Flutter Widget Key to be nullable

Fixes #46913

Change-Id: Id2d72ce497eaa1512c2bb95f023c9ff0160c5005
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210128
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/test/mock_packages/flutter/lib/src/material/app_bar.dart

@@ -6,7 +6,7 @@ import 'package:flutter/widgets.dart';
 
 class AppBar extends StatefulWidget {
   AppBar({
-    Key key,
+    Key? key,
     title,
     backgroundColor,
   });

pkg/analysis_server/test/mock_packages/flutter/lib/src/material/scaffold.dart

@@ -6,7 +6,7 @@ import 'package:flutter/widgets.dart';
 
 class Scaffold extends StatefulWidget {
   const Scaffold({
-    Key key,
+    Key? key,
     Widget body,
   });
 }

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/async.dart

@@ -10,8 +10,8 @@ typedef AsyncWidgetBuilder<T> = Widget Function(
 class AsyncSnapshot<T> {}
 
 class StreamBuilder<T> {
-  final T initialData;
+  final T? initialData;
   final AsyncWidgetBuilder<T> builder;
   const StreamBuilder(
-      {Key key, this.initialData, Stream<T> stream, @required this.builder});
+      {Key? key, this.initialData, Stream<T>? stream, @required this.builder});
 }

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/basic.dart

@@ -32,22 +32,22 @@ class Align extends SingleChildRenderObjectWidget {
   /// If non-null, sets its width to the child's width multiplied by this factor.
   ///
   /// Can be both greater and less than 1.0 but must be positive.
-  final double widthFactor;
+  final double? widthFactor;
 
   /// If non-null, sets its height to the child's height multiplied by this factor.
   ///
   /// Can be both greater and less than 1.0 but must be positive.
-  final double heightFactor;
+  final double? heightFactor;
 
   /// Creates an alignment widget.
   ///
   /// The alignment defaults to [Alignment.center].
   const Align({
-    Key key,
+    Key? key,
     this.alignment = Alignment.center,
     this.widthFactor,
     this.heightFactor,
-    Widget child,
+    Widget? child,
   })  : assert(alignment != null),
         assert(widthFactor == null || widthFactor >= 0.0),
         assert(heightFactor == null || heightFactor >= 0.0),
@@ -56,50 +56,51 @@ class Align extends SingleChildRenderObjectWidget {
 
 class AspectRatio extends SingleChildRenderObjectWidget {
   const AspectRatio({
-    Key key,
+    Key? key,
     @required double aspectRatio,
-    Widget child,
+    Widget? child,
   });
 }
 
 class Center extends StatelessWidget {
-  const Center({Key key, double heightFactor, Widget child});
+  const Center({Key? key, double? heightFactor, Widget? child});
 }
 
 class SizedBox extends SingleChildRenderObjectWidget {
-  const SizedBox({Key key, this.width, this.height, Widget child})
+  const SizedBox({Key? key, this.width, this.height, Widget? child})
       : super(key: key, child: child);
 
-  const SizedBox.expand({Key key, Widget child})
+  const SizedBox.expand({Key? key, Widget? child})
       : width = double.infinity,
         height = double.infinity,
         super(key: key, child: child);
 
-  const SizedBox.shrink({Key key, Widget child})
+  const SizedBox.shrink({Key? key, Widget? child})
       : width = 0.0,
         height = 0.0,
         super(key: key, child: child);
 
-  SizedBox.fromSize({Key key, Widget child, Size size})
+  SizedBox.fromSize({Key? key, Widget? child, Size? size})
       : width = size?.width,
         height = size?.height,
         super(key: key, child: child);
 
-  final double width;
+  final double? width;
 
-  final double height;
+  final double? height;
 }
 
 class ClipRect extends SingleChildRenderObjectWidget {
-  const ClipRect({Key key, Widget child}) : super(key: key, child: child);
+  const ClipRect({Key? key, Widget? child}) : super(key: key, child: child);
 
   /// Does not actually exist in Flutter.
-  const ClipRect.rect({Key key, Widget child}) : super(key: key, child: child);
+  const ClipRect.rect({Key? key, Widget? child})
+      : super(key: key, child: child);
 }
 
 class Column extends Flex {
   Column({
-    Key key,
+    Key? key,
     MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,
     MainAxisSize mainAxisSize = MainAxisSize.max,
     CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,
@@ -112,7 +113,7 @@ class Column extends Flex {
 
 class Expanded extends StatelessWidget {
   const Expanded({
-    Key key,
+    Key? key,
     int flex = 1,
     @required Widget child,
   });
@@ -120,7 +121,7 @@ class Expanded extends StatelessWidget {
 
 class Flex extends Widget {
   Flex({
-    Key key,
+    Key? key,
     List<Widget> children = const <Widget>[],
   });
 }
@@ -129,15 +130,15 @@ class Padding extends SingleChildRenderObjectWidget {
   final EdgeInsetsGeometry padding;
 
   const Padding({
-    Key key,
+    Key? key,
     @required this.padding,
-    Widget child,
+    Widget? child,
   });
 }
 
 class Row extends Flex {
   Row({
-    Key key,
+    Key? key,
     MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,
     MainAxisSize mainAxisSize = MainAxisSize.max,
     CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,
@@ -150,12 +151,12 @@ class Row extends Flex {
 
 class Transform extends SingleChildRenderObjectWidget {
   const Transform({
-    Key key,
+    Key? key,
     @required transform,
     origin,
     alignment,
     transformHitTests = true,
-    Widget child,
+    Widget? child,
   });
 }
 
@@ -163,5 +164,5 @@ typedef WidgetBuilder = Widget Function(BuildContext context);
 
 class Builder {
   final WidgetBuilder builder;
-  const Builder({Key key, @required this.builder});
+  const Builder({Key? key, @required this.builder});
 }

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/container.dart

@@ -7,7 +7,7 @@ import 'package:flutter/painting.dart';
 import 'framework.dart';
 
 class Container extends StatelessWidget {
-  final Widget child;
+  final Widget? child;
 
   /// Align the [child] within the container.
   ///
@@ -23,14 +23,14 @@ class Container extends StatelessWidget {
   ///    specify an [AlignmentGeometry].
   ///  * [AlignmentDirectional], like [Alignment] for specifying alignments
   ///    relative to text direction.
-  final AlignmentGeometry alignment;
+  final AlignmentGeometry? alignment;
 
   /// Empty space to inscribe inside the [decoration]. The [child], if any, is
   /// placed inside this padding.
   ///
   /// This padding is in addition to any padding inherent in the [decoration];
   /// see [Decoration.padding].
-  final EdgeInsetsGeometry padding;
+  final EdgeInsetsGeometry? padding;
 
   /// The decoration to paint behind the [child].
   ///
@@ -40,23 +40,23 @@ class Container extends StatelessWidget {
   ///
   /// The [child] is not clipped to the decoration. To clip a child to the shape
   /// of a particular [ShapeDecoration], consider using a [ClipPath] widget.
-  final Decoration decoration;
+  final Decoration? decoration;
 
   /// The decoration to paint in front of the [child].
-  final Decoration foregroundDecoration;
+  final Decoration? foregroundDecoration;
 
   /// Empty space to surround the [decoration] and [child].
-  final EdgeInsetsGeometry margin;
+  final EdgeInsetsGeometry? margin;
 
   Container({
-    Key key,
+    Key? key,
     this.alignment,
     this.padding,
-    Color color,
-    Decoration decoration,
+    Color? color,
+    Decoration? decoration,
     this.foregroundDecoration,
-    double width,
-    double height,
+    double? width,
+    double? height,
     this.margin,
     this.child,
   })  : decoration = decoration,

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/framework.dart

@@ -14,13 +14,13 @@ abstract class BuildContext {
 }
 
 abstract class RenderObjectWidget extends Widget {
-  const RenderObjectWidget({Key key}) : super(key: key);
+  const RenderObjectWidget({Key? key}) : super(key: key);
 }
 
 abstract class SingleChildRenderObjectWidget extends RenderObjectWidget {
-  final Widget child;
+  final Widget? child;
 
