apply upcoming rule use_collection_literals_when_possible (#8649)

dev/manual_tests/overlay_geometry.dart

@@ -134,7 +134,7 @@ class CardBuilder extends SliverChildDelegate {
 
 class OverlayGeometryAppState extends State<OverlayGeometryApp> {
   List<CardModel> cardModels;
-  Map<MarkerType, Point> markers = new Map<MarkerType, Point>();
+  Map<MarkerType, Point> markers = <MarkerType, Point>{};
   double markersScrollOffset = 0.0;
 
   @override

examples/flutter_gallery/lib/demo/calculator/logic.dart

@@ -303,7 +303,7 @@ class CalcExpression {
           assert(false);
       }
     }
-    final List<ExpressionToken> outList = new List<ExpressionToken>();
+    final List<ExpressionToken> outList = <ExpressionToken>[];
     outList.add(new ResultToken(currentTermValue));
     return new CalcExpression(outList, ExpressionState.Result);
   }

examples/flutter_gallery/test_driver/transitions_perf_test.dart

@@ -82,7 +82,7 @@ Future<Null> saveDurationsHistogram(List<Map<String, dynamic>> events, String ou
       startEvent = event;
     } else if (startEvent != null && eventName == 'Frame') {
       final String routeName = startEvent['args']['to'];
-      durations[routeName] ??= new List<int>();
+      durations[routeName] ??= <int>[];
       durations[routeName].add(event['dur']);
       startEvent = null;
     }

packages/flutter/lib/src/foundation/observer_list.dart

@@ -9,7 +9,7 @@ import 'dart:collection';
 /// Consider using an [ObserverList] instead of a [List] when the number of
 /// [contains] calls dominates the number of [add] and [remove] calls.
 class ObserverList<T> extends Iterable<T> {
-  final List<T> _list = new List<T>();
+  final List<T> _list = <T>[];
   bool _isDirty = false;
   HashSet<T> _set;
 

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

@@ -49,7 +49,7 @@ class GestureArenaEntry {
 }
 
 class _GestureArena {
-  final List<GestureArenaMember> members = new List<GestureArenaMember>();
+  final List<GestureArenaMember> members = <GestureArenaMember>[];
   bool isOpen = true;
   bool isHeld = false;
   bool hasPendingSweep = false;
@@ -71,7 +71,7 @@ class _GestureArena {
 /// See [https://flutter.io/gestures/#gesture-disambiguation] for more
 /// information about the role this class plays in the gesture system.
 class GestureArenaManager {
-  final Map<int, _GestureArena> _arenas = new Map<int, _GestureArena>();
+  final Map<int, _GestureArena> _arenas = <int, _GestureArena>{};
 
   /// Adds a new member (e.g., gesture recognizer) to the arena.
   GestureArenaEntry add(int pointer, GestureArenaMember member) {

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

@@ -264,7 +264,7 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
   double _getPrimaryValueFromOffset(Offset value);
   bool get _hasSufficientPendingDragDeltaToAccept;
 
-  Map<int, VelocityTracker> _velocityTrackers = new Map<int, VelocityTracker>();
+  Map<int, VelocityTracker> _velocityTrackers = <int, VelocityTracker>{};
 
   @override
   void addPointer(PointerEvent event) {

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

@@ -94,7 +94,7 @@ class DoubleTapGestureRecognizer extends GestureRecognizer {
 
   Timer _doubleTapTimer;
   _TapTracker _firstTap;
-  final Map<int, _TapTracker> _trackers = new Map<int, _TapTracker>();
+  final Map<int, _TapTracker> _trackers = <int, _TapTracker>{};
 
   @override
   void addPointer(PointerEvent event) {
@@ -341,7 +341,7 @@ class MultiTapGestureRecognizer extends GestureRecognizer {
   /// particular location after [longTapDelay].
   GestureMultiTapDownCallback onLongTapDown;
 
-  final Map<int, _TapGesture> _gestureMap = new Map<int, _TapGesture>();
+  final Map<int, _TapGesture> _gestureMap = <int, _TapGesture>{};
 
   @override
   void addPointer(PointerEvent event) {

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

@@ -13,7 +13,7 @@ typedef void PointerRoute(PointerEvent event);
 
 /// A routing table for [PointerEvent] events.
 class PointerRouter {
-  final Map<int, LinkedHashSet<PointerRoute>> _routeMap = new Map<int, LinkedHashSet<PointerRoute>>();
+  final Map<int, LinkedHashSet<PointerRoute>> _routeMap = <int, LinkedHashSet<PointerRoute>>{};
   final LinkedHashSet<PointerRoute> _globalRoutes = new LinkedHashSet<PointerRoute>();
 
   /// Adds a route to the routing table.

