[go_router_builder] Adds support for required $extra parameter (#3627)

[go_router_builder] Adds support for required $extra parameter

Author: dancamdev

packages/go_router_builder/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.2.1
+
+* Supports opt-in required extra parameters. [#117261](https://github.com/flutter/flutter/issues/117261)
+
 ## 1.2.0
 
 * Adds Support for ShellRoute

packages/go_router_builder/example/lib/extra_example.dart

@@ -0,0 +1,123 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// ignore_for_file: public_member_api_docs
+
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+part 'extra_example.g.dart';
+
+void main() => runApp(const App());
+
+final GoRouter _router = GoRouter(
+  routes: $appRoutes,
+  initialLocation: '/splash',
+);
+
+class App extends StatelessWidget {
+  const App({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp.router(
+      routerConfig: _router,
+    );
+  }
+}
+
+class Extra {
+  const Extra(this.value);
+
+  final int value;
+}
+
+@TypedGoRoute<RequiredExtraRoute>(path: '/requiredExtra')
+class RequiredExtraRoute extends GoRouteData {
+  const RequiredExtraRoute({required this.$extra});
+
+  final Extra $extra;
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) =>
+      RequiredExtraScreen(extra: $extra);
+}
+
+class RequiredExtraScreen extends StatelessWidget {
+  const RequiredExtraScreen({super.key, required this.extra});
+
+  final Extra extra;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Required Extra')),
+      body: Center(child: Text('Extra: ${extra.value}')),
+    );
+  }
+}
+
+@TypedGoRoute<OptionalExtraRoute>(path: '/optionalExtra')
+class OptionalExtraRoute extends GoRouteData {
+  const OptionalExtraRoute({this.$extra});
+
+  final Extra? $extra;
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) =>
+      OptionalExtraScreen(extra: $extra);
+}
+
+class OptionalExtraScreen extends StatelessWidget {
+  const OptionalExtraScreen({super.key, this.extra});
+
+  final Extra? extra;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Optional Extra')),
+      body: Center(child: Text('Extra: ${extra?.value}')),
+    );
+  }
+}
+
+@TypedGoRoute<SplashRoute>(path: '/splash')
+class SplashRoute extends GoRouteData {
+  const SplashRoute();
+
+  @override
+  Widget build(BuildContext context, GoRouterState state) => const Splash();
+}
+
+class Splash extends StatelessWidget {
+  const Splash({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Splash')),
+      body: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: <Widget>[
+          const Placeholder(),
+          ElevatedButton(
+            onPressed: () =>
+                const RequiredExtraRoute($extra: Extra(1)).go(context),
+            child: const Text('Required Extra'),
+          ),
+          ElevatedButton(
+            onPressed: () =>
+                const OptionalExtraRoute($extra: Extra(2)).go(context),
+            child: const Text('Optional Extra'),
+          ),
+          ElevatedButton(
+            onPressed: () => const OptionalExtraRoute().go(context),
+            child: const Text('Optional Extra (null)'),
+          ),
+        ],
+      ),
+    );
+  }
+}

packages/go_router_builder/example/lib/extra_example.g.dart

@@ -265,7 +265,10 @@ RouteBase get $_routeGetterName => ${_routeDefinition()};
 
   String get _newFromState {
     final StringBuffer buffer = StringBuffer('=>');
-    if (_ctor.isConst && _ctorParams.isEmpty && _ctorQueryParams.isEmpty) {
+    if (_ctor.isConst &&
+        _ctorParams.isEmpty &&
+        _ctorQueryParams.isEmpty &&
+        _extraParam == null) {
       buffer.writeln('const ');
     }
 
