apply prefer_asserts_in_initializer_list lint (#10540)

examples/catalog/lib/animated_list.dart

@@ -117,10 +117,9 @@ class ListModel<E> {
     @required this.listKey,
     @required this.removedItemBuilder,
     Iterable<E> initialItems,
-  }) : _items =  new List<E>.from(initialItems ?? <E>[]) {
-    assert(listKey != null);
-    assert(removedItemBuilder != null);
-  }
+  }) : assert(listKey != null),
+       assert(removedItemBuilder != null),
+       _items = new List<E>.from(initialItems ?? <E>[]);
 
   final GlobalKey<AnimatedListState> listKey;
   final dynamic removedItemBuilder;
@@ -159,11 +158,10 @@ class CardItem extends StatelessWidget {
     this.onTap,
     @required this.item,
     this.selected: false
-  }) : super(key: key) {
-    assert(animation != null);
-    assert(item != null && item >= 0);
-    assert(selected != null);
-  }
+  }) : assert(animation != null),
+       assert(item != null && item >= 0),
+       assert(selected != null),
+       super(key: key);
 
   final Animation<double> animation;
   final VoidCallback onTap;

examples/flutter_gallery/lib/demo/animation/home.dart

@@ -35,10 +35,10 @@ class _RenderStatusBarPaddingSliver extends RenderSliver {
   _RenderStatusBarPaddingSliver({
     @required double maxHeight,
     @required double scrollFactor,
-  }) : _maxHeight = maxHeight, _scrollFactor = scrollFactor {
-    assert(maxHeight != null && maxHeight >= 0.0);
-    assert(scrollFactor != null && scrollFactor >= 1.0);
-  }
+  }) : assert(maxHeight != null && maxHeight >= 0.0),
+       assert(scrollFactor != null && scrollFactor >= 1.0),
+       _maxHeight = maxHeight,
+       _scrollFactor = scrollFactor;
 
   // The height of the status bar
   double get maxHeight => _maxHeight;
@@ -79,10 +79,9 @@ class _StatusBarPaddingSliver extends SingleChildRenderObjectWidget {
     Key key,
     @required this.maxHeight,
     this.scrollFactor: 5.0,
-  }) : super(key: key) {
-    assert(maxHeight != null && maxHeight >= 0.0);
-    assert(scrollFactor != null && scrollFactor >= 1.0);
-  }
+  }) : assert(maxHeight != null && maxHeight >= 0.0),
+       assert(scrollFactor != null && scrollFactor >= 1.0),
+       super(key: key);
 
   final double maxHeight;
   final double scrollFactor;
@@ -272,14 +271,13 @@ class _AllSectionsView extends AnimatedWidget {
     this.midHeight,
     this.maxHeight,
     this.sectionCards: const <Widget>[],
-  }) : super(key: key, listenable: selectedIndex) {
-    assert(sections != null);
-    assert(sectionCards != null);
-    assert(sectionCards.length == sections.length);
-    assert(sectionIndex >= 0 && sectionIndex < sections.length);
-    assert(selectedIndex != null);
-    assert(selectedIndex.value >= 0.0 && selectedIndex.value < sections.length.toDouble());
-  }
+  }) : assert(sections != null),
+       assert(sectionCards != null),
+       assert(sectionCards.length == sections.length),
+       assert(sectionIndex >= 0 && sectionIndex < sections.length),
+       assert(selectedIndex != null),
+       assert(selectedIndex.value >= 0.0 && selectedIndex.value < sections.length.toDouble()),
+       super(key: key, listenable: selectedIndex);
 
   final int sectionIndex;
   final List<Section> sections;

examples/flutter_gallery/lib/demo/animation/widgets.dart

@@ -11,9 +11,9 @@ const double kSectionIndicatorWidth = 32.0;
 
 // The card for a single section. Displays the section's gradient and background image.
 class SectionCard extends StatelessWidget {
-  SectionCard({ Key key, @required this.section }) : super(key: key) {
-    assert(section != null);
-  }
+  SectionCard({ Key key, @required this.section })
+    : assert(section != null),
+      super(key: key);
 
   final Section section;
 
@@ -65,11 +65,10 @@ class SectionTitle extends StatelessWidget {
     @required this.section,
     @required this.scale,
     @required this.opacity,
-  }) : super(key: key) {
-    assert(section != null);
-    assert(scale != null);
-    assert(opacity != null && opacity >= 0.0 && opacity <= 1.0);
-  }
+  }) : assert(section != null),
+       assert(scale != null),
+       assert(opacity != null && opacity >= 0.0 && opacity <= 1.0),
+       super(key: key);
 
   final Section section;
   final double scale;
@@ -118,10 +117,10 @@ class SectionIndicator extends StatelessWidget {
 
