packages/animations/test/modal_test.dart - mirrors/packages - Git at Google

 // Copyright 2013 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:ui' as ui;

 import 'package:animations/src/modal.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';

 void main() {
   testWidgets(
     'showModal builds a new route with specified barrier properties',
     (WidgetTester tester) async {
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: ElevatedButton(
                   onPressed: () {
                     showModal<void>(
                       context: context,
                       configuration: _TestModalConfiguration(),
                       builder: (BuildContext context) {
                         return const _FlutterLogoModal();
                       },
                     );
                   },
                   child: const Icon(Icons.add),
                 ),
               );
             }),
           ),
         ),
       );
       await tester.tap(find.byType(ElevatedButton));
       await tester.pumpAndSettle();

       // New route containing _FlutterLogoModal is present.
       expect(find.byType(_FlutterLogoModal), findsOneWidget);
       final ModalBarrier topModalBarrier = tester.widget<ModalBarrier>(
         find.byType(ModalBarrier).at(1),
       );

       // Verify new route's modal barrier properties are correct.
       expect(topModalBarrier.color, Colors.green);
       expect(topModalBarrier.barrierSemanticsDismissible, true);
       expect(topModalBarrier.semanticsLabel, 'customLabel');
     },
   );

   testWidgets(
     'showModal forwards animation',
     (WidgetTester tester) async {
       final GlobalKey key = GlobalKey();
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: ElevatedButton(
                   onPressed: () {
                     showModal<void>(
                       context: context,
                       configuration: _TestModalConfiguration(),
                       builder: (BuildContext context) {
                         return _FlutterLogoModal(key: key);
                       },
                     );
                   },
                   child: const Icon(Icons.add),
                 ),
               );
             }),
           ),
         ),
       );

       // Start forwards animation
       await tester.tap(find.byType(ElevatedButton));
       await tester.pump();

       // Opacity duration: Linear transition throughout 300ms
       double topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 0.0);

       // Halfway through forwards animation.
       await tester.pump(const Duration(milliseconds: 150));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 0.5);

       // The end of the transition.
       await tester.pump(const Duration(milliseconds: 150));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 1.0);

       await tester.pump(const Duration(milliseconds: 1));
       expect(find.byType(_FlutterLogoModal), findsOneWidget);
     },
   );

   testWidgets(
     'showModal reverse animation',
     (WidgetTester tester) async {
       final GlobalKey key = GlobalKey();
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: ElevatedButton(
                   onPressed: () {
                     showModal<void>(
                       context: context,
                       configuration: _TestModalConfiguration(),
                       builder: (BuildContext context) {
                         return _FlutterLogoModal(key: key);
                       },
                     );
                   },
                   child: const Icon(Icons.add),
                 ),
               );
             }),
           ),
         ),
       );

       // Start forwards animation
       await tester.tap(find.byType(ElevatedButton));
       await tester.pumpAndSettle();
       expect(find.byType(_FlutterLogoModal), findsOneWidget);

       await tester.tapAt(Offset.zero);
       await tester.pump();

       // Opacity duration: Linear transition throughout 200ms
       double topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 1.0);

       // Halfway through forwards animation.
       await tester.pump(const Duration(milliseconds: 100));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 0.5);

       // The end of the transition.
       await tester.pump(const Duration(milliseconds: 100));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 0.0);

       await tester.pump(const Duration(milliseconds: 1));
       expect(find.byType(_FlutterLogoModal), findsNothing);
     },
   );

   testWidgets(
     'showModal builds a new route with specified barrier properties '
     'with default configuration(FadeScaleTransitionConfiguration)',
     (WidgetTester tester) async {
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: ElevatedButton(
                   onPressed: () {
                     showModal<void>(
                       context: context,
                       builder: (BuildContext context) {
                         return const _FlutterLogoModal();
                       },
                     );
                   },
                   child: const Icon(Icons.add),
                 ),
               );
             }),
           ),
         ),
       );
       await tester.tap(find.byType(ElevatedButton));
       await tester.pumpAndSettle();

       // New route containing _FlutterLogoModal is present.
       expect(find.byType(_FlutterLogoModal), findsOneWidget);
       final ModalBarrier topModalBarrier = tester.widget<ModalBarrier>(
         find.byType(ModalBarrier).at(1),
       );

       // Verify new route's modal barrier properties are correct.
       expect(topModalBarrier.color, Colors.black54);
       expect(topModalBarrier.barrierSemanticsDismissible, true);
       expect(topModalBarrier.semanticsLabel, 'Dismiss');
     },
   );

   testWidgets(
     'showModal forwards animation '
     'with default configuration(FadeScaleTransitionConfiguration)',
     (WidgetTester tester) async {
       final GlobalKey key = GlobalKey();
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: ElevatedButton(
                   onPressed: () {
                     showModal<void>(
                       context: context,
                       builder: (BuildContext context) {
                         return _FlutterLogoModal(key: key);
                       },
                     );
                   },
                   child: const Icon(Icons.add),
                 ),
               );
             }),
           ),
         ),
       );

       // Start forwards animation
       await tester.tap(find.byType(ElevatedButton));
       await tester.pump();

       // Opacity duration: First 30% of 150ms, linear transition
       double topFadeTransitionOpacity = _getOpacity(key, tester);
       double topScale = _getScale(key, tester);
       expect(topFadeTransitionOpacity, 0.0);
       expect(topScale, 0.80);

       // 3/10 * 150ms = 45ms (total opacity animation duration)
       // 1/2 * 45ms = ~23ms elapsed for halfway point of opacity
       // animation
       await tester.pump(const Duration(milliseconds: 23));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, closeTo(0.5, 0.05));
       topScale = _getScale(key, tester);
       expect(topScale, greaterThan(0.80));
       expect(topScale, lessThan(1.0));

       // End of opacity animation.
       await tester.pump(const Duration(milliseconds: 22));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 1.0);
       topScale = _getScale(key, tester);
       expect(topScale, greaterThan(0.80));
       expect(topScale, lessThan(1.0));

       // 100ms into the animation
       await tester.pump(const Duration(milliseconds: 55));
       topScale = _getScale(key, tester);
       expect(topScale, greaterThan(0.80));
       expect(topScale, lessThan(1.0));

       // Get to the end of the animation
       await tester.pump(const Duration(milliseconds: 50));
       topScale = _getScale(key, tester);
       expect(topScale, 1.0);

       await tester.pump(const Duration(milliseconds: 1));
       expect(find.byType(_FlutterLogoModal), findsOneWidget);
     },
   );

   testWidgets(
     'showModal reverse animation '
     'with default configuration(FadeScaleTransitionConfiguration)',
     (WidgetTester tester) async {
       final GlobalKey key = GlobalKey();
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: ElevatedButton(
                   onPressed: () {
                     showModal<void>(
                       context: context,
                       builder: (BuildContext context) {
                         return _FlutterLogoModal(key: key);
                       },
                     );
                   },
                   child: const Icon(Icons.add),
                 ),
               );
             }),
           ),
         ),
       );

       // Start forwards animation
       await tester.tap(find.byType(ElevatedButton));
       await tester.pumpAndSettle();
       expect(find.byType(_FlutterLogoModal), findsOneWidget);

       // Tap on modal barrier to start reverse animation.
       await tester.tapAt(Offset.zero);
       await tester.pump();

       // Opacity duration: Linear transition throughout 75ms
       // No scale animations on exit transition.
       double topFadeTransitionOpacity = _getOpacity(key, tester);
       double topScale = _getScale(key, tester);
       expect(topFadeTransitionOpacity, 1.0);
       expect(topScale, 1.0);

       await tester.pump(const Duration(milliseconds: 25));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       topScale = _getScale(key, tester);
       expect(topFadeTransitionOpacity, closeTo(0.66, 0.05));
       expect(topScale, 1.0);

       await tester.pump(const Duration(milliseconds: 25));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       topScale = _getScale(key, tester);
       expect(topFadeTransitionOpacity, closeTo(0.33, 0.05));
       expect(topScale, 1.0);

       // End of opacity animation
       await tester.pump(const Duration(milliseconds: 25));
       topFadeTransitionOpacity = _getOpacity(key, tester);
       expect(topFadeTransitionOpacity, 0.0);
       topScale = _getScale(key, tester);
       expect(topScale, 1.0);

       await tester.pump(const Duration(milliseconds: 1));
       expect(find.byType(_FlutterLogoModal), findsNothing);
     },
   );

   testWidgets(
     'State is not lost when transitioning',
     (WidgetTester tester) async {
       final GlobalKey bottomKey = GlobalKey();
       final GlobalKey topKey = GlobalKey();

