lint unnecessary_const on samples (#21155)

dev/bots/analyze-sample-code.dart

@@ -107,6 +107,7 @@ Future<Null> main(List<String> arguments) async {
   try {
     final File mainDart = new File(path.join(tempDir.path, 'main.dart'));
     final File pubSpec = new File(path.join(tempDir.path, 'pubspec.yaml'));
+    final File analysisOptions = new File(path.join(tempDir.path, 'analysis_options.yaml'));
     Directory flutterPackage;
     if (arguments.length == 1) {
       // Used for testing.
@@ -212,6 +213,11 @@ dependencies:
     sdk: flutter
   flutter_test:
     sdk: flutter
+''');
+    analysisOptions.writeAsStringSync('''
+linter:
+  rules:
+    - unnecessary_const
 ''');
     print('Found $sampleCodeSections sample code sections.');
     final Process process = await Process.start(

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

@@ -135,8 +135,8 @@ class CupertinoSegmentedControl<T> extends StatefulWidget {
   ///
   /// class SegmentedControlExampleState extends State<SegmentedControlExample> {
   ///   final Map<int, Widget> children = const {
-  ///     0: const Text('Child 1'),
-  ///     1: const Text('Child 2'),
+  ///     0: Text('Child 1'),
+  ///     1: Text('Child 2'),
   ///   };
   ///
   ///   int currentValue;

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

@@ -18,8 +18,8 @@
 /// ```dart
 /// /// A copper coffee pot, as desired by Ben Turpin.
 /// /// ...documentation...
-/// @Category(const <String>['Pots', 'Coffee'])
-/// @Category(const <String>['Copper', 'Cookware'])
+/// @Category(<String>['Pots', 'Coffee'])
+/// @Category(<String>['Copper', 'Cookware'])
 /// @DocumentationIcon('https://example.com/images/coffee.png')
 /// @Summary('A proper cup of coffee is made in a proper copper coffee pot.')
 /// class CopperCoffeePot {
@@ -55,7 +55,7 @@ class Category {
 /// ```dart
 /// /// Utility class for beginning a dream-sharing sequence.
 /// /// ...documentation...
-/// @Category(const <String>['Military Technology', 'Experimental'])
+/// @Category(<String>['Military Technology', 'Experimental'])
 /// @DocumentationIcon('https://docs.example.org/icons/top.png')
 /// class DreamSharing {
 ///   // ...code...
@@ -89,8 +89,8 @@ class DocumentationIcon {
 /// ///
 /// /// Instances of this class can hunt small animals.
 /// /// This cat has three legs.
-/// @Category(const <String>['Animals', 'Cats'])
-/// @Category(const <String>['Cute', 'Pets'])
+/// @Category(<String>['Animals', 'Cats'])
+/// @Category(<String>['Cute', 'Pets'])
 /// @DocumentationIcon('https://www.examples.net/docs/images/icons/pillar.jpeg')
 /// @Summary('A famous three-legged cat.')
 /// class Pillar extends Cat {

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

@@ -696,7 +696,7 @@ class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
 /// new SliverAppBar(
 ///   expandedHeight: 150.0,
 ///   flexibleSpace: const FlexibleSpaceBar(
-///     title: const Text('Available seats'),
+///     title: Text('Available seats'),
 ///   ),
 ///   actions: <Widget>[
 ///     new IconButton(

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

@@ -22,9 +22,9 @@ import 'theme.dart';
 ///     mainAxisSize: MainAxisSize.min,
 ///     children: <Widget>[
 ///       const ListTile(
-///         leading: const Icon(Icons.album),
-///         title: const Text('The Enchanted Nightingale'),
-///         subtitle: const Text('Music by Julie Gable. Lyrics by Sidney Stein.'),
+///         leading: Icon(Icons.album),
+///         title: Text('The Enchanted Nightingale'),
+///         subtitle: Text('Music by Julie Gable. Lyrics by Sidney Stein.'),
 ///       ),
 ///       new ButtonTheme.bar( // make buttons use the appropriate styles for cards
 ///         child: new ButtonBar(

