packages/flutter/test/rendering/rendering_tester.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:async';

 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart' show EnginePhase, TestDefaultBinaryMessengerBinding, fail;

 export 'package:flutter/foundation.dart' show FlutterError, FlutterErrorDetails;
 export 'package:flutter_test/flutter_test.dart' show EnginePhase, TestDefaultBinaryMessengerBinding;

 class TestRenderingFlutterBinding extends BindingBase with SchedulerBinding, ServicesBinding, GestureBinding, PaintingBinding, SemanticsBinding, RendererBinding, TestDefaultBinaryMessengerBinding {
   /// Creates a binding for testing rendering library functionality.
   ///
   /// If [onErrors] is not null, it is called if [FlutterError] caught any errors
   /// while drawing the frame. If [onErrors] is null and [FlutterError] caught at least
   /// one error, this function fails the test. A test may override [onErrors] and
   /// inspect errors using [takeFlutterErrorDetails].
   ///
   /// Errors caught between frames will cause the test to fail unless
   /// [FlutterError.onError] has been overridden.
   TestRenderingFlutterBinding({ this.onErrors }) {
     FlutterError.onError = (FlutterErrorDetails details) {
       FlutterError.dumpErrorToConsole(details);
       Zone.current.parent!.handleUncaughtError(details.exception, details.stack!);
     };
   }

   /// The current [TestRenderingFlutterBinding], if one has been created.
   ///
   /// Provides access to the features exposed by this binding. The binding must
   /// be initialized before using this getter; this is typically done by calling
   /// [TestRenderingFlutterBinding.ensureInitialized].
   static TestRenderingFlutterBinding get instance => BindingBase.checkInstance(_instance);
   static TestRenderingFlutterBinding? _instance;

   @override
   void initInstances() {
     super.initInstances();
     _instance = this;
   }

   /// Creates and initializes the binding. This function is
   /// idempotent; calling it a second time will just return the
   /// previously-created instance.
   static TestRenderingFlutterBinding ensureInitialized({ VoidCallback? onErrors }) {
     if (_instance != null) {
       return _instance!;
     }
     return TestRenderingFlutterBinding(onErrors: onErrors);
   }

   final List<FlutterErrorDetails> _errors = <FlutterErrorDetails>[];

   /// A function called after drawing a frame if [FlutterError] caught any errors.
   ///
   /// This function is expected to inspect these errors and decide whether they
   /// are expected or not. Use [takeFlutterErrorDetails] to take one error at a
   /// time, or [takeAllFlutterErrorDetails] to iterate over all errors.
   VoidCallback? onErrors;

   /// Returns the error least recently caught by [FlutterError] and removes it
   /// from the list of captured errors.
   ///
   /// Returns null if no errors were captures, or if the list was exhausted by
   /// calling this method repeatedly.
   FlutterErrorDetails? takeFlutterErrorDetails() {
     if (_errors.isEmpty) {
       return null;
     }
     return _errors.removeAt(0);
   }

   /// Returns all error details caught by [FlutterError] from least recently caught to
   /// most recently caught, and removes them from the list of captured errors.
   ///
   /// The returned iterable takes errors lazily. If, for example, you iterate over 2
   /// errors, but there are 5 errors total, this binding will still fail the test.
   /// Tests are expected to take and inspect all errors.
   Iterable<FlutterErrorDetails> takeAllFlutterErrorDetails() sync* {
     // sync* and yield are used for lazy evaluation. Otherwise, the list would be
     // drained eagerly and allow a test pass with unexpected errors.
     while (_errors.isNotEmpty) {
       yield _errors.removeAt(0);
     }
   }

   /// Returns all exceptions caught by [FlutterError] from least recently caught to
   /// most recently caught, and removes them from the list of captured errors.
   ///
   /// The returned iterable takes errors lazily. If, for example, you iterate over 2
   /// errors, but there are 5 errors total, this binding will still fail the test.
   /// Tests are expected to take and inspect all errors.
   Iterable<dynamic> takeAllFlutterExceptions() sync* {
     // sync* and yield are used for lazy evaluation. Otherwise, the list would be
     // drained eagerly and allow a test pass with unexpected errors.
     while (_errors.isNotEmpty) {
       yield _errors.removeAt(0).exception;
     }
   }

   EnginePhase phase = EnginePhase.composite;

   /// Pumps a frame and runs its entire life cycle.
   ///
   /// This method runs all of the [SchedulerPhase]s in a frame, this is useful
   /// to test [SchedulerPhase.postFrameCallbacks].
   void pumpCompleteFrame() {
     final FlutterExceptionHandler? oldErrorHandler = FlutterError.onError;
     FlutterError.onError = (FlutterErrorDetails details) {
       _errors.add(details);
     };
     try {
       TestRenderingFlutterBinding.instance.handleBeginFrame(null);
       TestRenderingFlutterBinding.instance.handleDrawFrame();
     } finally {
       FlutterError.onError = oldErrorHandler;
       if (_errors.isNotEmpty) {
         if (onErrors != null) {
           onErrors!();
           if (_errors.isNotEmpty) {
             _errors.forEach(FlutterError.dumpErrorToConsole);
             fail('There are more errors than the test inspected using TestRenderingFlutterBinding.takeFlutterErrorDetails.');
           }
         } else {
           _errors.forEach(FlutterError.dumpErrorToConsole);
           fail('Caught error while rendering frame. See preceding logs for details.');
         }
       }
     }
   }

   @override
   void drawFrame() {
     assert(phase != EnginePhase.build, 'rendering_tester does not support testing the build phase; use flutter_test instead');
     final FlutterExceptionHandler? oldErrorHandler = FlutterError.onError;
     FlutterError.onError = (FlutterErrorDetails details) {
       _errors.add(details);
     };
     try {
       pipelineOwner.flushLayout();
       if (phase == EnginePhase.layout) {
         return;
       }
       pipelineOwner.flushCompositingBits();
       if (phase == EnginePhase.compositingBits) {
         return;
       }
       pipelineOwner.flushPaint();
       if (phase == EnginePhase.paint) {
         return;
       }
       renderView.compositeFrame();
       if (phase == EnginePhase.composite) {
         return;
       }
       pipelineOwner.flushSemantics();
       if (phase == EnginePhase.flushSemantics) {
         return;
       }
       assert(phase == EnginePhase.flushSemantics || phase == EnginePhase.sendSemanticsUpdate);
     } finally {
       FlutterError.onError = oldErrorHandler;
       if (_errors.isNotEmpty) {
         if (onErrors != null) {
           onErrors!();
           if (_errors.isNotEmpty) {
             _errors.forEach(FlutterError.dumpErrorToConsole);
             fail('There are more errors than the test inspected using TestRenderingFlutterBinding.takeFlutterErrorDetails.');
           }
         } else {
           _errors.forEach(FlutterError.dumpErrorToConsole);
           fail('Caught error while rendering frame. See preceding logs for details.');
         }
       }
     }
   }
 }

 /// Place the box in the render tree, at the given size and with the given
 /// alignment on the screen.
 ///
 /// If you've updated `box` and want to lay it out again, use [pumpFrame].
 ///
 /// Once a particular [RenderBox] has been passed to [layout], it cannot easily
 /// be put in a different place in the tree or passed to [layout] again, because
 /// [layout] places the given object into another [RenderBox] which you would
 /// need to unparent it from (but that box isn't itself made available).
 ///
 /// The EnginePhase must not be [EnginePhase.build], since the rendering layer
 /// has no build phase.
 ///
 /// If `onErrors` is not null, it is set as [TestRenderingFlutterBinding.onError].
 void layout(
   RenderBox box, {
   BoxConstraints? constraints,
   Alignment alignment = Alignment.center,
   EnginePhase phase = EnginePhase.layout,
   VoidCallback? onErrors,
 }) {
   assert(box != null); // If you want to just repump the last box, call pumpFrame().
   assert(box.parent == null); // We stick the box in another, so you can't reuse it easily, sorry.

   TestRenderingFlutterBinding.instance.renderView.child = null;
   if (constraints != null) {
     box = RenderPositionedBox(
       alignment: alignment,
       child: RenderConstrainedBox(
         additionalConstraints: constraints,
         child: box,
       ),
     );
   }
   TestRenderingFlutterBinding.instance.renderView.child = box;

   pumpFrame(phase: phase, onErrors: onErrors);
 }

 /// Pumps a single frame.
 ///
 /// If `onErrors` is not null, it is set as [TestRenderingFlutterBinding.onError].
 void pumpFrame({ EnginePhase phase = EnginePhase.layout, VoidCallback? onErrors }) {
   assert(TestRenderingFlutterBinding.instance != null);
   assert(TestRenderingFlutterBinding.instance.renderView != null);
   assert(TestRenderingFlutterBinding.instance.renderView.child != null); // call layout() first!

   if (onErrors != null) {
     TestRenderingFlutterBinding.instance.onErrors = onErrors;
   }

   TestRenderingFlutterBinding.instance.phase = phase;
   TestRenderingFlutterBinding.instance.drawFrame();
 }

 class TestCallbackPainter extends CustomPainter {
   const TestCallbackPainter({ required this.onPaint });

   final VoidCallback onPaint;

   @override
   void paint(Canvas canvas, Size size) {
     onPaint();
   }

   @override
   bool shouldRepaint(TestCallbackPainter oldPainter) => true;
 }

 class RenderSizedBox extends RenderBox {
   RenderSizedBox(this._size);

   final Size _size;

   @override
   double computeMinIntrinsicWidth(double height) {
     return _size.width;
   }

   @override
   double computeMaxIntrinsicWidth(double height) {
     return _size.width;
   }

   @override
   double computeMinIntrinsicHeight(double width) {
     return _size.height;
   }

   @override
   double computeMaxIntrinsicHeight(double width) {
     return _size.height;
   }

   @override
   bool get sizedByParent => true;

   @override
   void performResize() {
     size = constraints.constrain(_size);
   }

   @override
   void performLayout() { }

   @override
   bool hitTestSelf(Offset position) => true;
 }

 class FakeTickerProvider implements TickerProvider {
   @override
   Ticker createTicker(TickerCallback onTick, [ bool disableAnimations = false ]) {
     return FakeTicker();
   }
 }

 class FakeTicker implements Ticker {
   @override
   bool muted = false;

   @override
   void absorbTicker(Ticker originalTicker) { }

   @override
   String? get debugLabel => null;

   @override
   bool get isActive => throw UnimplementedError();

   @override
   bool get isTicking => throw UnimplementedError();

   @override
   bool get scheduled => throw UnimplementedError();

   @override
   bool get shouldScheduleTick => throw UnimplementedError();

   @override
   void dispose() { }

   @override
   void scheduleTick({ bool rescheduling = false }) { }

   @override
   TickerFuture start() {
     throw UnimplementedError();
   }

   @override
   void stop({ bool canceled = false }) { }

   @override
   void unscheduleTick() { }

   @override
   String toString({ bool debugIncludeStack = false }) => super.toString();

   @override
   DiagnosticsNode describeForError(String name) {
     return DiagnosticsProperty<Ticker>(name, this, style: DiagnosticsTreeStyle.errorProperty);
   }
 }

 class TestClipPaintingContext extends PaintingContext {
   TestClipPaintingContext() : super(ContainerLayer(), Rect.zero);

   @override
   ClipRectLayer? pushClipRect(
     bool needsCompositing,
     Offset offset,
     Rect clipRect,
     PaintingContextCallback painter, {
     Clip clipBehavior = Clip.hardEdge,
     ClipRectLayer? oldLayer,
   }) {
     this.clipBehavior = clipBehavior;
     return null;
   }

   Clip clipBehavior = Clip.none;
 }

 class TestPushLayerPaintingContext extends PaintingContext {
   TestPushLayerPaintingContext() : super(ContainerLayer(), Rect.zero);

   final List<ContainerLayer> pushedLayers = <ContainerLayer>[];

   @override
   void pushLayer(
     ContainerLayer childLayer,
     PaintingContextCallback painter,
     Offset offset, {
     Rect? childPaintBounds
   }) {
     pushedLayers.add(childLayer);
     super.pushLayer(childLayer, painter, offset, childPaintBounds: childPaintBounds);
   }
 }

 // Absorbs errors that don't have "overflowed" in their error details.
 void absorbOverflowedErrors() {
   final Iterable<FlutterErrorDetails> errorDetails = TestRenderingFlutterBinding.instance.takeAllFlutterErrorDetails();
   final Iterable<FlutterErrorDetails> filtered = errorDetails.where((FlutterErrorDetails details) {
     return !details.toString().contains('overflowed');
   });
   if (filtered.isNotEmpty) {
     filtered.forEach(FlutterError.reportError);
   }
 }

 // Reports any FlutterErrors.
 void expectNoFlutterErrors() {
   final Iterable<FlutterErrorDetails> errorDetails = TestRenderingFlutterBinding.instance.takeAllFlutterErrorDetails();
   errorDetails.forEach(FlutterError.reportError);
 }

 RenderConstrainedBox get box200x200 =>
     RenderConstrainedBox(additionalConstraints: const BoxConstraints.tightFor(height: 200.0, width: 200.0));
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:async';

	import 'package:flutter/foundation.dart';
	import 'package:flutter/gestures.dart';
	import 'package:flutter/rendering.dart';
	import 'package:flutter/scheduler.dart';
	import 'package:flutter/services.dart';
	import 'package:flutter_test/flutter_test.dart' show EnginePhase, TestDefaultBinaryMessengerBinding, fail;

	export 'package:flutter/foundation.dart' show FlutterError, FlutterErrorDetails;
	export 'package:flutter_test/flutter_test.dart' show EnginePhase, TestDefaultBinaryMessengerBinding;

	class TestRenderingFlutterBinding extends BindingBase with SchedulerBinding, ServicesBinding, GestureBinding, PaintingBinding, SemanticsBinding, RendererBinding, TestDefaultBinaryMessengerBinding {
	/// Creates a binding for testing rendering library functionality.
	///
	/// If [onErrors] is not null, it is called if [FlutterError] caught any errors
	/// while drawing the frame. If [onErrors] is null and [FlutterError] caught at least
	/// one error, this function fails the test. A test may override [onErrors] and
	/// inspect errors using [takeFlutterErrorDetails].
	///
	/// Errors caught between frames will cause the test to fail unless
	/// [FlutterError.onError] has been overridden.
	TestRenderingFlutterBinding({ this.onErrors }) {
	FlutterError.onError = (FlutterErrorDetails details) {
	FlutterError.dumpErrorToConsole(details);
	Zone.current.parent!.handleUncaughtError(details.exception, details.stack!);
	};
	}

	/// The current [TestRenderingFlutterBinding], if one has been created.
	///
	/// Provides access to the features exposed by this binding. The binding must
	/// be initialized before using this getter; this is typically done by calling
	/// [TestRenderingFlutterBinding.ensureInitialized].
	static TestRenderingFlutterBinding get instance => BindingBase.checkInstance(_instance);
	static TestRenderingFlutterBinding? _instance;

	@override
	void initInstances() {
	super.initInstances();
	_instance = this;
	}

	/// Creates and initializes the binding. This function is
	/// idempotent; calling it a second time will just return the
	/// previously-created instance.
	static TestRenderingFlutterBinding ensureInitialized({ VoidCallback? onErrors }) {
	if (_instance != null) {
	return _instance!;
	}
	return TestRenderingFlutterBinding(onErrors: onErrors);
	}

	final List<FlutterErrorDetails> _errors = <FlutterErrorDetails>[];

	/// A function called after drawing a frame if [FlutterError] caught any errors.
	///
	/// This function is expected to inspect these errors and decide whether they
	/// are expected or not. Use [takeFlutterErrorDetails] to take one error at a
	/// time, or [takeAllFlutterErrorDetails] to iterate over all errors.
	VoidCallback? onErrors;

	/// Returns the error least recently caught by [FlutterError] and removes it
	/// from the list of captured errors.
	///
	/// Returns null if no errors were captures, or if the list was exhausted by
	/// calling this method repeatedly.
	FlutterErrorDetails? takeFlutterErrorDetails() {
	if (_errors.isEmpty) {
	return null;
	}
	return _errors.removeAt(0);
	}

	/// Returns all error details caught by [FlutterError] from least recently caught to
	/// most recently caught, and removes them from the list of captured errors.
	///
	/// The returned iterable takes errors lazily. If, for example, you iterate over 2
	/// errors, but there are 5 errors total, this binding will still fail the test.
	/// Tests are expected to take and inspect all errors.
	Iterable<FlutterErrorDetails> takeAllFlutterErrorDetails() sync* {
	// sync* and yield are used for lazy evaluation. Otherwise, the list would be
	// drained eagerly and allow a test pass with unexpected errors.
	while (_errors.isNotEmpty) {
	yield _errors.removeAt(0);
	}
	}

	/// Returns all exceptions caught by [FlutterError] from least recently caught to
	/// most recently caught, and removes them from the list of captured errors.
	///
	/// The returned iterable takes errors lazily. If, for example, you iterate over 2
	/// errors, but there are 5 errors total, this binding will still fail the test.
	/// Tests are expected to take and inspect all errors.
	Iterable<dynamic> takeAllFlutterExceptions() sync* {
	// sync* and yield are used for lazy evaluation. Otherwise, the list would be
	// drained eagerly and allow a test pass with unexpected errors.
	while (_errors.isNotEmpty) {
	yield _errors.removeAt(0).exception;
	}
	}

	EnginePhase phase = EnginePhase.composite;

