[go_router] Fix routing to treat URLs with different cases (e.g., /Home vs /home) as distinct routes. (#9426)

Fixes flutter/flutter#169809

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: ValentinVignal

packages/go_router/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 15.2.4
+
+- Fixes routing to treat URLs with different cases (e.g., `/Home` vs `/home`) as distinct routes.
+
 ## 15.2.3
 
 - Updates Type-safe routes topic documentation to use the mixin from `go_router_builder` 3.0.0.

packages/go_router/lib/src/configuration.dart

@@ -20,6 +20,8 @@ import 'state.dart';
 typedef GoRouterRedirect = FutureOr<String?> Function(
     BuildContext context, GoRouterState state);
 
+typedef _NamedPath = ({String path, bool caseSensitive});
+
 /// The route configuration for GoRouter configured by the app.
 class RouteConfiguration {
   /// Constructs a [RouteConfiguration].
@@ -246,7 +248,7 @@ class RouteConfiguration {
   ///    example.
   final Codec<Object?, Object?>? extraCodec;
 
-  final Map<String, String> _nameToPath = <String, String>{};
+  final Map<String, _NamedPath> _nameToPath = <String, _NamedPath>{};
 
   /// Looks up the url location by a [GoRoute]'s name.
   String namedLocation(
@@ -264,11 +266,11 @@ class RouteConfiguration {
       return true;
     }());
     assert(_nameToPath.containsKey(name), 'unknown route name: $name');
-    final String path = _nameToPath[name]!;
+    final _NamedPath path = _nameToPath[name]!;
     assert(() {
       // Check that all required params are present
       final List<String> paramNames = <String>[];
-      patternToRegExp(path, paramNames);
+      patternToRegExp(path.path, paramNames, caseSensitive: path.caseSensitive);
       for (final String paramName in paramNames) {
         assert(pathParameters.containsKey(paramName),
             'missing param "$paramName" for $path');
@@ -284,7 +286,10 @@ class RouteConfiguration {
       for (final MapEntry<String, String> param in pathParameters.entries)
         param.key: Uri.encodeComponent(param.value)
     };
-    final String location = patternToPath(path, encodedParams);
+    final String location = patternToPath(
+      path.path,
+      encodedParams,
+    );
     return Uri(
             path: location,
             queryParameters: queryParameters.isEmpty ? null : queryParameters,
@@ -528,8 +533,9 @@ class RouteConfiguration {
 
     if (_nameToPath.isNotEmpty) {
       sb.writeln('known full paths for route names:');
-      for (final MapEntry<String, String> e in _nameToPath.entries) {
-        sb.writeln('  ${e.key} => ${e.value}');
+      for (final MapEntry<String, _NamedPath> e in _nameToPath.entries) {
+        sb.writeln(
+            '  ${e.key} => ${e.value.path}${e.value.caseSensitive ? '' : ' (case-insensitive)'}');
       }
     }
 
@@ -594,8 +600,9 @@ class RouteConfiguration {
           assert(
               !_nameToPath.containsKey(name),
               'duplication fullpaths for name '
-              '"$name":${_nameToPath[name]}, $fullPath');
-          _nameToPath[name] = fullPath;
+              '"$name":${_nameToPath[name]!.path}, $fullPath');
+          _nameToPath[name] =
+              (path: fullPath, caseSensitive: route.caseSensitive);
         }
 
         if (route.routes.isNotEmpty) {

packages/go_router/lib/src/match.dart

@@ -660,9 +660,20 @@ class RouteMatchList with Diagnosticable {
         matches: newMatches,
       );
     }
+
+    if (newMatches.isEmpty) {
+      return RouteMatchList.empty;
+    }
+
+    RouteBase newRoute = newMatches.last.route;
+    while (newRoute is ShellRouteBase) {
+      newRoute = newRoute.routes.last;
+    }
+    newRoute as GoRoute;
     // Need to remove path parameters that are no longer in the fullPath.
     final List<String> newParameters = <String>[];
-    patternToRegExp(fullPath, newParameters);
+    patternToRegExp(fullPath, newParameters,
+        caseSensitive: newRoute.caseSensitive);
     final Set<String> validParameters = newParameters.toSet();
     final Map<String, String> newPathParameters =
         Map<String, String>.fromEntries(

