[go_router] Fixes use of Iterable (#5421)

Replaces an `extends Iterable` with `implements Iterable` for Dart 3.0 compatibility, and updates the minimum version of the Dart SDK to 3.0 to test it.

This helps unblock rolling the entire repo forward to Flutter 3.10/Dart 3.0 as a minimum version.

Author: stuartmorgan-g

packages/go_router/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 12.1.2
+
+* Fixes an incorrect use of `extends` for Dart 3 compatibility.
+* Updates minimum supported SDK version to Flutter 3.10/Dart 3.0.
+
 ## 12.1.1
 
 - Retains query parameters during refresh and first redirect.
@@ -75,7 +80,7 @@
 
 ## 10.1.1
 
-- Fixes mapping from `Page` to `RouteMatch`s. 
+- Fixes mapping from `Page` to `RouteMatch`s.
 - Updates minimum supported SDK version to Flutter 3.7/Dart 2.19.
 
 ## 10.1.0

packages/go_router/example/pubspec.yaml

@@ -4,8 +4,8 @@ version: 3.0.1
 publish_to: none
 
 environment:
-  sdk: ">=2.19.0 <4.0.0"
-  flutter: ">=3.7.0"
+  sdk: ">=3.0.0 <4.0.0"
+  flutter: ">=3.10.0"
 
 dependencies:
   adaptive_navigation: ^0.0.4

packages/go_router/lib/src/delegate.dart

@@ -247,7 +247,7 @@ class GoRouterDelegate extends RouterDelegate<RouteMatchList>
 /// The iterator starts with the navigator that hosts the top-most route. This
 /// navigator may not be the inner-most navigator if the top-most route is a
 /// pageless route, such as a dialog or bottom sheet.
-class _NavigatorStateIterator extends Iterator<NavigatorState> {
+class _NavigatorStateIterator implements Iterator<NavigatorState> {
   _NavigatorStateIterator(this.matchList, this.root)
       : index = matchList.matches.length - 1;
 

packages/go_router/pubspec.yaml

@@ -1,13 +1,13 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 12.1.1
+version: 12.1.2
 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
 
 environment:
-  sdk: ">=2.19.0 <4.0.0"
-  flutter: ">=3.7.0"
+  sdk: ">=3.0.0 <4.0.0"
+  flutter: ">=3.10.0"
 
 dependencies:
   collection: ^1.15.0