Re-land "Migrate android_semantics_testing to null safety (#84136)" (#84156)

dev/integration_tests/android_semantics_testing/lib/main.dart

@@ -23,18 +23,18 @@ void main() {
 
 const MethodChannel kSemanticsChannel = MethodChannel('semantics');
 
-Future<String> dataHandler(String message) async {
-  if (message.contains('getSemanticsNode')) {
+Future<String> dataHandler(String? message) async {
+  if (message!.contains('getSemanticsNode')) {
     final Completer<String> completer = Completer<String>();
     final int id = int.tryParse(message.split('#')[1]) ?? 0;
-    Future<void> completeSemantics([Object _]) async {
+    Future<void> completeSemantics([Object? _]) async {
       final dynamic result = await kSemanticsChannel.invokeMethod<dynamic>('getSemanticsNode', <String, dynamic>{
         'id': id,
       });
       completer.complete(json.encode(result));
     }
-    if (SchedulerBinding.instance.hasScheduledFrame)
-      SchedulerBinding.instance.addPostFrameCallback(completeSemantics);
+    if (SchedulerBinding.instance!.hasScheduledFrame)
+      SchedulerBinding.instance!.addPostFrameCallback(completeSemantics);
     else
       completeSemantics();
     return completer.future;
@@ -50,7 +50,7 @@ Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
 };
 
 class TestApp extends StatelessWidget {
-  const TestApp({Key key}) : super(key: key);
+  const TestApp({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

dev/integration_tests/android_semantics_testing/lib/src/common.dart

@@ -53,19 +53,19 @@ class AndroidSemanticsNode  {
   ///       ]
   ///     }
   factory AndroidSemanticsNode.deserialize(String value) {
-    return AndroidSemanticsNode._(json.decode(value) as Map<String, Object>);
+    return AndroidSemanticsNode._(json.decode(value) as Map<String, Object?>);
   }
 
-  final Map<String, Object> _values;
+  final Map<String, Object?> _values;
   final List<AndroidSemanticsNode> _children = <AndroidSemanticsNode>[];
 
-  Map<String, Object> get _flags => _values['flags'] as Map<String, Object>;
+  Map<String, Object?> get _flags => _values['flags']! as Map<String, Object?>;
 
   /// The text value of the semantics node.
   ///
   /// This is produced by combining the value, label, and hint fields from
   /// the Flutter [SemanticsNode].
-  String get text => _values['text'] as String;
+  String get text => _values['text']! as String;
 
   /// The contentDescription of the semantics node.
   ///
@@ -75,7 +75,7 @@ class AndroidSemanticsNode  {
   ///
   /// This is produced by combining the value, label, and hint fields from
   /// the Flutter [SemanticsNode].
-  String get contentDescription => _values['contentDescription'] as String;
+  String get contentDescription => _values['contentDescription']! as String;
 
   /// The className of the semantics node.
   ///
@@ -84,10 +84,10 @@ class AndroidSemanticsNode  {
   ///
   /// If a more specific value isn't provided, it defaults to
   /// "android.view.View".
-  String get className => _values['className'] as String;
+  String get className => _values['className']! as String;
 
   /// The identifier for this semantics node.
-  int get id => _values['id'] as int;
+  int get id => _values['id']! as int;
 
   /// The children of this semantics node.
   List<AndroidSemanticsNode> get children => _children;
@@ -95,50 +95,50 @@ class AndroidSemanticsNode  {
   /// Whether the node is currently in a checked state.
   ///
   /// Equivalent to [SemanticsFlag.isChecked].
-  bool get isChecked => _flags['isChecked'] as bool;
+  bool get isChecked => _flags['isChecked']! as bool;
 
   /// Whether the node can be in a checked state.
   ///
   /// Equivalent to [SemanticsFlag.hasCheckedState]
-  bool get isCheckable => _flags['isCheckable'] as bool;
+  bool get isCheckable => _flags['isCheckable']! as bool;
 
   /// Whether the node is editable.
   ///
   /// This is usually only applied to text fields, which map
   /// to "android.widget.EditText".
-  bool get isEditable => _flags['isEditable'] as bool;
+  bool get isEditable => _flags['isEditable']! as bool;
 
