Enable avoid_setters_without_getters (#91067)

analysis_options.yaml

@@ -81,11 +81,11 @@ linter:
     - avoid_relative_lib_imports
     - avoid_renaming_method_parameters
     - avoid_return_types_on_setters
-    # - avoid_returning_null # there are plenty of valid reasons to return null
-    # - avoid_returning_null_for_future # not yet tested
+    # - avoid_returning_null # still violated by some pre-nnbd code that we haven't yet migrated
+    - avoid_returning_null_for_future
     - avoid_returning_null_for_void
     # - avoid_returning_this # there are plenty of valid reasons to return this
-    # - avoid_setters_without_getters # not yet tested
+    - avoid_setters_without_getters
     - avoid_shadowing_type_parameters
     - avoid_single_cascade_in_expression_statements
     - avoid_slow_async_io

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

@@ -2012,6 +2012,7 @@ class _RenderCupertinoDialogActions extends RenderBox
     markNeedsLayout();
   }
 
+  Color get dialogColor => _buttonBackgroundPaint.color;
   final Paint _buttonBackgroundPaint;
   set dialogColor(Color value) {
     if (value == _buttonBackgroundPaint.color)
@@ -2021,6 +2022,7 @@ class _RenderCupertinoDialogActions extends RenderBox
     markNeedsPaint();
   }
 
+  Color get dialogPressedColor => _pressedButtonBackgroundPaint.color;
   final Paint _pressedButtonBackgroundPaint;
   set dialogPressedColor(Color value) {
     if (value == _pressedButtonBackgroundPaint.color)
@@ -2030,6 +2032,7 @@ class _RenderCupertinoDialogActions extends RenderBox
     markNeedsPaint();
   }
 
+  Color get dividerColor => _dividerPaint.color;
   final Paint _dividerPaint;
   set dividerColor(Color value) {
     if (value == _dividerPaint.color)
@@ -2039,8 +2042,8 @@ class _RenderCupertinoDialogActions extends RenderBox
     markNeedsPaint();
   }
 
-  bool _isActionSheet;
   bool get isActionSheet => _isActionSheet;
+  bool _isActionSheet;
   set isActionSheet(bool value) {
     if (value == _isActionSheet)
       return;

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

@@ -196,6 +196,7 @@ class _RenderCupertinoTextSelectionToolbarShape extends RenderShiftedBox {
   @override
   bool get isRepaintBoundary => true;
 
+  Offset get anchor => _anchor;
   Offset _anchor;
   set anchor(Offset value) {
     if (value == _anchor) {
@@ -205,6 +206,7 @@ class _RenderCupertinoTextSelectionToolbarShape extends RenderShiftedBox {
     markNeedsLayout();
   }
 
+  bool get isAbove => _isAbove;
   bool _isAbove;
   set isAbove(bool value) {
     if (_isAbove == value) {

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

@@ -13,7 +13,6 @@ import 'box.dart';
 import 'layer.dart';
 import 'object.dart';
 
-
 /// How an embedded platform view behave during hit tests.
 enum PlatformViewHitTestBehavior {
   /// Opaque targets can be hit by hit tests, causing them to both receive
@@ -75,7 +74,6 @@ Set<Type> _factoriesTypeSet<T>(Set<Factory<T>> factories) {
 ///  * [AndroidView] which is a widget that is used to show an Android view.
 ///  * [PlatformViewsService] which is a service for controlling platform views.
 class RenderAndroidView extends RenderBox with _PlatformViewGestureMixin {
-
   /// Creates a render object for an Android view.
   RenderAndroidView({
     required AndroidViewController viewController,
@@ -97,7 +95,7 @@ class RenderAndroidView extends RenderBox with _PlatformViewGestureMixin {
   _PlatformViewState _state = _PlatformViewState.uninitialized;
 
   /// The Android view controller for the Android view associated with this render object.
-  AndroidViewController get viewcontroller => _viewController;
+  AndroidViewController get viewController => _viewController;
   AndroidViewController _viewController;
   /// Sets a new Android view controller.
   ///
@@ -451,7 +449,6 @@ class _UiKitViewGestureRecognizer extends OneSequenceGestureRecognizer {
     ).toSet();
   }
 
-
   // We use OneSequenceGestureRecognizers as they support gesture arena teams.
   // TODO(amirh): get a list of GestureRecognizers here.
   // https://github.com/flutter/flutter/issues/20953
@@ -615,7 +612,6 @@ class _PlatformViewGestureRecognizer extends OneSequenceGestureRecognizer {
 /// [PlatformViewRenderBox] presents a platform view by adding a [PlatformViewLayer] layer,
 /// integrates it with the gesture arenas system and adds relevant semantic nodes to the semantics tree.
 class PlatformViewRenderBox extends RenderBox with _PlatformViewGestureMixin {
-
   /// Creating a render object for a [PlatformViewSurface].
   ///
   /// The `controller` parameter must not be null.
@@ -631,8 +627,9 @@ class PlatformViewRenderBox extends RenderBox with _PlatformViewGestureMixin {
     updateGestureRecognizers(gestureRecognizers);
   }
 
-  /// Sets the [controller] for this render object.
-  ///
+  /// The controller for this render object.
+  PlatformViewController get controller => _controller;
+  PlatformViewController _controller;
   /// This value must not be null, and setting it to a new value will result in a repaint.
   set controller(PlatformViewController controller) {
     assert(controller != null);
@@ -657,8 +654,6 @@ class PlatformViewRenderBox extends RenderBox with _PlatformViewGestureMixin {
     _updateGestureRecognizersWithCallBack(gestureRecognizers, _controller.dispatchPointerEvent);
   }
 
-  PlatformViewController _controller;
-
   @override
   bool get sizedByParent => true;
 

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

@@ -2265,11 +2265,14 @@ class RenderTransform extends RenderProxyBox {
   /// always honor the transformation, regardless of the value of this property.
   bool transformHitTests;
 
-  // Note the lack of a getter for transform because Matrix4 is not immutable
   Matrix4? _transform;
-
-  /// The matrix to transform the child by during painting.
-  set transform(Matrix4 value) {
+  /// The matrix to transform the child by during painting. The provided value
+  /// is copied on assignment.
+  ///
+  /// There is no getter for [transform], because [Matrix4] is mutable, and
+  /// mutations outside of the control of the render object could not reliably
+  /// be reflected in the rendering.
+  set transform(Matrix4 value) { // ignore: avoid_setters_without_getters
     assert(value != null);
     if (_transform == value)
       return;

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

@@ -522,8 +522,8 @@ class _AndroidMotionEventConverter {
       <int, AndroidPointerProperties>{};
   final Set<int> usedAndroidPointerIds = <int>{};
 
+  PointTransformer get pointTransformer => _pointTransformer;
   late PointTransformer _pointTransformer;
-
   set pointTransformer(PointTransformer transformer) {
     assert(transformer != null);
     _pointTransformer = transformer;
@@ -813,10 +813,12 @@ abstract class AndroidViewController extends PlatformViewController {
     );
   }
 
-  /// Converts a given point from the global coordinate system in logical pixels to the local coordinate system for this box.
+  /// Converts a given point from the global coordinate system in logical pixels
+  /// to the local coordinate system for this box.
   ///
   /// This is required to convert a [PointerEvent] to an [AndroidMotionEvent].
   /// It is typically provided by using [RenderBox.globalToLocal].
+  PointTransformer get pointTransformer => _motionEventConverter._pointTransformer;
   set pointTransformer(PointTransformer transformer) {
     assert(transformer != null);
     _motionEventConverter._pointTransformer = transformer;
@@ -1146,18 +1148,17 @@ class UiKitViewController {
   }
 }
 
-/// An interface for a controlling a single platform view.
+/// An interface for controlling a single platform view.
 ///
 /// Used by [PlatformViewSurface] to interface with the platform view it embeds.
 abstract class PlatformViewController {
-
   /// The viewId associated with this controller.
   ///
-  /// The viewId should always be unique and non-negative. And it must not be null.
+  /// The viewId should always be unique and non-negative.
   ///
   /// See also:
   ///
-  ///  * [PlatformViewsRegistry], which is a helper for managing platform view ids.
+  ///  * [PlatformViewsRegistry], which is a helper for managing platform view IDs.
   int get viewId;
 
   /// Dispatches the `event` to the platform view.

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

@@ -160,13 +160,10 @@ abstract class Action<T extends Intent> with Diagnosticable {
   final ObserverList<ActionListenerCallback> _listeners = ObserverList<ActionListenerCallback>();
 
   Action<T>? _currentCallingAction;
-  set _callingAction(Action<T>? newAction) {
-    if (newAction == _currentCallingAction) {
-      return;
-    }
-    assert(newAction == null || _currentCallingAction == null);
-    _currentCallingAction = newAction;
+  void _updateCallingAction(Action<T>? value) {
+    _currentCallingAction = value;
   }
+
   /// The [Action] overridden by this [Action].
   ///
   /// The [Action.overridable] constructor creates an overridable [Action] that
@@ -1526,9 +1523,9 @@ mixin _OverridableActionMixin<T extends Intent> on Action<T> {
   }
 
   @override
-  set _callingAction(Action<T>? newAction) {
-    super._callingAction = newAction;
-    defaultAction._callingAction = newAction;
+  void _updateCallingAction(Action<T>? value) {
+    super._updateCallingAction(value);
+    defaultAction._updateCallingAction(value);
   }
 
   Object? _invokeOverride(Action<T> overrideAction, T intent, BuildContext? context) {
@@ -1537,11 +1534,11 @@ mixin _OverridableActionMixin<T extends Intent> on Action<T> {
       debugAssertMutuallyRecursive = true;
       return true;
     }());
-    overrideAction._callingAction = defaultAction;
+    overrideAction._updateCallingAction(defaultAction);
     final Object? returnValue = overrideAction is ContextAction<T>
       ? overrideAction.invoke(intent, context)
       : overrideAction.invoke(intent);
-    overrideAction._callingAction = null;
+    overrideAction._updateCallingAction(null);
     assert(() {
       debugAssertMutuallyRecursive = false;
       return true;
@@ -1564,9 +1561,9 @@ mixin _OverridableActionMixin<T extends Intent> on Action<T> {
       debugAssertIsActionEnabledMutuallyRecursive = true;
       return true;
     }());
-    overrideAction._callingAction = defaultAction;
+    overrideAction._updateCallingAction(defaultAction);
     final bool isOverrideEnabled = overrideAction.isActionEnabled;
-    overrideAction._callingAction = null;
+    overrideAction._updateCallingAction(null);
     assert(() {
       debugAssertIsActionEnabledMutuallyRecursive = false;
       return true;
@@ -1592,9 +1589,9 @@ mixin _OverridableActionMixin<T extends Intent> on Action<T> {
     }());
 
     final Action<T>? overrideAction = getOverrideAction();
-    overrideAction?._callingAction = defaultAction;
+    overrideAction?._updateCallingAction(defaultAction);
     final bool returnValue = (overrideAction ?? defaultAction).isEnabled(intent);
-    overrideAction?._callingAction = null;
+    overrideAction?._updateCallingAction(null);
     assert(() {
       debugAssertIsEnabledMutuallyRecursive = false;
       return true;
@@ -1610,9 +1607,9 @@ mixin _OverridableActionMixin<T extends Intent> on Action<T> {
       return true;
     }());
     final Action<T>? overrideAction = getOverrideAction();
-    overrideAction?._callingAction = defaultAction;
+    overrideAction?._updateCallingAction(defaultAction);
     final bool isEnabled = (overrideAction ?? defaultAction).consumesKey(intent);
-    overrideAction?._callingAction = null;
+    overrideAction?._updateCallingAction(null);
     assert(() {
       debugAssertConsumeKeyMutuallyRecursive = false;
       return true;
@@ -1674,11 +1671,11 @@ class _OverridableContextAction<T extends Intent> extends ContextAction<T> with
     // overrideAction is not a ContextAction and thus have no access to the
     // calling BuildContext.
     final Action<T> wrappedDefault = _ContextActionToActionAdapter<T>(invokeContext: context!, action: defaultAction);
-    overrideAction._callingAction = wrappedDefault;
+    overrideAction._updateCallingAction(wrappedDefault);
     final Object? returnValue = overrideAction is ContextAction<T>
       ? overrideAction.invoke(intent, context)
       : overrideAction.invoke(intent);
-    overrideAction._callingAction = null;
+    overrideAction._updateCallingAction(null);
 
     assert(() {
       debugAssertMutuallyRecursive = false;
@@ -1710,8 +1707,8 @@ class _ContextActionToActionAdapter<T extends Intent> extends Action<T> {
   final ContextAction<T> action;
 
   @override
-  set _callingAction(Action<T>? newAction) {
-    action._callingAction = newAction;
+  void _updateCallingAction(Action<T>? value) {
+    action._updateCallingAction(value);
   }
 
   @override

packages/flutter/test/services/fake_platform_views.dart

@@ -59,7 +59,7 @@ class FakeAndroidViewController implements AndroidViewController {
   final int viewId;
 
   @override
-  Offset Function(Offset position)? pointTransformer;
+  late PointTransformer pointTransformer;
 
   @override
   Future<void> dispatchPointerEvent(PointerEvent event) async {

packages/flutter/test/widgets/semantics_10_test.dart

@@ -92,7 +92,6 @@ class TestWidget extends SingleChildRenderObjectWidget {
 }
 
 class RenderTest extends RenderProxyBox {
-
   @override
   void describeSemanticsConfiguration(SemanticsConfiguration config) {
     super.describeSemanticsConfiguration(config);
@@ -107,6 +106,7 @@ class RenderTest extends RenderProxyBox {
 
   }
 
+  String get label => _label;
   String _label = '<>';
   set label(String value) {
     if (value == _label)
@@ -116,6 +116,7 @@ class RenderTest extends RenderProxyBox {
   }
 
 
+  bool get isSemanticBoundary => _isSemanticBoundary;
   bool _isSemanticBoundary = false;
   set isSemanticBoundary(bool value) {
     if (_isSemanticBoundary == value)

packages/flutter_test/lib/src/_binding_io.dart

@@ -120,13 +120,13 @@ class _MockHttpClient implements HttpClient {
   void addProxyCredentials(String host, int port, String realm, HttpClientCredentials credentials) { }
 
   @override
-  set authenticate(Future<bool> Function(Uri url, String scheme, String realm)? f) { }
+  Future<bool> Function(Uri url, String scheme, String realm)? authenticate;
 
   @override
-  set authenticateProxy(Future<bool> Function(String host, int port, String scheme, String realm)? f) { }
+  Future<bool> Function(String host, int port, String scheme, String realm)? authenticateProxy;
 
   @override
-  set badCertificateCallback(bool Function(X509Certificate cert, String host, int port)? callback) { }
+  bool Function(X509Certificate cert, String host, int port)? badCertificateCallback;
 