packages/go_router/lib/src/path_utils.dart

@@ -23,7 +23,8 @@ final RegExp _parameterRegExp = RegExp(r':(\w+)(\((?:\\.|[^\\()])+\))?');
 /// To extract the path parameter values from a [RegExpMatch], pass the
 /// [RegExpMatch] into [extractPathParameters] with the `parameters` that are
 /// used for generating the [RegExp].
-RegExp patternToRegExp(String pattern, List<String> parameters) {
+RegExp patternToRegExp(String pattern, List<String> parameters,
+    {required bool caseSensitive}) {
   final StringBuffer buffer = StringBuffer('^');
   int start = 0;
   for (final RegExpMatch match in _parameterRegExp.allMatches(pattern)) {
@@ -47,7 +48,7 @@ RegExp patternToRegExp(String pattern, List<String> parameters) {
   if (!pattern.endsWith('/')) {
     buffer.write(r'(?=/|$)');
   }
-  return RegExp(buffer.toString(), caseSensitive: false);
+  return RegExp(buffer.toString(), caseSensitive: caseSensitive);
 }
 
 String _escapeGroup(String group, [String? name]) {

packages/go_router/lib/src/route.dart

@@ -285,7 +285,8 @@ class GoRoute extends RouteBase {
             'if onExit is provided, one of pageBuilder or builder must be provided'),
         super._() {
     // cache the path regexp and parameters
-    _pathRE = patternToRegExp(path, pathParameters);
+    _pathRE =
+        patternToRegExp(path, pathParameters, caseSensitive: caseSensitive);
   }
 
   /// Whether this [GoRoute] only redirects to another route.
@@ -1193,7 +1194,8 @@ class StatefulNavigationShell extends StatefulWidget {
       /// find the first GoRoute, from which a full path will be derived.
       final GoRoute route = branch.defaultRoute!;
       final List<String> parameters = <String>[];
-      patternToRegExp(route.path, parameters);
+      patternToRegExp(route.path, parameters,
+          caseSensitive: route.caseSensitive);
       assert(parameters.isEmpty);
       final String fullPath = _router.configuration.locationForRoute(route)!;
       return patternToPath(

packages/go_router/pubspec.yaml

@@ -1,7 +1,7 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 15.2.3
+version: 15.2.4
 repository: https://github.com/flutter/packages/tree/main/packages/go_router
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router%22
 

packages/go_router/test/go_router_test.dart

@@ -13,6 +13,7 @@ import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:go_router/go_router.dart';
 import 'package:go_router/src/match.dart';
+import 'package:go_router/src/pages/material.dart';
 import 'package:logging/logging.dart';
 
 import 'test_helpers.dart';
@@ -782,12 +783,6 @@ void main() {
     });
 
     testWidgets('match path case sensitively', (WidgetTester tester) async {
-      final FlutterExceptionHandler? oldFlutterError = FlutterError.onError;
-      addTearDown(() => FlutterError.onError = oldFlutterError);
-      final List<FlutterErrorDetails> errors = <FlutterErrorDetails>[];
-      FlutterError.onError = (FlutterErrorDetails details) {
-        errors.add(details);
-      };
       final List<GoRoute> routes = <GoRoute>[
         GoRoute(
           path: '/',
@@ -804,16 +799,11 @@ void main() {
       final GoRouter router = await createRouter(routes, tester);
       const String wrongLoc = '/FaMiLy/f2';
 
-      expect(errors, isEmpty);
       router.go(wrongLoc);
       await tester.pumpAndSettle();
 
