[web] Make window.locale(s) non-null; upgrade to null safe deps (flutter/engine#24922)

* Make window.locale(s) non-null

* upgrade deps to null-safe; migrate some test libs

engine/src/flutter/lib/web_ui/dev/chrome_installer.dart

@@ -270,7 +270,7 @@ Future<String> fetchLatestChromeVersion() async {
   final Client client = Client();
   try {
     final Response response = await client.get(
-        'https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/Linux_x64%2FLAST_CHANGE?alt=media');
+        Uri.parse('https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/Linux_x64%2FLAST_CHANGE?alt=media'));
     if (response.statusCode != 200) {
       throw BrowserInstallerException(
           'Failed to fetch latest Chrome version. Server returned status code ${response.statusCode}');

engine/src/flutter/lib/web_ui/lib/src/ui/window.dart

@@ -32,8 +32,8 @@ abstract class SingletonFlutterWindow extends FlutterWindow {
     platformDispatcher.onMetricsChanged = callback;
   }
 
-  Locale? get locale => platformDispatcher.locale;
-  List<Locale>? get locales => platformDispatcher.locales;
+  Locale get locale => platformDispatcher.locale;
+  List<Locale> get locales => platformDispatcher.locales;
 
   Locale? computePlatformResolvedLocale(List<Locale> supportedLocales) {
     return platformDispatcher.computePlatformResolvedLocale(supportedLocales);

engine/src/flutter/lib/web_ui/pubspec.yaml

@@ -5,20 +5,21 @@ environment:
   sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
-  js: 0.6.3-nullsafety.3
-  meta: 1.3.0-nullsafety.6
+  js: 0.6.3
+  meta: 1.3.0
 
 dev_dependencies:
-  analyzer: 0.39.15
-  archive: 2.0.13
-  http: 0.12.1
-  image: 2.1.13
-  mockito: 4.1.1
-  path: 1.8.0-nullsafety.3
-  test: 1.16.0-nullsafety.9
-  quiver: 3.0.0-nullsafety.2
-  yaml: 2.2.1
-  watcher: 0.9.7+15
+  analyzer: 1.1.0
+  archive: 3.1.2
+  html: 0.15.0
+  http: 0.13.0
+  image: 3.0.1
+  mockito: 5.0.0
+  path: 1.8.0
+  quiver: 3.0.0
+  test: 1.16.6
+  yaml: 3.0.0
+  watcher: 1.0.0
   web_test_utils:
     path: ../../web_sdk/web_test_utils
   web_engine_tester:
@@ -32,4 +33,4 @@ dev_dependencies:
     git:
       url: git://github.com/flutter/web_installers.git
       path: packages/web_drivers/
-      ref: 58081a8b2fbf234e9c8da86fce28adfefe3c2093
+      ref: 946111ae3248132e3773bf5c5327bcbbefa0c5f2

engine/src/flutter/lib/web_ui/test/engine/history_test.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.6
+// @dart = 2.12
 @TestOn('!safari')
 // TODO(nurhan): https://github.com/flutter/flutter/issues/51169
 
@@ -471,14 +471,14 @@ void testMain() {
   });
 
   group('$HashUrlStrategy', () {
-    TestPlatformLocation location;
+    late TestPlatformLocation location;
 
     setUp(() {
       location = TestPlatformLocation();
     });
 
     tearDown(() {
-      location = null;
+      location = TestPlatformLocation();
     });
 
     test('leading slash is optional', () {
@@ -544,11 +544,15 @@ Future<void> systemNavigatorPop() {
 
 /// A mock implementation of [PlatformLocation] that doesn't access the browser.
 class TestPlatformLocation extends PlatformLocation {
-  String pathname;
-  String search;
-  String hash;
+  String? hash;
   dynamic state;
 
+  @override
+  String get pathname => throw UnimplementedError();
+
+  @override
+  String get search => throw UnimplementedError();
+
   @override
   void addPopStateListener(html.EventListener fn) {
     throw UnimplementedError();

engine/src/flutter/lib/web_ui/test/matchers.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 /// Provides utilities for testing engine code.
-// @dart = 2.6
+// @dart = 2.12
 library matchers;
 
 import 'dart:html' as html;
@@ -12,7 +12,6 @@ import 'dart:math' as math;
 import 'package:html/parser.dart' as html_package;
 import 'package:html/dom.dart' as html_package;
 