       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Builder(builder: (BuildContext context) {
               return Center(
                 child: Column(
                   children: <Widget>[
                     ElevatedButton(
                       onPressed: () {
                         showModal<void>(
                           context: context,
                           configuration: _TestModalConfiguration(),
                           builder: (BuildContext context) {
                             return _FlutterLogoModal(
                               key: topKey,
                               name: 'top route',
                             );
                           },
                         );
                       },
                       child: const Icon(Icons.add),
                     ),
                     _FlutterLogoModal(
                       key: bottomKey,
                       name: 'bottom route',
                     ),
                   ],
                 ),
               );
             }),
           ),
         ),
       );

       // The bottom route's state should already exist.
       final _FlutterLogoModalState bottomState = tester.state(
         find.byKey(bottomKey),
       );
       expect(bottomState.widget.name, 'bottom route');

       // Start the enter transition of the modal route.
       await tester.tap(find.byType(ElevatedButton));
       await tester.pump();
       await tester.pump();

       // The bottom route's state should be retained at the start of the
       // transition.
       expect(
         tester.state(find.byKey(bottomKey)),
         bottomState,
       );
       // The top route's state should be created.
       final _FlutterLogoModalState topState = tester.state(
         find.byKey(topKey),
       );
       expect(topState.widget.name, 'top route');

       // Halfway point of forwards animation.
       await tester.pump(const Duration(milliseconds: 150));
       expect(
         tester.state(find.byKey(bottomKey)),
         bottomState,
       );
       expect(
         tester.state(find.byKey(topKey)),
         topState,
       );

       // End the transition and see if top and bottom routes'
       // states persist.
       await tester.pumpAndSettle();
       expect(
         tester.state(find.byKey(
           bottomKey,
           skipOffstage: false,
         )),
         bottomState,
       );
       expect(
         tester.state(find.byKey(topKey)),
         topState,
       );

       // Start the reverse animation. Both top and bottom
       // routes' states should persist.
       await tester.tapAt(Offset.zero);
       await tester.pump();
       expect(
         tester.state(find.byKey(bottomKey)),
         bottomState,
       );
       expect(
         tester.state(find.byKey(topKey)),
         topState,
       );

       // Halfway point of the exit transition.
       await tester.pump(const Duration(milliseconds: 100));
       expect(
         tester.state(find.byKey(bottomKey)),
         bottomState,
       );
       expect(
         tester.state(find.byKey(topKey)),
         topState,
       );

       // End the exit transition. The bottom route's state should
       // persist, whereas the top route's state should no longer
       // be present.
       await tester.pumpAndSettle();
       expect(
         tester.state(find.byKey(bottomKey)),
         bottomState,
       );
       expect(find.byKey(topKey), findsNothing);
     },
   );

   testWidgets(
     'showModal builds a new route with specified route settings',
     (WidgetTester tester) async {
       const RouteSettings routeSettings = RouteSettings(
         name: 'route-name',
         arguments: 'arguments',
       );

       final Widget button = Builder(builder: (BuildContext context) {
         return Center(
           child: ElevatedButton(
             onPressed: () {
               showModal<void>(
                 context: context,
                 configuration: _TestModalConfiguration(),
                 routeSettings: routeSettings,
                 builder: (BuildContext context) {
                   return const _FlutterLogoModal();
                 },
               );
             },
             child: const Icon(Icons.add),
           ),
         );
       });

       await tester.pumpWidget(_boilerplate(button));
       await tester.tap(find.byType(ElevatedButton));
       await tester.pumpAndSettle();

       // New route containing _FlutterLogoModal is present.
       expect(find.byType(_FlutterLogoModal), findsOneWidget);

       // Expect the last route pushed to the navigator to contain RouteSettings
       // equal to the RouteSettings passed to showModal
       final ModalRoute<dynamic> modalRoute = ModalRoute.of(
         tester.element(find.byType(_FlutterLogoModal)),
       )!;
       expect(modalRoute.settings, routeSettings);
     },
   );

   testWidgets(
     'showModal builds a new route with specified image filter',
     (WidgetTester tester) async {
       final ui.ImageFilter filter = ui.ImageFilter.blur(sigmaX: 1, sigmaY: 1);

       final Widget button = Builder(builder: (BuildContext context) {
         return Center(
           child: ElevatedButton(
             onPressed: () {
               showModal<void>(
                 context: context,
                 configuration: _TestModalConfiguration(),
                 filter: filter,
                 builder: (BuildContext context) {
                   return const _FlutterLogoModal();
                 },
               );
             },
             child: const Icon(Icons.add),
           ),
         );
       });

       await tester.pumpWidget(_boilerplate(button));
       await tester.tap(find.byType(ElevatedButton));
       await tester.pumpAndSettle();

