set literal conversions (#27811)

analysis_options.yaml

@@ -120,7 +120,7 @@ linter:
     # - parameter_assignments # we do this commonly
     - prefer_adjacent_string_concatenation
     - prefer_asserts_in_initializer_lists
-    # - prefer_collection_literals # temporary until all platforms support set literals
+    - prefer_collection_literals
     - prefer_conditional_assignment
     - prefer_const_constructors
     - prefer_const_constructors_in_immutables

dev/bots/analyze.dart

@@ -401,7 +401,7 @@ Set<String> _findFlutterDependencies(String srcPath, List<String> errors, { bool
   return Directory(srcPath).listSync(recursive: true).where((FileSystemEntity entity) {
     return entity is File && path.extension(entity.path) == '.dart';
   }).map<Set<String>>((FileSystemEntity entity) {
-    final Set<String> result = Set<String>();
+    final Set<String> result = <String>{};
     final File file = entity;
     for (String line in file.readAsLinesSync()) {
       Match match = _importPattern.firstMatch(line);
@@ -419,7 +419,7 @@ Set<String> _findFlutterDependencies(String srcPath, List<String> errors, { bool
     }
     return result;
   }).reduce((Set<String> value, Set<String> element) {
-    value ??= Set<String>();
+    value ??= <String>{};
     value.addAll(element);
     return value;
   });
@@ -434,7 +434,7 @@ List<T> _deepSearch<T>(Map<T, Set<T>> map, T start, [ Set<T> seen ]) {
     final List<T> result = _deepSearch<T>(
       map,
       key,
-      (seen == null ? Set<T>.from(<T>[start]) : Set<T>.from(seen))..add(key),
+      (seen == null ? <T>{start} : Set<T>.from(seen))..add(key),
     );
     if (result != null) {
       result.insert(0, start);
@@ -543,7 +543,7 @@ Future<void> _verifyGeneratedPluginRegistrants(String flutterRoot) async {
     }
   }
 
-  final Set<String> outOfDate = Set<String>();
+  final Set<String> outOfDate = <String>{};
 
   for (String package in packageToRegistrants.keys) {
     final Map<File, String> fileToContent = <File, String>{};

dev/manual_tests/lib/text.dart

@@ -1382,7 +1382,7 @@ String zalgo(math.Random random, int targetLength, { bool includeSpacingCombinin
     0x16F7E, 0x1D165, 0x1D166, 0x1D16D, 0x1D16E, 0x1D16F, 0x1D170,
     0x1D171, 0x1D172,
   ];
-  final Set<int> these = Set<int>();
+  final Set<int> these = <int>{};
   int combiningCount = enclosingCombiningMarks.length + nonspacingCombiningMarks.length;
   if (includeSpacingCombiningMarks)
     combiningCount += spacingCombiningMarks.length;

dev/tools/gen_localizations.dart

@@ -80,7 +80,7 @@ final Map<LocaleInfo, Map<String, dynamic>> localeToResourceAttributes = <Locale
 /// the first Hant Chinese locale as a default by repeating the data. If an
 /// explicit match is later found, we can reference this set to see if we should
 /// overwrite the existing assumed data.
-final Set<LocaleInfo> assumedLocales = Set<LocaleInfo>();
+final Set<LocaleInfo> assumedLocales = <LocaleInfo>{};
 
 /// Return `s` as a Dart-parseable raw string in single or double quotes.
 ///
@@ -124,15 +124,15 @@ String generateTranslationBundles() {
   final Map<String, Set<String>> languageToScriptCodes = <String, Set<String>>{};
   // Used to calculate if there are any corresponding countries for a given language and script.
   final Map<LocaleInfo, Set<String>> languageAndScriptToCountryCodes = <LocaleInfo, Set<String>>{};
-  final Set<String> allResourceIdentifiers = Set<String>();
+  final Set<String> allResourceIdentifiers = <String>{};
   for (LocaleInfo locale in localeToResources.keys.toList()..sort()) {
     if (locale.scriptCode != null) {
-      languageToScriptCodes[locale.languageCode] ??= Set<String>();
+      languageToScriptCodes[locale.languageCode] ??= <String>{};
       languageToScriptCodes[locale.languageCode].add(locale.scriptCode);
     }
     if (locale.countryCode != null && locale.scriptCode != null) {
       final LocaleInfo key = LocaleInfo.fromString(locale.languageCode + '_' + locale.scriptCode);
-      languageAndScriptToCountryCodes[key] ??= Set<String>();
+      languageAndScriptToCountryCodes[key] ??= <String>{};
       languageAndScriptToCountryCodes[key].add(locale.countryCode);
     }
     languageToLocales[locale.languageCode] ??= <LocaleInfo>[];

dev/tools/update_icons.dart

@@ -71,7 +71,7 @@ const Map<String, String> kIdentifierRewrites = <String, String>{
 
 };
 
-final Set<String> kMirroredIcons = Set<String>.from(<String>[
+const Set<String> kMirroredIcons = <String>{
   // This list is obtained from:
   // http://google.github.io/material-design-icons/#icons-in-rtl
   'arrow_back',
@@ -145,7 +145,7 @@ final Set<String> kMirroredIcons = Set<String>.from(<String>[
   'view_list',
   'view_quilt',
   'wrap_text',
-]);
+};
 
 void main(List<String> args) {
   // If we're run from the `tools` dir, set the cwd to the repo root.

examples/flutter_gallery/lib/demo/material/chip_demo.dart

@@ -54,20 +54,20 @@ const Map<String, String> _avatars = <String, String>{
   'customer': 'people/square/peter.png',
 };
 
-final Map<String, Set<String>> _toolActions = <String, Set<String>>{
-  'hammer': Set<String>()..addAll(<String>['flake', 'fragment', 'splinter']),
-  'chisel': Set<String>()..addAll(<String>['flake', 'nick', 'splinter']),
-  'fryer': Set<String>()..addAll(<String>['fry']),
-  'fabricator': Set<String>()..addAll(<String>['solder']),
-  'customer': Set<String>()..addAll(<String>['cash in', 'eat']),
+const Map<String, Set<String>> _toolActions = <String, Set<String>>{
+  'hammer': <String>{'flake', 'fragment', 'splinter'},
+  'chisel': <String>{'flake', 'nick', 'splinter'},
+  'fryer': <String>{'fry'},
+  'fabricator': <String>{'solder'},
+  'customer': <String>{'cash in', 'eat'},
 };
 
