packages/flutter_test/test/controller_test.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:ui';

 import 'package:flutter/semantics.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/gestures.dart';

 class TestDragData {
   const TestDragData(
     this.slop,
     this.dragDistance,
     this.expectedOffsets,
   );

   final Offset slop;
   final Offset dragDistance;
   final List<Offset> expectedOffsets;
 }

 void main() {
   group('getSemanticsData', () {
     testWidgets('throws when there are no semantics', (WidgetTester tester) async {
       await tester.pumpWidget(
         const MaterialApp(
           home: Scaffold(
             body: Text('hello'),
           ),
         ),
       );

       expect(() => tester.getSemantics(find.text('hello')), throwsStateError);
     }, semanticsEnabled: false);

     testWidgets('throws when there are multiple results from the finder', (WidgetTester tester) async {
       final SemanticsHandle semanticsHandle = tester.ensureSemantics();

       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Row(
               children: const <Widget>[
                 Text('hello'),
                 Text('hello'),
               ],
             ),
           ),
         ),
       );

       expect(() => tester.getSemantics(find.text('hello')), throwsStateError);
       semanticsHandle.dispose();
     });

     testWidgets('Returns the correct SemanticsData', (WidgetTester tester) async {
       final SemanticsHandle semanticsHandle = tester.ensureSemantics();

       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: OutlinedButton(
                 onPressed: () { },
                 child: const Text('hello'),
             ),
           ),
         ),
       );

       final SemanticsNode node = tester.getSemantics(find.text('hello'));
       final SemanticsData semantics = node.getSemanticsData();
       expect(semantics.label, 'hello');
       expect(semantics.hasAction(SemanticsAction.tap), true);
       expect(semantics.hasFlag(SemanticsFlag.isButton), true);
       semanticsHandle.dispose();
     });

     testWidgets('Can enable semantics for tests via semanticsEnabled', (WidgetTester tester) async {
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: OutlinedButton(
                 onPressed: () { },
                 child: const Text('hello'),
             ),
           ),
         ),
       );

       final SemanticsNode node = tester.getSemantics(find.text('hello'));
       final SemanticsData semantics = node.getSemanticsData();
       expect(semantics.label, 'hello');
       expect(semantics.hasAction(SemanticsAction.tap), true);
       expect(semantics.hasFlag(SemanticsFlag.isButton), true);
     }, semanticsEnabled: true);

     testWidgets('Returns merged SemanticsData', (WidgetTester tester) async {
       final SemanticsHandle semanticsHandle = tester.ensureSemantics();
       const Key key = Key('test');
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Semantics(
               label: 'A',
               child: Semantics(
                 label: 'B',
                 child: Semantics(
                   key: key,
                   label: 'C',
                   child: Container(),
                 ),
               ),
             ),
           ),
         ),
       );

       final SemanticsNode node = tester.getSemantics(find.byKey(key));
       final SemanticsData semantics = node.getSemanticsData();
       expect(semantics.label, 'A\nB\nC');
       semanticsHandle.dispose();
     });

     testWidgets('Does not return partial semantics', (WidgetTester tester) async {
       final SemanticsHandle semanticsHandle = tester.ensureSemantics();
       final Key key = UniqueKey();
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: MergeSemantics(
               child: Semantics(
                 container: true,
                 label: 'A',
                 child: Semantics(
                   container: true,
                   key: key,
                   label: 'B',
                   child: Container(),
                 ),
               ),
             ),
           ),
         ),
       );

       final SemanticsNode node = tester.getSemantics(find.byKey(key));
       final SemanticsData semantics = node.getSemanticsData();
       expect(semantics.label, 'A\nB');
       semanticsHandle.dispose();
     });
   });

   testWidgets(
     'WidgetTester.drag must break the offset into multiple parallel components if '
     'the drag goes outside the touch slop values',
     (WidgetTester tester) async {
       // This test checks to make sure that the total drag will be correctly split into
       // pieces such that the first (and potentially second) moveBy function call(s) in
       // controller.drag() will never have a component greater than the touch
       // slop in that component's respective axis.
       const List<TestDragData> offsetResults = <TestDragData>[
         TestDragData(
           Offset(10.0, 10.0),
           Offset(-150.0, 200.0),
           <Offset>[
             Offset(-7.5, 10.0),
             Offset(-2.5, 3.333333333333333),
             Offset(-140.0, 186.66666666666666),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(150, -200),
           <Offset>[
             Offset(7.5, -10),
             Offset(2.5, -3.333333333333333),
             Offset(140.0, -186.66666666666666),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(-200, 150),
           <Offset>[
             Offset(-10, 7.5),
             Offset(-3.333333333333333, 2.5),
             Offset(-186.66666666666666, 140.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(200.0, -150.0),
           <Offset>[
             Offset(10, -7.5),
             Offset(3.333333333333333, -2.5),
             Offset(186.66666666666666, -140.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(-150.0, -200.0),
           <Offset>[
             Offset(-7.5, -10.0),
             Offset(-2.5, -3.333333333333333),
             Offset(-140.0, -186.66666666666666),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(8.0, 3.0),
           <Offset>[
             Offset(8.0, 3.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(3.0, 8.0),
           <Offset>[
             Offset(3.0, 8.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(20.0, 5.0),
           <Offset>[
             Offset(10.0, 2.5),
             Offset(10.0, 2.5),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(5.0, 20.0),
           <Offset>[
             Offset(2.5, 10.0),
             Offset(2.5, 10.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(20.0, 15.0),
           <Offset>[
             Offset(10.0, 7.5),
             Offset(3.333333333333333, 2.5),
             Offset(6.666666666666668, 5.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(15.0, 20.0),
           <Offset>[
             Offset(7.5, 10.0),
             Offset(2.5, 3.333333333333333),
             Offset(5.0, 6.666666666666668),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(20.0, 20.0),
           <Offset>[
             Offset(10.0, 10.0),
             Offset(10.0, 10.0),
           ],
         ),
         TestDragData(
           Offset(10.0, 10.0),
           Offset(0.0, 5.0),
           <Offset>[
             Offset(0.0, 5.0),
           ],
         ),

         //// Varying touch slops
         TestDragData(
           Offset(12.0, 5.0),
           Offset(0.0, 5.0),
           <Offset>[
             Offset(0.0, 5.0),
           ],
         ),
         TestDragData(
           Offset(12.0, 5.0),
           Offset(20.0, 5.0),
           <Offset>[
             Offset(12.0, 3.0),
             Offset(8.0, 2.0),
           ],
         ),
         TestDragData(
           Offset(12.0, 5.0),
           Offset(5.0, 20.0),
           <Offset>[
             Offset(1.25, 5.0),
             Offset(3.75, 15.0),
           ],
         ),
         TestDragData(
           Offset(5.0, 12.0),
           Offset(5.0, 20.0),
           <Offset>[
             Offset(3.0, 12.0),
             Offset(2.0, 8.0),
           ],
         ),
         TestDragData(
           Offset(5.0, 12.0),
           Offset(20.0, 5.0),
           <Offset>[
             Offset(5.0, 1.25),
             Offset(15.0, 3.75),
           ],
         ),
         TestDragData(
           Offset(18.0, 18.0),
           Offset(0.0, 150.0),
           <Offset>[
             Offset(0.0, 18.0),
             Offset(0.0, 132.0),
           ],
         ),
         TestDragData(
           Offset(18.0, 18.0),
           Offset(0.0, -150.0),
           <Offset>[
             Offset(0.0, -18.0),
             Offset(0.0, -132.0),
           ],
         ),
         TestDragData(
           Offset(18.0, 18.0),
           Offset(-150.0, 0.0),
           <Offset>[
             Offset(-18.0, 0.0),
             Offset(-132.0, 0.0),
           ],
         ),
         TestDragData(
           Offset.zero,
           Offset(-150.0, 0.0),
           <Offset>[
             Offset(-150.0, 0.0),
           ],
         ),
         TestDragData(
           Offset(18.0, 18.0),
           Offset(-32.0, 0.0),
           <Offset>[
             Offset(-18.0, 0.0),
             Offset(-14.0, 0.0),
           ],
         ),
       ];

       final List<Offset> dragOffsets = <Offset>[];

       await tester.pumpWidget(
         Listener(
           onPointerMove: (PointerMoveEvent event) {
             dragOffsets.add(event.delta);
           },
           child: const Text('test', textDirection: TextDirection.ltr),
         ),
       );

       for (int resultIndex = 0; resultIndex < offsetResults.length; resultIndex += 1) {
         final TestDragData testResult = offsetResults[resultIndex];
         await tester.drag(
           find.text('test'),
           testResult.dragDistance,
           touchSlopX: testResult.slop.dx,
           touchSlopY: testResult.slop.dy,
         );
         expect(
           testResult.expectedOffsets.length,
           dragOffsets.length,
           reason:
             'There is a difference in the number of expected and actual split offsets for the drag with:\n'
             'Touch Slop: ${testResult.slop}\n'
             'Delta:      ${testResult.dragDistance}\n',
         );
         for (int valueIndex = 0; valueIndex < offsetResults[resultIndex].expectedOffsets.length; valueIndex += 1) {
           expect(
             testResult.expectedOffsets[valueIndex],
             offsetMoreOrLessEquals(dragOffsets[valueIndex]),
             reason:
               'There is a difference in the expected and actual value of the ' +
               (valueIndex == 2 ? 'first' : valueIndex == 3 ? 'second' : 'third') +
               ' split offset for the drag with:\n'
               'Touch slop: ${testResult.slop}\n'
               'Delta:      ${testResult.dragDistance}\n'
           );
         }
         dragOffsets.clear();
       }
     },
   );