-  const SingleChildRenderObjectWidget({Key key, this.child}) : super(key: key);
+  const SingleChildRenderObjectWidget({Key? key, this.child}) : super(key: key);
 }
 
 abstract class State<T extends StatefulWidget> {
@@ -36,19 +36,19 @@ abstract class State<T extends StatefulWidget> {
 }
 
 abstract class StatefulWidget extends Widget {
-  const StatefulWidget({Key key}) : super(key: key);
+  const StatefulWidget({Key? key}) : super(key: key);
 
   State createState() => null;
 }
 
 abstract class StatelessWidget extends Widget {
-  const StatelessWidget({Key key}) : super(key: key);
+  const StatelessWidget({Key? key}) : super(key: key);
 
   Widget build(BuildContext context) => null;
 }
 
 class Widget extends DiagnosticableTree {
-  final Key key;
+  final Key? key;
 
   const Widget({this.key});
 

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/gesture_detector.dart

@@ -6,8 +6,8 @@ import 'package:flutter/widgets.dart';
 
 class GestureDetector extends StatelessWidget {
   GestureDetector({
-    Key key,
-    Widget child,
+    Key? key,
+    Widget? child,
     onTap,
   });
 }

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/icon.dart

@@ -5,17 +5,17 @@
 import 'framework.dart';
 
 class Icon extends StatelessWidget {
-  final IconData icon;
+  final IconData? icon;
 
   const Icon(
     this.icon, {
-    Key key,
+    Key? key,
   }) : super(key: key);
 }
 
 class IconData {
   final int codePoint;
-  final String fontFamily;
+  final String? fontFamily;
 
   const IconData(
     this.codePoint, {

pkg/analysis_server/test/mock_packages/flutter/lib/src/widgets/text.dart

@@ -16,17 +16,17 @@ class Text extends StatelessWidget {
   /// The text to display.
   ///
   /// This will be null if a [textSpan] is provided instead.
-  final String data;
+  final String? data;
 
   /// If non-null, the style to use for this text.
   ///
   /// If the style's "inherit" property is true, the style will be merged with
   /// the closest enclosing [DefaultTextStyle]. Otherwise, the style will
   /// replace the closest enclosing [DefaultTextStyle].
-  final TextStyle style;
+  final TextStyle? style;
 
   /// How the text should be aligned horizontally.
-  final TextAlign textAlign;
+  final TextAlign? textAlign;
 
   /// The directionality of the text.
   ///
@@ -41,15 +41,15 @@ class Text extends StatelessWidget {
   /// its left.
   ///
   /// Defaults to the ambient [Directionality], if any.
-  final TextDirection textDirection;
+  final TextDirection? textDirection;
 
   /// Whether the text should break at soft line breaks.
   ///
   /// If false, the glyphs in the text will be positioned as if there was unlimited horizontal space.
-  final bool softWrap;
+  final bool? softWrap;
 
   /// How visual overflow should be handled.
-  final TextOverflow overflow;
+  final TextOverflow? overflow;
 
   /// The number of font pixels for each logical pixel.
   ///
@@ -59,7 +59,7 @@ class Text extends StatelessWidget {
   /// The value given to the constructor as textScaleFactor. If null, will
   /// use the [MediaQueryData.textScaleFactor] obtained from the ambient
   /// [MediaQuery], or 1.0 if there is no [MediaQuery] in scope.
-  final double textScaleFactor;
+  final double? textScaleFactor;
 
   /// An optional maximum number of lines for the text to span, wrapping if necessary.
   /// If the text exceeds the given number of lines, it will be truncated according
@@ -72,7 +72,7 @@ class Text extends StatelessWidget {
   /// an explicit number for its [DefaultTextStyle.maxLines], then the
   /// [DefaultTextStyle] value will take precedence. You can use a [RichText]
   /// widget directly to entirely override the [DefaultTextStyle].
-  final int maxLines;
+  final int? maxLines;
 
   /// An alternative semantics label for this text.
   ///
@@ -86,10 +86,10 @@ class Text extends StatelessWidget {
   /// ```dart
   /// Text(r'$$', semanticsLabel: 'Double dollars')
   /// ```
-  final String semanticsLabel;
+  final String? semanticsLabel;
 