 // Display a single SectionDetail.
 class SectionDetailView extends StatelessWidget {
-  SectionDetailView({ Key key, @required this.detail }) : super(key: key) {
-    assert(detail != null && detail.imageAsset != null);
-    assert((detail.imageAsset ?? detail.title) != null);
-  }
+  SectionDetailView({ Key key, @required this.detail })
+    : assert(detail != null && detail.imageAsset != null),
+      assert((detail.imageAsset ?? detail.title) != null),
+      super(key: key);
 
   final SectionDetail detail;
 

examples/flutter_gallery/lib/demo/colors_demo.dart

@@ -47,11 +47,10 @@ class ColorItem extends StatelessWidget {
     @required this.index,
     @required this.color,
     this.prefix: '',
-  }) : super(key: key) {
-    assert(index != null);
-    assert(color != null);
-    assert(prefix != null);
-  }
+  }) : assert(index != null),
+       assert(color != null),
+       assert(prefix != null),
+       super(key: key);
 
   final int index;
   final Color color;
@@ -84,9 +83,8 @@ class PaletteTabView extends StatelessWidget {
   PaletteTabView({
     Key key,
     @required this.colors,
-  }) : super(key: key) {
-    assert(colors != null && colors.isValid);
-  }
+  }) : assert(colors != null && colors.isValid),
+       super(key: key);
 
   final Palette colors;
 

examples/flutter_gallery/lib/demo/contacts_demo.dart

@@ -37,9 +37,9 @@ class _ContactCategory extends StatelessWidget {
 }
 
 class _ContactItem extends StatelessWidget {
-  _ContactItem({ Key key, this.icon, this.lines, this.tooltip, this.onPressed }) : super(key: key) {
-    assert(lines.length > 1);
-  }
+  _ContactItem({ Key key, this.icon, this.lines, this.tooltip, this.onPressed })
+    : assert(lines.length > 1),
+      super(key: key);
 
   final IconData icon;
   final List<String> lines;

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

@@ -37,9 +37,9 @@ final List<TravelDestination> destinations = <TravelDestination>[
 ];
 
 class TravelDestinationItem extends StatelessWidget {
-  TravelDestinationItem({ Key key, @required this.destination }) : super(key: key) {
-    assert(destination != null && destination.isValid);
-  }
+  TravelDestinationItem({ Key key, @required this.destination })
+    : assert(destination != null && destination.isValid),
+      super(key: key);
 
   static final double height = 366.0;
   final TravelDestination destination;

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

@@ -19,11 +19,10 @@ enum DismissDialogAction {
 
 class DateTimeItem extends StatelessWidget {
   DateTimeItem({ Key key, DateTime dateTime, @required this.onChanged })
-    : date = new DateTime(dateTime.year, dateTime.month, dateTime.day),
+    : assert(onChanged != null),
+      date = new DateTime(dateTime.year, dateTime.month, dateTime.day),
       time = new TimeOfDay(hour: dateTime.hour, minute: dateTime.minute),
-      super(key: key) {
-    assert(onChanged != null);
-  }
+      super(key: key);
 
   final DateTime date;
   final TimeOfDay time;

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

@@ -143,11 +143,10 @@ class GridDemoPhotoItem extends StatelessWidget {
     @required this.photo,
     @required this.tileStyle,
     @required this.onBannerTap
-  }) : super(key: key) {
-    assert(photo != null && photo.isValid);
-    assert(tileStyle != null);
-    assert(onBannerTap != null);
-  }
+  }) : assert(photo != null && photo.isValid),
+       assert(tileStyle != null),
+       assert(onBannerTap != null),
+       super(key: key);
 
   final Photo photo;
   final GridDemoTileStyle tileStyle;

examples/flutter_gallery/lib/demo/shrine/shrine_home.dart

@@ -116,9 +116,9 @@ class _ShrineGridDelegate extends SliverGridDelegate {
 
 // Displays the Vendor's name and avatar.
 class _VendorItem extends StatelessWidget {
-  _VendorItem({ Key key, @required this.vendor }) : super(key: key) {
-    assert(vendor != null);
-  }
+  _VendorItem({ Key key, @required this.vendor })
+    : assert(vendor != null),
+      super(key: key);
 
   final Vendor vendor;
 
