++ (#74862)

dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart

@@ -9,7 +9,7 @@ import 'package:flutter_test/flutter_test.dart';
 class TestTestBinding extends AutomatedTestWidgetsFlutterBinding {
   @override
   DebugPrintCallback get debugPrintOverride => testPrint;
-  static void testPrint(String message, { int wrapWidth }) { print(message); }
+  static void testPrint(String? message, { int? wrapWidth }) { print(message); }
 }
 
 Future<void> guardedHelper(WidgetTester tester) {

dev/automated_tests/flutter_test/test_async_utils_unguarded_test.dart

@@ -8,7 +8,7 @@ import 'package:flutter_test/flutter_test.dart';
 class TestTestBinding extends AutomatedTestWidgetsFlutterBinding {
   @override
   DebugPrintCallback get debugPrintOverride => testPrint;
-  static void testPrint(String message, { int wrapWidth }) { print(message); }
+  static void testPrint(String? message, { int? wrapWidth }) { print(message); }
 }
 
 Future<void> helperFunction(WidgetTester tester) async {

dev/automated_tests/flutter_test/ticker_test.dart

@@ -10,7 +10,7 @@ void main() {
   testWidgets('Does flutter_test catch leaking tickers?', (WidgetTester tester) async {
     Ticker((Duration duration) { }).start();
 
-    final ByteData message = const StringCodec().encodeMessage('AppLifecycleState.paused');
-    await ServicesBinding.instance.defaultBinaryMessenger.handlePlatformMessage('flutter/lifecycle', message, (_) {});
+    final ByteData? message = const StringCodec().encodeMessage('AppLifecycleState.paused');
+    await ServicesBinding.instance!.defaultBinaryMessenger.handlePlatformMessage('flutter/lifecycle', message, (_) {});
   });
 }

dev/automated_tests/pubspec.yaml

 name: flutter_automated_tests
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
   flutter: