Implementing null-aware operators throughout the repository (#143804)

This pull request fixes #143803 by taking advantage of Dart's null-aware operators.

And unlike `switch` expressions ([9 PRs](https://github.com/flutter/flutter/pull/143634) and counting), the Flutter codebase is already fantastic when it comes to null-aware coding. After refactoring the entire repo, all the changes involving `?.` and `??` can fit into a single pull request.

dev/benchmarks/microbenchmarks/lib/language/sync_star_semantics_bench.dart

@@ -91,11 +91,7 @@ Iterable<InlineSpanSemanticsInformation> combineSemanticsInfoSyncStar(List<Inlin
       workingText += info.text;
       workingLabel ??= '';
       final String? infoSemanticsLabel = info.semanticsLabel;
-      if (infoSemanticsLabel != null) {
+      workingLabel += infoSemanticsLabel ?? info.text;
-        workingLabel += infoSemanticsLabel;
-      } else {
-        workingLabel += info.text;
-      }
     }
   }
   assert(workingLabel != null);
@@ -115,11 +111,7 @@ Iterable<InlineSpanSemanticsInformation> combineSemanticsInfoList(List<InlineSpa
       workingText += info.text;
       workingLabel ??= '';
       final String? infoSemanticsLabel = info.semanticsLabel;
-      if (infoSemanticsLabel != null) {
+      workingLabel += infoSemanticsLabel ?? info.text;
-        workingLabel += infoSemanticsLabel;
-      } else {
-        workingLabel += info.text;
-      }
     }
   }
   assert(workingLabel != null);

dev/bots/tool_subsharding.dart

@@ -16,20 +16,13 @@ class TestSpecs {
   int startTime;
   int? _endTime;
 
-  int get milliseconds {
+  int get milliseconds => endTime - startTime;
-    return endTime - startTime;
-  }
 
   set endTime(int value) {
     _endTime = value;
   }
 
-  int get endTime {
+  int get endTime => _endTime ?? 0;
-    if (_endTime == null) {
-      return 0;
-    }
-    return _endTime!;
-  }
 
   String toJson() {
     return json.encode(

dev/conductor/core/lib/src/version.dart

@@ -158,13 +158,10 @@ class Version {
     int nextZ = previousVersion.z;
     int? nextM = previousVersion.m;
     int? nextN = previousVersion.n;
-    if (nextVersionType == null) {
+    nextVersionType ??= switch (previousVersion.type) {
-      if (previousVersion.type == VersionType.latest || previousVersion.type == VersionType.gitDescribe) {
+      VersionType.stable => VersionType.stable,
-        nextVersionType = VersionType.development;
+      VersionType.latest || VersionType.gitDescribe || VersionType.development => VersionType.development,
-      } else {
+    };
-        nextVersionType = previousVersion.type;
-      }
-    }
 
     switch (increment) {
       case 'x':

dev/devicelab/bin/tasks/flavors_test.dart

@@ -32,11 +32,7 @@ Future<void> main() async {
         final TaskResult? firstInstallFailure = testResults
           .firstWhereOrNull((TaskResult element) => element.failed);
 
-        if (firstInstallFailure != null) {
+        return firstInstallFailure ?? TaskResult.success(null);
-          return firstInstallFailure;
-        }
-
-        return TaskResult.success(null);
       },
     );
 

dev/devicelab/bin/tasks/flavors_test_ios.dart

@@ -32,11 +32,7 @@ Future<void> main() async {
         final TaskResult? firstInstallFailure = testResults
           .firstWhereOrNull((TaskResult element) => element.failed);
 
-        if (firstInstallFailure != null) {
+        return firstInstallFailure ?? TaskResult.success(null);
-          return firstInstallFailure;
-        }
-
-        return TaskResult.success(null);
       },
     );
 

dev/devicelab/lib/framework/browser.dart

@@ -572,12 +572,7 @@ class BlinkTraceEvent {
 /// Returns null if the value is null.
 int? _readInt(Map<String, dynamic> json, String key) {
   final num? jsonValue = json[key] as num?;
-
+  return jsonValue?.toInt();
-  if (jsonValue == null) {
-    return null;
-  }
-
-  return jsonValue.toInt();
 }
 