-final Map<String, Set<String>> _materialActions = <String, Set<String>>{
-  'poker': Set<String>()..addAll(<String>['cash in']),
-  'tortilla': Set<String>()..addAll(<String>['fry', 'eat']),
-  'fish and': Set<String>()..addAll(<String>['fry', 'eat']),
-  'micro': Set<String>()..addAll(<String>['solder', 'fragment']),
-  'wood': Set<String>()..addAll(<String>['flake', 'cut', 'splinter', 'nick']),
+const Map<String, Set<String>> _materialActions = <String, Set<String>>{
+  'poker': <String>{'cash in'},
+  'tortilla': <String>{'fry', 'eat'},
+  'fish and': <String>{'fry', 'eat'},
+  'micro': <String>{'solder', 'fragment'},
+  'wood': <String>{'flake', 'cut', 'splinter', 'nick'},
 };
 
 class _ChipsTile extends StatelessWidget {
@@ -134,12 +134,12 @@ class _ChipDemoState extends State<ChipDemo> {
     _reset();
   }
 
-  final Set<String> _materials = Set<String>();
+  final Set<String> _materials = <String>{};
   String _selectedMaterial = '';
   String _selectedAction = '';
-  final Set<String> _tools = Set<String>();
-  final Set<String> _selectedTools = Set<String>();
-  final Set<String> _actions = Set<String>();
+  final Set<String> _tools = <String>{};
+  final Set<String> _selectedTools = <String>{};
+  final Set<String> _actions = <String>{};
   bool _showShapeBorder = false;
 
   // Initialize members with the default data.
@@ -262,7 +262,7 @@ class _ChipDemoState extends State<ChipDemo> {
       );
     }).toList();
 
-    Set<String> allowedActions = Set<String>();
+    Set<String> allowedActions = <String>{};
     if (_selectedMaterial != null && _selectedMaterial.isNotEmpty) {
       for (String tool in _selectedTools) {
         allowedActions.addAll(_toolActions[tool]);

examples/flutter_gallery/lib/demo/pesto_demo.dart

@@ -21,7 +21,7 @@ const double _kAppBarHeight = 128.0;
 const double _kFabHalfSize = 28.0; // TODO(mpcomplete): needs to adapt to screen size
 const double _kRecipePageMaxWidth = 500.0;
 
-final Set<Recipe> _favoriteRecipes = Set<Recipe>();
+final Set<Recipe> _favoriteRecipes = <Recipe>{};
 
 final ThemeData _kTheme = ThemeData(
   brightness: Brightness.light,

packages/flutter/lib/src/cupertino/route.dart

@@ -193,7 +193,7 @@ class CupertinoPageRoute<T> extends PageRoute<T> {
   ///  * [popGestureEnabled], which returns true if a user-triggered pop gesture
   ///    would be allowed.
   static bool isPopGestureInProgress(PageRoute<dynamic> route) => _popGestureInProgress.contains(route);
-  static final Set<PageRoute<dynamic>> _popGestureInProgress = Set<PageRoute<dynamic>>();
+  static final Set<PageRoute<dynamic>> _popGestureInProgress = <PageRoute<dynamic>>{};
 
   /// True if a Cupertino pop gesture is currently underway for this route.
   ///

packages/flutter/lib/src/gestures/mouse_tracking.dart

@@ -70,7 +70,7 @@ class _TrackedAnnotation {
   ///
   /// This is used to detect layers that used to have the mouse pointer inside
   /// them, but now no longer do (to facilitate exit notification).
-  Set<int> activeDevices = Set<int>();
+  Set<int> activeDevices = <int>{};
 }
 
 /// Describes a function that finds an annotation given an offset in logical

packages/flutter/lib/src/material/time_picker.dart

@@ -965,10 +965,10 @@ class _DialPainter extends CustomPainter {
             textDirection: textDirection,
             onTap: label.onTap,
           ),
-          tags: Set<SemanticsTag>.from(const <SemanticsTag>[
+          tags: <SemanticsTag>{
             // Used by tests to find this node.
-            SemanticsTag('dial-label'),
-          ]),
+            const SemanticsTag('dial-label'),
+          },
         );
         nodes.add(node);
         labelTheta += labelThetaIncrement;

packages/flutter/lib/src/rendering/custom_layout.dart

@@ -183,7 +183,7 @@ abstract class MultiChildLayoutDelegate {
     Set<RenderBox> debugPreviousChildrenNeedingLayout;
     assert(() {
       debugPreviousChildrenNeedingLayout = _debugChildrenNeedingLayout;
-      _debugChildrenNeedingLayout = Set<RenderBox>();
+      _debugChildrenNeedingLayout = <RenderBox>{};
       return true;
     }());
 

packages/flutter/lib/src/rendering/object.dart

@@ -921,7 +921,7 @@ class PipelineOwner {
   }
 
   bool _debugDoingSemantics = false;
-  final Set<RenderObject> _nodesNeedingSemantics = Set<RenderObject>();
+  final Set<RenderObject> _nodesNeedingSemantics = <RenderObject>{};
 
   /// Update the semantics for render objects marked as needing a semantics
   /// update.
@@ -2422,7 +2422,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
 
     final bool producesForkingFragment = !config.hasBeenAnnotated && !config.isSemanticBoundary;
     final List<_InterestingSemanticsFragment> fragments = <_InterestingSemanticsFragment>[];
-    final Set<_InterestingSemanticsFragment> toBeMarkedExplicit = Set<_InterestingSemanticsFragment>();
+    final Set<_InterestingSemanticsFragment> toBeMarkedExplicit = <_InterestingSemanticsFragment>{};
     final bool childrenMergeIntoParent = mergeIntoParent || config.isMergingSemanticsOfDescendants;
 
     // When set to true there's currently not enough information in this subtree
@@ -3244,7 +3244,7 @@ abstract class _InterestingSemanticsFragment extends _SemanticsFragment {
   void addTags(Iterable<SemanticsTag> tags) {
     if (tags == null || tags.isEmpty)
       return;
-    _tagsForChildren ??= Set<SemanticsTag>();
+    _tagsForChildren ??= <SemanticsTag>{};
     _tagsForChildren.addAll(tags);
   }
 

packages/flutter/lib/src/rendering/platform_view.dart

@@ -481,7 +481,7 @@ class _AndroidViewGestureRecognizer extends OneSequenceGestureRecognizer {
 