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

@@ -115,7 +115,7 @@ class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
   double _initialSpan;
   double _currentSpan;
   Map<int, Point> _pointerLocations;
-  Map<int, VelocityTracker> _velocityTrackers = new Map<int, VelocityTracker>();
+  Map<int, VelocityTracker> _velocityTrackers = <int, VelocityTracker>{};
 
   double get _scaleFactor => _initialSpan > 0.0 ? _currentSpan / _initialSpan : 1.0;
 
@@ -127,7 +127,7 @@ class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
       _state = ScaleState.possible;
       _initialSpan = 0.0;
       _currentSpan = 0.0;
-      _pointerLocations = new Map<int, Point>();
+      _pointerLocations = <int, Point>{};
     }
   }
 

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

@@ -90,7 +90,7 @@ class _CombiningGestureArenaMember extends GestureArenaMember {
 /// To assign a gesture recognizer to a team, see
 /// [OneSequenceGestureRecognizer.team].
 class GestureArenaTeam {
-  final Map<int, _CombiningGestureArenaMember> _combiners = new Map<int, _CombiningGestureArenaMember>();
+  final Map<int, _CombiningGestureArenaMember> _combiners = <int, _CombiningGestureArenaMember>{};
 
   /// Adds a new member to the arena on behalf of this team.
   ///

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

@@ -63,10 +63,10 @@ class _LeastSquaresVelocityTrackerStrategy extends _VelocityTrackerStrategy {
   @override
   _Estimate getEstimate() {
     // Iterate over movement samples in reverse time order and collect samples.
-    final List<double> x = new List<double>();
-    final List<double> y = new List<double>();
-    final List<double> w = new List<double>();
-    final List<double> time = new List<double>();
+    final List<double> x = <double>[];
+    final List<double> y = <double>[];
+    final List<double> w = <double>[];
+    final List<double> time = <double>[];
     int m = 0;
     int index = _index;
 

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

@@ -134,7 +134,7 @@ class AlertDialog extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final List<Widget> children = new List<Widget>();
+    final List<Widget> children = <Widget>[];
 
     if (title != null) {
       children.add(new Padding(

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

@@ -233,7 +233,7 @@ class _FloatingActionButtonTransitionState extends State<_FloatingActionButtonTr
 
   @override
   Widget build(BuildContext context) {
-    final List<Widget> children = new List<Widget>();
+    final List<Widget> children = <Widget>[];
     if (_previousAnimation.status != AnimationStatus.dismissed) {
       children.add(new ScaleTransition(
         scale: _previousAnimation,
@@ -777,7 +777,7 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
       }
     }
 
-    final List<LayoutId> children = new List<LayoutId>();
+    final List<LayoutId> children = <LayoutId>[];
 
     _addIfNonNull(children, config.body, _ScaffoldSlot.body);
 

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

@@ -178,7 +178,7 @@ class Stepper extends StatefulWidget {
 
 class _StepperState extends State<Stepper> with TickerProviderStateMixin {
   List<GlobalKey> _keys;
-  final Map<int, StepState> _oldStates = new Map<int, StepState>();
+  final Map<int, StepState> _oldStates = <int, StepState>{};
 
   @override
   void initState() {

packages/flutter/lib/src/painting/box_painter.dart

@@ -578,10 +578,10 @@ class BoxShadow {
     if (a == null && b == null)
       return null;
     if (a == null)
-      a = new List<BoxShadow>();
+      a = <BoxShadow>[];
     if (b == null)
-      b = new List<BoxShadow>();
-    final List<BoxShadow> result = new List<BoxShadow>();
+      b = <BoxShadow>[];
+    final List<BoxShadow> result = <BoxShadow>[];
     final int commonLength = math.min(a.length, b.length);
     for (int i = 0; i < commonLength; ++i)
       result.add(BoxShadow.lerp(a[i], b[i], t));

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

@@ -1483,7 +1483,7 @@ abstract class RenderBox extends RenderObject {
   double getDistanceToActualBaseline(TextBaseline baseline) {
     assert(_debugDoingBaseline);
     if (_cachedBaselines == null)
-      _cachedBaselines = new Map<TextBaseline, double>();
+      _cachedBaselines = <TextBaseline, double>{};
     _cachedBaselines.putIfAbsent(baseline, () => computeDistanceToActualBaseline(baseline));
     return _cachedBaselines[baseline];
   }