   /// Whether the node is enabled.
-  bool get isEnabled => _flags['isEnabled'] as bool;
+  bool get isEnabled => _flags['isEnabled']! as bool;
 
   /// Whether the node is focusable.
-  bool get isFocusable => _flags['isFocusable'] as bool;
+  bool get isFocusable => _flags['isFocusable']! as bool;
 
   /// Whether the node is focused.
-  bool get isFocused => _flags['isFocused'] as bool;
+  bool get isFocused => _flags['isFocused']! as bool;
 
   /// Whether the node is considered a heading.
-  bool get isHeading => _flags['isHeading'] as bool;
+  bool get isHeading => _flags['isHeading']! as bool;
 
   /// Whether the node represents a password field.
   ///
   /// Equivalent to [SemanticsFlag.isObscured].
-  bool get isPassword => _flags['isPassword'] as bool;
+  bool get isPassword => _flags['isPassword']! as bool;
 
   /// Whether the node is long clickable.
   ///
   /// Equivalent to having [SemanticsAction.longPress].
-  bool get isLongClickable => _flags['isLongClickable'] as bool;
+  bool get isLongClickable => _flags['isLongClickable']! as bool;
 
   /// Gets a [Rect] which defines the position and size of the semantics node.
   Rect getRect() {
-    final Map<String, Object> rawRect = _values['rect'] as Map<String, Object>;
+    final Map<String, Object?> rawRect = _values['rect']! as Map<String, Object?>;
     final Map<String, int> rect = rawRect.cast<String, int>();
     return Rect.fromLTRB(
-      rect['left'].toDouble(),
-      rect['top'].toDouble(),
-      rect['right'].toDouble(),
-      rect['bottom'].toDouble(),
+      rect['left']!.toDouble(),
+      rect['top']!.toDouble(),
+      rect['right']!.toDouble(),
+      rect['bottom']!.toDouble(),
     );
   }
 
@@ -150,7 +150,7 @@ class AndroidSemanticsNode  {
 
   /// Gets a list of [AndroidSemanticsActions] which are defined for the node.
   List<AndroidSemanticsAction> getActions() => <AndroidSemanticsAction>[
-    for (final int id in (_values['actions'] as List<dynamic>).cast<int>()) AndroidSemanticsAction.deserialize(id),
+    for (final int id in (_values['actions']! as List<dynamic>).cast<int>()) AndroidSemanticsAction.deserialize(id)!,
   ];
 
   @override

dev/integration_tests/android_semantics_testing/lib/src/constants.dart

@@ -168,7 +168,7 @@ class AndroidSemanticsAction {
       case _kSetText:
         return 'AndroidSemanticsAction.setText';
       default:
-        return null;
+        return 'INVALID';
     }
   }
 
@@ -210,7 +210,7 @@ class AndroidSemanticsAction {
   /// Creates a new [AndroidSemanticsAction] from an integer `value`.
   ///
   /// Returns `null` if the id is not a known Android accessibility action.
-  static AndroidSemanticsAction deserialize(int value) {
+  static AndroidSemanticsAction? deserialize(int value) {
     return _kActionById[value];
   }
 }

dev/integration_tests/android_semantics_testing/lib/src/matcher.dart

@@ -18,23 +18,23 @@ import 'constants.dart';
 /// the Android accessibility bridge, and not the semantics object created by
 /// the Flutter framework.
 Matcher hasAndroidSemantics({
-  String text,
-  String contentDescription,
-  String className,
-  int id,
-  Rect rect,
-  Size size,
-  List<AndroidSemanticsAction> actions,
-  List<AndroidSemanticsNode> children,
-  bool isChecked,
-  bool isCheckable,
-  bool isEditable,
-  bool isEnabled,
-  bool isFocusable,
-  bool isFocused,
-  bool isHeading,
-  bool isPassword,
-  bool isLongClickable,
+  String? text,
+  String? contentDescription,
+  String? className,
+  int? id,
+  Rect? rect,
+  Size? size,
+  List<AndroidSemanticsAction>? actions,
+  List<AndroidSemanticsNode>? children,
+  bool? isChecked,
+  bool? isCheckable,
+  bool? isEditable,
+  bool? isEnabled,
+  bool? isFocusable,
+  bool? isFocused,
+  bool? isHeading,
+  bool? isPassword,
+  bool? isLongClickable,
 }) {
   return _AndroidSemanticsMatcher(
     text: text,
@@ -76,22 +76,22 @@ class _AndroidSemanticsMatcher extends Matcher {
     this.isLongClickable,
   });
 