   // Pointer for which we have already won the arena, events for pointers in this set are
   // immediately dispatched to the Android view.
-  final Set<int> forwardedPointers = Set<int>();
+  final Set<int> forwardedPointers = <int>{};
 
   // We use OneSequenceGestureRecognizers as they support gesture arena teams.
   // TODO(amirh): get a list of GestureRecognizers here.

packages/flutter/lib/src/semantics/semantics.dart

@@ -1284,7 +1284,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
       return true;
     }());
     assert(() {
-      final Set<SemanticsNode> seenChildren = Set<SemanticsNode>();
+      final Set<SemanticsNode> seenChildren = <SemanticsNode>{};
       for (SemanticsNode child in newChildren)
         assert(seenChildren.add(child)); // check for duplicate adds
       return true;
@@ -1742,7 +1742,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
     double scrollExtentMin = _scrollExtentMin;
     final double elevation = _elevation;
     double thickness = _thickness;
-    final Set<int> customSemanticsActionIds = Set<int>();
+    final Set<int> customSemanticsActionIds = <int>{};
     for (CustomSemanticsAction action in _customSemanticsActions.keys)
       customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
     if (hintOverrides != null) {
@@ -1781,7 +1781,7 @@ class SemanticsNode extends AbstractNode with DiagnosticableTreeMixin {
         if (decreasedValue == '' || decreasedValue == null)
           decreasedValue = node._decreasedValue;
         if (node.tags != null) {
-          mergedTags ??= Set<SemanticsTag>();
+          mergedTags ??= <SemanticsTag>{};
           mergedTags.addAll(node.tags);
         }
         if (node._customSemanticsActions != null) {
@@ -2270,7 +2270,7 @@ class _SemanticsSortGroup extends Comparable<_SemanticsSortGroup> {
     }
 
     final List<int> sortedIds = <int>[];
-    final Set<int> visitedIds = Set<int>();
+    final Set<int> visitedIds = <int>{};
     final List<SemanticsNode> startNodes = nodes.toList()..sort((SemanticsNode a, SemanticsNode b) {
       final Offset aTopLeft = _pointInParentCoordinates(a, a.rect.topLeft);
       final Offset bTopLeft = _pointInParentCoordinates(b, b.rect.topLeft);
@@ -2410,9 +2410,9 @@ class _TraversalSortNode implements Comparable<_TraversalSortNode> {
 /// obtain a [SemanticsHandle]. This will create a [SemanticsOwner] if
 /// necessary.
 class SemanticsOwner extends ChangeNotifier {
-  final Set<SemanticsNode> _dirtyNodes = Set<SemanticsNode>();
+  final Set<SemanticsNode> _dirtyNodes = <SemanticsNode>{};
   final Map<int, SemanticsNode> _nodes = <int, SemanticsNode>{};
-  final Set<SemanticsNode> _detachedNodes = Set<SemanticsNode>();
+  final Set<SemanticsNode> _detachedNodes = <SemanticsNode>{};
   final Map<int, CustomSemanticsAction> _actions = <int, CustomSemanticsAction>{};
 
   /// The root node of the semantics tree, if any.
@@ -2432,7 +2432,7 @@ class SemanticsOwner extends ChangeNotifier {
   void sendSemanticsUpdate() {
     if (_dirtyNodes.isEmpty)
       return;
-    final Set<int> customSemanticsActionIds = Set<int>();
+    final Set<int> customSemanticsActionIds = <int>{};
     final List<SemanticsNode> visitedNodes = <SemanticsNode>[];
     while (_dirtyNodes.isNotEmpty) {
       final List<SemanticsNode> localDirtyNodes = _dirtyNodes.where((SemanticsNode node) => !_detachedNodes.contains(node)).toList();
@@ -3551,7 +3551,7 @@ class SemanticsConfiguration {
   ///  * [RenderSemanticsGestureHandler.excludeFromScrolling] for an example of
   ///    how tags are used.
   void addTagForChildren(SemanticsTag tag) {
-    _tagsForChildren ??= Set<SemanticsTag>();
+    _tagsForChildren ??= <SemanticsTag>{};
     _tagsForChildren.add(tag);
   }
 

packages/flutter/lib/src/services/raw_keyboard.dart

@@ -478,7 +478,7 @@ class RawKeyboard {
     }
   }
 
-  final Set<LogicalKeyboardKey> _keysPressed = Set<LogicalKeyboardKey>();
+  final Set<LogicalKeyboardKey> _keysPressed = <LogicalKeyboardKey>{};
 
   /// Returns the set of keys currently pressed.
   Set<LogicalKeyboardKey> get keysPressed {

packages/flutter/lib/src/widgets/animated_switcher.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:collection';
-
 import 'package:flutter/animation.dart';
 import 'package:flutter/foundation.dart';
 
@@ -278,7 +276,7 @@ class AnimatedSwitcher extends StatefulWidget {
 
 class _AnimatedSwitcherState extends State<AnimatedSwitcher> with TickerProviderStateMixin {
   _ChildEntry _currentEntry;
-  final Set<_ChildEntry> _outgoingEntries = LinkedHashSet<_ChildEntry>();
+  final Set<_ChildEntry> _outgoingEntries = <_ChildEntry>{};
   List<Widget> _outgoingWidgets = const <Widget>[];
   int _childNumber = 0;
 

packages/flutter/lib/src/widgets/form.dart

@@ -83,7 +83,7 @@ class Form extends StatefulWidget {
 /// Typically obtained via [Form.of].
 class FormState extends State<Form> {
   int _generation = 0;
-  final Set<FormFieldState<dynamic>> _fields = Set<FormFieldState<dynamic>>();
+  final Set<FormFieldState<dynamic>> _fields = <FormFieldState<dynamic>>{};
 
   // Called when a form field has changed. This will cause all form fields
   // to rebuild, useful if form fields have interdependencies.

packages/flutter/lib/src/widgets/localizations.dart

@@ -44,7 +44,7 @@ Future<Map<Type, dynamic>> _loadAll(Locale locale, Iterable<LocalizationsDelegat
 