       // New route containing _FlutterLogoModal is present.
       expect(find.byType(_FlutterLogoModal), findsOneWidget);
       final BackdropFilter backdropFilter = tester.widget<BackdropFilter>(
         find.byType(BackdropFilter),
       );

       // Verify new route's backdrop filter has been applied
       expect(backdropFilter.filter, filter);
     },
   );
 }

 Widget _boilerplate(Widget child) => MaterialApp(home: Scaffold(body: child));

 double _getOpacity(GlobalKey key, WidgetTester tester) {
   final Finder finder = find.ancestor(
     of: find.byKey(key),
     matching: find.byType(FadeTransition),
   );
   return tester.widgetList(finder).fold<double>(1.0, (double a, Widget widget) {
     final FadeTransition transition = widget as FadeTransition;
     return a * transition.opacity.value;
   });
 }

 double _getScale(GlobalKey key, WidgetTester tester) {
   final Finder finder = find.ancestor(
     of: find.byKey(key),
     matching: find.byType(ScaleTransition),
   );
   return tester.widgetList(finder).fold<double>(1.0, (double a, Widget widget) {
     final ScaleTransition transition = widget as ScaleTransition;
     return a * transition.scale.value;
   });
 }

 class _FlutterLogoModal extends StatefulWidget {
   const _FlutterLogoModal({
     Key? key,
     this.name,
   }) : super(key: key);

   final String? name;

   @override
   _FlutterLogoModalState createState() => _FlutterLogoModalState();
 }

 class _FlutterLogoModalState extends State<_FlutterLogoModal> {
   @override
   Widget build(BuildContext context) {
     return const Center(
       child: SizedBox(
         width: 250,
         height: 250,
         child: Material(
           child: Center(
             child: FlutterLogo(size: 250),
           ),
         ),
       ),
     );
   }
 }

 class _TestModalConfiguration extends ModalConfiguration {
   _TestModalConfiguration({
     Color barrierColor = Colors.green,
     bool barrierDismissible = true,
     String barrierLabel = 'customLabel',
     Duration transitionDuration = const Duration(milliseconds: 300),
     Duration reverseTransitionDuration = const Duration(milliseconds: 200),
   }) : super(
           barrierColor: barrierColor,
           barrierDismissible: barrierDismissible,
           barrierLabel: barrierLabel,
           transitionDuration: transitionDuration,
           reverseTransitionDuration: reverseTransitionDuration,
         );

   @override
   Widget transitionBuilder(
     BuildContext context,
     Animation<double> animation,
     Animation<double> secondaryAnimation,
     Widget child,
   ) {
     return FadeTransition(
       opacity: animation,
       child: child,
     );
   }
 }
	// Copyright 2013 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:ui' as ui;

	import 'package:animations/src/modal.dart';
	import 'package:flutter/material.dart';
	import 'package:flutter_test/flutter_test.dart';

	void main() {
	testWidgets(
	'showModal builds a new route with specified barrier properties',
	(WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	configuration: _TestModalConfiguration(),
	builder: (BuildContext context) {
	return const _FlutterLogoModal();
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	}),
	),
	),
	);
	await tester.tap(find.byType(ElevatedButton));
	await tester.pumpAndSettle();

	// New route containing _FlutterLogoModal is present.
	expect(find.byType(_FlutterLogoModal), findsOneWidget);
	final ModalBarrier topModalBarrier = tester.widget<ModalBarrier>(
	find.byType(ModalBarrier).at(1),
	);

	// Verify new route's modal barrier properties are correct.
	expect(topModalBarrier.color, Colors.green);
	expect(topModalBarrier.barrierSemanticsDismissible, true);
	expect(topModalBarrier.semanticsLabel, 'customLabel');
	},
	);

	testWidgets(
	'showModal forwards animation',
	(WidgetTester tester) async {
	final GlobalKey key = GlobalKey();
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	configuration: _TestModalConfiguration(),
	builder: (BuildContext context) {
	return _FlutterLogoModal(key: key);
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	}),
	),
	),
	);