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

@@ -170,7 +170,7 @@ abstract class MultiChildLayoutDelegate {
     });
 
     try {
-      _idToChild = new Map<Object, RenderBox>();
+      _idToChild = <Object, RenderBox>{};
       RenderBox child = firstChild;
       while (child != null) {
         final MultiChildLayoutParentData childParentData = child.parentData;

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

@@ -494,7 +494,7 @@ class RenderTable extends RenderBox {
     assert(configuration != null);
     _columns = columns ?? (children != null && children.isNotEmpty ? children.first.length : 0);
     _rows = rows ?? 0;
-    _children = new List<RenderBox>()..length = _columns * _rows;
+    _children = <RenderBox>[]..length = _columns * _rows;
     _columnWidths = columnWidths ?? new HashMap<int, TableColumnWidth>();
     _defaultColumnWidth = defaultColumnWidth;
     _border = border;
@@ -529,7 +529,7 @@ class RenderTable extends RenderBox {
     final int oldColumns = columns;
     final List<RenderBox> oldChildren = _children;
     _columns = value;
-    _children = new List<RenderBox>()..length = columns * rows;
+    _children = <RenderBox>[]..length = columns * rows;
     final int columnsToCopy = math.min(columns, oldColumns);
     for (int y = 0; y < rows; y += 1) {
       for (int x = 0; x < columnsToCopy; x += 1)

packages/flutter/lib/src/scheduler/binding.dart

@@ -402,7 +402,7 @@ abstract class SchedulerBinding extends BindingBase {
     });
   }
 
-  final List<FrameCallback> _persistentCallbacks = new List<FrameCallback>();
+  final List<FrameCallback> _persistentCallbacks = <FrameCallback>[];
 
   /// Adds a persistent frame callback.
   ///
@@ -420,7 +420,7 @@ abstract class SchedulerBinding extends BindingBase {
     _persistentCallbacks.add(callback);
   }
 
-  final List<FrameCallback> _postFrameCallbacks = new List<FrameCallback>();
+  final List<FrameCallback> _postFrameCallbacks = <FrameCallback>[];
 
   /// Schedule a callback for the end of this frame.
   ///
@@ -637,7 +637,7 @@ abstract class SchedulerBinding extends BindingBase {
     Timeline.startSync('Animate');
     assert(schedulerPhase == SchedulerPhase.transientCallbacks);
     final Map<int, _FrameCallbackEntry> callbacks = _transientCallbacks;
-    _transientCallbacks = new Map<int, _FrameCallbackEntry>();
+    _transientCallbacks = <int, _FrameCallbackEntry>{};
     callbacks.forEach((int id, _FrameCallbackEntry callbackEntry) {
       if (!_removedIds.contains(id))
         _invokeFrameCallback(callbackEntry.callback, timeStamp, callbackEntry.debugStack);

packages/flutter/lib/src/services/image_cache.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 'image_stream.dart';
 
 const int _kDefaultSize = 1000;
@@ -27,7 +25,7 @@ const int _kDefaultSize = 1000;
 /// Generally this class is not used directly. The [ImageProvider] class and its
 /// subclasses automatically handle the caching of images.
 class ImageCache {
-  final LinkedHashMap<Object, ImageStreamCompleter> _cache = new LinkedHashMap<Object, ImageStreamCompleter>();
+  final Map<Object, ImageStreamCompleter> _cache = <Object, ImageStreamCompleter>{};
 
   /// Maximum number of entries to store in the cache.
   ///

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

@@ -358,7 +358,7 @@ class StandardMessageCodec implements MessageCodec<dynamic> {
         break;
       case _kMap:
         final int length = _readSize(buffer);
-        result = new Map<dynamic, dynamic>();
+        result = <dynamic, dynamic>{};
         for (int i = 0; i < length; i++) {
           result[_readValue(buffer)] = _readValue(buffer);
         }
@@ -418,4 +418,3 @@ class StandardMethodCodec implements MethodCodec {
       throw new FormatException('Invalid envelope');
   }
 }
-

