Modernize framework lints (flutter#179089)

WIP

Commits separated as follows:
- Update lints in analysis_options files
- Run `dart fix --apply`
- Clean up leftover analysis issues 
- Run `dart format .` in the right places.

Local analysis and testing passes. Checking CI now.

Part of flutter#178827
- Adoption of flutter_lints in examples/api coming in a separate change
(cc @loic-sharma)

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Author: Piinks

analysis_options.yaml

@@ -40,11 +40,11 @@ linter:
     - always_declare_return_types
     - always_put_control_body_on_new_line
     # - always_put_required_named_parameters_first # we prefer having parameters in the same order as fields https://github.com/flutter/flutter/issues/10219
-    - always_specify_types
+    # - always_specify_types # conflicts with omit_obvious_local_variable_types
     # - always_use_package_imports # we do this commonly
     - annotate_overrides
     - annotate_redeclares
-    # - avoid_annotating_with_dynamic # conflicts with always_specify_types
+    # - avoid_annotating_with_dynamic # conflicts with type_annotate_public_apis
     - avoid_bool_literals_in_conditional_expressions
     # - avoid_catches_without_on_clauses # blocked on https://github.com/dart-lang/linter/issues/3023
     # - avoid_catching_errors # blocked on https://github.com/dart-lang/linter/issues/4998
@@ -78,7 +78,7 @@ linter:
     - avoid_slow_async_io
     - avoid_type_to_string
     - avoid_types_as_parameter_names
-    # - avoid_types_on_closure_parameters # conflicts with always_specify_types
+    # - avoid_types_on_closure_parameters # not yet tested
     - avoid_unnecessary_containers
     - avoid_unused_constructor_parameters
     - avoid_void_async
@@ -144,9 +144,9 @@ linter:
     - noop_primitive_operations
     - null_check_on_nullable_type_parameter
     - null_closures
-    # - omit_local_variable_types # opposite of always_specify_types
-    # - omit_obvious_local_variable_types # not yet tested
-    # - omit_obvious_property_types # not yet tested
+    # - omit_local_variable_types # superset of omit_obvious_local_variable_types
+    - omit_obvious_local_variable_types # not yet tested
+    # - omit_obvious_property_types # conflicts with type_annotate_public_apis
     # - one_member_abstracts # too many false positives
     - only_throw_errors # this does get disabled in a few places where we have legacy code that uses strings et al
     - overridden_fields
@@ -204,13 +204,13 @@ linter:
     - sort_constructors_first
     # - sort_pub_dependencies # prevents separating pinned transitive dependencies
     - sort_unnamed_constructors_first
-    # - specify_nonobvious_local_variable_types # not yet tested
-    # - specify_nonobvious_property_types # not yet tested
+    - specify_nonobvious_local_variable_types
+    - specify_nonobvious_property_types
     - strict_top_level_inference
     - test_types_in_equals
     - throw_in_finally
     - tighten_type_of_initializing_formals
-    # - type_annotate_public_apis # subset of always_specify_types
+    - type_annotate_public_apis
     - type_init_formals
     - type_literal_in_constant_pattern
     # - unawaited_futures # too many false positives, especially with the way AnimationController works

dev/a11y_assessments/lib/main.dart

@@ -20,21 +20,21 @@ class App extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final ThemeData lightTheme = ThemeData(
+    final lightTheme = ThemeData(
       colorScheme: ColorScheme.fromSeed(
         seedColor: const Color(0xff6750a4),
         contrastLevel: MediaQuery.highContrastOf(context) ? 1.0 : 0.0,
       ),
     );
-    final ThemeData darkTheme = ThemeData(
+    final darkTheme = ThemeData(
       colorScheme: ColorScheme.fromSeed(
         brightness: Brightness.dark,
         seedColor: const Color(0xff6750a4),
         contrastLevel: MediaQuery.highContrastOf(context) ? 1.0 : 0.0,
       ),
     );
 
-    final Map<String, WidgetBuilder> routes = Map<String, WidgetBuilder>.fromEntries(
+    final routes = Map<String, WidgetBuilder>.fromEntries(
       useCases.map(
         (UseCase useCase) => MapEntry<String, WidgetBuilder>(
           useCase.route,

dev/a11y_assessments/test/accessibility_guideline_test.dart

@@ -42,7 +42,7 @@ void main() {
       final SemanticsFinder tappables = find.semantics.byAction(SemanticsAction.tap);
       final int tappableCount = tappables.evaluate().length;
 
-      for (int i = 0; i < tappableCount; i++) {
+      for (var i = 0; i < tappableCount; i++) {
         final FinderBase<SemanticsNode> tappable = tappables.at(i);
         final SemanticsNode node = tappable.evaluate().first;
 

dev/a11y_assessments/test/auto_complete_test.dart

@@ -36,10 +36,9 @@ void main() {
     await pumpsUseCase(tester, AutoCompleteUseCase());
     await tester.pumpAndSettle();
 