@@ -240,11 +240,11 @@ class _HeadingLayout extends MultiChildLayoutDelegate {
 
 // A card that highlights the "featured" catalog item.
 class _Heading extends StatelessWidget {
-  _Heading({ Key key, @required this.product }) : super(key: key) {
-    assert(product != null);
-    assert(product.featureTitle != null);
-    assert(product.featureDescription != null);
-  }
+  _Heading({ Key key, @required this.product })
+    : assert(product != null),
+      assert(product.featureTitle != null),
+      assert(product.featureDescription != null),
+      super(key: key);
 
   final Product product;
 
@@ -294,9 +294,9 @@ class _Heading extends StatelessWidget {
 // A card that displays a product's image, price, and vendor. The _ProductItem
 // cards appear in a grid below the heading.
 class _ProductItem extends StatelessWidget {
-  _ProductItem({ Key key, @required this.product, this.onPressed }) : super(key: key) {
-    assert(product != null);
-  }
+  _ProductItem({ Key key, @required this.product, this.onPressed })
+    : assert(product != null),
+      super(key: key);
 
   final Product product;
   final VoidCallback onPressed;

examples/flutter_gallery/lib/demo/shrine/shrine_order.dart

@@ -17,11 +17,10 @@ class _ProductItem extends StatelessWidget {
     @required this.product,
     @required this.quantity,
     @required this.onChanged,
-  }) : super(key: key) {
-    assert(product != null);
-    assert(quantity != null);
-    assert(onChanged != null);
-  }
+  }) : assert(product != null),
+       assert(quantity != null),
+       assert(onChanged != null),
+       super(key: key);
 
   final Product product;
   final int quantity;
@@ -70,9 +69,9 @@ class _ProductItem extends StatelessWidget {
 
 // Vendor name and description
 class _VendorItem extends StatelessWidget {
-  _VendorItem({ Key key, @required this.vendor }) : super(key: key) {
-    assert(vendor != null);
-  }
+  _VendorItem({ Key key, @required this.vendor })
+    : assert(vendor != null),
+      super(key: key);
 
   final Vendor vendor;
 
@@ -146,10 +145,9 @@ class _Heading extends StatelessWidget {
     @required this.product,
     @required this.quantity,
     this.quantityChanged,
-  }) : super(key: key) {
-    assert(product != null);
-    assert(quantity != null && quantity >= 0 && quantity <= 5);
-  }
+  }) : assert(product != null),
+       assert(quantity != null && quantity >= 0 && quantity <= 5),
+       super(key: key);
 
   final Product product;
   final int quantity;
@@ -213,11 +211,10 @@ class OrderPage extends StatefulWidget {
     @required this.order,
     @required this.products,
     @required this.shoppingCart,
-  }) : super(key: key) {
-    assert(order != null);
-    assert(products != null && products.isNotEmpty);
-    assert(shoppingCart != null);
-  }
+  }) : assert(order != null),
+       assert(products != null && products.isNotEmpty),
+       assert(shoppingCart != null),
+       super(key: key);
 
   final Order order;
   final List<Product> products;
@@ -328,9 +325,8 @@ class ShrineOrderRoute extends ShrinePageRoute<Order> {
     @required this.order,
     WidgetBuilder builder,
     RouteSettings settings: const RouteSettings(),
-  }) : super(builder: builder, settings: settings) {
-    assert(order != null);
-  }
+  }) : assert(order != null),
+       super(builder: builder, settings: settings);
 
   Order order;
 

examples/flutter_gallery/lib/demo/shrine/shrine_page.dart

@@ -22,10 +22,9 @@ class ShrinePage extends StatefulWidget {
     this.floatingActionButton,
     this.products,
     this.shoppingCart
-  }) : super(key: key) {
-    assert(body != null);
-    assert(scaffoldKey != null);
-  }
+  }) : assert(body != null),
+       assert(scaffoldKey != null),
+       super(key: key);
 
   final GlobalKey<ScaffoldState> scaffoldKey;
   final Widget body;

examples/flutter_gallery/lib/demo/shrine/shrine_theme.dart

@@ -27,9 +27,9 @@ TextStyle abrilFatfaceRegular34(Color color) => new ShrineStyle.abrilFatface(34.
 /// InheritedWidget is shared by all of the routes and widgets created for
 /// the Shrine app.
 class ShrineTheme extends InheritedWidget {
-  ShrineTheme({ Key key, @required Widget child }) : super(key: key, child: child) {
-    assert(child != null);
-  }
+  ShrineTheme({ Key key, @required Widget child })
+    : assert(child != null),
+      super(key: key, child: child);
 
   final Color cardBackgroundColor = Colors.white;
   final Color appBarBackgroundColor = Colors.white;