   @override
   void close({ bool force = false }) { }
@@ -142,7 +142,7 @@ class _MockHttpClient implements HttpClient {
   }
 
   @override
-  set findProxy(String Function(Uri url)? f) { }
+  String Function(Uri url)? findProxy;
 
   @override
   Future<HttpClientRequest> get(String host, int port, String path) {

packages/flutter_test/lib/src/window.dart

@@ -59,7 +59,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   double? _devicePixelRatio;
   /// Hides the real device pixel ratio and reports the given [devicePixelRatio]
   /// instead.
-  set devicePixelRatioTestValue(double devicePixelRatio) {
+  set devicePixelRatioTestValue(double devicePixelRatio) { // ignore: avoid_setters_without_getters
     _devicePixelRatio = devicePixelRatio;
     onMetricsChanged?.call();
   }
@@ -75,7 +75,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.Size? _physicalSizeTestValue;
   /// Hides the real physical size and reports the given [physicalSizeTestValue]
   /// instead.
-  set physicalSizeTestValue (ui.Size physicalSizeTestValue) {
+  set physicalSizeTestValue (ui.Size physicalSizeTestValue) { // ignore: avoid_setters_without_getters
     _physicalSizeTestValue = physicalSizeTestValue;
     onMetricsChanged?.call();
   }
@@ -91,7 +91,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.WindowPadding? _viewInsetsTestValue;
   /// Hides the real view insets and reports the given [viewInsetsTestValue]
   /// instead.
-  set viewInsetsTestValue(ui.WindowPadding viewInsetsTestValue) {
+  set viewInsetsTestValue(ui.WindowPadding viewInsetsTestValue) { // ignore: avoid_setters_without_getters
     _viewInsetsTestValue = viewInsetsTestValue;
     onMetricsChanged?.call();
   }
@@ -107,7 +107,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.WindowPadding? _viewPaddingTestValue;
   /// Hides the real view padding and reports the given [paddingTestValue]
   /// instead.
-  set viewPaddingTestValue(ui.WindowPadding viewPaddingTestValue) {
+  set viewPaddingTestValue(ui.WindowPadding viewPaddingTestValue) { // ignore: avoid_setters_without_getters
     _viewPaddingTestValue = viewPaddingTestValue;
     onMetricsChanged?.call();
   }
@@ -122,7 +122,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.WindowPadding get padding => _paddingTestValue ?? _window.padding;
   ui.WindowPadding? _paddingTestValue;
   /// Hides the real padding and reports the given [paddingTestValue] instead.
-  set paddingTestValue(ui.WindowPadding paddingTestValue) {
+  set paddingTestValue(ui.WindowPadding paddingTestValue) { // ignore: avoid_setters_without_getters
     _paddingTestValue = paddingTestValue;
     onMetricsChanged?.call();
   }
@@ -136,7 +136,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.WindowPadding get systemGestureInsets => _systemGestureInsetsTestValue ?? _window.systemGestureInsets;
   ui.WindowPadding? _systemGestureInsetsTestValue;
   /// Hides the real system gesture insets and reports the given [systemGestureInsetsTestValue] instead.
-  set systemGestureInsetsTestValue(ui.WindowPadding systemGestureInsetsTestValue) {
+  set systemGestureInsetsTestValue(ui.WindowPadding systemGestureInsetsTestValue) { // ignore: avoid_setters_without_getters
     _systemGestureInsetsTestValue = systemGestureInsetsTestValue;
     onMetricsChanged?.call();
   }
@@ -157,7 +157,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.Locale get locale => _localeTestValue ?? platformDispatcher.locale;
   ui.Locale? _localeTestValue;
   /// Hides the real locale and reports the given [localeTestValue] instead.
-  set localeTestValue(ui.Locale localeTestValue) {
+  set localeTestValue(ui.Locale localeTestValue) { // ignore: avoid_setters_without_getters
     _localeTestValue = localeTestValue;
     onLocaleChanged?.call();
   }
@@ -171,7 +171,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   List<ui.Locale> get locales => _localesTestValue ?? platformDispatcher.locales;
   List<ui.Locale>? _localesTestValue;
   /// Hides the real locales and reports the given [localesTestValue] instead.
-  set localesTestValue(List<ui.Locale> localesTestValue) {
+  set localesTestValue(List<ui.Locale> localesTestValue) { // ignore: avoid_setters_without_getters
     _localesTestValue = localesTestValue;
     onLocaleChanged?.call();
   }
@@ -192,7 +192,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   String get initialLifecycleState => _initialLifecycleStateTestValue;
   String _initialLifecycleStateTestValue = '';
   /// Sets a faked initialLifecycleState for testing.
-  set initialLifecycleStateTestValue(String state) {
+  set initialLifecycleStateTestValue(String state) { // ignore: avoid_setters_without_getters
     _initialLifecycleStateTestValue = state;
   }
 
