unnessary parenthesis (#14475)

examples/catalog/bin/sample_page.dart

@@ -57,7 +57,7 @@ String expandTemplate(String template, Map<String, String> values) {
     if (match.groupCount != 1)
       throw new SampleError('bad template keyword $match[0]');
     final String keyword = match[1];
-    return (values[keyword] ?? '');
+    return values[keyword] ?? '';
   });
 }
 

examples/flutter_gallery/lib/demo/pesto_demo.dart

@@ -326,7 +326,7 @@ class _RecipePageState extends State<RecipePage> {
     // the edge of the screen, use a slightly different layout.
     final double appBarHeight = _getAppBarHeight(context);
     final Size screenSize = MediaQuery.of(context).size;
-    final bool fullWidth = (screenSize.width < _kRecipePageMaxWidth);
+    final bool fullWidth = screenSize.width < _kRecipePageMaxWidth;
     final bool isFavorite = _favoriteRecipes.contains(widget.recipe);
     return new Scaffold(
       key: _scaffoldKey,

examples/layers/rendering/src/sector_layout.dart

@@ -170,7 +170,7 @@ abstract class RenderDecoratedSector extends RenderSector {
       final Canvas canvas = context.canvas;
       final Paint paint = new Paint()..color = _decoration.color;
       final Path path = new Path();
-      final double outerRadius = (parentData.radius + deltaRadius);
+      final double outerRadius = parentData.radius + deltaRadius;
       final Rect outerBounds = new Rect.fromLTRB(offset.dx-outerRadius, offset.dy-outerRadius, offset.dx+outerRadius, offset.dy+outerRadius);
       path.arcTo(outerBounds, parentData.theta, deltaTheta, true);
       final double innerRadius = parentData.radius;

examples/layers/widgets/gestures.dart

@@ -27,7 +27,7 @@ class _GesturePainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    final Offset center = (size.center(Offset.zero) * zoom + offset);
+    final Offset center = size.center(Offset.zero) * zoom + offset;
     final double radius = size.width / 2.0 * zoom;
     final Gradient gradient = new RadialGradient(
       colors: forward ? <Color>[swatch.shade50, swatch.shade900]

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

@@ -196,7 +196,7 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
         invokeCallback<void>('onCancel', onCancel);
       return;
     }
-    final bool wasAccepted = (_state == _DragState.accepted);
+    final bool wasAccepted = _state == _DragState.accepted;
     _state = _DragState.ready;
     if (wasAccepted && onEnd != null) {
       final VelocityTracker tracker = _velocityTrackers[pointer];

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

@@ -121,7 +121,7 @@ class InkHighlight extends InteractiveInkFeature {
   void paintFeature(Canvas canvas, Matrix4 transform) {
     final Paint paint = new Paint()..color = color.withAlpha(_alpha.value);
     final Offset originOffset = MatrixUtils.getAsTranslation(transform);
-    final Rect rect = (_rectCallback != null ? _rectCallback() : Offset.zero & referenceBox.size);
+    final Rect rect = _rectCallback != null ? _rectCallback() : Offset.zero & referenceBox.size;
     if (originOffset == null) {
       canvas.save();
       canvas.transform(transform.storage);

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

@@ -129,7 +129,7 @@ class MaterialPageRoute<T> extends PageRoute<T> {
 
   @override
   bool canTransitionFrom(TransitionRoute<dynamic> previousRoute) {
-    return (previousRoute is MaterialPageRoute || previousRoute is CupertinoPageRoute);
+    return previousRoute is MaterialPageRoute || previousRoute is CupertinoPageRoute;
   }
 
   @override

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

@@ -324,7 +324,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
     final List<Widget> footerWidgets = <Widget>[];
     if (widget.onRowsPerPageChanged != null) {
       final List<Widget> availableRowsPerPage = widget.availableRowsPerPage
-        .where((int value) => (value <= _rowCount || value == widget.rowsPerPage))
+        .where((int value) => value <= _rowCount || value == widget.rowsPerPage)
         .map<DropdownMenuItem<int>>((int value) {
           return new DropdownMenuItem<int>(
             value: value,

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

@@ -363,7 +363,7 @@ class _StadiumToRoundedRectangleBorder extends ShapeBorder {
     return BorderRadius.lerp(
       borderRadius,
       new BorderRadius.all(new Radius.circular(rect.shortestSide / 2.0)),
-      (1.0 - rectness)
+      1.0 - rectness
     );
   }
 

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

@@ -703,7 +703,7 @@ class TextStyle extends Diagnosticable {
     if (decoration != null || decorationColor != null || decorationStyle != null) {
       final List<String> decorationDescription = <String>[];
       if (decorationStyle != null)
-        decorationDescription.add(describeEnum((decorationStyle)));
+        decorationDescription.add(describeEnum(decorationStyle));
 
       // Hide decorationColor from the default text view as it is shown in the
       // terse decoration summary as well.