examples/flutter_gallery/lib/demo/shrine/shrine_types.dart

@@ -66,11 +66,10 @@ class Product {
 }
 
 class Order {
-  Order({ @required this.product, this.quantity: 1, this.inCart: false }) {
-    assert(product != null);
-    assert(quantity != null && quantity >= 0);
-    assert(inCart != null);
-  }
+  Order({ @required this.product, this.quantity: 1, this.inCart: false })
+    : assert(product != null),
+      assert(quantity != null && quantity >= 0),
+      assert(inCart != null);
 
   final Product product;
   final int quantity;

examples/flutter_gallery/lib/demo/typography_demo.dart

@@ -11,11 +11,10 @@ class TextStyleItem extends StatelessWidget {
     @required this.name,
     @required this.style,
     @required this.text,
-  }) : super(key: key) {
-    assert(name != null);
-    assert(style != null);
-    assert(text != null);
-  }
+  }) : assert(name != null),
+       assert(style != null),
+       assert(text != null),
+       super(key: key);
 
   final String name;
   final TextStyle style;

examples/flutter_gallery/lib/gallery/drawer.dart

@@ -102,10 +102,9 @@ class GalleryDrawer extends StatelessWidget {
     this.onCheckerboardOffscreenLayersChanged,
     this.onPlatformChanged,
     this.onSendFeedback,
-  }) : super(key: key) {
-    assert(onThemeChanged != null);
-    assert(onTimeDilationChanged != null);
-  }
+  }) : assert(onThemeChanged != null),
+       assert(onTimeDilationChanged != null),
+       super(key: key);
 
   final bool useLightTheme;
   final ValueChanged<bool> onThemeChanged;

examples/flutter_gallery/lib/gallery/home.dart

@@ -80,10 +80,9 @@ class GalleryHome extends StatefulWidget {
     this.onCheckerboardOffscreenLayersChanged,
     this.onPlatformChanged,
     this.onSendFeedback,
-  }) : super(key: key) {
-    assert(onThemeChanged != null);
-    assert(onTimeDilationChanged != null);
-  }
+  }) : assert(onThemeChanged != null),
+       assert(onTimeDilationChanged != null),
+       super(key: key);
 
   final bool useLightTheme;
   final ValueChanged<bool> onThemeChanged;

examples/flutter_gallery/lib/gallery/item.dart

@@ -18,12 +18,10 @@ class GalleryItem extends StatelessWidget {
     @required this.category,
     @required this.routeName,
     @required this.buildRoute,
-  }) {
-    assert(title != null);
-    assert(category != null);
-    assert(routeName != null);
-    assert(buildRoute != null);
-  }
+  }) : assert(title != null),
+       assert(category != null),
+       assert(routeName != null),
+       assert(buildRoute != null);
 
   final String title;
   final String subtitle;

examples/flutter_gallery/lib/gallery/updates.dart

@@ -12,9 +12,9 @@ import 'package:url_launcher/url_launcher.dart';
 typedef Future<String> UpdateUrlFetcher();
 
 class Updater extends StatefulWidget {
-  Updater({ @required this.updateUrlFetcher, this.child, Key key }) : super(key: key) {
-    assert(updateUrlFetcher != null);
-  }
+  Updater({ @required this.updateUrlFetcher, this.child, Key key })
+    : assert(updateUrlFetcher != null),
+      super(key: key);
 
   final UpdateUrlFetcher updateUrlFetcher;
   final Widget child;

examples/layers/services/isolate.dart

@@ -18,12 +18,11 @@ typedef void OnResultListener(String result);
 // in real-world applications.
 class Calculator {
   Calculator({ @required this.onProgressListener, @required this.onResultListener, String data })
-  // In order to keep the example files smaller, we "cheat" a little and
-  // replicate our small json string into a 10,000-element array.
-  : _data = _replicateJson(data, 10000) {
-    assert(onProgressListener != null);
-    assert(onResultListener != null);
-  }
+    : assert(onProgressListener != null),
+      assert(onResultListener != null),
+      // In order to keep the example files smaller, we "cheat" a little and
+      // replicate our small json string into a 10,000-element array.
+      _data = _replicateJson(data, 10000);
 
   final OnProgressListener onProgressListener;
   final OnResultListener onResultListener;
@@ -87,9 +86,9 @@ class CalculationMessage {
 // progress of the background computation.
 class CalculationManager {
   CalculationManager({ @required this.onProgressListener, @required this.onResultListener })
-  : _receivePort = new ReceivePort() {
-    assert(onProgressListener != null);
-    assert(onResultListener != null);
+    : assert(onProgressListener != null),
+      assert(onResultListener != null),
+      _receivePort = new ReceivePort() {
     _receivePort.listen(_handleMessage);
   }
 