@@ -201,7 +201,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   double? _textScaleFactorTestValue;
   /// Hides the real text scale factor and reports the given
   /// [textScaleFactorTestValue] instead.
-  set textScaleFactorTestValue(double textScaleFactorTestValue) {
+  set textScaleFactorTestValue(double textScaleFactorTestValue) { // ignore: avoid_setters_without_getters
     _textScaleFactorTestValue = textScaleFactorTestValue;
     onTextScaleFactorChanged?.call();
   }
@@ -223,7 +223,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   }
   /// Hides the real text scale factor and reports the given
   /// [platformBrightnessTestValue] instead.
-  set platformBrightnessTestValue(ui.Brightness platformBrightnessTestValue) {
+  set platformBrightnessTestValue(ui.Brightness platformBrightnessTestValue) { // ignore: avoid_setters_without_getters
     _platformBrightnessTestValue = platformBrightnessTestValue;
     onPlatformBrightnessChanged?.call();
   }
@@ -239,7 +239,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   bool? _alwaysUse24HourFormatTestValue;
   /// Hides the real clock format and reports the given
   /// [alwaysUse24HourFormatTestValue] instead.
-  set alwaysUse24HourFormatTestValue(bool alwaysUse24HourFormatTestValue) {
+  set alwaysUse24HourFormatTestValue(bool alwaysUse24HourFormatTestValue) { // ignore: avoid_setters_without_getters
     _alwaysUse24HourFormatTestValue = alwaysUse24HourFormatTestValue;
   }
   /// Deletes any existing test clock format and returns to using the real clock
@@ -288,7 +288,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   String? _defaultRouteNameTestValue;
   /// Hides the real default route name and reports the given
   /// [defaultRouteNameTestValue] instead.
-  set defaultRouteNameTestValue(String defaultRouteNameTestValue) {
+  set defaultRouteNameTestValue(String defaultRouteNameTestValue) { // ignore: avoid_setters_without_getters
     _defaultRouteNameTestValue = defaultRouteNameTestValue;
   }
   /// Deletes any existing test default route name and returns to using the real
@@ -312,7 +312,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   bool? _semanticsEnabledTestValue;
   /// Hides the real semantics enabled and reports the given
   /// [semanticsEnabledTestValue] instead.
-  set semanticsEnabledTestValue(bool semanticsEnabledTestValue) {
+  set semanticsEnabledTestValue(bool semanticsEnabledTestValue) { // ignore: avoid_setters_without_getters
     _semanticsEnabledTestValue = semanticsEnabledTestValue;
     onSemanticsEnabledChanged?.call();
   }
@@ -342,7 +342,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.AccessibilityFeatures? _accessibilityFeaturesTestValue;
   /// Hides the real accessibility features and reports the given
   /// [accessibilityFeaturesTestValue] instead.
-  set accessibilityFeaturesTestValue(ui.AccessibilityFeatures accessibilityFeaturesTestValue) {
+  set accessibilityFeaturesTestValue(ui.AccessibilityFeatures accessibilityFeaturesTestValue) { // ignore: avoid_setters_without_getters
     _accessibilityFeaturesTestValue = accessibilityFeaturesTestValue;
     onAccessibilityFeaturesChanged?.call();
   }
@@ -358,7 +358,7 @@ class TestWindow implements ui.SingletonFlutterWindow {
   ui.ViewConfiguration? _viewConfiguration;
 
   /// Hide the real view configuration and report the provided [value] instead.
-  set viewConfigurationTestValue(ui.ViewConfiguration? value) {
+  set viewConfigurationTestValue(ui.ViewConfiguration? value) { // ignore: avoid_setters_without_getters
     _viewConfiguration = value;
     onMetricsChanged?.call();
   }

packages/flutter_tools/lib/src/base/bot_detector.dart

@@ -37,14 +37,15 @@ class BotDetector {
       // When set, GA logs to a local file (normally for tests) so we don't need to filter.
       || _platform.environment.containsKey('FLUTTER_ANALYTICS_LOG_FILE')
     ) {
-      return _persistentToolState.runningOnBot = false;
+      _persistentToolState.setIsRunningOnBot(false);
+      return false;
     }
 
     if (_persistentToolState.isRunningOnBot != null) {
       return _persistentToolState.isRunningOnBot!;
     }
 
-    return _persistentToolState.runningOnBot = _platform.environment['BOT'] == 'true'
+    final bool result = _platform.environment['BOT'] == 'true'
 
       // https://docs.travis-ci.com/user/environment-variables/#Default-Environment-Variables
       || _platform.environment['TRAVIS'] == 'true'
@@ -77,6 +78,9 @@ class BotDetector {
 
       // Property when running on Azure.
       || await _azureDetector.isRunningOnAzure;
+
+    _persistentToolState.setIsRunningOnBot(result);
+    return result;
   }
 }
 

packages/flutter_tools/lib/src/base/terminal.dart

@@ -111,6 +111,7 @@ abstract class Terminal {
 
   String clearScreen();
 
+  bool get singleCharMode;
   set singleCharMode(bool value);
 
   /// Return keystrokes from the console.
@@ -269,6 +270,14 @@ class AnsiTerminal implements Terminal {
   @override
   String clearScreen() => supportsColor ? clear : '\n\n';
 