 /// Used by [Chrome.launch] to detect a glibc bug and retry launching the

dev/devicelab/lib/tasks/perf_tests.dart

@@ -1290,11 +1290,7 @@ class PerfTest {
   }) {
     return inDirectory<TaskResult>(testDirectory, () async {
       late Device selectedDevice;
-      if (device != null) {
+      selectedDevice = device ?? await devices.workingDevice;
-        selectedDevice = device!;
-      } else {
-        selectedDevice = await devices.workingDevice;
-      }
       await selectedDevice.unlock();
       final String deviceId = selectedDevice.deviceId;
       final String? localEngine = localEngineFromEnv;

dev/integration_tests/android_semantics_testing/lib/src/matcher.dart

@@ -223,10 +223,7 @@ class _AndroidSemanticsMatcher extends Matcher {
   Description describeMismatch(dynamic item, Description mismatchDescription,
       Map<dynamic, dynamic> matchState, bool verbose) {
     final String? failure = matchState['failure'] as String?;
-    if (failure == null) {
+    return mismatchDescription.add(failure ?? 'hasAndroidSemantics matcher does not complete successfully');
-      return mismatchDescription.add('hasAndroidSemantics matcher does not complete successfully');
-    }
-    return mismatchDescription.add(failure);
   }
 
   bool _failWithMessage(String value, Map<dynamic, dynamic> matchState) {

dev/integration_tests/flutter_gallery/lib/demo/shrine/model/app_state_model.dart

@@ -62,12 +62,8 @@ class AppStateModel extends Model {
 
   // Adds a product to the cart.
   void addProductToCart(int productId) {
-    final int? value = _productsInCart[productId];
+    final int value = _productsInCart[productId] ?? 0;
-    if (value == null) {
+    _productsInCart[productId] = value + 1;
-      _productsInCart[productId] = 1;
-    } else {
-      _productsInCart[productId] = value+1;
-    }
 
     notifyListeners();
   }

dev/tools/gen_defaults/bin/gen_defaults.dart

@@ -86,9 +86,7 @@ Future<void> main(List<String> args) async {
     final Map<String, dynamic> tokenFileTokens = _readTokenFile(tokenFile as File);
     final String version = tokenFileTokens['version'] as String;
     tokenFileTokens.remove('version');
-    if (versionMap[version] == null) {
+    versionMap[version] ??= <String>[];
-      versionMap[version] = List<String>.empty(growable: true);
-    }
     versionMap[version]!.add(tokenFile.uri.pathSegments.last);
 
     tokens.addAll(tokenFileTokens);

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

@@ -953,9 +953,6 @@ class CupertinoDynamicColor extends Color with Diagnosticable {
   ///  * [resolve], which is similar to this function, but returns a
   ///    non-nullable value, and does not allow a null `resolvable` color.
   static Color? maybeResolve(Color? resolvable, BuildContext context) {
-    if (resolvable == null) {
-      return null;
-    }
     return (resolvable is CupertinoDynamicColor)
       ? resolvable.resolveFrom(context)
       : resolvable;

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

@@ -684,10 +684,8 @@ class _CupertinoDatePickerDateTimeState extends State<CupertinoDatePicker> {
 
   // Lazily calculate the column width of the column being displayed only.
   double _getEstimatedColumnWidth(_PickerColumnType columnType) {
-    if (estimatedColumnWidths[columnType.index] == null) {
+    estimatedColumnWidths[columnType.index] ??=
-      estimatedColumnWidths[columnType.index] =
+        CupertinoDatePicker._getColumnWidth(columnType, localizations, context, widget.showDayOfWeek);
-          CupertinoDatePicker._getColumnWidth(columnType, localizations, context, widget.showDayOfWeek);
-    }
 
     return estimatedColumnWidths[columnType.index]!;
   }

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

@@ -94,10 +94,7 @@ class CupertinoUserInterfaceLevel extends InheritedWidget {
   ///    [CupertinoUserInterfaceLevel] encloses the given context.
   static CupertinoUserInterfaceLevelData? maybeOf(BuildContext context) {
     final CupertinoUserInterfaceLevel? query = context.dependOnInheritedWidgetOfExactType<CupertinoUserInterfaceLevel>();
-    if (query != null) {
+    return query?._data;
-      return query._data;
-    }
-    return null;
   }
 
   @override

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

@@ -2257,10 +2257,7 @@ class EnumProperty<T extends Enum?> extends DiagnosticsProperty<T> {
 
   @override
   String valueToString({ TextTreeConfiguration? parentConfiguration }) {
-    if (value == null) {
+    return value?.name ?? 'null';
-      return value.toString();
-    }
-    return value!.name;
   }
 }
 

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

@@ -47,13 +47,9 @@ class PersistentHashMap<K extends Object, V> {
   /// is not in the map.
   @pragma('dart2js:as:trust')
   V? operator[](K key) {
-    if (_root == null) {
-      return null;
-    }
-
     // Unfortunately can not use unsafeCast<V?>(...) here because it leads
     // to worse code generation on VM.
-    return _root.get(0, key, key.hashCode) as V?;
+    return _root?.get(0, key, key.hashCode) as V?;
   }
 }
 

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

@@ -461,10 +461,7 @@ abstract class OneSequenceGestureRecognizer extends GestureRecognizer {
   }
 
   GestureArenaEntry _addPointerToArena(int pointer) {
-    if (_team != null) {
+    return _team?.add(pointer, this) ?? GestureBinding.instance.gestureArena.add(pointer, this);
-      return _team!.add(pointer, this);
-    }
-    return GestureBinding.instance.gestureArena.add(pointer, this);
   }
 
   /// Causes events related to the given pointer ID to be routed to this recognizer.