-  final String text;
-  final String className;
-  final String contentDescription;
-  final int id;
-  final List<AndroidSemanticsAction> actions;
-  final Rect rect;
-  final Size size;
-  final bool isChecked;
-  final bool isCheckable;
-  final bool isEditable;
-  final bool isEnabled;
-  final bool isFocusable;
-  final bool isFocused;
-  final bool isHeading;
-  final bool isPassword;
-  final bool isLongClickable;
+  final String? text;
+  final String? className;
+  final String? contentDescription;
+  final int? id;
+  final List<AndroidSemanticsAction>? actions;
+  final Rect? rect;
+  final Size? size;
+  final bool? isChecked;
+  final bool? isCheckable;
+  final bool? isEditable;
+  final bool? isEnabled;
+  final bool? isFocusable;
+  final bool? isFocused;
+  final bool? isHeading;
+  final bool? isPassword;
+  final bool? isLongClickable;
 
   @override
   Description describe(Description description) {
@@ -130,7 +130,9 @@ class _AndroidSemanticsMatcher extends Matcher {
   }
 
   @override
-  bool matches(covariant AndroidSemanticsNode item, Map<Object, Object> matchState) {
+  bool matches(covariant AndroidSemanticsNode? item, Map<Object?, Object?> matchState) {
+    if (item is! AndroidSemanticsNode)
+      return _failWithMessage('Expected an AndroidSemanticsNode, but got: $item', matchState);
     if (text != null && text != item.text)
       return _failWithMessage('Expected text: $text', matchState);
     if (contentDescription != null && contentDescription != item.contentDescription)
@@ -145,8 +147,8 @@ class _AndroidSemanticsMatcher extends Matcher {
       return _failWithMessage('Expected size: $size', matchState);
     if (actions != null) {
       final List<AndroidSemanticsAction> itemActions = item.getActions();
-      if (!unorderedEquals(actions).matches(itemActions, matchState)) {
-        final List<String> actionsString = actions.map<String>((AndroidSemanticsAction action) => action.toString()).toList()..sort();
+      if (!unorderedEquals(actions!).matches(itemActions, matchState)) {
+        final List<String> actionsString = actions!.map<String>((AndroidSemanticsAction action) => action.toString()).toList()..sort();
         final List<String> itemActionsString = itemActions.map<String>((AndroidSemanticsAction action) => action.toString()).toList()..sort();
         final Set<String> unexpected = itemActionsString.toSet().difference(actionsString.toSet());
         final Set<String> missing = actionsString.toSet().difference(itemActionsString.toSet());
@@ -176,12 +178,16 @@ class _AndroidSemanticsMatcher extends Matcher {
   }
 
   @override
-  Description describeMismatch(Object item, Description mismatchDescription,
-      Map<Object, Object> matchState, bool verbose) {
-    return mismatchDescription.add(matchState['failure'] as String);
+  Description describeMismatch(
+    Object? item,
+    Description mismatchDescription,
+    Map<Object?, Object?> matchState,
+    bool verbose,
+  ) {
+    return mismatchDescription.add(matchState['failure']! as String);
   }
 
-  bool _failWithMessage(String value, Map<dynamic, dynamic> matchState) {
+  bool _failWithMessage(String value, Map<Object?, Object?> matchState) {
     matchState['failure'] = value;
     return false;
   }

dev/integration_tests/android_semantics_testing/lib/src/tests/controls_page.dart

@@ -9,7 +9,7 @@ export 'controls_constants.dart';
 
 /// A test page with a checkbox, three radio buttons, and a switch.
 class SelectionControlsPage extends StatefulWidget {
-  const SelectionControlsPage({Key key}) : super(key: key);
+  const SelectionControlsPage({Key? key}) : super(key: key);
 
   @override
   State<StatefulWidget> createState() => _SelectionControlsPageState();
@@ -28,15 +28,15 @@ class _SelectionControlsPageState extends State<SelectionControlsPage> {
   bool _isLabeledOn = false;
   int _radio = 0;
 