   testWidgets(
     'WidgetTester.tap must respect buttons',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
             onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
             onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.tap(find.text('test'), buttons: kSecondaryMouseButton);

       const String b = '$kSecondaryMouseButton';
       for(int i = 0; i < logs.length; i++) {
         if (i == 0)
           expect(logs[i], 'down $b');
         else if (i != logs.length - 1)
           expect(logs[i], 'move $b');
         else
           expect(logs[i], 'up 0');
       }
     },
   );

   testWidgets(
     'WidgetTester.press must respect buttons',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
             onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
             onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.press(find.text('test'), buttons: kSecondaryMouseButton);

       const String b = '$kSecondaryMouseButton';
       expect(logs, equals(<String>['down $b']));
     },
   );

   testWidgets(
     'WidgetTester.longPress must respect buttons',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
             onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
             onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.longPress(find.text('test'), buttons: kSecondaryMouseButton);
       await tester.pumpAndSettle();

       const String b = '$kSecondaryMouseButton';
       for(int i = 0; i < logs.length; i++) {
         if (i == 0)
           expect(logs[i], 'down $b');
         else if (i != logs.length - 1)
           expect(logs[i], 'move $b');
         else
           expect(logs[i], 'up 0');
       }
     },
   );

   testWidgets(
     'WidgetTester.drag must respect buttons',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
             onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
             onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.drag(find.text('test'), const Offset(-150.0, 200.0), buttons: kSecondaryMouseButton);

       const String b = '$kSecondaryMouseButton';
       for(int i = 0; i < logs.length; i++) {
         if (i == 0)
           expect(logs[i], 'down $b');
         else if (i != logs.length - 1)
           expect(logs[i], 'move $b');
         else
           expect(logs[i], 'up 0');
       }
     },
   );

   testWidgets(
     'WidgetTester.fling must respect buttons',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
             onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
             onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.fling(find.text('test'), const Offset(-10.0, 0.0), 1000.0, buttons: kSecondaryMouseButton);
       await tester.pumpAndSettle();

       const String b = '$kSecondaryMouseButton';
       for(int i = 0; i < logs.length; i++) {
         if (i == 0)
           expect(logs[i], 'down $b');
         else if (i != logs.length - 1)
           expect(logs[i], 'move $b');
         else
           expect(logs[i], 'up 0');
       }
     },
   );

   testWidgets(
     'WidgetTester.fling produces strictly monotonically increasing timestamps, '
     'when given a large velocity',
     (WidgetTester tester) async {
       // Velocity trackers may misbehave if the `PointerMoveEvent`s' have the
       // same timestamp. This is more likely to happen when the velocity tracker
       // has a small sample size.
       final List<Duration> logs = <Duration>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerMove: (PointerMoveEvent event) => logs.add(event.timeStamp),
             child: const Text('test'),
           ),
         ),
       );

       await tester.fling(find.text('test'), const Offset(0.0, -50.0), 10000.0);
       await tester.pumpAndSettle();

       for (int i = 0; i + 1 < logs.length; i += 1) {
         expect(logs[i + 1],  greaterThan(logs[i]));
       }
   });

   testWidgets(
     'WidgetTester.timedDrag must respect buttons',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
             onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
             onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.timedDrag(
         find.text('test'),
         const Offset(-200.0, 0.0),
         const Duration(seconds: 1),
         buttons: kSecondaryMouseButton,
       );
       await tester.pumpAndSettle();

       const String b = '$kSecondaryMouseButton';
       for(int i = 0; i < logs.length; i++) {
         if (i == 0)
           expect(logs[i], 'down $b');
         else if (i != logs.length - 1)
           expect(logs[i], 'move $b');
         else
           expect(logs[i], 'up 0');
       }
     },
   );

   testWidgets(
     'WidgetTester.timedDrag uses correct pointer',
     (WidgetTester tester) async {
       final List<String> logs = <String>[];