-import 'package:meta/meta.dart';
 import 'package:test/test.dart';
 
 import 'package:ui/ui.dart';
@@ -23,9 +22,9 @@ import 'package:ui/src/engine.dart';
 /// If [root] is `null` returns all surfaces from the last rendered scene.
 ///
 /// Surfaces are returned in a depth-first order.
-Iterable<PersistedSurface> enumerateSurfaces([PersistedSurface root]) {
+Iterable<PersistedSurface> enumerateSurfaces([PersistedSurface? root]) {
   root ??= SurfaceSceneBuilder.debugLastFrameScene;
-  final List<PersistedSurface> surfaces = <PersistedSurface>[root];
+  final List<PersistedSurface> surfaces = <PersistedSurface>[root!];
 
   root.visitChildren((PersistedSurface surface) {
     surfaces.addAll(enumerateSurfaces(surface));
@@ -37,7 +36,7 @@ Iterable<PersistedSurface> enumerateSurfaces([PersistedSurface root]) {
 /// Enumerates all pictures nested under [root].
 ///
 /// If [root] is `null` returns all pictures from the last rendered scene.
-Iterable<PersistedPicture> enumeratePictures([PersistedSurface root]) {
+Iterable<PersistedPicture> enumeratePictures([PersistedSurface? root]) {
   root ??= SurfaceSceneBuilder.debugLastFrameScene;
   return enumerateSurfaces(root).whereType<PersistedPicture>();
 }
@@ -45,7 +44,7 @@ Iterable<PersistedPicture> enumeratePictures([PersistedSurface root]) {
 /// Enumerates all offset surfaces nested under [root].
 ///
 /// If [root] is `null` returns all pictures from the last rendered scene.
-Iterable<PersistedOffset> enumerateOffsets([PersistedSurface root]) {
+Iterable<PersistedOffset> enumerateOffsets([PersistedSurface? root]) {
   root ??= SurfaceSceneBuilder.debugLastFrameScene;
   return enumerateSurfaces(root).whereType<PersistedOffset>();
 }
@@ -76,7 +75,7 @@ typedef DistanceFunction<T> = num Function(T a, T b);
 ///
 /// Calling an instance of this type must either be done dynamically, or by
 /// first casting it to a [DistanceFunction<T>] for some concrete T.
-typedef AnyDistanceFunction = num Function(Null a, Null b);
+typedef AnyDistanceFunction = num Function(Never a, Never b);
 
 const Map<Type, AnyDistanceFunction> _kStandardDistanceFunctions =
     <Type, AnyDistanceFunction>{
@@ -108,7 +107,7 @@ double _rectDistance(Rect a, Rect b) {
 }
 
 double _sizeDistance(Size a, Size b) {
-  final Offset delta = b - a;
+  final Offset delta = (b - a) as Offset;
   return delta.distance;
 }
 
@@ -134,11 +133,11 @@ double _sizeDistance(Size a, Size b) {
 ///    [double]s and has an optional `epsilon` parameter.
 ///  * [closeTo], which specializes in numbers only.
 Matcher within<T>({
-  @required num distance,
-  @required T from,
-  DistanceFunction<T> distanceFunction,
+  required num distance,
+  required T from,
+  DistanceFunction<T>? distanceFunction,
 }) {
-  distanceFunction ??= _kStandardDistanceFunctions[T];
+  distanceFunction ??= _kStandardDistanceFunctions[T] as DistanceFunction<T>?;
 
   if (distanceFunction == null) {
     throw ArgumentError(
@@ -158,7 +157,7 @@ class _IsWithinDistance<T> extends Matcher {
   final num epsilon;
 
   @override
-  bool matches(Object object, Map<dynamic, dynamic> matchState) {
+  bool matches(Object? object, Map<dynamic, dynamic> matchState) {
     if (object is! T) {
       return false;
     }
@@ -183,7 +182,7 @@ class _IsWithinDistance<T> extends Matcher {
 
   @override
   Description describeMismatch(
-    Object object,
+    Object? object,
     Description mismatchDescription,
     Map<dynamic, dynamic> matchState,
     bool verbose,
@@ -230,11 +229,11 @@ enum HtmlComparisonMode {
 String canonicalizeHtml(String htmlContent,
     {HtmlComparisonMode mode = HtmlComparisonMode.nonLayoutOnly,
     bool throwOnUnusedAttributes = false}) {
-  if (htmlContent == null || htmlContent.trim().isEmpty) {
+  if (htmlContent.trim().isEmpty) {
     return '';
   }
 
