+    ),
+  );
+}
+
+/// Builds a breadcrumb-style title for the AppBar.
+///
+/// Shows a primary title with the festival name as a subtitle for context.
+/// This provides consistent navigation breadcrumbs across detail screens.
+///
+/// The [title] is the main heading (e.g., brewery name, style name, drink name).
+/// The [festivalName] appears as a smaller subtitle below the title.
+///
+/// Example:
+/// ```dart
+/// AppBar(
+///   title: buildBreadcrumbTitle(
+///     context,
+///     title: 'IPA',
+///     festivalName: 'Cambridge Beer Festival 2025',
+///   ),
+/// )
+/// ```
+Widget buildBreadcrumbTitle(
+  BuildContext context, {
+  required String title,
+  required String festivalName,
+}) {
+  final theme = Theme.of(context);
+
+  return Column(
+    mainAxisSize: MainAxisSize.min,
+    crossAxisAlignment: CrossAxisAlignment.start,
+    children: [
+      Text(
+        title,
+        style: theme.textTheme.titleLarge,
+        overflow: TextOverflow.ellipsis,
+      ),
+      Text(
+        festivalName,
+        style: theme.textTheme.bodySmall?.copyWith(
+          color: theme.colorScheme.onSurfaceVariant,
+        ),
+        overflow: TextOverflow.ellipsis,
+      ),
+    ],
+  );
+}

test/utils/navigation_helpers_test.dart

@@ -1,4 +1,5 @@
 import 'package:cambridge_beer_festival/utils/utils.dart';
+import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
@@ -315,5 +316,28 @@ void main() {
         );
       });
     });
+
+    group('canPopNavigation', () {
+      testWidgets('returns false when GoRouter is not available', (tester) async {
+        // In test environment with MaterialApp but without GoRouter
+        await tester.pumpWidget(
+          MaterialApp(
+            home: Builder(
+              builder: (context) {
+                final result = canPopNavigation(context);
+                return Scaffold(
+                  body: Text('Can pop: $result'),
+                );
+              },
+            ),
+          ),
+        );
+
+        await tester.pumpAndSettle();
+
+        // Without GoRouter, canPopNavigation should return false
+        expect(find.text('Can pop: false'), findsOneWidget);
+      });
+    });
   });
 }