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

@@ -137,7 +137,7 @@ class _PopupMenuDividerState extends State<PopupMenuDivider> {
 /// ```dart
 /// const PopupMenuItem<WhyFarther>(
 ///   value: WhyFarther.harder,
-///   child: const Text('Working a lot harder'),
+///   child: Text('Working a lot harder'),
 /// )
 /// ```
 ///
@@ -312,7 +312,7 @@ class PopupMenuItemState<T, W extends PopupMenuItem<T>> extends State<W> {
 ///     const PopupMenuDivider(),
 ///     const PopupMenuItem<Commands>(
 ///       value: Commands.hurricaneCame,
-///       child: const ListTile(leading: const Icon(null), title: const Text('Bring hurricane')),
+///       child: ListTile(leading: Icon(null), title: Text('Bring hurricane')),
 ///     ),
 ///     // ...other items listed here
 ///   ],
@@ -779,19 +779,19 @@ typedef List<PopupMenuEntry<T>> PopupMenuItemBuilder<T>(BuildContext context);
 ///   itemBuilder: (BuildContext context) => <PopupMenuEntry<WhyFarther>>[
 ///     const PopupMenuItem<WhyFarther>(
 ///       value: WhyFarther.harder,
-///       child: const Text('Working a lot harder'),
+///       child: Text('Working a lot harder'),
 ///     ),
 ///     const PopupMenuItem<WhyFarther>(
 ///       value: WhyFarther.smarter,
-///       child: const Text('Being a lot smarter'),
+///       child: Text('Being a lot smarter'),
 ///     ),
 ///     const PopupMenuItem<WhyFarther>(
 ///       value: WhyFarther.selfStarter,
-///       child: const Text('Being a self-starter'),
+///       child: Text('Being a self-starter'),
 ///     ),
 ///     const PopupMenuItem<WhyFarther>(
 ///       value: WhyFarther.tradingCharter,
-///       child: const Text('Placed in charge of trading charter'),
+///       child: Text('Placed in charge of trading charter'),
 ///     ),
 ///   ],
 /// )

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

@@ -265,28 +265,28 @@ abstract class BoxBorder extends ShapeBorder {
 /// ```dart
 /// new Container(
 ///   decoration: const BoxDecoration(
-///     border: const Border(
-///       top: const BorderSide(width: 1.0, color: const Color(0xFFFFFFFFFF)),
-///       left: const BorderSide(width: 1.0, color: const Color(0xFFFFFFFFFF)),
-///       right: const BorderSide(width: 1.0, color: const Color(0xFFFF000000)),
-///       bottom: const BorderSide(width: 1.0, color: const Color(0xFFFF000000)),
+///     border: Border(
+///       top: BorderSide(width: 1.0, color: Color(0xFFFFFFFFFF)),
+///       left: BorderSide(width: 1.0, color: Color(0xFFFFFFFFFF)),
+///       right: BorderSide(width: 1.0, color: Color(0xFFFF000000)),
+///       bottom: BorderSide(width: 1.0, color: Color(0xFFFF000000)),
 ///     ),
 ///   ),
 ///   child: new Container(
 ///     padding: const EdgeInsets.symmetric(horizontal: 20.0, vertical: 2.0),
 ///     decoration: const BoxDecoration(
-///       border: const Border(
-///         top: const BorderSide(width: 1.0, color: const Color(0xFFFFDFDFDF)),
-///         left: const BorderSide(width: 1.0, color: const Color(0xFFFFDFDFDF)),
-///         right: const BorderSide(width: 1.0, color: const Color(0xFFFF7F7F7F)),
-///         bottom: const BorderSide(width: 1.0, color: const Color(0xFFFF7F7F7F)),
+///       border: Border(
+///         top: BorderSide(width: 1.0, color: Color(0xFFFFDFDFDF)),
+///         left: BorderSide(width: 1.0, color: Color(0xFFFFDFDFDF)),
+///         right: BorderSide(width: 1.0, color: Color(0xFFFF7F7F7F)),
+///         bottom: BorderSide(width: 1.0, color: Color(0xFFFF7F7F7F)),
 ///       ),
-///       color: const Color(0xFFBFBFBF),
+///       color: Color(0xFFBFBFBF),
 ///     ),
 ///     child: const Text(
 ///       'OK',
 ///       textAlign: TextAlign.center,
-///       style: const TextStyle(color: const Color(0xFF000000))
+///       style: TextStyle(color: Color(0xFF000000))
 ///     ),
 ///   ),
 /// )