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

@@ -560,10 +560,8 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
 
   double get _width {
     final RenderBox? box = _drawerKey.currentContext?.findRenderObject() as RenderBox?;
-    if (box != null) {
+    // return _kWidth if drawer not being shown currently
-      return box.size.width;
+    return box?.size.width ?? _kWidth;
-    }
-    return _kWidth; // drawer not being shown currently
   }
 
   bool _previouslyOpened = false;

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

@@ -154,10 +154,7 @@ class _RenderMenuItem extends RenderShiftedBox {
 
   @override
   Size computeDryLayout(BoxConstraints constraints) {
-    if (child == null) {
+    return child?.getDryLayout(constraints) ?? Size.zero;
-      return Size.zero;
-    }
-    return child!.getDryLayout(constraints);
   }
 
   @override

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

@@ -442,10 +442,8 @@ class _StepperState extends State<Stepper> with TickerProviderStateMixin {
       if (isActive) MaterialState.selected else MaterialState.disabled,
     };
     final Color? resolvedConnectorColor = widget.connectorColor?.resolve(states);
-    if (resolvedConnectorColor != null) {
+
-      return resolvedConnectorColor;
+    return resolvedConnectorColor ?? (isActive ? colorScheme.primary : Colors.grey.shade400);
-    }
-    return isActive ? colorScheme.primary : Colors.grey.shade400;
   }
 
   Widget _buildLine(bool visible, bool isActive) {

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

@@ -238,13 +238,7 @@ abstract class BorderRadiusGeometry {
     if (visual != null && logical != null) {
       return '$visual + $logical';
     }
-    if (visual != null) {
+    return visual ?? logical ?? 'BorderRadius.zero';
-      return visual;
-    }
-    if (logical != null) {
-      return logical;
-    }
-    return 'BorderRadius.zero';
   }
 
   @override

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

@@ -510,13 +510,7 @@ abstract class ShapeBorder {
     if (identical(a, b)) {
       return a;
     }
-    ShapeBorder? result;
+    final ShapeBorder? result = b?.lerpFrom(a, t) ?? a?.lerpTo(b, t);
-    if (b != null) {
-      result = b.lerpFrom(a, t);
-    }
-    if (result == null && a != null) {
-      result = a.lerpTo(b, t);
-    }
     return result ?? (t < 0.5 ? a : b);
   }
 
@@ -700,13 +694,7 @@ abstract class OutlinedBorder extends ShapeBorder {
     if (identical(a, b)) {
       return a;
     }
-    ShapeBorder? result;
+    final ShapeBorder? result = b?.lerpFrom(a, t) ?? a?.lerpTo(b, t);
-    if (b != null) {
-      result = b.lerpFrom(a, t);
-    }
-    if (result == null && a != null) {
-      result = a.lerpTo(b, t);
-    }
     return result as OutlinedBorder? ?? (t < 0.5 ? a : b);
   }
 }

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

@@ -468,10 +468,7 @@ class RenderAspectRatio extends RenderProxyBox {
     if (height.isFinite) {
       return height * _aspectRatio;
     }
-    if (child != null) {
+    return child?.getMinIntrinsicWidth(height) ?? 0.0;
-      return child!.getMinIntrinsicWidth(height);
-    }
-    return 0.0;
   }
 
   @override
@@ -479,10 +476,7 @@ class RenderAspectRatio extends RenderProxyBox {
     if (height.isFinite) {
       return height * _aspectRatio;
     }
-    if (child != null) {
+    return child?.getMaxIntrinsicWidth(height) ?? 0.0;
-      return child!.getMaxIntrinsicWidth(height);
-    }
-    return 0.0;
   }
 
   @override
@@ -490,10 +484,7 @@ class RenderAspectRatio extends RenderProxyBox {
     if (width.isFinite) {
       return width / _aspectRatio;
     }
-    if (child != null) {
+    return child?.getMinIntrinsicHeight(width) ?? 0.0;
-      return child!.getMinIntrinsicHeight(width);
-    }
-    return 0.0;
   }
 
   @override
@@ -501,10 +492,7 @@ class RenderAspectRatio extends RenderProxyBox {
     if (width.isFinite) {
       return width / _aspectRatio;
     }
-    if (child != null) {
+    return child?.getMaxIntrinsicHeight(width) ?? 0.0;
-      return child!.getMaxIntrinsicHeight(width);
-    }
-    return 0.0;
   }
 