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

@@ -168,7 +168,7 @@ class PaintingContext {
   }
 
   bool get _isRecording {
-    final bool hasCanvas = (_canvas != null);
+    final bool hasCanvas = _canvas != null;
     assert(() {
       if (hasCanvas) {
         assert(_currentLayer != null);
@@ -2222,7 +2222,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   /// any way to update the semantics tree.
   void markNeedsSemanticsUpdate() {
     assert(!attached || !owner._debugDoingSemantics);
-    if ((attached && owner._semanticsOwner == null))
+    if (attached && owner._semanticsOwner == null)
       return;
 
     // Dirty the semantics tree starting at `this` until we have reached a

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

@@ -515,8 +515,8 @@ abstract class RenderSliverFloatingPinnedPersistentHeader extends RenderSliverFl
   double updateGeometry() {
     final double minExtent = this.minExtent;
     final double maxExtent = this.maxExtent;
-    final double paintExtent = (maxExtent - _effectiveScrollOffset);
-    final double layoutExtent = (maxExtent - constraints.scrollOffset);
+    final double paintExtent = maxExtent - _effectiveScrollOffset;
+    final double layoutExtent = maxExtent - constraints.scrollOffset;
     geometry = new SliverGeometry(
       scrollExtent: maxExtent,
       paintExtent: paintExtent.clamp(minExtent, constraints.remainingPaintExtent),

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

@@ -2965,7 +2965,7 @@ abstract class Element extends DiagnosticableTree implements BuildContext {
     assert(owner != null);
     assert(depth != null);
     assert(!_active);
-    final bool hadDependencies = ((_dependencies != null && _dependencies.isNotEmpty) || _hadUnsatisfiedDependencies);
+    final bool hadDependencies = (_dependencies != null && _dependencies.isNotEmpty) || _hadUnsatisfiedDependencies;
     _active = true;
     // We unregistered our dependencies in deactivate, but never cleared the list.
     // Since we're going to be reused, let's clear our list now.

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

@@ -362,7 +362,7 @@ class _GlowController extends ChangeNotifier {
     _glowOpacityTween.end = math.min(_glowOpacity.value + overscroll / extent * _pullOpacityGlowFactor, _maxOpacity);
     final double height = math.min(extent, crossExtent * _kWidthToHeightFactor);
     _glowSizeTween.begin = _glowSize.value;
-    _glowSizeTween.end = math.max((1.0 - 1.0 / (0.7 * math.sqrt(_pullDistance * height))), _glowSize.value);
+    _glowSizeTween.end = math.max(1.0 - 1.0 / (0.7 * math.sqrt(_pullDistance * height)), _glowSize.value);
     _displacementTarget = crossAxisOffset / crossExtent;
     if (_displacementTarget != _displacement) {
       if (!_displacementTicker.isTicking) {

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

@@ -40,12 +40,11 @@ class PerformanceOverlay extends LeafRenderObjectWidget {
                                   this.rasterizerThreshold: 0,
                                   this.checkerboardRasterCacheImages: false,
                                   this.checkerboardOffscreenLayers: false })
-    : optionsMask = (
+    : optionsMask =
         1 << PerformanceOverlayOption.displayRasterizerStatistics.index |
         1 << PerformanceOverlayOption.visualizeRasterizerStatistics.index |
         1 << PerformanceOverlayOption.displayEngineStatistics.index |
-        1 << PerformanceOverlayOption.visualizeEngineStatistics.index
-      ),
+        1 << PerformanceOverlayOption.visualizeEngineStatistics.index,
       super(key: key);
 