-      expect(errors, hasLength(1));
-      expect(
-        errors.single.exception,
-        isAssertionError,
-        reason: 'The path is case sensitive',
-      );
+      expect(find.byType(MaterialErrorScreen), findsOne);
+      expect(find.text('Page Not Found'), findsOne);
 
       const String loc = '/family/f2';
       router.go(loc);
@@ -827,8 +817,42 @@ void main() {
       );
 
       expect(matches, hasLength(1));
-      expect(find.byType(FamilyScreen), findsOneWidget);
-      expect(errors, hasLength(1), reason: 'No new errors should be thrown');
+      expect(find.byType(FamilyScreen), findsOne);
+    });
+
+    testWidgets('supports routes with a different case',
+        (WidgetTester tester) async {
+      final List<GoRoute> routes = <GoRoute>[
+        GoRoute(
+          path: '/',
+          builder: (BuildContext context, GoRouterState state) =>
+              const HomeScreen(),
+        ),
+        GoRoute(
+          path: '/abc',
+          builder: (BuildContext context, GoRouterState state) =>
+              const SizedBox(key: Key('abc')),
+        ),
+        GoRoute(
+          path: '/ABC',
+          builder: (BuildContext context, GoRouterState state) =>
+              const SizedBox(key: Key('ABC')),
+        ),
+      ];
+
+      final GoRouter router = await createRouter(routes, tester);
+      const String loc1 = '/abc';
+
+      router.go(loc1);
+      await tester.pumpAndSettle();
+
+      expect(find.byKey(const Key('abc')), findsOne);
+
+      const String loc = '/ABC';
+      router.go(loc);
+      await tester.pumpAndSettle();
+
+      expect(find.byKey(const Key('ABC')), findsOne);
     });
 
     testWidgets(

packages/go_router/test/path_utils_test.dart

@@ -9,7 +9,8 @@ void main() {
   test('patternToRegExp without path parameter', () async {
     const String pattern = '/settings/detail';
     final List<String> pathParameter = <String>[];
-    final RegExp regex = patternToRegExp(pattern, pathParameter);
+    final RegExp regex =
+        patternToRegExp(pattern, pathParameter, caseSensitive: true);
     expect(pathParameter.isEmpty, isTrue);
     expect(regex.hasMatch('/settings/detail'), isTrue);
     expect(regex.hasMatch('/settings/'), isFalse);
@@ -22,7 +23,8 @@ void main() {
   test('patternToRegExp with path parameter', () async {
     const String pattern = '/user/:id/book/:bookId';
     final List<String> pathParameter = <String>[];
-    final RegExp regex = patternToRegExp(pattern, pathParameter);
+    final RegExp regex =
+        patternToRegExp(pattern, pathParameter, caseSensitive: true);
     expect(pathParameter.length, 2);
     expect(pathParameter[0], 'id');
     expect(pathParameter[1], 'bookId');
@@ -44,7 +46,8 @@ void main() {
   test('patternToPath without path parameter', () async {
     const String pattern = '/settings/detail';
     final List<String> pathParameter = <String>[];
-    final RegExp regex = patternToRegExp(pattern, pathParameter);
+    final RegExp regex =
+        patternToRegExp(pattern, pathParameter, caseSensitive: true);
 
     const String url = '/settings/detail';
     final RegExpMatch? match = regex.firstMatch(url);
@@ -60,7 +63,8 @@ void main() {
   test('patternToPath with path parameter', () async {
     const String pattern = '/user/:id/book/:bookId';
     final List<String> pathParameter = <String>[];
-    final RegExp regex = patternToRegExp(pattern, pathParameter);
+    final RegExp regex =
+        patternToRegExp(pattern, pathParameter, caseSensitive: true);
 
     const String url = '/user/123/book/456';
     final RegExpMatch? match = regex.firstMatch(url);

packages/go_router/test/route_data_test.dart

@@ -50,7 +50,7 @@ class _ShellRouteDataWithKey extends ShellRouteData {
     GoRouterState state,
     Widget navigator,
   ) =>
-      SizedBox(
+      KeyedSubtree(
         key: key,
         child: navigator,
       );