	/// Pumps a frame and runs its entire life cycle.
	///
	/// This method runs all of the [SchedulerPhase]s in a frame, this is useful
	/// to test [SchedulerPhase.postFrameCallbacks].
	void pumpCompleteFrame() {
	final FlutterExceptionHandler? oldErrorHandler = FlutterError.onError;
	FlutterError.onError = (FlutterErrorDetails details) {
	_errors.add(details);
	};
	try {
	TestRenderingFlutterBinding.instance.handleBeginFrame(null);
	TestRenderingFlutterBinding.instance.handleDrawFrame();
	} finally {
	FlutterError.onError = oldErrorHandler;
	if (_errors.isNotEmpty) {
	if (onErrors != null) {
	onErrors!();
	if (_errors.isNotEmpty) {
	_errors.forEach(FlutterError.dumpErrorToConsole);
	fail('There are more errors than the test inspected using TestRenderingFlutterBinding.takeFlutterErrorDetails.');
	}
	} else {
	_errors.forEach(FlutterError.dumpErrorToConsole);
	fail('Caught error while rendering frame. See preceding logs for details.');
	}
	}
	}
	}

	@override
	void drawFrame() {
	assert(phase != EnginePhase.build, 'rendering_tester does not support testing the build phase; use flutter_test instead');
	final FlutterExceptionHandler? oldErrorHandler = FlutterError.onError;
	FlutterError.onError = (FlutterErrorDetails details) {
	_errors.add(details);
	};
	try {
	pipelineOwner.flushLayout();
	if (phase == EnginePhase.layout) {
	return;
	}
	pipelineOwner.flushCompositingBits();
	if (phase == EnginePhase.compositingBits) {
	return;
	}
	pipelineOwner.flushPaint();
	if (phase == EnginePhase.paint) {
	return;
	}
	renderView.compositeFrame();
	if (phase == EnginePhase.composite) {
	return;
	}
	pipelineOwner.flushSemantics();
	if (phase == EnginePhase.flushSemantics) {
	return;
	}
	assert(phase == EnginePhase.flushSemantics \|\| phase == EnginePhase.sendSemanticsUpdate);
	} finally {
	FlutterError.onError = oldErrorHandler;
	if (_errors.isNotEmpty) {
	if (onErrors != null) {
	onErrors!();
	if (_errors.isNotEmpty) {
	_errors.forEach(FlutterError.dumpErrorToConsole);
	fail('There are more errors than the test inspected using TestRenderingFlutterBinding.takeFlutterErrorDetails.');
	}
	} else {
	_errors.forEach(FlutterError.dumpErrorToConsole);
	fail('Caught error while rendering frame. See preceding logs for details.');
	}
	}
	}
	}
	}

	/// Place the box in the render tree, at the given size and with the given
	/// alignment on the screen.
	///
	/// If you've updated `box` and want to lay it out again, use [pumpFrame].
	///
	/// Once a particular [RenderBox] has been passed to [layout], it cannot easily
	/// be put in a different place in the tree or passed to [layout] again, because
	/// [layout] places the given object into another [RenderBox] which you would
	/// need to unparent it from (but that box isn't itself made available).
	///
	/// The EnginePhase must not be [EnginePhase.build], since the rendering layer
	/// has no build phase.
	///
	/// If `onErrors` is not null, it is set as [TestRenderingFlutterBinding.onError].
	void layout(
	RenderBox box, {
	BoxConstraints? constraints,
	Alignment alignment = Alignment.center,
	EnginePhase phase = EnginePhase.layout,
	VoidCallback? onErrors,
	}) {
	assert(box != null); // If you want to just repump the last box, call pumpFrame().
	assert(box.parent == null); // We stick the box in another, so you can't reuse it easily, sorry.

	TestRenderingFlutterBinding.instance.renderView.child = null;
	if (constraints != null) {
	box = RenderPositionedBox(
	alignment: alignment,
	child: RenderConstrainedBox(
	additionalConstraints: constraints,
	child: box,
	),
	);
	}
	TestRenderingFlutterBinding.instance.renderView.child = box;

	pumpFrame(phase: phase, onErrors: onErrors);
	}

	/// Pumps a single frame.
	///
	/// If `onErrors` is not null, it is set as [TestRenderingFlutterBinding.onError].
	void pumpFrame({ EnginePhase phase = EnginePhase.layout, VoidCallback? onErrors }) {
	assert(TestRenderingFlutterBinding.instance != null);
	assert(TestRenderingFlutterBinding.instance.renderView != null);
	assert(TestRenderingFlutterBinding.instance.renderView.child != null); // call layout() first!