-  String _unusedAttribute(String name) {
+  String? _unusedAttribute(String name) {
     if (throwOnUnusedAttributes) {
       fail('Provided HTML contains style attribute "$name" which '
           'is not used for comparison in the test. The HTML was:\n\n$htmlContent');
@@ -244,7 +243,7 @@ String canonicalizeHtml(String htmlContent,
   }
 
   html_package.Element _cleanup(html_package.Element original) {
-    String replacementTag = original.localName;
+    String replacementTag = original.localName!;
     switch (replacementTag) {
       case 'flt-scene':
         replacementTag = 's';
@@ -256,7 +255,7 @@ String canonicalizeHtml(String htmlContent,
         replacementTag = 'o';
         break;
       case 'flt-clip':
-        final String clipType = original.attributes['clip-type'];
+        final String? clipType = original.attributes['clip-type'];
         switch (clipType) {
           case 'rect':
             replacementTag = 'clip';
@@ -314,7 +313,7 @@ String canonicalizeHtml(String htmlContent,
       });
 
       if (original.attributes.containsKey('style')) {
-        final String styleValue = original.attributes['style'];
+        final String styleValue = original.attributes['style']!;
 
         int attrCount = 0;
         final String processedAttributes = styleValue
@@ -368,7 +367,7 @@ String canonicalizeHtml(String htmlContent,
               attrCount++;
               return attr.trim();
             })
-            .where((String attr) => attr != null && attr.isNotEmpty)
+            .where((String? attr) => attr != null && attr.isNotEmpty)
             .join('; ');
 
         if (attrCount > 0) {
@@ -412,7 +411,7 @@ void expectHtml(html.Element element, String expectedHtml,
     {HtmlComparisonMode mode = HtmlComparisonMode.nonLayoutOnly}) {
   expectedHtml =
       canonicalizeHtml(expectedHtml, mode: mode, throwOnUnusedAttributes: true);
-  final String actualHtml = canonicalizeHtml(element.outerHtml, mode: mode);
+  final String actualHtml = canonicalizeHtml(element.outerHtml!, mode: mode);
   expect(actualHtml, expectedHtml);
 }
 
@@ -462,7 +461,7 @@ class SceneTester {
   final SurfaceScene scene;
 
   void expectSceneHtml(String expectedHtml) {
-    expectHtml(scene.webOnlyRootElement, expectedHtml,
+    expectHtml(scene.webOnlyRootElement!, expectedHtml,
         mode: HtmlComparisonMode.noAttributes);
   }
 }

engine/src/flutter/lib/web_ui/test/spy.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.6
+// @dart = 2.12
 import 'dart:typed_data';
 
 import 'package:ui/src/engine.dart' hide window;
@@ -31,8 +31,8 @@ class PlatformMessage {
 /// It holds all intercepted platform messages in a [messages] list that can
 /// be inspected in tests.
 class PlatformMessagesSpy {
-  PlatformMessageCallback _callback;
-  PlatformMessageCallback _backup;
+  PlatformMessageCallback? _callback;
+  PlatformMessageCallback? _backup;
 
   bool get _isActive => _callback != null;
 
@@ -44,8 +44,8 @@ class PlatformMessagesSpy {
   /// This is typically called inside a test's `setUp` callback.
   void setUp() {
     assert(!_isActive);
-    _callback = (String channel, ByteData data,
-        PlatformMessageResponseCallback callback) {
+    _callback = (String channel, ByteData? data,
+        PlatformMessageResponseCallback? callback) {
       messages.add(PlatformMessage(
         channel,
         const JSONMethodCodec().decodeMethodCall(data),

engine/src/flutter/lib/web_ui/test/window_test.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.6
+// @dart = 2.12
 import 'dart:async';
 import 'dart:html' as html;
 import 'dart:js_util' as js_util;
@@ -22,7 +22,7 @@ void main() {
 }
 
 void testMain() {
-  EngineSingletonFlutterWindow window;
+  late EngineSingletonFlutterWindow window;
 
   setUp(() {
     ui.webOnlyInitializeEngine();
@@ -31,7 +31,6 @@ void testMain() {
 
   tearDown(() async {
     await window.resetHistory();
-    window = null;
   });
 
   test('window.defaultRouteName should not change', () async {
@@ -42,7 +41,7 @@ void testMain() {
     expect(window.defaultRouteName, '/initial');
 