@@ -367,7 +370,7 @@ GoRouteData.\$route(
         );
       }
 
-      if (!_pathParams.contains(element.name)) {
+      if (!_pathParams.contains(element.name) && !element.isExtraField) {
         throw InvalidGenerationSourceError(
           'Missing param `${element.name}` in path.',
           element: element,
@@ -438,13 +441,7 @@ GoRouteData.\$route(
 
   late final List<ParameterElement> _ctorParams =
       _ctor.parameters.where((ParameterElement element) {
-    if (element.isRequired) {
-      if (element.isExtraField) {
-        throw InvalidGenerationSourceError(
-          'Parameters named `$extraFieldName` cannot be required.',
-          element: element,
-        );
-      }
+    if (element.isRequired && !element.isExtraField) {
       return true;
     }
     return false;

packages/go_router_builder/lib/src/route_config.dart

@@ -93,12 +93,12 @@ String encodeField(PropertyAccessorElement element) {
 String enumMapName(InterfaceType type) => '_\$${type.element.name}EnumMap';
 
 String _stateValueAccess(ParameterElement element) {
-  if (element.isRequired) {
-    return 'params[${escapeDartString(element.name)}]!';
+  if (element.isExtraField) {
+    return 'extra as ${element.type.getDisplayString(withNullability: element.isOptional)}';
   }
 
-  if (element.isExtraField) {
-    return 'extra as ${element.type.getDisplayString(withNullability: true)}';
+  if (element.isRequired) {
+    return 'params[${escapeDartString(element.name)}]!';
   }
 
   if (element.isOptional) {

packages/go_router_builder/lib/src/type_helpers.dart

@@ -2,7 +2,7 @@ name: go_router_builder
 description: >-
   A builder that supports generated strongly-typed route helpers for
   package:go_router
-version: 1.2.0
+version: 1.2.1
 repository: https://github.com/flutter/packages/tree/main/packages/go_router_builder
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router_builder%22
 

packages/go_router_builder/pubspec.yaml

@@ -24,8 +24,8 @@ Future<void> main() async {
 const Set<String> _expectedAnnotatedTests = <String>{
   'AppliedToWrongClassType',
   'BadPathParam',
-  'ExtraMustBeOptional',
   'ExtraValueRoute',
+  'RequiredExtraValueRoute',
   'MissingPathParam',
   'MissingPathValue',
   'MissingTypeAnnotation',

packages/go_router_builder/test/builder_test.dart

@@ -53,15 +53,6 @@ class NullableRequiredParam extends GoRouteData {
   final int? id;
 }
 
-@ShouldThrow(
-  r'Parameters named `$extra` cannot be required.',
-)
-@TypedGoRoute<ExtraMustBeOptional>(path: r'bob/:$extra')
-class ExtraMustBeOptional extends GoRouteData {
-  ExtraMustBeOptional({required this.$extra});
-  final int $extra;
-}
-
 @ShouldThrow(
   'Missing param `id` in path.',
 )
@@ -204,6 +195,36 @@ class ExtraValueRoute extends GoRouteData {
   final int? $extra;
 }
 
+@ShouldGenerate(r'''
+RouteBase get $requiredExtraValueRoute => GoRouteData.$route(
+      path: '/default-value-route',
+      factory: $RequiredExtraValueRouteExtension._fromState,
+    );
+
+extension $RequiredExtraValueRouteExtension on RequiredExtraValueRoute {
+  static RequiredExtraValueRoute _fromState(GoRouterState state) =>
+      RequiredExtraValueRoute(
+        $extra: state.extra as int,
+      );
+
+  String get location => GoRouteData.$location(
+        '/default-value-route',
+      );
+
+  void go(BuildContext context) => context.go(location, extra: $extra);
+
+  void push(BuildContext context) => context.push(location, extra: $extra);
+
+  void pushReplacement(BuildContext context) =>
+      context.pushReplacement(location, extra: $extra);
+}
+''')
+@TypedGoRoute<RequiredExtraValueRoute>(path: '/default-value-route')
+class RequiredExtraValueRoute extends GoRouteData {
+  RequiredExtraValueRoute({required this.$extra});
+  final int $extra;
+}
+
 @ShouldThrow(
   'Default value used with a nullable type. Only non-nullable type can have a default value.',
   todo: 'Remove the default value or make the type non-nullable.',