   Size _applyAspectRatio(BoxConstraints constraints) {

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

@@ -51,10 +51,7 @@ class DisposableBuildContext<T extends State> {
   /// Otherwise, asserts the [_state] is still mounted and returns its context.
   BuildContext? get context {
     assert(_debugValidate());
-    if (_state == null) {
+    return _state?.context;
-      return null;
-    }
-    return _state!.context;
   }
 
   /// Called from asserts or tests to determine whether this object is in a

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

@@ -1039,10 +1039,7 @@ class DraggableScrollableActuator extends StatefulWidget {
   /// otherwise.
   static bool reset(BuildContext context) {
     final _InheritedResetNotifier? notifier = context.dependOnInheritedWidgetOfExactType<_InheritedResetNotifier>();
-    if (notifier == null) {
+    return notifier?._sendReset() ?? false;
-      return false;
-    }
-    return notifier._sendReset();
   }
 
   @override

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

@@ -578,10 +578,7 @@ abstract class Route<T> {
   /// rendered. It is even possible for the route to be active but for the stateful
   /// widgets within the route to not be instantiated. See [ModalRoute.maintainState].
   bool get isActive {
-    if (_navigator == null) {
+    return _navigator?._firstRouteEntryWhereOrNull(_RouteEntry.isRoutePredicate(this))?.isPresent ?? false;
-      return false;
-    }
-    return _navigator!._firstRouteEntryWhereOrNull(_RouteEntry.isRoutePredicate(this))?.isPresent ?? false;
   }
 }
 

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

@@ -64,10 +64,7 @@ class RouteInformation {
     'This feature was deprecated after v3.8.0-3.0.pre.'
   )
   String get location {
-    if (_location != null) {
+    return _location ?? Uri.decodeComponent(
-      return _location;
-    }
-    return Uri.decodeComponent(
       Uri(
         path: uri.path.isEmpty ? '/' : uri.path,
         queryParameters: uri.queryParametersAll.isEmpty ? null : uri.queryParametersAll,
@@ -1562,10 +1559,7 @@ mixin PopNavigatorRouterDelegateMixin<T> on RouterDelegate<T> {
   @override
   Future<bool> popRoute() {
     final NavigatorState? navigator = navigatorKey?.currentState;
-    if (navigator == null) {
+    return navigator?.maybePop() ?? SynchronousFuture<bool>(false);
-      return SynchronousFuture<bool>(false);
-    }
-    return navigator.maybePop();
   }
 }
 

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

@@ -190,10 +190,7 @@ class ScrollPhysics {
   /// reference to it to use later, as the values may update, may not update, or
   /// may update to reflect an entirely unrelated scrollable.
   double applyPhysicsToUserOffset(ScrollMetrics position, double offset) {
-    if (parent == null) {
+    return parent?.applyPhysicsToUserOffset(position, offset) ?? offset;
-      return offset;
-    }
-    return parent!.applyPhysicsToUserOffset(position, offset);
   }
 
   /// Whether the scrollable should let the user adjust the scroll offset, for
@@ -297,10 +294,7 @@ class ScrollPhysics {
   /// scrolling back from being overscrolled, if for some reason the position
   /// ends up overscrolled.
   double applyBoundaryConditions(ScrollMetrics position, double value) {
-    if (parent == null) {
+    return parent?.applyBoundaryConditions(position, value) ?? 0.0;
-      return 0.0;
-    }
-    return parent!.applyBoundaryConditions(position, value);
   }
 
   /// Describes what the scroll position should be given new viewport dimensions.
@@ -394,10 +388,7 @@ class ScrollPhysics {
   //     https://github.com/flutter/flutter/issues/120340
   //     https://github.com/flutter/flutter/issues/109675
   Simulation? createBallisticSimulation(ScrollMetrics position, double velocity) {
-    if (parent == null) {
+    return parent?.createBallisticSimulation(position, velocity);
-      return null;
-    }
-    return parent!.createBallisticSimulation(position, velocity);
   }
 
   static final SpringDescription _kDefaultSpring = SpringDescription.withDampingRatio(
@@ -467,10 +458,7 @@ class ScrollPhysics {
   ///
   /// By default, physics for platforms other than iOS doesn't carry momentum.
   double carriedMomentum(double existingVelocity) {
-    if (parent == null) {
+    return parent?.carriedMomentum(existingVelocity) ?? 0.0;
-      return 0.0;
-    }
-    return parent!.carriedMomentum(existingVelocity);
   }
 
   /// The minimum amount of pixel distance drags must move by to start motion

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

@@ -2059,10 +2059,7 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
       final List<Rect> selectionRectsWithinDrawableArea = currSelectableSelectionRects.map((Rect selectionRect) {
         final Matrix4 transform = getTransformFrom(selectables[index]);
         final Rect localRect = MatrixUtils.transformRect(transform, selectionRect);
-        if (drawableArea != null) {
+        return drawableArea?.intersect(localRect) ?? localRect;
-          return drawableArea.intersect(localRect);
-        }
-        return localRect;
       }).where((Rect selectionRect) {
         return selectionRect.isFinite && !selectionRect.isEmpty;
       }).toList();