	// Start forwards animation
	await tester.tap(find.byType(ElevatedButton));
	await tester.pump();

	// Opacity duration: Linear transition throughout 300ms
	double topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 0.0);

	// Halfway through forwards animation.
	await tester.pump(const Duration(milliseconds: 150));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 0.5);

	// The end of the transition.
	await tester.pump(const Duration(milliseconds: 150));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 1.0);

	await tester.pump(const Duration(milliseconds: 1));
	expect(find.byType(_FlutterLogoModal), findsOneWidget);
	},
	);

	testWidgets(
	'showModal reverse animation',
	(WidgetTester tester) async {
	final GlobalKey key = GlobalKey();
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	configuration: _TestModalConfiguration(),
	builder: (BuildContext context) {
	return _FlutterLogoModal(key: key);
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	}),
	),
	),
	);

	// Start forwards animation
	await tester.tap(find.byType(ElevatedButton));
	await tester.pumpAndSettle();
	expect(find.byType(_FlutterLogoModal), findsOneWidget);

	await tester.tapAt(Offset.zero);
	await tester.pump();

	// Opacity duration: Linear transition throughout 200ms
	double topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 1.0);

	// Halfway through forwards animation.
	await tester.pump(const Duration(milliseconds: 100));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 0.5);

	// The end of the transition.
	await tester.pump(const Duration(milliseconds: 100));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 0.0);

	await tester.pump(const Duration(milliseconds: 1));
	expect(find.byType(_FlutterLogoModal), findsNothing);
	},
	);

	testWidgets(
	'showModal builds a new route with specified barrier properties '
	'with default configuration(FadeScaleTransitionConfiguration)',
	(WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	builder: (BuildContext context) {
	return const _FlutterLogoModal();
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	}),
	),
	),
	);
	await tester.tap(find.byType(ElevatedButton));
	await tester.pumpAndSettle();

	// New route containing _FlutterLogoModal is present.
	expect(find.byType(_FlutterLogoModal), findsOneWidget);
	final ModalBarrier topModalBarrier = tester.widget<ModalBarrier>(
	find.byType(ModalBarrier).at(1),
	);

	// Verify new route's modal barrier properties are correct.
	expect(topModalBarrier.color, Colors.black54);
	expect(topModalBarrier.barrierSemanticsDismissible, true);
	expect(topModalBarrier.semanticsLabel, 'Dismiss');
	},
	);

	testWidgets(
	'showModal forwards animation '
	'with default configuration(FadeScaleTransitionConfiguration)',
	(WidgetTester tester) async {
	final GlobalKey key = GlobalKey();
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	builder: (BuildContext context) {
	return _FlutterLogoModal(key: key);
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	}),
	),
	),
	);

	// Start forwards animation
	await tester.tap(find.byType(ElevatedButton));
	await tester.pump();

	// Opacity duration: First 30% of 150ms, linear transition
	double topFadeTransitionOpacity = _getOpacity(key, tester);
	double topScale = _getScale(key, tester);
	expect(topFadeTransitionOpacity, 0.0);
	expect(topScale, 0.80);

	// 3/10 * 150ms = 45ms (total opacity animation duration)
	// 1/2 * 45ms = ~23ms elapsed for halfway point of opacity
	// animation
	await tester.pump(const Duration(milliseconds: 23));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, closeTo(0.5, 0.05));
	topScale = _getScale(key, tester);
	expect(topScale, greaterThan(0.80));
	expect(topScale, lessThan(1.0));

	// End of opacity animation.
	await tester.pump(const Duration(milliseconds: 22));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 1.0);
	topScale = _getScale(key, tester);
	expect(topScale, greaterThan(0.80));
	expect(topScale, lessThan(1.0));

	// 100ms into the animation
	await tester.pump(const Duration(milliseconds: 55));
	topScale = _getScale(key, tester);
	expect(topScale, greaterThan(0.80));
	expect(topScale, lessThan(1.0));

	// Get to the end of the animation
	await tester.pump(const Duration(milliseconds: 50));
	topScale = _getScale(key, tester);
	expect(topScale, 1.0);

	await tester.pump(const Duration(milliseconds: 1));
	expect(find.byType(_FlutterLogoModal), findsOneWidget);
	},
	);

	testWidgets(
	'showModal reverse animation '
	'with default configuration(FadeScaleTransitionConfiguration)',
	(WidgetTester tester) async {
	final GlobalKey key = GlobalKey();
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	builder: (BuildContext context) {
	return _FlutterLogoModal(key: key);
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	}),
	),
	),
	);