       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
           child: Listener(
             onPointerDown: (PointerDownEvent event) => logs.add('down ${event.pointer}'),
             child: const Text('test'),
           ),
         ),
       );

       await tester.timedDrag(
         find.text('test'),
         const Offset(-200.0, 0.0),
         const Duration(seconds: 1),
         buttons: kSecondaryMouseButton,
       );
       await tester.pumpAndSettle();

       await tester.timedDrag(
         find.text('test'),
         const Offset(200.0, 0.0),
         const Duration(seconds: 1),
         buttons: kSecondaryMouseButton,
       );
       await tester.pumpAndSettle();

       expect(logs.length, 2);
       expect(logs[0], isNotNull);
       expect(logs[1], isNotNull);
       expect(logs[1] != logs[0], isTrue);
     },
   );

   testWidgets(
     'ensureVisible: scrolls to make widget visible',
     (WidgetTester tester) async {
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: ListView.builder(
               itemCount: 20,
               shrinkWrap: true,
               itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item $i')),
             ),
           ),
         ),
       );

       // Make sure widget isn't on screen
       expect(find.text('Item 15', skipOffstage: true), findsNothing);

       await tester.ensureVisible(find.text('Item 15', skipOffstage: false));
       await tester.pumpAndSettle();

       expect(find.text('Item 15', skipOffstage: true), findsOneWidget);
     },
   );

   group('scrollUntilVisible: scrolls to make unbuilt widget visible', () {
     testWidgets(
       'Vertical',
       (WidgetTester tester) async {
         await tester.pumpWidget(
           MaterialApp(
             home: Scaffold(
               body: ListView.builder(
                 itemCount: 50,
                 shrinkWrap: true,
                 itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item $i')),
               ),
             ),
           ),
         );

         // Make sure widget isn't built yet.
         expect(find.text('Item 45', skipOffstage: false), findsNothing);

         await tester.scrollUntilVisible(
           find.text('Item 45', skipOffstage: false),
           100,
         );
         await tester.pumpAndSettle();

         // Now the widget is on screen.
         expect(find.text('Item 45', skipOffstage: true), findsOneWidget);
       },
     );

     testWidgets(
       'Horizontal',
       (WidgetTester tester) async {
         await tester.pumpWidget(
           MaterialApp(
             home: Scaffold(
               body: ListView.builder(
                 itemCount: 50,
                 shrinkWrap: true,
                 scrollDirection: Axis.horizontal,
                 // ListTile does not support horizontal list
                 itemBuilder: (BuildContext context, int i) => Text('Item $i'),
               ),
             ),
           ),
         );

         // Make sure widget isn't built yet.
         expect(find.text('Item 45', skipOffstage: false), findsNothing);

         await tester.scrollUntilVisible(
           find.text('Item 45', skipOffstage: false),
           100,
         );
         await tester.pumpAndSettle();

         // Now the widget is on screen.
         expect(find.text('Item 45', skipOffstage: true), findsOneWidget);
       },
     );

     testWidgets(
       'Fail',
       (WidgetTester tester) async {
         await tester.pumpWidget(
           MaterialApp(
             home: Scaffold(
               body: ListView.builder(
                 itemCount: 50,
                 shrinkWrap: true,
                 itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item $i')),
               ),
             ),
           ),
         );

         try {
           await tester.scrollUntilVisible(
             find.text('Item 55', skipOffstage: false),
             100,
           );
         } on StateError catch (e) {
           expect(e.message, 'No element');
         }
       },
     );

     testWidgets('Drag Until Visible', (WidgetTester tester) async {
       // when there are two implicit [Scrollable], `scrollUntilVisible` is hard
       // to use.
       await tester.pumpWidget(
         MaterialApp(
           home: Scaffold(
             body: Column(
               children: <Widget>[
                 SizedBox(height: 200, child: ListView.builder(
                   key: const Key('listView-a'),
                   itemCount: 50,
                   shrinkWrap: true,
                   itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item a-$i')),
                 )),
                 const Divider(thickness: 5),
                 Expanded(child: ListView.builder(
                   key: const Key('listView-b'),
                   itemCount: 50,
                   shrinkWrap: true,
                   itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item b-$i')),
                 )),
               ],
             ),
           ),
         ),
       );
       await tester.pumpAndSettle();
       expect(find.byType(Scrollable), findsNWidgets(2));

       // Make sure widget isn't built yet.
       expect(find.text('Item b-45', skipOffstage: false), findsNothing);

       await tester.dragUntilVisible(
         find.text('Item b-45', skipOffstage: false),
         find.byKey(const ValueKey<String>('listView-b')),
         const Offset(0, -100),
       );
       await tester.pumpAndSettle();