   // Only load the first delegate for each delegate type that supports
   // locale.languageCode.
-  final Set<Type> types = Set<Type>();
+  final Set<Type> types = <Type>{};
   final List<LocalizationsDelegate<dynamic>> delegates = <LocalizationsDelegate<dynamic>>[];
   for (LocalizationsDelegate<dynamic> delegate in allDelegates) {
     if (!types.contains(delegate.type) && delegate.isSupported(locale)) {

packages/flutter/lib/src/widgets/navigator.dart

@@ -1465,7 +1465,7 @@ class Navigator extends StatefulWidget {
 class NavigatorState extends State<Navigator> with TickerProviderStateMixin {
   final GlobalKey<OverlayState> _overlayKey = GlobalKey<OverlayState>();
   final List<Route<dynamic>> _history = <Route<dynamic>>[];
-  final Set<Route<dynamic>> _poppedRoutes = Set<Route<dynamic>>();
+  final Set<Route<dynamic>> _poppedRoutes = <Route<dynamic>>{};
 
   /// The [FocusScopeNode] for the [FocusScope] that encloses the routes.
   final FocusScopeNode focusScopeNode = FocusScopeNode();
@@ -2145,7 +2145,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin {
     }
   }
 
-  final Set<int> _activePointers = Set<int>();
+  final Set<int> _activePointers = <int>{};
 
   void _handlePointerDown(PointerDownEvent event) {
     _activePointers.add(event.pointer);

packages/flutter/lib/src/widgets/platform_view.dart

@@ -297,7 +297,7 @@ class _AndroidViewState extends State<AndroidView> {
   bool _initialized = false;
 
   static final Set<Factory<OneSequenceGestureRecognizer>> _emptyRecognizersSet =
-    Set<Factory<OneSequenceGestureRecognizer>>();
+    <Factory<OneSequenceGestureRecognizer>>{};
 
   @override
   Widget build(BuildContext context) {
@@ -380,7 +380,7 @@ class _UiKitViewState extends State<UiKitView> {
   bool _initialized = false;
 
   static final Set<Factory<OneSequenceGestureRecognizer>> _emptyRecognizersSet =
-    Set<Factory<OneSequenceGestureRecognizer>>();
+    <Factory<OneSequenceGestureRecognizer>>{};
 
   @override
   Widget build(BuildContext context) {

packages/flutter/lib/src/widgets/routes.dart

@@ -1363,7 +1363,7 @@ class RouteObserver<R extends Route<dynamic>> extends NavigatorObserver {
   void subscribe(RouteAware routeAware, R route) {
     assert(routeAware != null);
     assert(route != null);
-    final Set<RouteAware> subscribers = _listeners.putIfAbsent(route, () => Set<RouteAware>());
+    final Set<RouteAware> subscribers = _listeners.putIfAbsent(route, () => <RouteAware>{});
     if (subscribers.add(routeAware)) {
       routeAware.didPush();
     }

packages/flutter/lib/src/widgets/scroll_position.dart

@@ -432,7 +432,7 @@ abstract class ScrollPosition extends ViewportOffset with ScrollMetrics {
         break;
     }
 
-    final Set<SemanticsAction> actions = Set<SemanticsAction>();
+    final Set<SemanticsAction> actions = <SemanticsAction>{};
     if (pixels > minScrollExtent)
       actions.add(backward);
     if (pixels < maxScrollExtent)

packages/flutter/lib/src/widgets/table.dart

@@ -308,7 +308,7 @@ class _TableElement extends RenderObjectElement {
     }
     final Iterator<_TableElementRow> oldUnkeyedRows = _children.where((_TableElementRow row) => row.key == null).iterator;
     final List<_TableElementRow> newChildren = <_TableElementRow>[];
-    final Set<List<Element>> taken = Set<List<Element>>();
+    final Set<List<Element>> taken = <List<Element>>{};
     for (TableRow row in newWidget.children) {
       List<Element> oldChildren;
       if (row.key != null && oldKeyedRows.containsKey(row.key)) {

packages/flutter/lib/src/widgets/ticker_provider.dart

@@ -157,7 +157,7 @@ mixin TickerProviderStateMixin<T extends StatefulWidget> on State<T> implements
 
   @override
   Ticker createTicker(TickerCallback onTick) {
-    _tickers ??= Set<_WidgetTicker>();
+    _tickers ??= <_WidgetTicker>{};
     final _WidgetTicker result = _WidgetTicker(onTick, this, debugLabel: 'created by $this');
     _tickers.add(result);
     return result;

packages/flutter/lib/src/widgets/widget_inspector.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:collection';
 import 'dart:convert';
 import 'dart:developer' as developer;
 import 'dart:math' as math;
@@ -2259,7 +2258,7 @@ class _WidgetInspectorState extends State<WidgetInspector>
       return size == null ? double.maxFinite : size.width * size.height;
     }
     regularHits.sort((RenderObject a, RenderObject b) => _area(a).compareTo(_area(b)));
-    final Set<RenderObject> hits = LinkedHashSet<RenderObject>();
+    final Set<RenderObject> hits = <RenderObject>{};
     hits..addAll(edgeHits)..addAll(regularHits);
     return hits.toList();
   }

packages/flutter/test/rendering/proxy_box_test.dart

@@ -89,7 +89,7 @@ void main() {
     expect(config.getActionHandler(SemanticsAction.scrollRight), isNotNull);
 
     config = SemanticsConfiguration();
-    renderObj.validActions = <SemanticsAction>[SemanticsAction.tap, SemanticsAction.scrollLeft].toSet();
+    renderObj.validActions = <SemanticsAction>{SemanticsAction.tap, SemanticsAction.scrollLeft};
 
     renderObj.describeSemanticsConfiguration(config);
     expect(config.getActionHandler(SemanticsAction.tap), isNotNull);

packages/flutter/test/semantics/semantics_test.dart

@@ -26,7 +26,7 @@ void main() {
       expect(node.isTagged(tag1), isFalse);
       expect(node.isTagged(tag2), isFalse);
 
-      node.tags = Set<SemanticsTag>()..add(tag1);
+      node.tags = <SemanticsTag>{tag1};
       expect(node.isTagged(tag1), isTrue);
       expect(node.isTagged(tag2), isFalse);
 
@@ -36,9 +36,7 @@ void main() {
     });
 
     test('getSemanticsData includes tags', () {
-      final Set<SemanticsTag> tags = Set<SemanticsTag>()
-        ..add(tag1)
-        ..add(tag2);
+      final Set<SemanticsTag> tags = <SemanticsTag>{tag1, tag2};
 
       final SemanticsNode node = SemanticsNode()
         ..rect = Rect.fromLTRB(0.0, 0.0, 10.0, 10.0)

packages/flutter/test/services/fake_platform_views.dart

@@ -20,7 +20,7 @@ class FakeAndroidPlatformViewsController {
 
   final Map<int, List<FakeAndroidMotionEvent>> motionEvents = <int, List<FakeAndroidMotionEvent>>{};
 
-  final Set<String> _registeredViewTypes = Set<String>();
+  final Set<String> _registeredViewTypes = <String>{};
 
   int _textureCounter = 0;
 
@@ -153,7 +153,7 @@ class FakeIosPlatformViewsController {
   Iterable<FakeUiKitView> get views => _views.values;
   final Map<int, FakeUiKitView> _views = <int, FakeUiKitView>{};
 
-  final Set<String> _registeredViewTypes = Set<String>();
+  final Set<String> _registeredViewTypes = <String>{};
 
   // When this completer is non null, the 'create' method channel call will be
   // delayed until it completes.

packages/flutter/test/widgets/inherited_model_test.dart

@@ -241,7 +241,7 @@ void main() {
                 child: ABCModel( // The "inner" model
                   a: 100 + _a,
                   b: 100 + _b,
-                  aspects: Set<String>.of(<String>['a']),
+                  aspects: <String>{'a'},
                   child: Center(
                     child: Column(
                       mainAxisSize: MainAxisSize.min,
@@ -328,7 +328,7 @@ void main() {
     int _a = 0;
     int _b = 1;
     int _c = 2;
-    Set<String> _innerModelAspects = Set<String>.of(<String>['a']);
+    Set<String> _innerModelAspects = <String>{'a'};
 
     // Same as in abcPage in the "Inner InheritedModel shadows the outer one"
     // test except: the "Add b aspect" changes adds 'b' to the set of
@@ -406,14 +406,14 @@ void main() {
       },
     );
 
-    _innerModelAspects = Set<String>.of(<String>['a']);
+    _innerModelAspects = <String>{'a'};
     await tester.pumpWidget(MaterialApp(home: abcPage));
     expect(find.text('a: 100 [0]'), findsOneWidget); // showA depends on the inner model
     expect(find.text('b: 1 [0]'), findsOneWidget); // showB depends on the outer model
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 100 b: 101 c: null'), findsOneWidget); // inner model's a, b, c
 
-    _innerModelAspects = Set<String>.of(<String>['a', 'b']);
+    _innerModelAspects = <String>{'a', 'b'};
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 100 [1]'), findsOneWidget); // rebuilt showA still depend on the inner model
@@ -448,7 +448,7 @@ void main() {
     expect(find.text('c: 3 [2]'), findsOneWidget); // rebuilt showC still depends on the outer model
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget);
 
-    _innerModelAspects = Set<String>.of(<String>['a', 'b', 'c']);
+    _innerModelAspects = <String>{'a', 'b', 'c'};
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 101 [3]'), findsOneWidget); // rebuilt showA still depend on the inner model
@@ -457,7 +457,7 @@ void main() {
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c
 
     // Now the inner model supports no aspects
-    _innerModelAspects = Set<String>.of(<String>[]);
+    _innerModelAspects = <String>{};
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 1 [4]'), findsOneWidget); // rebuilt showA now depends on the outer model

packages/flutter/test/widgets/list_wheel_scroll_view_test.dart

@@ -277,7 +277,7 @@ void main() {
     });
 
     testWidgets('builder is never called twice for same index', (WidgetTester tester) async {
-      final Set<int> builtChildren = Set<int>();
+      final Set<int> builtChildren = <int>{};
       final FixedExtentScrollController controller =
         FixedExtentScrollController();
 

packages/flutter/test/widgets/platform_view_test.dart

@@ -590,11 +590,11 @@ void main() {
               height: 100.0,
               child: AndroidView(
                 viewType: 'webview',
-                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
                   Factory<VerticalDragGestureRecognizer>(
                         () => VerticalDragGestureRecognizer(),
                   ),
-                ].toSet(),
+                },
                 layoutDirection: TextDirection.ltr,
               ),
             ),
@@ -727,11 +727,11 @@ void main() {
               height: 100.0,
               child: AndroidView(
                 viewType: 'webview',
-                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
                   Factory<OneSequenceGestureRecognizer>(
                         () => EagerGestureRecognizer(),
                   ),
-                ].toSet(),
+                },
                 layoutDirection: TextDirection.ltr,
               ),
             ),
@@ -760,11 +760,11 @@ void main() {
 
       final AndroidView androidView = AndroidView(
         viewType: 'webview',
-        gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+        gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
           Factory<EagerGestureRecognizer>(
                 () => EagerGestureRecognizer(),
           ),
-        ].toSet(),
+        },
         layoutDirection: TextDirection.ltr,
       );
 
@@ -786,9 +786,9 @@ void main() {
       await tester.pumpWidget(
         AndroidView(
           viewType: 'webview',
-          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
             Factory<EagerGestureRecognizer>(constructRecognizer),
-          ].toSet(),
+          },
           layoutDirection: TextDirection.ltr,
         ),
       );
@@ -797,9 +797,9 @@ void main() {
         AndroidView(
           viewType: 'webview',
           hitTestBehavior: PlatformViewHitTestBehavior.translucent,
-          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
             Factory<EagerGestureRecognizer>(constructRecognizer),
-          ].toSet(),
+          },
           layoutDirection: TextDirection.ltr,
         ),
       );
@@ -1214,11 +1214,11 @@ void main() {
               height: 100.0,
               child: UiKitView(
                 viewType: 'webview',
-                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
                   Factory<VerticalDragGestureRecognizer>(
                         () => VerticalDragGestureRecognizer(),
                   ),
-                ].toSet(),
+                },
                 layoutDirection: TextDirection.ltr,
               ),
             ),
@@ -1338,11 +1338,11 @@ void main() {
               height: 100.0,
               child: UiKitView(
                 viewType: 'webview',
-                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+                gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
                   Factory<OneSequenceGestureRecognizer>(
                         () => EagerGestureRecognizer(),
                   ),
-                ].toSet(),
+                },
                 layoutDirection: TextDirection.ltr,
               ),
             ),
@@ -1407,9 +1407,9 @@ void main() {
       await tester.pumpWidget(
         UiKitView(
           viewType: 'webview',
-          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
             Factory<EagerGestureRecognizer>(constructRecognizer),
-          ].toSet(),
+          },
           layoutDirection: TextDirection.ltr,
         ),
       );
@@ -1418,9 +1418,9 @@ void main() {
         UiKitView(
           viewType: 'webview',
           hitTestBehavior: PlatformViewHitTestBehavior.translucent,
-          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>[
+          gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
             Factory<EagerGestureRecognizer>(constructRecognizer),
-          ].toSet(),
+          },
           layoutDirection: TextDirection.ltr,
         ),
       );