     // Changing the URL in the address bar later shouldn't affect [window.defaultRouteName].
-    strategy.replaceState(null, null, '/newpath');
+    strategy.replaceState(null, '', '/newpath');
     expect(window.defaultRouteName, '/initial');
   });
 
@@ -86,7 +85,7 @@ void testMain() {
     );
     await callback.future;
     expect(window.browserHistory is SingleEntryBrowserHistory, true);
-    expect(window.browserHistory.urlStrategy.getPath(), '/bar');
+    expect(window.browserHistory.urlStrategy!.getPath(), '/bar');
 
     // We can still receive nav2 update.
     callback = Completer<void>();
@@ -103,10 +102,10 @@ void testMain() {
     );
     await callback.future;
     expect(window.browserHistory is MultiEntriesBrowserHistory, true);
-    expect(window.browserHistory.urlStrategy.getPath(), '/baz');
+    expect(window.browserHistory.urlStrategy!.getPath(), '/baz');
 
     // Throws assertion error if it receives nav1 update after nav2 update.
-    AssertionError caughtAssertion;
+    late AssertionError caughtAssertion;
     await window.handleNavigationMessage(
       JSONMethodCodec().encodeMethodCall(MethodCall(
         'routeUpdated',
@@ -124,7 +123,7 @@ void testMain() {
     );
     // The history does not change.
     expect(window.browserHistory is MultiEntriesBrowserHistory, true);
-    expect(window.browserHistory.urlStrategy.getPath(), '/baz');
+    expect(window.browserHistory.urlStrategy!.getPath(), '/baz');
   });
 
   test('initialize browser history with default url strategy (single)', () async {
@@ -149,7 +148,7 @@ void testMain() {
     // The url strategy should've been set to the default, and the path
     // should've been correctly set to "/bar".
     expect(window.browserHistory.urlStrategy, isNot(isNull));
-    expect(window.browserHistory.urlStrategy.getPath(), '/bar');
+    expect(window.browserHistory.urlStrategy!.getPath(), '/bar');
   }, skip: browserEngine == BrowserEngine.webkit); // https://github.com/flutter/flutter/issues/50836
 
   test('initialize browser history with default url strategy (multiple)', () async {
@@ -177,7 +176,7 @@ void testMain() {
     // The url strategy should've been set to the default, and the path
     // should've been correctly set to "/baz".
     expect(window.browserHistory.urlStrategy, isNot(isNull));
-    expect(window.browserHistory.urlStrategy.getPath(), '/baz');
+    expect(window.browserHistory.urlStrategy!.getPath(), '/baz');
   }, skip: browserEngine == BrowserEngine.webkit); // https://github.com/flutter/flutter/issues/50836
 
   test('can disable location strategy', () async {
@@ -231,6 +230,13 @@ void testMain() {
     // Second time is not allowed.
     expect(() => jsSetUrlStrategy(null), throwsA(isAssertionError));
   });
+
+  // Regression test for https://github.com/flutter/flutter/issues/77817
+  test('window.locale(s) are not nullable', () {
+    // If the getters were nullable, these expressions would result in compiler errors.
+    ui.window.locale.countryCode;
+    ui.window.locales.first.countryCode;
+  });
 }
 
 void jsSetUrlStrategy(dynamic strategy) {

engine/src/flutter/web_sdk/web_engine_tester/pubspec.yaml

@@ -4,9 +4,9 @@ environment:
   sdk: ">=2.2.0 <3.0.0"
 
 dependencies:
-  js: 0.6.3-nullsafety.3
-  stream_channel: 2.1.0-nullsafety.3
-  test: 1.16.0-nullsafety.9
-  webkit_inspection_protocol: 0.5.0
+  js: 0.6.3
+  stream_channel: 2.1.0
+  test: 1.16.6
+  webkit_inspection_protocol: 1.0.0
   ui:
     path: ../../lib/web_ui

engine/src/flutter/web_sdk/web_test_utils/pubspec.yaml

@@ -4,7 +4,7 @@ environment:
   sdk: ">=2.11.0-0 <3.0.0"
 
 dependencies:
-  path: 1.8.0-nullsafety.3
-  image: 2.1.13
-  js: 0.6.3-nullsafety.3
-  yaml: 2.2.1
+  path: 1.8.0
+  image: 3.0.1
+  js: 0.6.3
+  yaml: 3.0.0