       // Now the widget is on screen.
       expect(find.text('Item b-45', skipOffstage: true), findsOneWidget);
     });
   });
 }
	// 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:ui';

	import 'package:flutter/semantics.dart';
	import 'package:flutter/material.dart';
	import 'package:flutter_test/flutter_test.dart';
	import 'package:flutter/gestures.dart';

	class TestDragData {
	const TestDragData(
	this.slop,
	this.dragDistance,
	this.expectedOffsets,
	);

	final Offset slop;
	final Offset dragDistance;
	final List<Offset> expectedOffsets;
	}

	void main() {
	group('getSemanticsData', () {
	testWidgets('throws when there are no semantics', (WidgetTester tester) async {
	await tester.pumpWidget(
	const MaterialApp(
	home: Scaffold(
	body: Text('hello'),
	),
	),
	);

	expect(() => tester.getSemantics(find.text('hello')), throwsStateError);
	}, semanticsEnabled: false);

	testWidgets('throws when there are multiple results from the finder', (WidgetTester tester) async {
	final SemanticsHandle semanticsHandle = tester.ensureSemantics();

	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Row(
	children: const <Widget>[
	Text('hello'),
	Text('hello'),
	],
	),
	),
	),
	);

	expect(() => tester.getSemantics(find.text('hello')), throwsStateError);
	semanticsHandle.dispose();
	});

	testWidgets('Returns the correct SemanticsData', (WidgetTester tester) async {
	final SemanticsHandle semanticsHandle = tester.ensureSemantics();

	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: OutlinedButton(
	onPressed: () { },
	child: const Text('hello'),
	),
	),
	),
	);

	final SemanticsNode node = tester.getSemantics(find.text('hello'));
	final SemanticsData semantics = node.getSemanticsData();
	expect(semantics.label, 'hello');
	expect(semantics.hasAction(SemanticsAction.tap), true);
	expect(semantics.hasFlag(SemanticsFlag.isButton), true);
	semanticsHandle.dispose();
	});

	testWidgets('Can enable semantics for tests via semanticsEnabled', (WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: OutlinedButton(
	onPressed: () { },
	child: const Text('hello'),
	),
	),
	),
	);

	final SemanticsNode node = tester.getSemantics(find.text('hello'));
	final SemanticsData semantics = node.getSemanticsData();
	expect(semantics.label, 'hello');
	expect(semantics.hasAction(SemanticsAction.tap), true);
	expect(semantics.hasFlag(SemanticsFlag.isButton), true);
	}, semanticsEnabled: true);

	testWidgets('Returns merged SemanticsData', (WidgetTester tester) async {
	final SemanticsHandle semanticsHandle = tester.ensureSemantics();
	const Key key = Key('test');
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Semantics(
	label: 'A',
	child: Semantics(
	label: 'B',
	child: Semantics(
	key: key,
	label: 'C',
	child: Container(),
	),
	),
	),
	),
	),
	);

	final SemanticsNode node = tester.getSemantics(find.byKey(key));
	final SemanticsData semantics = node.getSemanticsData();
	expect(semantics.label, 'A\nB\nC');
	semanticsHandle.dispose();
	});

	testWidgets('Does not return partial semantics', (WidgetTester tester) async {
	final SemanticsHandle semanticsHandle = tester.ensureSemantics();
	final Key key = UniqueKey();
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: MergeSemantics(
	child: Semantics(
	container: true,
	label: 'A',
	child: Semantics(
	container: true,
	key: key,
	label: 'B',
	child: Container(),
	),
	),
	),
	),
	),
	);

	final SemanticsNode node = tester.getSemantics(find.byKey(key));
	final SemanticsData semantics = node.getSemanticsData();
	expect(semantics.label, 'A\nB');
	semanticsHandle.dispose();
	});
	});