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

@@ -380,8 +380,8 @@ List<T> _mapAvatarsToData<T>(List<_DragAvatar<T>> avatars) {
 }
 
 class _DragTargetState<T> extends State<DragTarget<T>> {
-  final List<_DragAvatar<T>> _candidateAvatars = new List<_DragAvatar<T>>();
-  final List<_DragAvatar<dynamic>> _rejectedAvatars = new List<_DragAvatar<dynamic>>();
+  final List<_DragAvatar<T>> _candidateAvatars = <_DragAvatar<T>>[];
+  final List<_DragAvatar<dynamic>> _rejectedAvatars = <_DragAvatar<dynamic>>[];
 
   bool didEnter(_DragAvatar<dynamic> avatar) {
     assert(!_candidateAvatars.contains(avatar));

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

@@ -167,11 +167,11 @@ abstract class GlobalKey<T extends State<StatefulWidget>> extends Key {
   /// constructor.
   const GlobalKey.constructor() : super._();
 
-  static final Map<GlobalKey, Element> _registry = new Map<GlobalKey, Element>();
-  static final Map<GlobalKey, Set<GlobalKeyRemoveListener>> _removeListeners = new Map<GlobalKey, Set<GlobalKeyRemoveListener>>();
+  static final Map<GlobalKey, Element> _registry = <GlobalKey, Element>{};
+  static final Map<GlobalKey, Set<GlobalKeyRemoveListener>> _removeListeners = <GlobalKey, Set<GlobalKeyRemoveListener>>{};
   static final Set<GlobalKey> _removedKeys = new HashSet<GlobalKey>();
   static final Set<Element> _debugIllFatedElements = new HashSet<Element>();
-  static final Map<GlobalKey, Element> _debugReservations = new Map<GlobalKey, Element>();
+  static final Map<GlobalKey, Element> _debugReservations = <GlobalKey, Element>{};
 
   void _register(Element element) {
     assert(() {
@@ -3421,7 +3421,7 @@ class InheritedElement extends ProxyElement {
     if (incomingWidgets != null)
       _inheritedWidgets = new Map<Type, InheritedElement>.from(incomingWidgets);
     else
-      _inheritedWidgets = new Map<Type, InheritedElement>();
+      _inheritedWidgets = <Type, InheritedElement>{};
     _inheritedWidgets[widget.runtimeType] = this;
   }
 
@@ -3789,7 +3789,7 @@ abstract class RenderObjectElement extends BuildableElement {
     final bool haveOldChildren = oldChildrenTop <= oldChildrenBottom;
     Map<Key, Element> oldKeyedChildren;
     if (haveOldChildren) {
-      oldKeyedChildren = new Map<Key, Element>();
+      oldKeyedChildren = <Key, Element>{};
       while (oldChildrenTop <= oldChildrenBottom) {
         final Element oldChild = replaceWithNullIfForgotten(oldChildren[oldChildrenTop]);
         assert(oldChild == null || oldChild._debugLifecycleState == _ElementLifecycle.active);

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

@@ -697,7 +697,7 @@ class Navigator extends StatefulWidget {
 /// The state for a [Navigator] widget.
 class NavigatorState extends State<Navigator> with TickerProviderStateMixin {
   final GlobalKey<OverlayState> _overlayKey = new GlobalKey<OverlayState>();
-  final List<Route<dynamic>> _history = new List<Route<dynamic>>();
+  final List<Route<dynamic>> _history = <Route<dynamic>>[];
   final Set<Route<dynamic>> _poppedRoutes = new Set<Route<dynamic>>();
 
   @override

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

@@ -266,7 +266,7 @@ class Overlay extends StatefulWidget {
 /// Used to insert [OverlayEntry]s into the overlay using the [insert] and
 /// [insertAll] functions.
 class OverlayState extends State<Overlay> with TickerProviderStateMixin {
-  final List<OverlayEntry> _entries = new List<OverlayEntry>();
+  final List<OverlayEntry> _entries = <OverlayEntry>[];
 
   @override
   void initState() {

packages/flutter/test/widgets/listener_test.dart

@@ -7,7 +7,7 @@ import 'package:flutter/widgets.dart';
 
 void main() {
   testWidgets('Events bubble up the tree', (WidgetTester tester) async {
-    final List<String> log = new List<String>();
+    final List<String> log = <String>[];
 
     await tester.pumpWidget(
       new Listener(

packages/flutter_tools/lib/src/devfs.dart

@@ -330,7 +330,7 @@ class DevFS {
   final Set<String> assetPathsToEvict = new Set<String>();
 
   final List<Future<Map<String, dynamic>>> _pendingOperations =
-      new List<Future<Map<String, dynamic>>>();
+      <Future<Map<String, dynamic>>>[];
 
