[go_router_builder] Creating a TypedGoRoute with non nullable queryParameter generates an invalid _fromState extension

[dancamdev]

Using go_router_builder: 1.0.15 and generating this route:

enum HomeTab { home, profile, settings }

@TypedGoRoute<HomeRoute>(path: '/')
class HomeRoute extends GoRouteData {
  const HomeRoute({this.tab = HomeTab.home});
  final HomeTab tab;

  @override
  Widget build(BuildContext context) => HomeScreen(tab: tab);
}

which resolves to the following generated code:

GoRoute get $homeRoute => GoRouteData.$route(
      path: '/',
      factory: $HomeRouteExtension._fromState,
    );

extension $HomeRouteExtension on HomeRoute {
  static HomeRoute _fromState(GoRouterState state) => HomeRoute(
        tab: _$HomeTabEnumMap._$fromName(state.queryParams['tab']),
      );

  String get location => GoRouteData.$location(
        '/',
        queryParams: {
          if (tab != null) 'tab': _$HomeTabEnumMap[tab]!,
        },
      );

  void go(BuildContext context) => context.go(location, extra: this);

  void push(BuildContext context) => context.push(location, extra: this);
}

const _$HomeTabEnumMap = {
  HomeTab.home: 'home',
  HomeTab.profile: 'profile',
  HomeTab.settings: 'settings',
};

extension<T extends Enum> on Map<T, String> {
  T _$fromName(String value) =>
      entries.singleWhere((element) => element.value == value).key;
}

The problem here is that it straight doesn't compile.

the _fromState extension we're using _$HomeTabEnumMap._$fromName(state.queryParams['tab']) which should take a String while state.queryParams['tab'] returns a String? causing a compile error.

[darshankawar]

Thanks for the report. Seeing same behavior using code sample provided.

stable, master flutter doctor -v

[✓] Flutter (Channel stable, 3.3.9, on macOS 12.2.1 21D62 darwin-x64, locale
    en-GB)
    • Flutter version 3.3.9 on channel stable at
      /Users/dhs/documents/fluttersdk/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision b8f7f1f986 (12 days ago), 2022-11-23 06:43:51 +0900
    • Engine revision 8f2221fbef
    • Dart version 2.18.5
    • DevTools version 2.15.0

[!] Xcode - develop for iOS and macOS (Xcode 12.3)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    ! Flutter recommends a minimum Xcode version of 13.
      Download the latest version or update via the Mac App Store.
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0

[✓] Connected device (5 available)
    • SM G975F (mobile)       • RZ8M802WY0X • android-arm64   • Android 11 (API 30)
    • Darshan's iphone (mobile)  • 21150b119064aecc249dfcfe05e259197461ce23 •
      ios            • iOS 14.4.1 18D61
    • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729     •
      ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator)
    • macOS (desktop)            • macos                                    •
      darwin-x64     • Mac OS X 10.15.4 19E2269 darwin-x64
    • Chrome (web)               • chrome                                   •
      web-javascript • Google Chrome 98.0.4758.80

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.

[!] Flutter (Channel master, 3.7.0-5.0.pre.25, on macOS 12.2.1 21D62 darwin-x64,
    locale en-GB)
    • Flutter version 3.7.0-5.0.pre.25 on channel master at
      /Users/dhs/documents/fluttersdk/flutter
    ! Warning: `flutter` on your path resolves to
      /Users/dhs/Documents/Fluttersdk/flutter/bin/flutter, which is not inside
      your current Flutter SDK checkout at
      /Users/dhs/documents/fluttersdk/flutter. Consider adding
      /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path.
    ! Warning: `dart` on your path resolves to
      /Users/dhs/Documents/Fluttersdk/flutter/bin/dart, which is not inside your
      current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter.
      Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front
      of your path.
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 92aebc953d (2 hours ago), 2022-12-11 22:24:23 -0500
    • Engine revision 922546c919
    • Dart version 3.0.0 (build 3.0.0-12.0.dev)
    • DevTools version 2.20.0
    • If those were intentional, you can disregard the above warnings; however
      it is recommended to use "git" directly to perform update checks and
      upgrades.


[!] Xcode - develop for iOS and macOS (Xcode 12.3)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    ! Flutter recommends a minimum Xcode version of 13.
      Download the latest version or update via the Mac App Store.
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0

[✓] Connected device (5 available)
    • SM G975F (mobile)       • RZ8M802WY0X • android-arm64   • Android 11 (API 30)
    • Darshan's iphone (mobile)  • 21150b119064aecc249dfcfe05e259197461ce23 •
      ios            • iOS 14.4.1 18D61
    • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729     •
      ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator)
    • macOS (desktop)            • macos                                    •
      darwin-x64     • Mac OS X 10.15.4 19E2269 darwin-x64
    • Chrome (web)               • chrome                                   •
      web-javascript • Google Chrome 98.0.4758.80

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.

[johnpryan]

Thanks for filing an issue, this seems like a bug we should fix.

[dancamdev]

Closing this issue has it has been fixed by adding this method to go_router_builder that handles this edge case correctly.

T? _$convertMapValue<T>(
  String key,
  Map<String, String> map,
  T Function(String) converter,
) {
  final value = map[key];
  return value == null ? null : converter(value);
}

[github-actions[bot]]

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