	testWidgets(
	'WidgetTester.drag must break the offset into multiple parallel components if '
	'the drag goes outside the touch slop values',
	(WidgetTester tester) async {
	// This test checks to make sure that the total drag will be correctly split into
	// pieces such that the first (and potentially second) moveBy function call(s) in
	// controller.drag() will never have a component greater than the touch
	// slop in that component's respective axis.
	const List<TestDragData> offsetResults = <TestDragData>[
	TestDragData(
	Offset(10.0, 10.0),
	Offset(-150.0, 200.0),
	<Offset>[
	Offset(-7.5, 10.0),
	Offset(-2.5, 3.333333333333333),
	Offset(-140.0, 186.66666666666666),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(150, -200),
	<Offset>[
	Offset(7.5, -10),
	Offset(2.5, -3.333333333333333),
	Offset(140.0, -186.66666666666666),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(-200, 150),
	<Offset>[
	Offset(-10, 7.5),
	Offset(-3.333333333333333, 2.5),
	Offset(-186.66666666666666, 140.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(200.0, -150.0),
	<Offset>[
	Offset(10, -7.5),
	Offset(3.333333333333333, -2.5),
	Offset(186.66666666666666, -140.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(-150.0, -200.0),
	<Offset>[
	Offset(-7.5, -10.0),
	Offset(-2.5, -3.333333333333333),
	Offset(-140.0, -186.66666666666666),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(8.0, 3.0),
	<Offset>[
	Offset(8.0, 3.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(3.0, 8.0),
	<Offset>[
	Offset(3.0, 8.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(20.0, 5.0),
	<Offset>[
	Offset(10.0, 2.5),
	Offset(10.0, 2.5),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(5.0, 20.0),
	<Offset>[
	Offset(2.5, 10.0),
	Offset(2.5, 10.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(20.0, 15.0),
	<Offset>[
	Offset(10.0, 7.5),
	Offset(3.333333333333333, 2.5),
	Offset(6.666666666666668, 5.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(15.0, 20.0),
	<Offset>[
	Offset(7.5, 10.0),
	Offset(2.5, 3.333333333333333),
	Offset(5.0, 6.666666666666668),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(20.0, 20.0),
	<Offset>[
	Offset(10.0, 10.0),
	Offset(10.0, 10.0),
	],
	),
	TestDragData(
	Offset(10.0, 10.0),
	Offset(0.0, 5.0),
	<Offset>[
	Offset(0.0, 5.0),
	],
	),

	//// Varying touch slops
	TestDragData(
	Offset(12.0, 5.0),
	Offset(0.0, 5.0),
	<Offset>[
	Offset(0.0, 5.0),
	],
	),
	TestDragData(
	Offset(12.0, 5.0),
	Offset(20.0, 5.0),
	<Offset>[
	Offset(12.0, 3.0),
	Offset(8.0, 2.0),
	],
	),
	TestDragData(
	Offset(12.0, 5.0),
	Offset(5.0, 20.0),
	<Offset>[
	Offset(1.25, 5.0),
	Offset(3.75, 15.0),
	],
	),
	TestDragData(
	Offset(5.0, 12.0),
	Offset(5.0, 20.0),
	<Offset>[
	Offset(3.0, 12.0),
	Offset(2.0, 8.0),
	],
	),
	TestDragData(
	Offset(5.0, 12.0),
	Offset(20.0, 5.0),
	<Offset>[
	Offset(5.0, 1.25),
	Offset(15.0, 3.75),
	],
	),
	TestDragData(
	Offset(18.0, 18.0),
	Offset(0.0, 150.0),
	<Offset>[
	Offset(0.0, 18.0),
	Offset(0.0, 132.0),
	],
	),
	TestDragData(
	Offset(18.0, 18.0),
	Offset(0.0, -150.0),
	<Offset>[
	Offset(0.0, -18.0),
	Offset(0.0, -132.0),
	],
	),
	TestDragData(
	Offset(18.0, 18.0),
	Offset(-150.0, 0.0),
	<Offset>[
	Offset(-18.0, 0.0),
	Offset(-132.0, 0.0),
	],
	),
	TestDragData(
	Offset.zero,
	Offset(-150.0, 0.0),
	<Offset>[
	Offset(-150.0, 0.0),
	],
	),
	TestDragData(
	Offset(18.0, 18.0),
	Offset(-32.0, 0.0),
	<Offset>[
	Offset(-18.0, 0.0),
	Offset(-14.0, 0.0),
	],
	),
	];

	final List<Offset> dragOffsets = <Offset>[];

	await tester.pumpWidget(
	Listener(
	onPointerMove: (PointerMoveEvent event) {
	dragOffsets.add(event.delta);
	},
	child: const Text('test', textDirection: TextDirection.ltr),
	),
	);

	for (int resultIndex = 0; resultIndex < offsetResults.length; resultIndex += 1) {
	final TestDragData testResult = offsetResults[resultIndex];
	await tester.drag(
	find.text('test'),
	testResult.dragDistance,
	touchSlopX: testResult.slop.dx,
	touchSlopY: testResult.slop.dy,
	);
	expect(
	testResult.expectedOffsets.length,
	dragOffsets.length,
	reason:
	'There is a difference in the number of expected and actual split offsets for the drag with:\n'
	'Touch Slop: ${testResult.slop}\n'
	'Delta: ${testResult.dragDistance}\n',
	);
	for (int valueIndex = 0; valueIndex < offsetResults[resultIndex].expectedOffsets.length; valueIndex += 1) {
	expect(
	testResult.expectedOffsets[valueIndex],
	offsetMoreOrLessEquals(dragOffsets[valueIndex]),
	reason:
	'There is a difference in the expected and actual value of the ' +
	(valueIndex == 2 ? 'first' : valueIndex == 3 ? 'second' : 'third') +
	' split offset for the drag with:\n'
	'Touch slop: ${testResult.slop}\n'
	'Delta: ${testResult.dragDistance}\n'
	);
	}
	dragOffsets.clear();
	}
	},
	);