	if (onErrors != null) {
	TestRenderingFlutterBinding.instance.onErrors = onErrors;
	}

	TestRenderingFlutterBinding.instance.phase = phase;
	TestRenderingFlutterBinding.instance.drawFrame();
	}

	class TestCallbackPainter extends CustomPainter {
	const TestCallbackPainter({ required this.onPaint });

	final VoidCallback onPaint;

	@override
	void paint(Canvas canvas, Size size) {
	onPaint();
	}

	@override
	bool shouldRepaint(TestCallbackPainter oldPainter) => true;
	}

	class RenderSizedBox extends RenderBox {
	RenderSizedBox(this._size);

	final Size _size;

	@override
	double computeMinIntrinsicWidth(double height) {
	return _size.width;
	}

	@override
	double computeMaxIntrinsicWidth(double height) {
	return _size.width;
	}

	@override
	double computeMinIntrinsicHeight(double width) {
	return _size.height;
	}

	@override
	double computeMaxIntrinsicHeight(double width) {
	return _size.height;
	}

	@override
	bool get sizedByParent => true;

	@override
	void performResize() {
	size = constraints.constrain(_size);
	}

	@override
	void performLayout() { }

	@override
	bool hitTestSelf(Offset position) => true;
	}

	class FakeTickerProvider implements TickerProvider {
	@override
	Ticker createTicker(TickerCallback onTick, [ bool disableAnimations = false ]) {
	return FakeTicker();
	}
	}

	class FakeTicker implements Ticker {
	@override
	bool muted = false;

	@override
	void absorbTicker(Ticker originalTicker) { }

	@override
	String? get debugLabel => null;

	@override
	bool get isActive => throw UnimplementedError();

	@override
	bool get isTicking => throw UnimplementedError();

	@override
	bool get scheduled => throw UnimplementedError();

	@override
	bool get shouldScheduleTick => throw UnimplementedError();

	@override
	void dispose() { }

	@override
	void scheduleTick({ bool rescheduling = false }) { }

	@override
	TickerFuture start() {
	throw UnimplementedError();
	}

	@override
	void stop({ bool canceled = false }) { }

	@override
	void unscheduleTick() { }

	@override
	String toString({ bool debugIncludeStack = false }) => super.toString();

	@override
	DiagnosticsNode describeForError(String name) {
	return DiagnosticsProperty<Ticker>(name, this, style: DiagnosticsTreeStyle.errorProperty);
	}
	}

	class TestClipPaintingContext extends PaintingContext {
	TestClipPaintingContext() : super(ContainerLayer(), Rect.zero);

	@override
	ClipRectLayer? pushClipRect(
	bool needsCompositing,
	Offset offset,
	Rect clipRect,
	PaintingContextCallback painter, {
	Clip clipBehavior = Clip.hardEdge,
	ClipRectLayer? oldLayer,
	}) {
	this.clipBehavior = clipBehavior;
	return null;
	}

	Clip clipBehavior = Clip.none;
	}

	class TestPushLayerPaintingContext extends PaintingContext {
	TestPushLayerPaintingContext() : super(ContainerLayer(), Rect.zero);

	final List<ContainerLayer> pushedLayers = <ContainerLayer>[];

	@override
	void pushLayer(
	ContainerLayer childLayer,
	PaintingContextCallback painter,
	Offset offset, {
	Rect? childPaintBounds
	}) {
	pushedLayers.add(childLayer);
	super.pushLayer(childLayer, painter, offset, childPaintBounds: childPaintBounds);
	}
	}

	// Absorbs errors that don't have "overflowed" in their error details.
	void absorbOverflowedErrors() {
	final Iterable<FlutterErrorDetails> errorDetails = TestRenderingFlutterBinding.instance.takeAllFlutterErrorDetails();
	final Iterable<FlutterErrorDetails> filtered = errorDetails.where((FlutterErrorDetails details) {
	return !details.toString().contains('overflowed');
	});
	if (filtered.isNotEmpty) {
	filtered.forEach(FlutterError.reportError);
	}
	}

	// Reports any FlutterErrors.
	void expectNoFlutterErrors() {
	final Iterable<FlutterErrorDetails> errorDetails = TestRenderingFlutterBinding.instance.takeAllFlutterErrorDetails();
	errorDetails.forEach(FlutterError.reportError);
	}

	RenderConstrainedBox get box200x200 =>
	RenderConstrainedBox(additionalConstraints: const BoxConstraints.tightFor(height: 200.0, width: 200.0));