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

@@ -435,34 +435,22 @@ class _RenderSingleChildViewport extends RenderBox with RenderObjectWithChildMix
 
   @override
   double computeMinIntrinsicWidth(double height) {
-    if (child != null) {
+    return child?.getMinIntrinsicWidth(height) ?? 0.0;
-      return child!.getMinIntrinsicWidth(height);
-    }
-    return 0.0;
   }
 
   @override
   double computeMaxIntrinsicWidth(double height) {
-    if (child != null) {
+    return child?.getMaxIntrinsicWidth(height) ?? 0.0;
-      return child!.getMaxIntrinsicWidth(height);
-    }
-    return 0.0;
   }
 
   @override
   double computeMinIntrinsicHeight(double width) {
-    if (child != null) {
+    return child?.getMinIntrinsicHeight(width) ?? 0.0;
-      return child!.getMinIntrinsicHeight(width);
-    }
-    return 0.0;
   }
 
   @override
   double computeMaxIntrinsicHeight(double width) {
-    if (child != null) {
+    return child?.getMaxIntrinsicHeight(width) ?? 0.0;
-      return child!.getMaxIntrinsicHeight(width);
-    }
-    return 0.0;
   }
 
   // We don't override computeDistanceToActualBaseline(), because we

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

@@ -732,12 +732,7 @@ class InspectorReferenceData {
   int count = 1;
 
   /// The value.
-  Object? get value {
+  Object? get value => _ref?.target ?? _value;
-    if (_ref != null) {
-      return _ref!.target;
-    }
-    return _value;
-  }
 }
 
 // Production implementation of [WidgetInspectorService].

packages/flutter/test/cupertino/text_selection_toolbar_test.dart

@@ -471,12 +471,7 @@ void main() {
 
         // Theme brightness is preferred, otherwise MediaQuery brightness is
         // used. If both are null, defaults to light.
-        late final Brightness effectiveBrightness;
+        final Brightness effectiveBrightness = themeBrightness ?? mediaBrightness ?? Brightness.light;
-        if (themeBrightness != null) {
-          effectiveBrightness = themeBrightness;
-        } else {
-          effectiveBrightness = mediaBrightness ?? Brightness.light;
-        }
 
         expect(
           text.style!.color!.value,

packages/flutter/test/material/app_test.dart

@@ -23,10 +23,7 @@ class StateMarkerState extends State<StateMarker> {
 
   @override
   Widget build(BuildContext context) {
-    if (widget.child != null) {
+    return widget.child ?? Container();
-      return widget.child!;
-    }
-    return Container();
   }
 }
 

packages/flutter/test/material/tabs_test.dart

@@ -44,10 +44,7 @@ class StateMarkerState extends State<StateMarker> {
 
   @override
   Widget build(BuildContext context) {
-    if (widget.child != null) {
+    return widget.child ?? Container();
-      return widget.child!;
-    }
-    return Container();
   }
 }
 

packages/flutter/test/material/tooltip_test.dart

@@ -3128,8 +3128,5 @@ Future<void> _testGestureTap(WidgetTester tester, Finder tooltip) async {
 }
 
 SemanticsNode _findDebugSemantics(RenderObject object) {
-  if (object.debugSemantics != null) {
+  return object.debugSemantics ?? _findDebugSemantics(object.parent!);
-    return object.debugSemantics!;
-  }
-  return _findDebugSemantics(object.parent!);
 }

packages/flutter/test/material/tooltip_theme_test.dart

@@ -1495,8 +1495,5 @@ void main() {
 }
 
 SemanticsNode findDebugSemantics(RenderObject object) {
-  if (object.debugSemantics != null) {
+  return object.debugSemantics ?? findDebugSemantics(object.parent!);
-    return object.debugSemantics!;
-  }
-  return findDebugSemantics(object.parent!);
 }

packages/flutter/test/rendering/binding_pipeline_manifold_test.dart

@@ -59,10 +59,7 @@ class MyTestRenderingFlutterBinding extends TestRenderingFlutterBinding {
   static MyTestRenderingFlutterBinding? _instance;
 
   static MyTestRenderingFlutterBinding ensureInitialized() {
-    if (_instance != null) {
+    return _instance ?? MyTestRenderingFlutterBinding();
-      return _instance!;
-    }
-    return MyTestRenderingFlutterBinding();
   }
 