	testWidgets(
	'WidgetTester.tap must respect buttons',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
	onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
	onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
	child: const Text('test'),
	),
	),
	);

	await tester.tap(find.text('test'), buttons: kSecondaryMouseButton);

	const String b = '$kSecondaryMouseButton';
	for(int i = 0; i < logs.length; i++) {
	if (i == 0)
	expect(logs[i], 'down $b');
	else if (i != logs.length - 1)
	expect(logs[i], 'move $b');
	else
	expect(logs[i], 'up 0');
	}
	},
	);

	testWidgets(
	'WidgetTester.press must respect buttons',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
	onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
	onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
	child: const Text('test'),
	),
	),
	);

	await tester.press(find.text('test'), buttons: kSecondaryMouseButton);

	const String b = '$kSecondaryMouseButton';
	expect(logs, equals(<String>['down $b']));
	},
	);

	testWidgets(
	'WidgetTester.longPress must respect buttons',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
	onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
	onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
	child: const Text('test'),
	),
	),
	);

	await tester.longPress(find.text('test'), buttons: kSecondaryMouseButton);
	await tester.pumpAndSettle();

	const String b = '$kSecondaryMouseButton';
	for(int i = 0; i < logs.length; i++) {
	if (i == 0)
	expect(logs[i], 'down $b');
	else if (i != logs.length - 1)
	expect(logs[i], 'move $b');
	else
	expect(logs[i], 'up 0');
	}
	},
	);

	testWidgets(
	'WidgetTester.drag must respect buttons',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
	onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
	onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
	child: const Text('test'),
	),
	),
	);

	await tester.drag(find.text('test'), const Offset(-150.0, 200.0), buttons: kSecondaryMouseButton);

	const String b = '$kSecondaryMouseButton';
	for(int i = 0; i < logs.length; i++) {
	if (i == 0)
	expect(logs[i], 'down $b');
	else if (i != logs.length - 1)
	expect(logs[i], 'move $b');
	else
	expect(logs[i], 'up 0');
	}
	},
	);

	testWidgets(
	'WidgetTester.fling must respect buttons',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
	onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
	onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
	child: const Text('test'),
	),
	),
	);

	await tester.fling(find.text('test'), const Offset(-10.0, 0.0), 1000.0, buttons: kSecondaryMouseButton);
	await tester.pumpAndSettle();

	const String b = '$kSecondaryMouseButton';
	for(int i = 0; i < logs.length; i++) {
	if (i == 0)
	expect(logs[i], 'down $b');
	else if (i != logs.length - 1)
	expect(logs[i], 'move $b');
	else
	expect(logs[i], 'up 0');
	}
	},
	);

	testWidgets(
	'WidgetTester.fling produces strictly monotonically increasing timestamps, '
	'when given a large velocity',
	(WidgetTester tester) async {
	// Velocity trackers may misbehave if the `PointerMoveEvent`s' have the
	// same timestamp. This is more likely to happen when the velocity tracker
	// has a small sample size.
	final List<Duration> logs = <Duration>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerMove: (PointerMoveEvent event) => logs.add(event.timeStamp),
	child: const Text('test'),
	),
	),
	);

	await tester.fling(find.text('test'), const Offset(0.0, -50.0), 10000.0);
	await tester.pumpAndSettle();

	for (int i = 0; i + 1 < logs.length; i += 1) {
	expect(logs[i + 1], greaterThan(logs[i]));
	}
	});

	testWidgets(
	'WidgetTester.timedDrag must respect buttons',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.buttons}'),
	onPointerMove: (PointerMoveEvent event) => logs.add('move ${event.buttons}'),
	onPointerUp: (PointerUpEvent event) => logs.add('up ${event.buttons}'),
	child: const Text('test'),
	),
	),
	);

	await tester.timedDrag(
	find.text('test'),
	const Offset(-200.0, 0.0),
	const Duration(seconds: 1),
	buttons: kSecondaryMouseButton,
	);
	await tester.pumpAndSettle();

	const String b = '$kSecondaryMouseButton';
	for(int i = 0; i < logs.length; i++) {
	if (i == 0)
	expect(logs[i], 'down $b');
	else if (i != logs.length - 1)
	expect(logs[i], 'move $b');
	else
	expect(logs[i], 'up 0');
	}
	},
	);

	testWidgets(
	'WidgetTester.timedDrag uses correct pointer',
	(WidgetTester tester) async {
	final List<String> logs = <String>[];