	// Start forwards animation
	await tester.tap(find.byType(ElevatedButton));
	await tester.pumpAndSettle();
	expect(find.byType(_FlutterLogoModal), findsOneWidget);

	// Tap on modal barrier to start reverse animation.
	await tester.tapAt(Offset.zero);
	await tester.pump();

	// Opacity duration: Linear transition throughout 75ms
	// No scale animations on exit transition.
	double topFadeTransitionOpacity = _getOpacity(key, tester);
	double topScale = _getScale(key, tester);
	expect(topFadeTransitionOpacity, 1.0);
	expect(topScale, 1.0);

	await tester.pump(const Duration(milliseconds: 25));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	topScale = _getScale(key, tester);
	expect(topFadeTransitionOpacity, closeTo(0.66, 0.05));
	expect(topScale, 1.0);

	await tester.pump(const Duration(milliseconds: 25));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	topScale = _getScale(key, tester);
	expect(topFadeTransitionOpacity, closeTo(0.33, 0.05));
	expect(topScale, 1.0);

	// End of opacity animation
	await tester.pump(const Duration(milliseconds: 25));
	topFadeTransitionOpacity = _getOpacity(key, tester);
	expect(topFadeTransitionOpacity, 0.0);
	topScale = _getScale(key, tester);
	expect(topScale, 1.0);

	await tester.pump(const Duration(milliseconds: 1));
	expect(find.byType(_FlutterLogoModal), findsNothing);
	},
	);

	testWidgets(
	'State is not lost when transitioning',
	(WidgetTester tester) async {
	final GlobalKey bottomKey = GlobalKey();
	final GlobalKey topKey = GlobalKey();

	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Builder(builder: (BuildContext context) {
	return Center(
	child: Column(
	children: <Widget>[
	ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	configuration: _TestModalConfiguration(),
	builder: (BuildContext context) {
	return _FlutterLogoModal(
	key: topKey,
	name: 'top route',
	);
	},
	);
	},
	child: const Icon(Icons.add),
	),
	_FlutterLogoModal(
	key: bottomKey,
	name: 'bottom route',
	),
	],
	),
	);
	}),
	),
	),
	);

	// The bottom route's state should already exist.
	final _FlutterLogoModalState bottomState = tester.state(
	find.byKey(bottomKey),
	);
	expect(bottomState.widget.name, 'bottom route');

	// Start the enter transition of the modal route.
	await tester.tap(find.byType(ElevatedButton));
	await tester.pump();
	await tester.pump();

	// The bottom route's state should be retained at the start of the
	// transition.
	expect(
	tester.state(find.byKey(bottomKey)),
	bottomState,
	);
	// The top route's state should be created.
	final _FlutterLogoModalState topState = tester.state(
	find.byKey(topKey),
	);
	expect(topState.widget.name, 'top route');

	// Halfway point of forwards animation.
	await tester.pump(const Duration(milliseconds: 150));
	expect(
	tester.state(find.byKey(bottomKey)),
	bottomState,
	);
	expect(
	tester.state(find.byKey(topKey)),
	topState,
	);

	// End the transition and see if top and bottom routes'
	// states persist.
	await tester.pumpAndSettle();
	expect(
	tester.state(find.byKey(
	bottomKey,
	skipOffstage: false,
	)),
	bottomState,
	);
	expect(
	tester.state(find.byKey(topKey)),
	topState,
	);

	// Start the reverse animation. Both top and bottom
	// routes' states should persist.
	await tester.tapAt(Offset.zero);
	await tester.pump();
	expect(
	tester.state(find.byKey(bottomKey)),
	bottomState,
	);
	expect(
	tester.state(find.byKey(topKey)),
	topState,
	);

	// Halfway point of the exit transition.
	await tester.pump(const Duration(milliseconds: 100));
	expect(
	tester.state(find.byKey(bottomKey)),
	bottomState,
	);
	expect(
	tester.state(find.byKey(topKey)),
	topState,
	);