   @override

packages/flutter/test/rendering/proxy_box_test.dart

@@ -1055,10 +1055,7 @@ class ConditionalRepaintBoundary extends RenderProxyBox {
 
   @override
   OffsetLayer updateCompositedLayer({required covariant OffsetLayer? oldLayer}) {
-    if (offsetLayerFactory != null) {
+    return offsetLayerFactory?.call(oldLayer) ?? super.updateCompositedLayer(oldLayer: oldLayer);
-      return offsetLayerFactory!.call(oldLayer);
-    }
-    return super.updateCompositedLayer(oldLayer: oldLayer);
   }
 
   @override

packages/flutter/test/rendering/rendering_tester.dart

@@ -88,10 +88,7 @@ class TestRenderingFlutterBinding extends BindingBase with SchedulerBinding, Ser
   /// idempotent; calling it a second time will just return the
   /// previously-created instance.
   static TestRenderingFlutterBinding ensureInitialized({ VoidCallback? onErrors }) {
-    if (_instance != null) {
+    return _instance ?? TestRenderingFlutterBinding(onErrors: onErrors);
-      return _instance!;
-    }
-    return TestRenderingFlutterBinding(onErrors: onErrors);
   }
 
   final List<FlutterErrorDetails> _errors = <FlutterErrorDetails>[];

packages/flutter/test/widgets/reparent_state_test.dart

@@ -19,10 +19,7 @@ class StateMarkerState extends State<StateMarker> {
 
   @override
   Widget build(BuildContext context) {
-    if (widget.child != null) {
+    return widget.child ?? Container();
-      return widget.child!;
-    }
-    return Container();
   }
 }
 

packages/flutter/test/widgets/router_test.dart

@@ -50,10 +50,7 @@ void main() {
     final SimpleAsyncRouteInformationParser parser = SimpleAsyncRouteInformationParser();
     final SimpleAsyncRouterDelegate delegate = SimpleAsyncRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
-        if (information == null) {
+        return Text(information?.uri.toString() ?? 'waiting');
-          return const Text('waiting');
-        }
-        return Text(information.uri.toString());
       },
     );
     addTearDown(delegate.dispose);
@@ -97,10 +94,7 @@ void main() {
     final CompleterRouteInformationParser parser = CompleterRouteInformationParser();
     final SimpleAsyncRouterDelegate delegate = SimpleAsyncRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
-        if (information == null) {
+        return Text(information?.uri.toString() ?? 'waiting');
-          return const Text('waiting');
-        }
-        return Text(information.uri.toString());
       },
     );
     addTearDown(delegate.dispose);

packages/flutter/test/widgets/routes_test.dart

@@ -2080,12 +2080,8 @@ class _TestDialogRouteWithCustomBarrierCurve<T> extends PopupRoute<T> {
   final Color? barrierColor;
 
   @override
-  Curve get barrierCurve {
+  Curve get barrierCurve => _barrierCurve ?? super.barrierCurve;
-    if (_barrierCurve == null) {
+
-      return super.barrierCurve;
-    }
-    return _barrierCurve;
-  }
   final Curve? _barrierCurve;
 
   @override

packages/flutter_test/lib/src/binding.dart

@@ -366,10 +366,7 @@ abstract class TestWidgetsFlutterBinding extends BindingBase
   ///
   /// This is called automatically by [testWidgets].
   static TestWidgetsFlutterBinding ensureInitialized([@visibleForTesting Map<String, String>? environment]) {
-    if (_instance != null) {
+    return _instance ?? binding.ensureInitialized(environment);
-      return _instance!;
-    }
-    return binding.ensureInitialized(environment);
   }
 
   @override

packages/flutter_tools/lib/src/android/android_sdk.dart

@@ -521,11 +521,7 @@ class AndroidSdk {
     final String executable = globals.platform.isWindows
       ? 'sdkmanager.bat'
       : 'sdkmanager';
-    final String? path = getCmdlineToolsPath(executable, skipOldTools: true);
+    return getCmdlineToolsPath(executable, skipOldTools: true);
-    if (path != null) {
-      return path;
-    }
-    return null;
   }
 
   /// Returns the version of the Android SDK manager tool or null if not found.

packages/flutter_tools/lib/src/android/java.dart

@@ -163,11 +163,7 @@ class Java {
           RegExp(r'java\s+(?<version>\d+(\.\d+)?(\.\d+)?)\s+\d\d\d\d-\d\d-\d\d');
       final RegExpMatch? match = secondJdkVersionRegex.firstMatch(versionLines[0]);
       if (match != null) {
-        final Version? parsedVersion = Version.parse(match.namedGroup('version'));
+        return Version.parse(match.namedGroup('version'));
-        if (parsedVersion == null) {
-          return null;
-        }
-        return parsedVersion;
       }
       _logger.printWarning(_formatJavaVersionWarning(rawVersionOutput));
       return null;

packages/flutter_tools/lib/src/cache.dart

@@ -557,11 +557,9 @@ class Cache {
 
   /// Return the top-level directory in the cache; this is `bin/cache`.
   Directory getRoot() {
-    if (_rootOverride != null) {
+    return _fileSystem.directory(
-      return _fileSystem.directory(_fileSystem.path.join(_rootOverride.path, 'bin', 'cache'));
+      _fileSystem.path.join(_rootOverride?.path ?? flutterRoot!, 'bin', 'cache'),
-    } else {
+    );
-      return _fileSystem.directory(_fileSystem.path.join(flutterRoot!, 'bin', 'cache'));
-    }
   }
 