+  @override
+  bool get singleCharMode {
+    if (!_stdio.stdinHasTerminal) {
+      return false;
+    }
+    final io.Stdin stdin = _stdio.stdin as io.Stdin;
+    return stdin.lineMode && stdin.echoMode;
+  }
   @override
   set singleCharMode(bool value) {
     if (!_stdio.stdinHasTerminal) {
@@ -365,6 +374,8 @@ class _TestTerminal implements Terminal {
     throw UnsupportedError('promptForCharInput not supported in the test terminal.');
   }
 
+  @override
+  bool get singleCharMode => false;
   @override
   set singleCharMode(bool value) { }
 

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

@@ -198,12 +198,12 @@ class UpgradeCommandRunner {
   // re-entrantly with the `--continue` flag
   Future<void> runCommandSecondHalf(FlutterVersion flutterVersion) async {
     // Make sure the welcome message re-display is delayed until the end.
-    globals.persistentToolState.redisplayWelcomeMessage = false;
+    globals.persistentToolState.setShouldRedisplayWelcomeMessage(false);
     await precacheArtifacts();
     await updatePackages(flutterVersion);
     await runDoctor();
     // Force the welcome message to re-display following the upgrade.
-    globals.persistentToolState.redisplayWelcomeMessage = true;
+    globals.persistentToolState.setShouldRedisplayWelcomeMessage(true);
   }
 
   Future<bool> hasUncommittedChanges() async {

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

@@ -704,6 +704,7 @@ class IOSDeviceLogReader extends DeviceLogReader {
   }
 
   /// Log reader will listen to [debugger.logLines] and will detach debugger on dispose.
+  IOSDeployDebugger get debuggerStream => _iosDeployDebugger;
   set debuggerStream(IOSDeployDebugger debugger) {
     // Logging is gathered from syslog on iOS 13 and earlier.
     if (_majorSdkVersion < minimumUniversalLoggingSdkVersion) {
@@ -736,14 +737,13 @@ class IOSDeviceLogReader extends DeviceLogReader {
           _linesController.close();
         }
       });
-      assert(_idevicesyslogProcess == null);
-      _idevicesyslogProcess = process;
+      assert(idevicesyslogProcess == null);
+      idevicesyslogProcess = process;
     });
   }
 
   @visibleForTesting
-  set idevicesyslogProcess(Process process) => _idevicesyslogProcess = process;
-  Process _idevicesyslogProcess;
+  Process idevicesyslogProcess;
 
   // Returns a stateful line handler to properly capture multiline output.
   //
@@ -781,7 +781,7 @@ class IOSDeviceLogReader extends DeviceLogReader {
     for (final StreamSubscription<void> loggingSubscription in _loggingSubscriptions) {
       loggingSubscription.cancel();
     }
-    _idevicesyslogProcess?.kill();
+    idevicesyslogProcess?.kill();
     _iosDeployDebugger?.detach();
   }
 }

packages/flutter_tools/lib/src/persistent_tool_state.dart

@@ -38,7 +38,7 @@ abstract class PersistentToolState {
   ///
   /// May give null if the value has not been set.
   bool? get shouldRedisplayWelcomeMessage;
-  set redisplayWelcomeMessage(bool value); // Enforced nonnull setter.
+  void setShouldRedisplayWelcomeMessage(bool value); // Enforced nonnull setter.
 
   /// Returns the last active version for a given [channel].
   ///
@@ -50,11 +50,11 @@ abstract class PersistentToolState {
 
   /// Return the hash of the last active license terms.
   String? get lastActiveLicenseTermsHash;
-  set lastActiveLicenseTerms(String value); // Enforced nonnull setter.
+  void setLastActiveLicenseTermsHash(String value); // Enforced nonnull setter.
 
   /// Whether this client was already determined to be or not be a bot.
   bool? get isRunningOnBot;
-  set runningOnBot(bool value); // Enforced nonnull setter.
+  void setIsRunningOnBot(bool value); // Enforced nonnull setter.
 }
 
 class _DefaultPersistentToolState implements PersistentToolState {
@@ -98,7 +98,7 @@ class _DefaultPersistentToolState implements PersistentToolState {
   }
 
   @override
-  set redisplayWelcomeMessage(bool value) {
+  void setShouldRedisplayWelcomeMessage(bool value) {
     _config.setValue(_kRedisplayWelcomeMessage, value);
   }
 
@@ -120,7 +120,7 @@ class _DefaultPersistentToolState implements PersistentToolState {
   String? get lastActiveLicenseTermsHash => _config.getValue(_kLicenseHash) as String?;
 
   @override
-  set lastActiveLicenseTerms(String value) {
+  void setLastActiveLicenseTermsHash(String value) {
     _config.setValue(_kLicenseHash, value);
   }
 
@@ -132,7 +132,7 @@ class _DefaultPersistentToolState implements PersistentToolState {
   bool? get isRunningOnBot => _config.getValue(_kBotKey) as bool?;
 
   @override
-  set runningOnBot(bool value) {
+  void setIsRunningOnBot(bool value) {
     _config.setValue(_kBotKey, value);
   }
 }

packages/flutter_tools/lib/src/reporting/first_run.dart

@@ -67,7 +67,7 @@ class FirstRunMessenger {
 
   /// Update the cached license terms hash once the new terms have been displayed.
   void confirmLicenseTermsDisplayed() {
-    _persistentToolState.lastActiveLicenseTerms = _currentHash;
+    _persistentToolState.setLastActiveLicenseTermsHash(_currentHash);
   }
 
   /// The hash of the current license representation.