	// End the exit transition. The bottom route's state should
	// persist, whereas the top route's state should no longer
	// be present.
	await tester.pumpAndSettle();
	expect(
	tester.state(find.byKey(bottomKey)),
	bottomState,
	);
	expect(find.byKey(topKey), findsNothing);
	},
	);

	testWidgets(
	'showModal builds a new route with specified route settings',
	(WidgetTester tester) async {
	const RouteSettings routeSettings = RouteSettings(
	name: 'route-name',
	arguments: 'arguments',
	);

	final Widget button = Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	configuration: _TestModalConfiguration(),
	routeSettings: routeSettings,
	builder: (BuildContext context) {
	return const _FlutterLogoModal();
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	});

	await tester.pumpWidget(_boilerplate(button));
	await tester.tap(find.byType(ElevatedButton));
	await tester.pumpAndSettle();

	// New route containing _FlutterLogoModal is present.
	expect(find.byType(_FlutterLogoModal), findsOneWidget);

	// Expect the last route pushed to the navigator to contain RouteSettings
	// equal to the RouteSettings passed to showModal
	final ModalRoute<dynamic> modalRoute = ModalRoute.of(
	tester.element(find.byType(_FlutterLogoModal)),
	)!;
	expect(modalRoute.settings, routeSettings);
	},
	);

	testWidgets(
	'showModal builds a new route with specified image filter',
	(WidgetTester tester) async {
	final ui.ImageFilter filter = ui.ImageFilter.blur(sigmaX: 1, sigmaY: 1);

	final Widget button = Builder(builder: (BuildContext context) {
	return Center(
	child: ElevatedButton(
	onPressed: () {
	showModal<void>(
	context: context,
	configuration: _TestModalConfiguration(),
	filter: filter,
	builder: (BuildContext context) {
	return const _FlutterLogoModal();
	},
	);
	},
	child: const Icon(Icons.add),
	),
	);
	});

	await tester.pumpWidget(_boilerplate(button));
	await tester.tap(find.byType(ElevatedButton));
	await tester.pumpAndSettle();

	// New route containing _FlutterLogoModal is present.
	expect(find.byType(_FlutterLogoModal), findsOneWidget);
	final BackdropFilter backdropFilter = tester.widget<BackdropFilter>(
	find.byType(BackdropFilter),
	);

	// Verify new route's backdrop filter has been applied
	expect(backdropFilter.filter, filter);
	},
	);
	}

	Widget _boilerplate(Widget child) => MaterialApp(home: Scaffold(body: child));

	double _getOpacity(GlobalKey key, WidgetTester tester) {
	final Finder finder = find.ancestor(
	of: find.byKey(key),
	matching: find.byType(FadeTransition),
	);
	return tester.widgetList(finder).fold<double>(1.0, (double a, Widget widget) {
	final FadeTransition transition = widget as FadeTransition;
	return a * transition.opacity.value;
	});
	}

	double _getScale(GlobalKey key, WidgetTester tester) {
	final Finder finder = find.ancestor(
	of: find.byKey(key),
	matching: find.byType(ScaleTransition),
	);
	return tester.widgetList(finder).fold<double>(1.0, (double a, Widget widget) {
	final ScaleTransition transition = widget as ScaleTransition;
	return a * transition.scale.value;
	});
	}

	class _FlutterLogoModal extends StatefulWidget {
	const _FlutterLogoModal({
	Key? key,
	this.name,
	}) : super(key: key);

	final String? name;

	@override
	_FlutterLogoModalState createState() => _FlutterLogoModalState();
	}

	class _FlutterLogoModalState extends State<_FlutterLogoModal> {
	@override
	Widget build(BuildContext context) {
	return const Center(
	child: SizedBox(
	width: 250,
	height: 250,
	child: Material(
	child: Center(
	child: FlutterLogo(size: 250),
	),
	),
	),
	);
	}
	}

	class _TestModalConfiguration extends ModalConfiguration {
	_TestModalConfiguration({
	Color barrierColor = Colors.green,
	bool barrierDismissible = true,
	String barrierLabel = 'customLabel',
	Duration transitionDuration = const Duration(milliseconds: 300),
	Duration reverseTransitionDuration = const Duration(milliseconds: 200),
	}) : super(
	barrierColor: barrierColor,
	barrierDismissible: barrierDismissible,
	barrierLabel: barrierLabel,
	transitionDuration: transitionDuration,
	reverseTransitionDuration: reverseTransitionDuration,
	);

	@override
	Widget transitionBuilder(
	BuildContext context,
	Animation<double> animation,
	Animation<double> secondaryAnimation,
	Widget child,
	) {
	return FadeTransition(
	opacity: animation,
	child: child,
	);
	}
	}