packages/flutter/test/widgets/semantics_tester.dart

@@ -61,7 +61,7 @@ class TestSemantics {
        assert(decreasedValue != null),
        assert(hint != null),
        assert(children != null),
-       tags = tags?.toSet() ?? Set<SemanticsTag>();
+       tags = tags?.toSet() ?? <SemanticsTag>{};
 
   /// Creates an object with some test semantics data, with the [id] and [rect]
   /// set to the appropriate values for the root node.
@@ -92,7 +92,7 @@ class TestSemantics {
        elevation = 0.0,
        thickness = 0.0,
        assert(children != null),
-       tags = tags?.toSet() ?? Set<SemanticsTag>();
+       tags = tags?.toSet() ?? <SemanticsTag>{};
 
   /// Creates an object with some test semantics data, with the [id] and [rect]
   /// set to the appropriate values for direct children of the root node.
@@ -131,7 +131,7 @@ class TestSemantics {
        assert(hint != null),
        transform = _applyRootChildScale(transform),
        assert(children != null),
-       tags = tags?.toSet() ?? Set<SemanticsTag>();
+       tags = tags?.toSet() ?? <SemanticsTag>{};
 
   /// The unique identifier for this node.
   ///

packages/flutter_localizations/lib/src/material_localizations.dart

@@ -573,7 +573,7 @@ class _MaterialLocalizationsDelegate extends LocalizationsDelegate<MaterialLocal
       // Keep track of initialzed locales, or will fail on attempted double init.
       // This can only happen if a locale with a stripped scriptCode has already
       // been initialzed. This should be removed when scriptCode stripping is removed.
-      final Set<String> initializedLocales = Set<String>();
+      final Set<String> initializedLocales = <String>{};
       date_localizations.dateSymbols.forEach((String locale, dynamic data) {
         // Strip scriptCode from the locale, as we do not distinguish between scripts
         // for dates.

packages/flutter_test/lib/src/test_compat.dart

@@ -365,7 +365,7 @@ class _Reporter {
   String _lastProgressSuffix;
 
   /// The set of all subscriptions to various streams.
-  final Set<StreamSubscription<void>> _subscriptions = Set<StreamSubscription<void>>();
+  final Set<StreamSubscription<void>> _subscriptions = <StreamSubscription<void>>{};
 
   /// A callback called when the engine begins running [liveTest].
   void _onTestStarted(LiveTest liveTest) {

packages/flutter_test/lib/src/widget_tester.dart

@@ -551,7 +551,7 @@ class WidgetTester extends WidgetController implements HitTestDispatcher, Ticker
 
   @override
   Ticker createTicker(TickerCallback onTick) {
-    _tickers ??= Set<_TestTicker>();
+    _tickers ??= <_TestTicker>{};
     final _TestTicker result = _TestTicker(onTick, _removeTicker);
     _tickers.add(result);
     return result;

packages/flutter_tools/lib/src/android/gradle.dart

@@ -682,7 +682,7 @@ class GradleProject {
         .trim();
 
     // Extract build types and product flavors.
-    final Set<String> variants = Set<String>();
+    final Set<String> variants = <String>{};
     for (String s in tasks.split('\n')) {
       final Match match = _assembleTaskPattern.matchAsPrefix(s);
       if (match != null) {
@@ -691,8 +691,8 @@ class GradleProject {
           variants.add(variant);
       }
     }
-    final Set<String> buildTypes = Set<String>();
-    final Set<String> productFlavors = Set<String>();
+    final Set<String> buildTypes = <String>{};
+    final Set<String> productFlavors = <String>{};
     for (final String variant1 in variants) {
       for (final String variant2 in variants) {
         if (variant2.startsWith(variant1) && variant2 != variant1) {

packages/flutter_tools/lib/src/asset.dart

@@ -320,7 +320,7 @@ Future<DevFSContent> _obtainLicenses(
   // example, a package might itself contain code from multiple third-party
   // sources, and might need to include a license for each one.)
   final Map<String, Set<String>> packageLicenses = <String, Set<String>>{};
-  final Set<String> allPackages = Set<String>();
+  final Set<String> allPackages = <String>{};
   for (String packageName in packageMap.map.keys) {
     final Uri package = packageMap.map[packageName];
     if (package != null && package.scheme == 'file') {
@@ -342,7 +342,7 @@ Future<DevFSContent> _obtainLicenses(
             packageNames = <String>[packageName];
             licenseText = rawLicense;
           }
-          packageLicenses.putIfAbsent(licenseText, () => Set<String>())
+          packageLicenses.putIfAbsent(licenseText, () => <String>{})
             ..addAll(packageNames);
           allPackages.addAll(packageNames);
         }

packages/flutter_tools/lib/src/base/build.dart

@@ -118,7 +118,7 @@ class AOTSnapshotter {
     final String vmServicePath = fs.path.join(skyEnginePkg, 'sdk_ext', 'vmservice_io.dart');
 
     final List<String> inputPaths = <String>[uiPath, vmServicePath, mainPath];
-    final Set<String> outputPaths = Set<String>();
+    final Set<String> outputPaths = <String>{};
 
     final String depfilePath = fs.path.join(outputDir.path, 'snapshot.d');
     final List<String> genSnapshotArgs = <String>[
@@ -458,7 +458,7 @@ class JITSnapshotter {
       genSnapshotArgs.addAll(extraGenSnapshotOptions);
     }
 