-    const List<String> kOptions = <String>['apple', 'banana', 'lemon'];
-    const String label = 'Fruit';
-    final String message =
-        'Type below to autocomplete the following possible results: $kOptions.\n$label';
+    const kOptions = <String>['apple', 'banana', 'lemon'];
+    const label = 'Fruit';
+    final message = 'Type below to autocomplete the following possible results: $kOptions.\n$label';
 
     final SemanticsNode node = tester.semantics.find(find.bySemanticsLabel(message));
     expect(node.flagsCollection.isTextField, isTrue);

dev/a11y_assessments/test/home_page_test.dart

@@ -33,7 +33,7 @@ import 'test_utils.dart';
 void main() {
   testWidgets('Has light and dark theme', (WidgetTester tester) async {
     await tester.pumpWidget(const App());
-    final MaterialApp app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
+    final app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
     expect(app.theme!.brightness, equals(Brightness.light));
     expect(app.darkTheme!.brightness, equals(Brightness.dark));
   });
@@ -43,7 +43,7 @@ void main() {
       const MediaQuery(data: MediaQueryData(highContrast: true), child: App()),
     );
 
-    final MaterialApp app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
+    final app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
 
     final DynamicScheme highContrastScheme = SchemeTonalSpot(
       sourceColorHct: Hct.fromInt(const Color(0xff6750a4).value),
@@ -214,7 +214,7 @@ void main() {
   });
 
   testWidgets('Each A11y Assessments page has a unique page title.', (WidgetTester tester) async {
-    final List<MethodCall> log = <MethodCall>[];
+    final log = <MethodCall>[];
 
     tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(SystemChannels.platform, (
       MethodCall methodCall,

dev/a11y_assessments/test/snack_bar_test.dart

@@ -10,7 +10,7 @@ import 'test_utils.dart';
 void main() {
   testWidgets('snack bar can run', (WidgetTester tester) async {
     await pumpsUseCase(tester, SnackBarUseCase());
-    const String snackBarText = 'Awesome Snackbar!';
+    const snackBarText = 'Awesome Snackbar!';
     expect(find.text(snackBarText), findsNothing);
     await tester.tap(find.text('Show Snackbar'));
     expect(find.text(snackBarText), findsNothing);

dev/a11y_assessments/test/text_field_test.dart

@@ -59,7 +59,7 @@ void main() {
 
   testWidgets('text field wrapper exists', (WidgetTester tester) async {
     await pumpsUseCase(tester, TextFieldUseCase());
-    const String textFieldLabel = 'Input field with suffix @gmail.com';
+    const textFieldLabel = 'Input field with suffix @gmail.com';
 
     final Finder semanticsWidgets = find.bySemanticsLabel(RegExp(textFieldLabel));
     expect(semanticsWidgets, findsExactly(2));

dev/automated_tests/flutter_test/flutter_gold_test.dart

@@ -87,12 +87,12 @@ const List<int> _kFailPngBytes = <int>[
 ];
 
 void main() {
-  final List<String> log = <String>[];
-  final MemoryFileSystem fs = MemoryFileSystem();
+  final log = <String>[];
+  final fs = MemoryFileSystem();
   final Directory basedir = fs.directory('flutter/test/library/')..createSync(recursive: true);
-  final FakeSkiaGoldClient fakeSkiaClient = FakeSkiaGoldClient()
+  final fakeSkiaClient = FakeSkiaGoldClient()
     ..expectationForTestValues['flutter.new_golden_test.1'] = '';
-  final FlutterLocalFileComparator comparator = FlutterLocalFileComparator(
+  final comparator = FlutterLocalFileComparator(
     basedir.uri,
     fakeSkiaClient,
     fs: fs,
@@ -112,7 +112,7 @@ void main() {
       ),
       isTrue,
     );
-    const String expectation =
+    const expectation =
         'No expectations provided by Skia Gold for test: library.flutter.new_golden_test.1.png. '
         'This may be a new test. If this is an unexpected result, check https://flutter-gold.skia.org.\n'
         'Validate image output found at flutter/test/library/';
@@ -128,7 +128,7 @@ void main() {
       ),
       isTrue,
     );
-    const String expectation =
+    const expectation =
         'No expectations provided by Skia Gold for test: library.flutter.new_golden_test.2.png. '
         'This may be a new test. If this is an unexpected result, check https://flutter-gold.skia.org.\n'
         'Validate image output found at flutter/test/library/';

dev/automated_tests/test_smoke_test/fail_test_on_exception_after_test.dart

@@ -11,7 +11,7 @@ import 'package:flutter_test/flutter_test.dart';
 // See //flutter/dev/bots/test.dart
 
 void main() {
-  final Completer<void> complete = Completer<void>();
+  final complete = Completer<void>();
 
   testWidgets('test smoke test -- this test SHOULD FAIL', (WidgetTester tester) async {
     tester.runAsync(() async {

dev/benchmarks/complex_layout/lib/src/app.dart

@@ -514,7 +514,7 @@ class ItemGalleryBox extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final List<String> tabNames = <String>['A', 'B', 'C', 'D'];
+    final tabNames = <String>['A', 'B', 'C', 'D'];
 
     return SizedBox(
       height: 200.0,