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -188,8 +188,6 @@ abstract class FlutterCommand extends Command<void> {
   bool _excludeDebug = false;
   bool _excludeRelease = false;
 
-  BuildMode _defaultBuildMode;
-
   void requiresPubspecYaml() {
     _requiresPubspecYaml = true;
   }
@@ -833,9 +831,11 @@ abstract class FlutterCommand extends Command<void> {
     usesTrackWidgetCreation(verboseHelp: verboseHelp);
   }
 
-  set defaultBuildMode(BuildMode value) {
-    _defaultBuildMode = value;
-  }
+  /// The build mode that this command will use if no build mode is
+  /// explicitly specified.
+  ///
+  /// Use [getBuildMode] to obtain the actual effective build mode.
+  BuildMode defaultBuildMode;
 
   BuildMode getBuildMode() {
     // No debug when _excludeDebug is true.
@@ -865,7 +865,7 @@ abstract class FlutterCommand extends Command<void> {
     if (jitReleaseResult) {
       return BuildMode.jitRelease;
     }
-    return _defaultBuildMode;
+    return defaultBuildMode;
   }
 
   void usesFlavorOption() {

packages/flutter_tools/lib/src/test/test_compiler.dart

@@ -81,7 +81,7 @@ class TestCompiler {
   Future<String> compile(Uri mainDart) {
     final Completer<String> completer = Completer<String>();
     if (compilerController.isClosed) {
-      return null;
+      return Future<String>.value(null);
     }
     compilerController.add(CompilationRequest(mainDart, completer));
     return completer.future;

packages/flutter_tools/lib/src/web/web_device.dart

@@ -394,7 +394,7 @@ class WebServerDevice extends Device {
   void clearLogs() { }
 
   @override
-  Future<String> get emulatorId => null;
+  Future<String> get emulatorId async => null;
 
   DeviceLogReader _logReader;
 

packages/flutter_tools/lib/src/windows/windows_device.dart

@@ -125,7 +125,7 @@ class WindowsUWPDevice extends Device {
   Future<void> dispose() async { }
 
   @override
-  Future<String> get emulatorId => null;
+  Future<String> get emulatorId async => null;
 
   @override
   FutureOr<DeviceLogReader> getLogReader({covariant BuildableUwpApp app, bool includePastLogs = false}) {

packages/flutter_tools/test/commands.shard/hermetic/custom_devices.dart

@@ -233,6 +233,8 @@ class FakeTerminal implements Terminal {
       displayAcceptedCharacters: displayAcceptedCharacters
     );
 
+  @override
+  bool get singleCharMode => terminal.singleCharMode;
   @override
   set singleCharMode(bool value) => terminal.singleCharMode = value;
 

packages/flutter_tools/test/commands.shard/hermetic/doctor_test.dart

@@ -672,7 +672,7 @@ class NoOpDoctor implements Doctor {
   List<ValidatorTask> startValidatorTasks() => <ValidatorTask>[];
 
   @override
-  Future<void> summary() => null;
+  Future<void> summary() async { }
 
   @override
   List<DoctorValidator> get validators => <DoctorValidator>[];

packages/flutter_tools/test/general.shard/base/error_handling_io_test.dart

@@ -1264,6 +1264,10 @@ class FakeFileSystem extends Fake implements FileSystem {
   @override
   p.Context get path => p.Context();
 
+  @override
+  Directory get currentDirectory {
+    throw UnimplementedError();
+  }
   @override
   set currentDirectory(dynamic path) { }
 }

packages/flutter_tools/test/general.shard/base/terminal_test.dart

@@ -236,6 +236,7 @@ class TestTerminal extends AnsiTerminal {
     return mockStdInStream;
   }
 
+  @override
   bool singleCharMode = false;
 
   @override

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

@@ -21,10 +21,10 @@ void main() {
       logger: BufferLogger.test(),
     );
     expect(state1.shouldRedisplayWelcomeMessage, null);
-    state1.redisplayWelcomeMessage = true;
+    state1.setShouldRedisplayWelcomeMessage(true);
     expect(stateFile.existsSync(), true);
     expect(state1.shouldRedisplayWelcomeMessage, true);
-    state1.redisplayWelcomeMessage = false;
+    state1.setShouldRedisplayWelcomeMessage(false);
     expect(state1.shouldRedisplayWelcomeMessage, false);
 
     final PersistentToolState state2 = PersistentToolState.test(

packages/flutter_tools/test/general.shard/reporting/first_run_test.dart

@@ -50,7 +50,7 @@ FirstRunMessenger setUpFirstRunMessenger({bool? redisplayWelcomeMessage, bool te
   final MemoryFileSystem fileSystem = MemoryFileSystem.test();
   final PersistentToolState state = PersistentToolState.test(directory: fileSystem.currentDirectory, logger: BufferLogger.test());
   if (redisplayWelcomeMessage != null) {
-    state.redisplayWelcomeMessage = redisplayWelcomeMessage;
+    state.setShouldRedisplayWelcomeMessage(redisplayWelcomeMessage);
   }
   if (test) {
     return TestFirstRunMessenger(state);