   /// The mask is created by shifting 1 by the index of the specific

packages/flutter_test/lib/src/widget_tester.dart

@@ -356,9 +356,9 @@ class WidgetTester extends WidgetController implements HitTestDispatcher, Ticker
         if (element.widget.key is ValueKey<dynamic>) {
           final ValueKey<dynamic> key = element.widget.key;
           String keyLabel;
-          if ((key is ValueKey<int> ||
-               key is ValueKey<double> ||
-               key is ValueKey<bool>)) {
+          if (key is ValueKey<int> ||
+              key is ValueKey<double> ||
+              key is ValueKey<bool>) {
             keyLabel = 'const ${element.widget.key.runtimeType}(${key.value})';
           } else if (key is ValueKey<String>) {
             keyLabel = 'const Key(\'${key.value}\')';

packages/flutter_tools/lib/executable.dart

@@ -42,7 +42,7 @@ Future<Null> main(List<String> args) async {
       (args.length == 2 && verbose && args.last == 'doctor');
   final bool help = args.contains('-h') || args.contains('--help') ||
       (args.isNotEmpty && args.first == 'help') || (args.length == 1 && verbose);
-  final bool muteCommandLogging = (help || doctor);
+  final bool muteCommandLogging = help || doctor;
   final bool verboseHelp = help && verbose;
 
   await runner.run(args, <FlutterCommand>[

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

@@ -42,7 +42,7 @@ abstract class AnalyzeBase {
   void writeBenchmark(Stopwatch stopwatch, int errorCount, int membersMissingDocumentation) {
     const String benchmarkOut = 'analysis_benchmark.json';
     final Map<String, dynamic> data = <String, dynamic>{
-      'time': (stopwatch.elapsedMilliseconds / 1000.0),
+      'time': stopwatch.elapsedMilliseconds / 1000.0,
       'issues': errorCount,
       'missingDartDocs': membersMissingDocumentation
     };

packages/flutter_tools/lib/src/plugins.dart

@@ -82,7 +82,7 @@ List<Plugin> _findPlugins(String directory) {
 bool _writeFlutterPluginsList(String directory, List<Plugin> plugins) {
   final File pluginsProperties = fs.file(fs.path.join(directory, '.flutter-plugins'));
   final String previousFlutterPlugins =
-      (pluginsProperties.existsSync() ? pluginsProperties.readAsStringSync() : null);
+      pluginsProperties.existsSync() ? pluginsProperties.readAsStringSync() : null;
   final String pluginManifest =
       plugins.map((Plugin p) => '${p.name}=${escapePath(p.path)}').join('\n');
   if (pluginManifest.isNotEmpty) {
@@ -93,7 +93,7 @@ bool _writeFlutterPluginsList(String directory, List<Plugin> plugins) {
     }
   }
   final String currentFlutterPlugins =
-      (pluginsProperties.existsSync() ? pluginsProperties.readAsStringSync() : null);
+      pluginsProperties.existsSync() ? pluginsProperties.readAsStringSync() : null;
   return currentFlutterPlugins != previousFlutterPlugins;
 }
 

packages/flutter_tools/lib/src/vmservice.dart

@@ -269,7 +269,7 @@ bool _isServiceMap(Map<String, dynamic> m) {
   return (m != null) && (m['type'] != null);
 }
 bool _hasRef(String type) => (type != null) && type.startsWith('@');
-String _stripRef(String type) => (_hasRef(type) ? type.substring(1) : type);
+String _stripRef(String type) => _hasRef(type) ? type.substring(1) : type;
 
 /// Given a raw response from the service protocol and a [ServiceObjectOwner],
 /// recursively walk the response and replace values that are service maps with
@@ -522,13 +522,13 @@ class ServiceEvent extends ServiceObject {
   }
 
   bool get isPauseEvent {
-    return (kind == kPauseStart ||
-            kind == kPauseExit ||
-            kind == kPauseBreakpoint ||
-            kind == kPauseInterrupted ||
-            kind == kPauseException ||
-            kind == kPausePostRequest ||
-            kind == kNone);
+    return kind == kPauseStart ||
+           kind == kPauseExit ||
+           kind == kPauseBreakpoint ||
+           kind == kPauseInterrupted ||
+           kind == kPauseException ||
+           kind == kPausePostRequest ||
+           kind == kNone;
   }
 }
 
@@ -1192,7 +1192,7 @@ class Isolate extends ServiceObjectOwner {
   }
 
   Future<bool> flutterFrameworkPresent() async {
-    return (await invokeFlutterExtensionRpcRaw('ext.flutter.frameworkPresent') != null);
+    return await invokeFlutterExtensionRpcRaw('ext.flutter.frameworkPresent') != null;
   }
 
   Future<Map<String, dynamic>> uiWindowScheduleFrame() async {