   String getHostPlatformArchName() {

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

@@ -84,10 +84,7 @@ abstract class AnalyzeBase {
   bool get isFlutterRepo => argResults['flutter-repo'] as bool;
   String get sdkPath {
     final String? dartSdk = argResults['dart-sdk'] as String?;
-    if (dartSdk != null) {
+    return dartSdk ?? artifacts.getArtifactPath(Artifact.engineDartSdkPath);
-      return dartSdk;
-    }
-    return artifacts.getArtifactPath(Artifact.engineDartSdkPath);
   }
   bool get isBenchmarking => argResults['benchmark'] as bool;
   String? get protocolTrafficLog => argResults['protocol-traffic-log'] as String?;

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

@@ -399,14 +399,7 @@ class PackagesGetCommand extends FlutterCommand {
     return findPlugins(rootProject, throwOnError: false);
   })();
 
-  late final String? _androidEmbeddingVersion = (() {
+  late final String? _androidEmbeddingVersion = _rootProject?.android.getEmbeddingVersion().toString().split('.').last;
-    final FlutterProject? rootProject = _rootProject;
-    if (rootProject == null) {
-      return null;
-    }
-
-    return rootProject.android.getEmbeddingVersion().toString().split('.').last;
-  })();
 
   /// The pub packages usage values are incorrect since these are calculated/sent
   /// before pub get completes. This needs to be performed after dependency resolution.

packages/flutter_tools/lib/src/flutter_project_metadata.dart

@@ -224,10 +224,7 @@ ${migrateConfig.getOutputFileString()}''';
   /// Finds the fallback revision to use when no base revision is found in the migrate config.
   String getFallbackBaseRevision(Logger logger, FlutterVersion flutterVersion) {
     // Use the .metadata file if it exists.
-    if (versionRevision != null) {
+    return versionRevision ?? flutterVersion.frameworkRevision;
-      return versionRevision!;
-    }
-    return flutterVersion.frameworkRevision;
   }
 }
 

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

@@ -1178,12 +1178,7 @@ class IOSDeviceLogReader extends DeviceLogReader {
     bool isWirelesslyConnected = false,
     bool isCoreDevice = false,
   }) {
-    final int sdkVersion;
+    final int sdkVersion = majorSdkVersion ?? (useSyslog ? 12 : 13);
-    if (majorSdkVersion != null) {
-      sdkVersion = majorSdkVersion;
-    } else {
-      sdkVersion = useSyslog ? 12 : 13;
-    }
     return IOSDeviceLogReader._(
       iMobileDevice, sdkVersion, '1234', 'test', isWirelesslyConnected, isCoreDevice, 'Runner', usingCISystem);
   }

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

@@ -637,12 +637,7 @@ class IOSDeployDebugger {
       );
     }
 
-    if (_stdinWriteFuture != null) {
+    _stdinWriteFuture = _stdinWriteFuture?.then<void>((_) => writeln()) ?? writeln();
-      _stdinWriteFuture = _stdinWriteFuture!.then<void>((_) => writeln());
-    } else {
-      _stdinWriteFuture = writeln();
-    }
-
     return _stdinWriteFuture;
   }
 

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

@@ -847,12 +847,7 @@ void _parseIssueInStdout(XcodeBuildExecution xcodeBuildExecution, Logger logger,
 
 String? _parseMissingPlatform(String message) {
   final RegExp pattern = RegExp(r'error:(.*?) is not installed\. To use with Xcode, first download and install the platform');
-  final RegExpMatch? match = pattern.firstMatch(message);
+  return pattern.firstMatch(message)?.group(1);
-  if (match != null) {
-    final String? version = match.group(1);
-    return version;
-  }
-  return null;
 }
 
 // The result of [_handleXCResultIssue].

packages/flutter_tools/lib/src/version.dart

@@ -717,11 +717,7 @@ class VersionUpstreamValidator {
   // URLs without ".git" suffix will remain unaffected.
   static final RegExp _patternUrlDotGit = RegExp(r'(.*)(\.git)$');
   static String stripDotGit(String url) {
-    final RegExpMatch? match = _patternUrlDotGit.firstMatch(url);
+    return _patternUrlDotGit.firstMatch(url)?.group(1)! ?? url;
-    if (match == null) {
-      return url;
-    }
-    return match.group(1)!;
   }
 }
 

packages/flutter_tools/lib/src/xcode_project.dart

@@ -329,10 +329,7 @@ class IosProject extends XcodeBasedProject {
 
   Future<String?> _getTeamIdentifier(XcodeProjectBuildContext buildContext) async {
     final Map<String, String>? buildSettings = await _buildSettingsForXcodeProjectBuildContext(buildContext);
-    if (buildSettings != null) {
+    return buildSettings?[kTeamIdKey];
-      return buildSettings[kTeamIdKey];
-    }
-    return null;
   }
 
