Routing unencodes encoded hashes in the URL, producing in an incorrect URL #155992

import 'dart:html';
import 'dart:async';
import 'dart:collection';

import 'package:flutter_web_plugins/url_strategy.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

void main() {
  usePathUrlStrategy();
  runApp(const MainApp());
}

final routerDelegate = MyRouterDelegate();
final routeInfromationParser = MyRouteInformationParser();

class MainApp extends StatelessWidget {
  const MainApp({super.key});

  void printCurrentUrlInfo() {
    print('The current window.location.href is ${window.location.href}');
    var paramValue = Uri.parse(window.location.href).queryParameters['a'];
    print('The current query parameter "a" is ${paramValue}');
  }

  @override
  Widget build(BuildContext context) {
    printCurrentUrlInfo();
    Future.delayed(const Duration(seconds: 1))
        .then((_) => printCurrentUrlInfo());
    return MaterialApp.router(
      builder: (context, child) => child!,
      routerDelegate: routerDelegate,
      routeInformationParser: routeInfromationParser,
    );
  }
}

class MyRouteConfiguration {
  MyRouteConfiguration(this.page, this.params);

  final String page;
  final Map<String, String?> params;
}

class MyRouteInformationParser
    extends RouteInformationParser<MyRouteConfiguration> {
  @override
  Future<MyRouteConfiguration> parseRouteInformation(
    RouteInformation routeInformation,
  ) async {
    var uri = routeInformation.uri;

    // Paths start with /
    final page = uri.path.isNotEmpty ? uri.path.substring(1) : '';
    final configuration = MyRouteConfiguration(page, uri.queryParameters);
    return SynchronousFuture<MyRouteConfiguration>(configuration);
  }

  @override
  RouteInformation restoreRouteInformation(
    MyRouteConfiguration configuration,
  ) {
    return RouteInformation(
        uri: Uri(
      // Paths must always start with /
      path: '/${configuration.page}',
      queryParameters: configuration.params,
    ));
  }
}

class MyRouterDelegate extends RouterDelegate<MyRouteConfiguration>
    with ChangeNotifier, PopNavigatorRouterDelegateMixin<MyRouteConfiguration> {
  MyRouterDelegate() : navigatorKey = GlobalKey<NavigatorState>();

  static MyRouterDelegate of(BuildContext context) =>
      Router.of(context).routerDelegate as MyRouterDelegate;

  @override
  final GlobalKey<NavigatorState> navigatorKey;

  final _routes = ListQueue<MyRouteConfiguration>();

  @override
  MyRouteConfiguration? get currentConfiguration => _routes.lastOrNull;

  @override
  Widget build(BuildContext context) {
    final uri1 = Uri(path: '/home', queryParameters: {'a': 'bbb'});
    final uri2 = Uri(path: '/home', queryParameters: {'a': 'ccc#ddd'});

    return Navigator(
      key: navigatorKey,
      pages: [
        MaterialPage(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text('Open DevTools console!'),
              for (var uri in [uri1, uri2])
                TextButton(
                  onPressed: () => window.location.href = uri.toString(),
                  child: Text('Load page as $uri'),
                ),
            ],
          ),
        ),
      ],
      onDidRemovePage: (_) {
        if (_routes.length <= 1) return;
        _routes.removeLast();
        notifyListeners();
      },
    );
  }

  @override
  Future<void> setNewRoutePath(MyRouteConfiguration configuration) async {
    _routes
      ..clear()
      ..add(configuration);

    notifyListeners();
    return SynchronousFuture<void>(null);
  }
}