-    final Set<String> outputPaths = Set<String>();
+    final Set<String> outputPaths = <String>{};
     outputPaths.addAll(<String>[isolateSnapshotData]);
     if (!createPatch) {
       outputPaths.add(isolateSnapshotInstructions);

packages/flutter_tools/lib/src/base/utils.dart

@@ -146,7 +146,7 @@ String getDisplayPath(String fullPath) {
 /// available.
 class ItemListNotifier<T> {
   ItemListNotifier() {
-    _items = Set<T>();
+    _items = <T>{};
   }
 
   ItemListNotifier.from(List<T> items) {

packages/flutter_tools/lib/src/commands/analyze_continuously.dart

@@ -26,7 +26,7 @@ class AnalyzeContinuously extends AnalyzeBase {
 
   String analysisTarget;
   bool firstAnalysis = true;
-  Set<String> analyzedPaths = Set<String>();
+  Set<String> analyzedPaths = <String>{};
   Map<String, List<AnalysisError>> analysisErrors = <String, List<AnalysisError>>{};
   Stopwatch analysisTimer;
   int lastErrorCount = 0;

packages/flutter_tools/lib/src/commands/channel.dart

@@ -52,7 +52,7 @@ class ChannelCommand extends FlutterCommand {
     // Beware: currentBranch could contain PII. See getBranchName().
     final String currentChannel = FlutterVersion.instance.channel;
     final String currentBranch = FlutterVersion.instance.getBranchName();
-    final Set<String> seenChannels = Set<String>();
+    final Set<String> seenChannels = <String>{};
     final List<String> rawOutput = <String>[];
 
     showAll = showAll || currentChannel != currentBranch;

packages/flutter_tools/lib/src/commands/create.dart

@@ -612,7 +612,7 @@ String _createUTIIdentifier(String organization, String name) {
   return segments.join('.');
 }
 
-final Set<String> _packageDependencies = Set<String>.from(<String>[
+const Set<String> _packageDependencies = <String>{
   'analyzer',
   'args',
   'async',
@@ -639,7 +639,7 @@ final Set<String> _packageDependencies = Set<String>.from(<String>[
   'utf',
   'watcher',
   'yaml',
-]);
+};
 
 /// Return null if the project name is legal. Return a validation message if
 /// we should disallow the project name.

packages/flutter_tools/lib/src/commands/ide_config.dart

@@ -121,7 +121,7 @@ class IdeConfigCommand extends FlutterCommand {
       return;
     }
 
-    final Set<String> manifest = Set<String>();
+    final Set<String> manifest = <String>{};
     final List<FileSystemEntity> flutterFiles = _flutterRoot.listSync(recursive: true);
     for (FileSystemEntity entity in flutterFiles) {
       final String relativePath = fs.path.relative(entity.path, from: _flutterRoot.absolute.path);

packages/flutter_tools/lib/src/commands/update_packages.dart

@@ -200,7 +200,7 @@ class UpdatePackagesCommand extends FlutterCommand {
       // First, collect up the explicit dependencies:
       final List<PubspecYaml> pubspecs = <PubspecYaml>[];
       final Map<String, PubspecDependency> dependencies = <String, PubspecDependency>{};
-      final Set<String> specialDependencies = Set<String>();
+      final Set<String> specialDependencies = <String>{};
       for (Directory directory in packages) { // these are all the directories with pubspec.yamls we care about
         printTrace('Reading pubspec.yaml from: ${directory.path}');
         PubspecYaml pubspec;
@@ -279,7 +279,7 @@ class UpdatePackagesCommand extends FlutterCommand {
         for (PubspecDependency dependency in pubspec.dependencies) {
           if (dependency.kind == DependencyKind.normal) {
             tree._versions[package] = version;
-            tree._dependencyTree[package] ??= Set<String>();
+            tree._dependencyTree[package] ??= <String>{};
             tree._dependencyTree[package].add(dependency.name);
           }
         }
@@ -341,7 +341,7 @@ class UpdatePackagesCommand extends FlutterCommand {
       throwToolExit('Package $to not found in the dependency tree.');
 
     final Queue<_DependencyLink> traversalQueue = Queue<_DependencyLink>();
-    final Set<String> visited = Set<String>();
+    final Set<String> visited = <String>{};
     final List<_DependencyLink> paths = <_DependencyLink>[];
 
     traversalQueue.addFirst(_DependencyLink(from: null, to: from));
@@ -625,8 +625,8 @@ class PubspecYaml {
   void apply(PubDependencyTree versions, Set<String> specialDependencies) {
     assert(versions != null);
     final List<String> output = <String>[]; // the string data to output to the file, line by line
-    final Set<String> directDependencies = Set<String>(); // packages this pubspec directly depends on (i.e. not transitive)
-    final Set<String> devDependencies = Set<String>();
+    final Set<String> directDependencies = <String>{}; // packages this pubspec directly depends on (i.e. not transitive)
+    final Set<String> devDependencies = <String>{};
     Section section = Section.other; // the section we're currently handling
 
     // the line number where we're going to insert the transitive dependencies.
@@ -723,8 +723,8 @@ class PubspecYaml {
     final List<String> transitiveDevDependencyOutput = <String>[];
 
     // Which dependencies we need to handle for the transitive and dev dependency sections.
-    final Set<String> transitiveDependencies = Set<String>();
-    final Set<String> transitiveDevDependencies = Set<String>();
+    final Set<String> transitiveDependencies = <String>{};
+    final Set<String> transitiveDevDependencies = <String>{};
 
     // Merge the lists of dependencies we've seen in this file from dependencies, dev dependencies,
     // and the dependencies we know this file mentions that are already pinned
@@ -735,7 +735,7 @@ class PubspecYaml {
 
     // Create a new set to hold the list of packages we've already processed, so
     // that we don't redundantly process them multiple times.
-    final Set<String> done = Set<String>();
+    final Set<String> done = <String>{};
     for (String package in directDependencies)
       transitiveDependencies.addAll(versions.getTransitiveDependenciesFor(package, seen: done, exclude: implied));
     for (String package in devDependencies)
@@ -752,7 +752,7 @@ class PubspecYaml {
       transitiveDevDependencyOutput.add('  $package: ${versions.versionFor(package)} $kTransitiveMagicString');
 