   Future<List<String>> _getAssociatedDomains(XcodeProjectBuildContext buildContext) async {

packages/flutter_tools/test/general.shard/device_test.dart

@@ -1130,10 +1130,7 @@ class TestDeviceDiscoverySupportFilter extends DeviceDiscoverySupportFilter {
 
   @override
   bool isDeviceSupportedForProject(Device device) {
-    if (isAlwaysSupportedForProjectOverride != null) {
+    return isAlwaysSupportedForProjectOverride ?? super.isDeviceSupportedForProject(device);
-      return isAlwaysSupportedForProjectOverride!;
-    }
-    return super.isDeviceSupportedForProject(device);
   }
 }
 

packages/flutter_tools/test/src/io.dart

@@ -24,90 +24,60 @@ class FlutterIOOverrides extends io.IOOverrides {
 
   @override
   io.Directory createDirectory(String path) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.directory(path) ?? super.createDirectory(path);
-      return super.createDirectory(path);
-    }
-    return _fileSystemDelegate.directory(path);
   }
 
   @override
   io.File createFile(String path) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.file(path) ?? super.createFile(path);
-      return super.createFile(path);
-    }
-    return _fileSystemDelegate.file(path);
   }
 
   @override
   io.Link createLink(String path) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.link(path) ?? super.createLink(path);
-      return super.createLink(path);
-    }
-    return _fileSystemDelegate.link(path);
   }
 
   @override
   Stream<FileSystemEvent> fsWatch(String path, int events, bool recursive) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.file(path).watch(events: events, recursive: recursive)
-      return super.fsWatch(path, events, recursive);
+      ?? super.fsWatch(path, events, recursive);
-    }
-    return _fileSystemDelegate.file(path).watch(events: events, recursive: recursive);
   }
 
   @override
   bool fsWatchIsSupported() {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.isWatchSupported ?? super.fsWatchIsSupported();
-      return super.fsWatchIsSupported();
-    }
-    return _fileSystemDelegate.isWatchSupported;
   }
 
   @override
   Future<FileSystemEntityType> fseGetType(String path, bool followLinks) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.type(path, followLinks: followLinks)
-      return super.fseGetType(path, followLinks);
+      ?? super.fseGetType(path, followLinks);
-    }
-    return _fileSystemDelegate.type(path, followLinks: followLinks);
   }
 
   @override
   FileSystemEntityType fseGetTypeSync(String path, bool followLinks) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.typeSync(path, followLinks: followLinks)
-      return super.fseGetTypeSync(path, followLinks);
+      ?? super.fseGetTypeSync(path, followLinks);
-    }
-    return _fileSystemDelegate.typeSync(path, followLinks: followLinks);
   }
 
   @override
   Future<bool> fseIdentical(String path1, String path2) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.identical(path1, path2) ?? super.fseIdentical(path1, path2);
-      return super.fseIdentical(path1, path2);
-    }
-    return _fileSystemDelegate.identical(path1, path2);
   }
 
   @override
   bool fseIdenticalSync(String path1, String path2) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.identicalSync(path1, path2) ?? super.fseIdenticalSync(path1, path2);
-      return super.fseIdenticalSync(path1, path2);
-    }
-    return _fileSystemDelegate.identicalSync(path1, path2);
   }
 
   @override
   io.Directory getCurrentDirectory() {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.currentDirectory ?? super.getCurrentDirectory();
-      return super.getCurrentDirectory();
-    }
-    return _fileSystemDelegate.currentDirectory;
   }
 
   @override
   io.Directory getSystemTempDirectory() {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.systemTempDirectory ?? super.getSystemTempDirectory();
-      return super.getSystemTempDirectory();
-    }
-    return _fileSystemDelegate.systemTempDirectory;
   }
 
   @override
@@ -120,17 +90,11 @@ class FlutterIOOverrides extends io.IOOverrides {
 
   @override
   Future<FileStat> stat(String path) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.stat(path) ?? super.stat(path);
-      return super.stat(path);
-    }
-    return _fileSystemDelegate.stat(path);
   }
 
   @override
   FileStat statSync(String path) {
-    if (_fileSystemDelegate == null) {
+    return _fileSystemDelegate?.statSync(path) ?? super.statSync(path);
-      return super.statSync(path);
-    }
-    return _fileSystemDelegate.statSync(path);
   }
 }