[go_router_builder] Add support for TypedStatefulShellBranch's preload (flutter#8587)

Fixes flutter/flutter#162055

Follow up of flutter#8545

Author: ValentinVignal

packages/go_router_builder/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.8.0
+
+- Adds support for passing `preload` parameter to `StatefulShellBranchData`.
+
 ## 2.7.5
 
 - Fixes trailing `?` in the location when a go route has an empty default value.

packages/go_router_builder/lib/src/route_config.dart

@@ -149,6 +149,7 @@ class StatefulShellBranchConfig extends RouteBaseConfig {
     required this.observers,
     this.restorationScopeId,
     this.initialLocation,
+    this.preload,
   }) : super._();
 
   /// The command for calling the navigator key getter from the ShellRouteData.
@@ -163,6 +164,9 @@ class StatefulShellBranchConfig extends RouteBaseConfig {
   /// The navigator observers.
   final String? observers;
 
+  /// The preload parameter.
+  final String? preload;
+
   @override
   Iterable<String> classDeclarations() => <String>[];
 
@@ -173,7 +177,8 @@ class StatefulShellBranchConfig extends RouteBaseConfig {
       '${navigatorKey == null ? '' : 'navigatorKey: $navigatorKey,'}'
       '${restorationScopeId == null ? '' : 'restorationScopeId: $restorationScopeId,'}'
       '${initialLocation == null ? '' : 'initialLocation: $initialLocation,'}'
-      '${observers == null ? '' : 'observers: $observers,'}';
+      '${observers == null ? '' : 'observers: $observers,'}'
+      '${preload == null ? '' : 'preload: $preload,'}';
 
   @override
   String get routeDataClassName => 'StatefulShellBranchData';
@@ -532,6 +537,10 @@ abstract class RouteBaseConfig {
             classElement,
             parameterName: r'$observers',
           ),
+          preload: _generateParameterGetterCode(
+            classElement,
+            parameterName: r'$preload',
+          ),
         );
       case 'TypedGoRoute':
         final ConstantReader pathValue = reader.read('path');

packages/go_router_builder/pubspec.yaml

@@ -2,7 +2,7 @@ name: go_router_builder
 description: >-
   A builder that supports generated strongly-typed route helpers for
   package:go_router
-version: 2.7.5
+version: 2.8.0
 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
 
@@ -26,7 +26,7 @@ dev_dependencies:
   dart_style: '>=2.3.7 <4.0.0'
   flutter:
     sdk: flutter
-  go_router: ^14.0.0
+  go_router: ^14.8.0
   leak_tracker_flutter_testing: ">=3.0.0"
   package_config: ^2.1.1
   pub_semver: ^2.1.5

packages/go_router_builder/test_inputs/stateful_shell_branch_with_preload_data.dart

@@ -0,0 +1,13 @@
+// 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.
+
+import 'package:go_router/go_router.dart';
+
+@TypedStatefulShellBranch<StatefulShellBranchWithPreloadData>()
+class StatefulShellBranchWithPreloadData extends StatefulShellBranchData {
+  const StatefulShellBranchWithPreloadData();
+
+  static const String $initialLocation = '/main/second-tab';
+  static const bool $preload = true;
+}

packages/go_router_builder/test_inputs/stateful_shell_branch_with_preload_data.dart.expect

@@ -0,0 +1,5 @@
+RouteBase get $statefulShellBranchWithPreloadData =>
+    StatefulShellBranchData.$branch(
+      initialLocation: StatefulShellBranchWithPreloadData.$initialLocation,
+      preload: StatefulShellBranchWithPreloadData.$preload,
+    );