     // Build a sorted list of all dependencies for the checksum.
-    final Set<String> checksumDependencies = Set<String>()
+    final Set<String> checksumDependencies = <String>{}
       ..addAll(directDependencies)
       ..addAll(devDependencies)
       ..addAll(transitiveDependenciesAsList)

packages/flutter_tools/lib/src/dependency_checker.dart

@@ -11,7 +11,7 @@ class DependencyChecker {
   DependencyChecker(this.builder, this.assets);
 
   final DartDependencySetBuilder builder;
-  final Set<String> _dependencies = Set<String>();
+  final Set<String> _dependencies = <String>{};
   final AssetBundle assets;
 
   /// Returns [true] if any components have been modified after [threshold] or

packages/flutter_tools/lib/src/devfs.dart

@@ -403,7 +403,7 @@ class DevFS {
   final Directory rootDirectory;
   String _packagesFilePath;
   final Map<Uri, DevFSContent> _entries = <Uri, DevFSContent>{};
-  final Set<String> assetPathsToEvict = Set<String>();
+  final Set<String> assetPathsToEvict = <String>{};
 
   final List<Future<Map<String, dynamic>>> _pendingOperations =
       <Future<Map<String, dynamic>>>[];
@@ -533,7 +533,7 @@ class DevFS {
     // run with no changes is supposed to be fast (considering that it is
     // initiated by user key press).
     final List<String> invalidatedFiles = <String>[];
-    final Set<Uri> filesUris = Set<Uri>();
+    final Set<Uri> filesUris = <Uri>{};
     for (Uri uri in dirtyEntries.keys.toList()) {
       if (!uri.path.startsWith(assetBuildDirPrefix)) {
         final DevFSContent content = dirtyEntries[uri];

packages/flutter_tools/lib/src/flutter_manifest.dart

@@ -391,9 +391,9 @@ void _validateFonts(YamlList fonts, List<String> errors) {
   if (fonts == null) {
     return;
   }
-  final Set<int> fontWeights = Set<int>.from(const <int>[
+  const Set<int> fontWeights = <int>{
     100, 200, 300, 400, 500, 600, 700, 800, 900,
-  ]);
+  };
   for (final YamlMap fontMap in fonts) {
     for (dynamic key in fontMap.keys.where((dynamic key) => key != 'family' && key != 'fonts')) {
       errors.add('Unexpected child "$key" found under "fonts".');

packages/flutter_tools/lib/src/ios/mac.dart

@@ -733,7 +733,7 @@ Future<bool> upgradePbxProjWithFlutterAssets(IosProject project) async {
 
   final RegExp oldAssets = RegExp(r'\/\* (flutter_assets|app\.flx)');
   final StringBuffer buffer = StringBuffer();
-  final Set<String> printedStatuses = Set<String>();
+  final Set<String> printedStatuses = <String>{};
 
   for (final String line in lines) {
     final Match match = oldAssets.firstMatch(line);

packages/flutter_tools/lib/src/version.dart

@@ -43,12 +43,12 @@ class FlutterVersion {
   String _repositoryUrl;
   String get repositoryUrl => _repositoryUrl;
 
-  static Set<String> officialChannels = Set<String>.from(<String>[
+  static const Set<String> officialChannels = <String>{
     'master',
     'dev',
     'beta',
     'stable',
-  ]);
+  };
 
   /// This maps old branch names to the names of branches that replaced them.
   ///

packages/flutter_tools/lib/src/vmservice.dart

@@ -272,7 +272,7 @@ class VMService {
   final Map<String, StreamController<ServiceEvent>> _eventControllers =
       <String, StreamController<ServiceEvent>>{};
 
-  final Set<String> _listeningFor = Set<String>();
+  final Set<String> _listeningFor = <String>{};
 
   /// Whether our connection to the VM service has been closed;
   bool get isClosed => _peer.isClosed;
@@ -749,7 +749,7 @@ class VM extends ServiceObjectOwner {
 
   void _removeDeadIsolates(List<Isolate> newIsolates) {
     // Build a set of new isolates.
-    final Set<String> newIsolateSet = Set<String>();
+    final Set<String> newIsolateSet = <String>{};
     for (Isolate iso in newIsolates)
       newIsolateSet.add(iso.id);
 

packages/flutter_tools/test/devfs_test.dart

@@ -300,7 +300,7 @@ void main() {
       const String packageName = 'doubleslashpkg';
       await _createPackage(fs, packageName, 'somefile.txt', doubleSlash: true);
 
-      final Set<String> fileFilter = Set<String>();
+      final Set<String> fileFilter = <String>{};
       final List<Uri> pkgUris = <Uri>[fs.path.toUri(basePath)]..addAll(_packages.values);
       for (Uri pkgUri in pkgUris) {
         if (!pkgUri.isAbsolute) {

packages/flutter_tools/test/hot_test.dart

@@ -114,7 +114,7 @@ void main() {
       pathToReload: anyNamed('pathToReload'),
     )).thenAnswer((Invocation _) => Future<UpdateFSReport>.value(
         UpdateFSReport(success: true, syncedBytes: 1000, invalidatedSourcesCount: 1)));
-    when(mockDevFs.assetPathsToEvict).thenReturn(Set<String>());
+    when(mockDevFs.assetPathsToEvict).thenReturn(<String>{});
     when(mockDevFs.baseUri).thenReturn(Uri.file('test'));
 
     setUp(() {

packages/flutter_tools/test/utils_test.dart

@@ -62,7 +62,7 @@ baz=qux
     });
 
     test('is pretty random', () {
-      final Set<String> set = Set<String>();
+      final Set<String> set = <String>{};
 
       Uuid uuid = Uuid();
       for (int i = 0; i < 64; i++) {

packages/fuchsia_remote_debug_protocol/lib/src/fuchsia_remote_connection.dart

@@ -117,7 +117,7 @@ class FuchsiaRemoteConnection {
   final Map<int, PortForwarder> _dartVmPortMap = <int, PortForwarder>{};
 
   /// Tracks stale ports so as not to reconnect while polling.
-  final Set<int> _stalePorts = Set<int>();
+  final Set<int> _stalePorts = <int>{};
 
   /// A broadcast stream that emits events relating to Dart VM's as they update.
   Stream<DartVmEvent> get onDartVmEvent => _onDartVmEvent;