   Uri _baseUri;
   Uri get baseUri => _baseUri;
@@ -376,7 +376,7 @@ class DevFS {
     // Handle deletions.
     printTrace('Scanning for deleted files');
     final String assetBuildDirPrefix = _asUriPath(getAssetBuildDirectory());
-    final List<Uri> toRemove = new List<Uri>();
+    final List<Uri> toRemove = <Uri>[];
     _entries.forEach((Uri deviceUri, DevFSContent content) {
       if (!content._exists) {
         final Future<Map<String, dynamic>> operation =

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

@@ -434,7 +434,7 @@ class _IOSDeviceLogReader extends DeviceLogReader {
 }
 
 class _IOSDevicePortForwarder extends DevicePortForwarder {
-  _IOSDevicePortForwarder(this.device) : _forwardedPorts = new List<ForwardedPort>();
+  _IOSDevicePortForwarder(this.device) : _forwardedPorts = <ForwardedPort>[];
 
   final IOSDevice device;
 

packages/flutter_tools/lib/src/run_hot.dart

@@ -61,7 +61,7 @@ class HotRunner extends ResidentRunner {
   Uri _observatoryUri;
 
   final bool benchmarkMode;
-  final Map<String, int> benchmarkData = new Map<String, int>();
+  final Map<String, int> benchmarkData = <String, int>{};
   // The initial launch is from a snapshot.
   bool _runningFromSnapshot = true;
   String kernelFilePath;
@@ -141,7 +141,7 @@ class HotRunner extends ResidentRunner {
       return 1;
     }
 
-    final Map<String, dynamic> platformArgs = new Map<String, dynamic>();
+    final Map<String, dynamic> platformArgs = <String, dynamic>{};
 
     await startEchoingDeviceLog(package);
 

packages/flutter_tools/lib/src/template.dart

@@ -24,7 +24,7 @@ const String _kCopyTemplateExtension = '.copy.tmpl';
 /// extensions.
 class Template {
   Template(Directory templateSource, Directory baseDir) {
-    _templateFilePaths = new Map<String, String>();
+    _templateFilePaths = <String, String>{};
 
     if (!templateSource.existsSync()) {
       return;

packages/flutter_tools/lib/src/vmservice.dart

@@ -505,14 +505,14 @@ class VM extends ServiceObjectOwner {
     _removeDeadIsolates(map['isolates']);
   }
 
-  final Map<String, ServiceObject> _cache = new Map<String,ServiceObject>();
-  final Map<String,Isolate> _isolateCache = new Map<String,Isolate>();
+  final Map<String, ServiceObject> _cache = <String,ServiceObject>{};
+  final Map<String,Isolate> _isolateCache = <String,Isolate>{};
 
   /// The list of live isolates, ordered by isolate start time.
-  final List<Isolate> isolates = new List<Isolate>();
+  final List<Isolate> isolates = <Isolate>[];
 
   /// The set of live views.
-  final Map<String, FlutterView> _viewCache = new Map<String, FlutterView>();
+  final Map<String, FlutterView> _viewCache = <String, FlutterView>{};
 
   int _compareIsolates(Isolate a, Isolate b) {
     final DateTime aStart = a.startTime;
@@ -767,7 +767,7 @@ class Isolate extends ServiceObjectOwner {
   DateTime startTime;
   ServiceEvent pauseEvent;
 
-  final Map<String, ServiceObject> _cache = new Map<String, ServiceObject>();
+  final Map<String, ServiceObject> _cache = <String, ServiceObject>{};
 
   @override
   ServiceObject getFromMap(Map<String, dynamic> map) {
@@ -967,7 +967,7 @@ class Isolate extends ServiceObjectOwner {
 class ServiceMap extends ServiceObject implements Map<String, dynamic> {
   ServiceMap._empty(ServiceObjectOwner owner) : super._empty(owner);
 
-  final Map<String, dynamic> _map = new Map<String, dynamic>();
+  final Map<String, dynamic> _map = <String, dynamic>{};
 
   @override
   void _update(Map<String, dynamic> map, bool mapIsRef) {

packages/flutter_tools/test/src/mocks.dart

@@ -77,7 +77,7 @@ void applyMocksToCommand(FlutterCommand command) {
 
 /// Common functionality for tracking mock interaction
 class BasicMock {
-  final List<String> messages = new List<String>();
+  final List<String> messages = <String>[];
 
   void expectMessages(List<String> expectedMessages) {
     final List<String> actualMessages = new List<String>.from(messages);