examples/stocks/lib/stock_types.dart

@@ -19,18 +19,16 @@ class StockConfiguration {
     @required this.debugShowRainbow,
     @required this.showPerformanceOverlay,
     @required this.showSemanticsDebugger
-  }) {
-    assert(stockMode != null);
-    assert(backupMode != null);
-    assert(debugShowGrid != null);
-    assert(debugShowSizes != null);
-    assert(debugShowBaselines != null);
-    assert(debugShowLayers != null);
-    assert(debugShowPointers != null);
-    assert(debugShowRainbow != null);
-    assert(showPerformanceOverlay != null);
-    assert(showSemanticsDebugger != null);
-  }
+  }) : assert(stockMode != null),
+       assert(backupMode != null),
+       assert(debugShowGrid != null),
+       assert(debugShowSizes != null),
+       assert(debugShowBaselines != null),
+       assert(debugShowLayers != null),
+       assert(debugShowPointers != null),
+       assert(debugShowRainbow != null),
+       assert(showPerformanceOverlay != null),
+       assert(showSemanticsDebugger != null);
 
   final StockMode stockMode;
   final BackupMode backupMode;

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

@@ -79,9 +79,9 @@ class BitField<T extends dynamic> {
   /// Creates a bit field of all zeros.
   ///
   /// The given length must be at most 62.
-  BitField(this._length) : _bits = _kAllZeros {
-    assert(_length <= _kSMIBits);
-  }
+  BitField(this._length)
+    : assert(_length <= _kSMIBits),
+      _bits = _kAllZeros;
 
   /// Creates a bit field filled with a particular value.
   ///
@@ -89,9 +89,10 @@ class BitField<T extends dynamic> {
   /// the bits are filled with zeros.
   ///
   /// The given length must be at most 62.
-  BitField.filled(this._length, bool value) : _bits = value ? _kAllOnes : _kAllZeros {
-    assert(_length <= _kSMIBits);
-  }
+  BitField.filled(this._length, bool value)
+    : assert(_length <= _kSMIBits),
+      _bits = value ? _kAllOnes : _kAllZeros;
+
   final int _length;
   int _bits;
 

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

@@ -135,8 +135,8 @@ class ClampingScrollSimulation extends Simulation {
     @required this.velocity,
     this.friction: 0.015,
     Tolerance tolerance: Tolerance.defaultTolerance,
-  }) : super(tolerance: tolerance) {
-    assert(_flingVelocityPenetration(0.0) == _kInitialVelocityPenetration);
+  }) : assert(_flingVelocityPenetration(0.0) == _kInitialVelocityPenetration),
+       super(tolerance: tolerance) {
     _duration = _flingDuration(velocity);
     _distance = (velocity * _duration / _kInitialVelocityPenetration).abs();
   }

packages/flutter/test/widgets/layout_builder_mutations_test.dart

@@ -12,9 +12,8 @@ class Wrapper extends StatelessWidget {
   Wrapper({
     Key key,
     @required this.child
-  }) : super(key: key) {
-    assert(child != null);
-  }
+  }) : assert(child != null),
+       super(key: key);
 
   final Widget child;
 

packages/flutter/test/widgets/linked_scroll_view_test.dart

@@ -113,14 +113,13 @@ class LinkedScrollPosition extends ScrollPositionWithSingleContext {
     ScrollContext context,
     double initialPixels,
     ScrollPosition oldPosition,
-  }) : super(
-    physics: physics,
-    context: context,
-    initialPixels: initialPixels,
-    oldPosition: oldPosition,
-  ) {
-    assert(owner != null);
-  }
+  }) : assert(owner != null),
+       super(
+         physics: physics,
+         context: context,
+         initialPixels: initialPixels,
+         oldPosition: oldPosition,
+       );
 
   final LinkedScrollController owner;
 
@@ -547,4 +546,4 @@ void main() {
     await tester.pump(const Duration(seconds: 1));
     await tester.pump(const Duration(seconds: 60));
   });
-}
\ No newline at end of file
+}

packages/flutter_driver/lib/src/health.dart

@@ -29,9 +29,8 @@ final EnumIndex<HealthStatus> _healthStatusIndex =
 
 class Health extends Result {
   /// Creates a [Health] object with the given [status].
-  Health(this.status) {
-    assert(status != null);
-  }
+  Health(this.status)
+    : assert(status != null);
 
   /// Deserializes the result from JSON.
   static Health fromJson(Map<String, dynamic> json) {