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

@@ -740,11 +740,11 @@ class RadialGradient extends Gradient {
 ///       startAngle: 0.0,
 ///       endAngle: math.pi * 2,
 ///       colors: const <Color>[
-///         const Color(0xFF4285F4), // blue
-///         const Color(0xFF34A853), // green
-///         const Color(0xFFFBBC05), // yellow
-///         const Color(0xFFEA4335), // red
-///         const Color(0xFF4285F4), // blue again to seamlessly transition to the start
+///         Color(0xFF4285F4), // blue
+///         Color(0xFF34A853), // green
+///         Color(0xFFFBBC05), // yellow
+///         Color(0xFFEA4335), // red
+///         Color(0xFF4285F4), // blue again to seamlessly transition to the start
 ///       ],
 ///       stops: const <double>[0.0, 0.25, 0.5, 0.75, 1.0],
 ///      ),

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

@@ -144,7 +144,7 @@ class MethodChannel {
   ///
   /// ```dart
   /// class Music {
-  ///   static const MethodChannel _channel = const MethodChannel('music');
+  ///   static const MethodChannel _channel = MethodChannel('music');
   ///
   ///   static Future<bool> isLicensed() async {
   ///     // invokeMethod returns a Future<dynamic>, and we cannot pass that for

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

@@ -370,7 +370,7 @@ class BackdropFilter extends SingleChildRenderObjectWidget {
 ///       style: const TextStyle(
 ///         fontSize: 40.0,
 ///         fontWeight: FontWeight.w900,
-///         color: const Color(0xFFFFFFFF),
+///         color: Color(0xFFFFFFFF),
 ///       ),
 ///     ),
 ///   ),
@@ -1360,7 +1360,7 @@ class RotatedBox extends SingleChildRenderObjectWidget {
 /// ```dart
 /// new Padding(
 ///   padding: new EdgeInsets.all(8.0),
-///   child: const Card(child: const Text('Hello World!')),
+///   child: const Card(child: Text('Hello World!')),
 /// )
 /// ```
 ///
@@ -1700,7 +1700,7 @@ class CustomMultiChildLayout extends MultiChildRenderObjectWidget {
 /// new SizedBox(
 ///   width: 200.0,
 ///   height: 300.0,
-///   child: const Card(child: const Text('Hello World!')),
+///   child: const Card(child: Text('Hello World!')),
 /// )
 /// ```
 ///
@@ -1806,7 +1806,7 @@ class SizedBox extends SingleChildRenderObjectWidget {
 /// ```dart
 /// new ConstrainedBox(
 ///   constraints: const BoxConstraints.expand(),
-///   child: const Card(child: const Text('Hello World!')),
+///   child: const Card(child: Text('Hello World!')),
 /// )
 /// ```
 ///

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

@@ -279,8 +279,8 @@ abstract class ScrollView extends StatelessWidget {
 ///     const SliverAppBar(
 ///       pinned: true,
 ///       expandedHeight: 250.0,
-///       flexibleSpace: const FlexibleSpaceBar(
-///         title: const Text('Demo'),
+///       flexibleSpace: FlexibleSpaceBar(
+///         title: Text('Demo'),
 ///       ),
 ///     ),
 ///     new SliverGrid(

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

@@ -184,11 +184,11 @@ class DefaultTextStyle extends InheritedWidget {
 ///
 /// ```dart
 /// const Text.rich(
-///   const TextSpan(
+///   TextSpan(
 ///     text: 'Hello', // default text style
-///     children: const <TextSpan>[
-///       const TextSpan(text: ' beautiful ', style: const TextStyle(fontStyle: FontStyle.italic)),
-///       const TextSpan(text: 'world', style: const TextStyle(fontWeight: FontWeight.bold)),
+///     children: <TextSpan>[
+///       TextSpan(text: ' beautiful ', style: TextStyle(fontStyle: FontStyle.italic)),
+///       TextSpan(text: 'world', style: TextStyle(fontWeight: FontWeight.bold)),
 ///     ],
 ///   ),
 /// )