   /// {@macro flutter.dart:ui.text.TextWidthBasis}
-  final TextWidthBasis textWidthBasis;
+  final TextWidthBasis? textWidthBasis;
 
   /// Creates a text widget.
   ///
@@ -99,7 +99,7 @@ class Text extends StatelessWidget {
   /// The [data] parameter must not be null.
   const Text(
     this.data, {
-    Key key,
+    Key? key,
     this.style,
     this.textAlign,
     this.textDirection,

pkg/analysis_server/test/src/services/correction/assist/flutter_wrap_padding_test.dart

@@ -64,10 +64,7 @@ class FakeFlutter {
     await assertNoAssist();
   }
 
-  @failingTest
   Future<void> test_inConstantContext() async {
-    // TODO(brianwilkerson) Get this test to pass again. Not clear whether it's
-    //  a problem with the test code or the mock flutter package.
     await resolveTestCode('''
 import 'package:flutter/widgets.dart';
 class FakeFlutter {

pkg/analysis_server/test/src/services/correction/fix/add_key_to_constructors_test.dart

@@ -4,7 +4,6 @@
 
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analysis_server/src/services/linter/lint_names.dart';
-import 'package:analyzer/src/dart/error/lint_codes.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -211,7 +210,7 @@ class A extends StatelessWidget {
 class MyWidget extends A {
   MyWidget({super.key}) : super(text: '');
 }
-''', errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void>
@@ -241,7 +240,7 @@ class A extends StatelessWidget {
 class MyWidget extends A {
   MyWidget({super.key}) : super(text: '',);
 }
-''', errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void>
@@ -271,9 +270,7 @@ class A extends StatelessWidget {
 class B extends A {
   B({super.key}) : super(const Text(''),);
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_initializer_final_constant() async {
@@ -292,9 +289,7 @@ class MyWidget extends StatelessWidget {
 
   const MyWidget({super.key});
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_initializer_final_not_constant() async {
@@ -332,9 +327,7 @@ class MyWidget extends StatelessWidget {
 
   MyWidget({super.key});
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_initializer_not_final_not_constant() async {
@@ -372,9 +365,7 @@ class MyWidget extends StatelessWidget {
 
   const MyWidget({super.key});
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_super_not_constant() async {
@@ -402,7 +393,7 @@ class ParentWidget extends StatelessWidget {
 class MyWidget extends ParentWidget {
   MyWidget({super.key});
 }
-''', errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 }
 
@@ -452,9 +443,7 @@ class A extends StatelessWidget {
 class B extends A {
   B({Key? key}) : super(const Text(''), key: key);
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 }
 
@@ -637,7 +626,7 @@ class A extends StatelessWidget {
 class MyWidget extends A {
   MyWidget({Key? key}) : super(key: key, text: '');
 }
-''', errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void>
@@ -667,7 +656,7 @@ class A extends StatelessWidget {
 class MyWidget extends A {
   MyWidget({Key? key}) : super(key: key, text: '',);
 }
-''', errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void>
@@ -697,9 +686,7 @@ class A extends StatelessWidget {
 class B extends A {
   B({Key? key}) : super(const Text(''), key: key,);
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_initializer_final_constant() async {
@@ -718,9 +705,7 @@ class MyWidget extends StatelessWidget {
 
   const MyWidget({Key? key}) : super(key: key);
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_initializer_final_not_constant() async {
@@ -758,9 +743,7 @@ class MyWidget extends StatelessWidget {
 
   MyWidget({Key? key}) : super(key: key);
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_initializer_not_final_not_constant() async {
@@ -798,9 +781,7 @@ class MyWidget extends StatelessWidget {
 
   const MyWidget({Key? key}) : super(key: key);
 }
-''',
-        //TODO(asashour) there should be no other errors
-        errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 
   Future<void> test_super_not_constant() async {
@@ -828,6 +809,6 @@ class ParentWidget extends StatelessWidget {
 class MyWidget extends ParentWidget {
   MyWidget({Key? key}) : super(key: key);
 }
-''', errorFilter: (error) => error.errorCode is LintCode);
+''');
   }
 }