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

@@ -444,9 +444,7 @@ class FakeDevtoolsLauncher extends Fake implements DevtoolsLauncher {
   Uri devToolsUrl;
 
   @override
-  Future<DevToolsServerAddress> serve() {
-    return null;
-  }
+  Future<DevToolsServerAddress> serve() async => null;
 
   @override
   Future<void> get ready => readyCompleter.future;

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

@@ -494,7 +494,7 @@ void main() {
     _setupMocks();
     final TestChromiumLauncher chromiumLauncher = TestChromiumLauncher();
     final Chromium chrome = Chromium(1, chromeConnection, chromiumLauncher: chromiumLauncher);
-    chromiumLauncher.instance = chrome;
+    chromiumLauncher.setInstance(chrome);
 
     flutterDevice.device = GoogleChromeDevice(
       fileSystem: fileSystem,
@@ -551,7 +551,7 @@ void main() {
     _setupMocks();
     final TestChromiumLauncher chromiumLauncher = TestChromiumLauncher();
     final Chromium chrome = Chromium(1, chromeConnection, chromiumLauncher: chromiumLauncher);
-    chromiumLauncher.instance = chrome;
+    chromiumLauncher.setInstance(chrome);
 
     flutterDevice.device = GoogleChromeDevice(
       fileSystem: fileSystem,
@@ -848,7 +848,7 @@ void main() {
     final FakeChromeConnection chromeConnection = FakeChromeConnection();
     final TestChromiumLauncher chromiumLauncher = TestChromiumLauncher();
     final Chromium chrome = Chromium(1, chromeConnection, chromiumLauncher: chromiumLauncher);
-    chromiumLauncher.instance = chrome;
+    chromiumLauncher.setInstance(chrome);
 
     flutterDevice.device = GoogleChromeDevice(
       fileSystem: fileSystem,
@@ -1220,11 +1220,11 @@ class FakeWipConnection extends Fake implements WipConnection {
 class TestChromiumLauncher implements ChromiumLauncher {
   TestChromiumLauncher();
 
-  set instance(Chromium chromium) {
+  bool _hasInstance = false;
+  void setInstance(Chromium chromium) {
     _hasInstance = true;
     currentCompleter.complete(chromium);
   }
-  bool _hasInstance = false;
 
   @override
   Completer<Chromium> currentCompleter = Completer<Chromium>();

packages/flutter_tools/test/src/context.dart

@@ -312,9 +312,7 @@ class FakeXcodeProjectInterpreter implements XcodeProjectInterpreter {
   }
 
   @override
-  Future<void> cleanWorkspace(String workspacePath, String scheme, { bool verbose = false }) {
-    return null;
-  }
+  Future<void> cleanWorkspace(String workspacePath, String scheme, { bool verbose = false }) async { }
 
   @override
   Future<XcodeProjectInfo> getInfo(String projectPath, {String projectFilename}) async {

packages/flutter_tools/test/src/fake_http_client.dart

@@ -161,19 +161,13 @@ class FakeHttpClient implements HttpClient {
   }
 
   @override
-  set authenticate(Future<bool> Function(Uri url, String scheme, String realm)? f) {
-    throw UnimplementedError();
-  }
+  Future<bool> Function(Uri url, String scheme, String realm)? authenticate;
 
   @override
-  set authenticateProxy(Future<bool> Function(String host, int port, String scheme, String realm)? f) {
-    throw UnimplementedError();
-  }
+  Future<bool> Function(String host, int port, String scheme, String realm)? authenticateProxy;
 
   @override
-  set badCertificateCallback(bool Function(X509Certificate cert, String host, int port)? callback) {
-    throw UnimplementedError();
-  }
+  bool Function(X509Certificate cert, String host, int port)? badCertificateCallback;
 
   @override
   void close({bool force = false}) { }
@@ -190,7 +184,7 @@ class FakeHttpClient implements HttpClient {
   }
 
   @override
-  set findProxy(String Function(Uri url)? f) { }
+  String Function(Uri url)? findProxy;
 
   @override
   Future<HttpClientRequest> get(String host, int port, String path) {

packages/flutter_web_plugins/lib/src/plugin_event_channel.dart

@@ -71,7 +71,7 @@ class PluginEventChannel<T> {
     'Replace calls to the "controller" setter with calls to the "setController" method. '
     'This feature was deprecated after v1.23.0-7.0.pre.'
   )
-  set controller(StreamController<T> controller) {
+  set controller(StreamController<T> controller) { // ignore: avoid_setters_without_getters
     setController(controller);
   }