	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Listener(
	onPointerDown: (PointerDownEvent event) => logs.add('down ${event.pointer}'),
	child: const Text('test'),
	),
	),
	);

	await tester.timedDrag(
	find.text('test'),
	const Offset(-200.0, 0.0),
	const Duration(seconds: 1),
	buttons: kSecondaryMouseButton,
	);
	await tester.pumpAndSettle();

	await tester.timedDrag(
	find.text('test'),
	const Offset(200.0, 0.0),
	const Duration(seconds: 1),
	buttons: kSecondaryMouseButton,
	);
	await tester.pumpAndSettle();

	expect(logs.length, 2);
	expect(logs[0], isNotNull);
	expect(logs[1], isNotNull);
	expect(logs[1] != logs[0], isTrue);
	},
	);

	testWidgets(
	'ensureVisible: scrolls to make widget visible',
	(WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: ListView.builder(
	itemCount: 20,
	shrinkWrap: true,
	itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item $i')),
	),
	),
	),
	);

	// Make sure widget isn't on screen
	expect(find.text('Item 15', skipOffstage: true), findsNothing);

	await tester.ensureVisible(find.text('Item 15', skipOffstage: false));
	await tester.pumpAndSettle();

	expect(find.text('Item 15', skipOffstage: true), findsOneWidget);
	},
	);

	group('scrollUntilVisible: scrolls to make unbuilt widget visible', () {
	testWidgets(
	'Vertical',
	(WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: ListView.builder(
	itemCount: 50,
	shrinkWrap: true,
	itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item $i')),
	),
	),
	),
	);

	// Make sure widget isn't built yet.
	expect(find.text('Item 45', skipOffstage: false), findsNothing);

	await tester.scrollUntilVisible(
	find.text('Item 45', skipOffstage: false),
	100,
	);
	await tester.pumpAndSettle();

	// Now the widget is on screen.
	expect(find.text('Item 45', skipOffstage: true), findsOneWidget);
	},
	);

	testWidgets(
	'Horizontal',
	(WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: ListView.builder(
	itemCount: 50,
	shrinkWrap: true,
	scrollDirection: Axis.horizontal,
	// ListTile does not support horizontal list
	itemBuilder: (BuildContext context, int i) => Text('Item $i'),
	),
	),
	),
	);

	// Make sure widget isn't built yet.
	expect(find.text('Item 45', skipOffstage: false), findsNothing);

	await tester.scrollUntilVisible(
	find.text('Item 45', skipOffstage: false),
	100,
	);
	await tester.pumpAndSettle();

	// Now the widget is on screen.
	expect(find.text('Item 45', skipOffstage: true), findsOneWidget);
	},
	);

	testWidgets(
	'Fail',
	(WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: ListView.builder(
	itemCount: 50,
	shrinkWrap: true,
	itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item $i')),
	),
	),
	),
	);

	try {
	await tester.scrollUntilVisible(
	find.text('Item 55', skipOffstage: false),
	100,
	);
	} on StateError catch (e) {
	expect(e.message, 'No element');
	}
	},
	);

	testWidgets('Drag Until Visible', (WidgetTester tester) async {
	// when there are two implicit [Scrollable], `scrollUntilVisible` is hard
	// to use.
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	body: Column(
	children: <Widget>[
	SizedBox(height: 200, child: ListView.builder(
	key: const Key('listView-a'),
	itemCount: 50,
	shrinkWrap: true,
	itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item a-$i')),
	)),
	const Divider(thickness: 5),
	Expanded(child: ListView.builder(
	key: const Key('listView-b'),
	itemCount: 50,
	shrinkWrap: true,
	itemBuilder: (BuildContext context, int i) => ListTile(title: Text('Item b-$i')),
	)),
	],
	),
	),
	),
	);
	await tester.pumpAndSettle();
	expect(find.byType(Scrollable), findsNWidgets(2));

	// Make sure widget isn't built yet.
	expect(find.text('Item b-45', skipOffstage: false), findsNothing);

	await tester.dragUntilVisible(
	find.text('Item b-45', skipOffstage: false),
	find.byKey(const ValueKey<String>('listView-b')),
	const Offset(0, -100),
	);
	await tester.pumpAndSettle();

	// Now the widget is on screen.
	expect(find.text('Item b-45', skipOffstage: true), findsOneWidget);
	});
	});
	}