-  void _updateCheckbox(bool newValue) {
+  void _updateCheckbox(bool? newValue) {
     setState(() {
-      _isChecked = newValue;
+      _isChecked = newValue!;
     });
   }
 
-  void _updateRadio(int newValue) {
+  void _updateRadio(int? newValue) {
     setState(() {
-      _radio = newValue;
+      _radio = newValue!;
     });
   }
 

dev/integration_tests/android_semantics_testing/lib/src/tests/headings_page.dart

@@ -9,7 +9,7 @@ export 'headings_constants.dart';
 
 /// A test page with an app bar and some body text for testing heading flags.
 class HeadingsPage extends StatelessWidget {
-  const HeadingsPage({Key key}) : super(key: key);
+  const HeadingsPage({Key? key}) : super(key: key);
 
   static const ValueKey<String> _appBarTitleKey = ValueKey<String>(appBarTitleKeyValue);
   static const ValueKey<String> _bodyTextKey = ValueKey<String>(bodyTextKeyValue);

dev/integration_tests/android_semantics_testing/lib/src/tests/popup_page.dart

@@ -10,7 +10,7 @@ export 'popup_constants.dart';
 
 /// A page with a popup menu, a dropdown menu, and a modal alert.
 class PopupControlsPage extends StatefulWidget {
-  const PopupControlsPage({Key key}) : super(key: key);
+  const PopupControlsPage({Key? key}) : super(key: key);
 
   @override
   State<StatefulWidget> createState() => _PopupControlsPageState();
@@ -22,7 +22,7 @@ class _PopupControlsPageState extends State<PopupControlsPage> {
   final Key alertKey = const ValueKey<String>(alertKeyValue);
 
   String popupValue = popupItems.first;
-  String dropdownValue = popupItems.first;
+  String? dropdownValue = popupItems.first;
 
   @override
   Widget build(BuildContext context) {
@@ -60,7 +60,7 @@ class _PopupControlsPageState extends State<PopupControlsPage> {
                     child: Text(item),
                   );
                 }).toList(),
-                onChanged: (String value) {
+                onChanged: (String? value) {
                   setState(() {
                     dropdownValue = value;
                   });

dev/integration_tests/android_semantics_testing/lib/src/tests/text_field_page.dart

@@ -10,7 +10,7 @@ export 'text_field_constants.dart';
 
 /// A page with a normal text field and a password field.
 class TextFieldPage extends StatefulWidget {
-  const TextFieldPage({Key key}) : super(key: key);
+  const TextFieldPage({Key? key}) : super(key: key);
 
   @override
   State<StatefulWidget> createState() => _TextFieldPageState();

dev/integration_tests/android_semantics_testing/pubspec.yaml

@@ -1,7 +1,7 @@
 name: android_semantics_testing
 description: Integration testing library for Android semantics
 environment:
-  sdk: '>=2.9.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:

dev/integration_tests/android_semantics_testing/test_driver/main_test.dart

@@ -11,7 +11,7 @@ import 'package:path/path.dart' as path;
 import 'package:test/test.dart' hide isInstanceOf;
 
 String adbPath() {
-  final String androidHome = io.Platform.environment['ANDROID_HOME'] ?? io.Platform.environment['ANDROID_SDK_ROOT'];
+  final String? androidHome = io.Platform.environment['ANDROID_HOME'] ?? io.Platform.environment['ANDROID_SDK_ROOT'];
   if (androidHome == null) {
     return 'adb';
   } else {
@@ -21,7 +21,7 @@ String adbPath() {
 
 void main() {
   group('AccessibilityBridge', () {
-    FlutterDriver driver;
+    late FlutterDriver driver;
     Future<AndroidSemanticsNode> getSemantics(SerializableFinder finder) async {
       final int id = await driver.getSemanticsId(finder);
       final String data = await driver.requestData('getSemanticsNode#$id');
@@ -53,7 +53,7 @@ void main() {
         'null',
       ]);
       await run.exitCode;
-      driver?.close();
+      driver.close();
     });
 
     group('TextField', () {
@@ -658,6 +658,7 @@ void main() {
     group('Headings', () {
       setUpAll(() async {
         await driver.tap(find.text(headingsRoute));
+        await driver.waitFor(find.byValueKey(appBarTitleKeyValue));
       });
 
       test('AppBar title has correct Android heading semantics', () async {