packages/flutter/test/widgets/inherited_model_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 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';

 // A simple "flat" InheritedModel: the data model is just 3 integer
 // valued fields: a, b, c.
 class ABCModel extends InheritedModel<String> {
   const ABCModel({
     Key? key,
     this.a,
     this.b,
     this.c,
     this.aspects,
     required Widget child,
   }) : super(key: key, child: child);

   final int? a;
   final int? b;
   final int? c;

   // The aspects (fields) of this model that widgets can depend on with
   // inheritFrom.
   //
   // This property is null by default, which means that the model supports
   // all 3 fields.
   final Set<String>? aspects;

   @override
   bool isSupportedAspect(Object aspect) {
     return aspect == null || aspects == null || aspects!.contains(aspect);
   }

   @override
   bool updateShouldNotify(ABCModel old) {
     return !setEquals<String>(aspects, old.aspects) || a != old.a || b != old.b || c != old.c;
   }

   @override
   bool updateShouldNotifyDependent(ABCModel old, Set<String> dependencies) {
     return !setEquals<String>(aspects, old.aspects)
         || (a != old.a && dependencies.contains('a'))
         || (b != old.b && dependencies.contains('b'))
         || (c != old.c && dependencies.contains('c'));
   }

   static ABCModel? of(BuildContext context, { String? fieldName }) {
     return InheritedModel.inheritFrom<ABCModel>(context, aspect: fieldName);
   }
 }

 class ShowABCField extends StatefulWidget {
   const ShowABCField({ Key? key, required this.fieldName }) : super(key: key);

   final String fieldName;

   @override
   State<ShowABCField> createState() => _ShowABCFieldState();
 }

 class _ShowABCFieldState extends State<ShowABCField> {
   int _buildCount = 0;

   @override
   Widget build(BuildContext context) {
     final ABCModel abc = ABCModel.of(context, fieldName: widget.fieldName)!;
     final int? value = widget.fieldName == 'a' ? abc.a : (widget.fieldName == 'b' ? abc.b : abc.c);
     return Text('${widget.fieldName}: $value [${_buildCount++}]');
   }
 }

 void main() {
   testWidgets('InheritedModel basics', (WidgetTester tester) async {
     int _a = 0;
     int _b = 1;
     int _c = 2;

     final Widget abcPage = StatefulBuilder(
       builder: (BuildContext context, StateSetter setState) {
         const Widget showA = ShowABCField(fieldName: 'a');
         const Widget showB = ShowABCField(fieldName: 'b');
         const Widget showC = ShowABCField(fieldName: 'c');

         // Unconditionally depends on the ABCModel: rebuilt when any
         // aspect of the model changes.
         final Widget showABC = Builder(
           builder: (BuildContext context) {
             final ABCModel abc = ABCModel.of(context)!;
             return Text('a: ${abc.a} b: ${abc.b} c: ${abc.c}');
           },
         );

         return Scaffold(
           body: StatefulBuilder(
             builder: (BuildContext context, StateSetter setState) {
               return ABCModel(
                 a: _a,
                 b: _b,
                 c: _c,
                 child: Center(
                   child: Column(
                     mainAxisSize: MainAxisSize.min,
                     children: <Widget>[
                       showA,
                       showB,
                       showC,
                       showABC,
                       ElevatedButton(
                         child: const Text('Increment a'),
                         onPressed: () {
                           // Rebuilds the ABCModel which triggers a rebuild
                           // of showA because showA depends on the 'a' aspect
                           // of the ABCModel.
                           setState(() { _a += 1; });
                         },
                       ),
                       ElevatedButton(
                         child: const Text('Increment b'),
                         onPressed: () {
                           // Rebuilds the ABCModel which triggers a rebuild
                           // of showB because showB depends on the 'b' aspect
                           // of the ABCModel.
                           setState(() { _b += 1; });
                         },
                       ),
                       ElevatedButton(
                         child: const Text('Increment c'),
                         onPressed: () {
                           // Rebuilds the ABCModel which triggers a rebuild
                           // of showC because showC depends on the 'c' aspect
                           // of the ABCModel.
                           setState(() { _c += 1; });
                         },
                       ),
                     ],
                   ),
                 ),
               );
             },
           ),
         );
       },
     );

     await tester.pumpWidget(MaterialApp(home: abcPage));

     expect(find.text('a: 0 [0]'), findsOneWidget);
     expect(find.text('b: 1 [0]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 0 b: 1 c: 2'), findsOneWidget);

     await tester.tap(find.text('Increment a'));
     await tester.pumpAndSettle();
     // Verify that field 'a' was incremented, but only the showA
     // and showABC widgets were rebuilt.
     expect(find.text('a: 1 [1]'), findsOneWidget);
     expect(find.text('b: 1 [0]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 1 b: 1 c: 2'), findsOneWidget);

     // Verify that field 'a' was incremented, but only the showA
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment a'));
     await tester.pumpAndSettle();
     expect(find.text('a: 2 [2]'), findsOneWidget);
     expect(find.text('b: 1 [0]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 2 b: 1 c: 2'), findsOneWidget);

     // Verify that field 'b' was incremented, but only the showB
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment b'));
     await tester.pumpAndSettle();
     expect(find.text('a: 2 [2]'), findsOneWidget);
     expect(find.text('b: 2 [1]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 2 b: 2 c: 2'), findsOneWidget);

     // Verify that field 'c' was incremented, but only the showC
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment c'));
     await tester.pumpAndSettle();
     expect(find.text('a: 2 [2]'), findsOneWidget);
     expect(find.text('b: 2 [1]'), findsOneWidget);
     expect(find.text('c: 3 [1]'), findsOneWidget);
     expect(find.text('a: 2 b: 2 c: 3'), findsOneWidget);
   });

   testWidgets('Looking up an non existent InheritedModel ancestor returns null', (WidgetTester tester) async {
     ABCModel? inheritedModel;

     await tester.pumpWidget(
       Builder(
         builder: (BuildContext context) {
           inheritedModel = InheritedModel.inheritFrom(context);
           return Container();
         },
       ),
     );
     // Shouldn't crash first of all.

     expect(inheritedModel, null);
   });

   testWidgets('Inner InheritedModel shadows the outer one', (WidgetTester tester) async {
     int _a = 0;
     int _b = 1;
     int _c = 2;

     // Same as in abcPage in the "InheritedModel basics" test except:
     // there are two ABCModels and the inner model's "a" and "b"
     // properties shadow (override) the outer model. Further complicating
     // matters: the inner model only supports the model's "a" aspect,
     // so showB and showC will depend on the outer model.
     final Widget abcPage = StatefulBuilder(
       builder: (BuildContext context, StateSetter setState) {
         const Widget showA = ShowABCField(fieldName: 'a');
         const Widget showB = ShowABCField(fieldName: 'b');
         const Widget showC = ShowABCField(fieldName: 'c');

         // Unconditionally depends on the closest ABCModel ancestor.
         // Which is the inner model, for which b,c are null.
         final Widget showABC = Builder(
           builder: (BuildContext context) {
             final ABCModel abc = ABCModel.of(context)!;
             return Text('a: ${abc.a} b: ${abc.b} c: ${abc.c}', style: Theme.of(context).textTheme.headline6);
           },
         );

         return Scaffold(
           body: StatefulBuilder(
             builder: (BuildContext context, StateSetter setState) {
               return ABCModel( // The "outer" model
                 a: _a,
                 b: _b,
                 c: _c,
                 child: ABCModel( // The "inner" model
                   a: 100 + _a,
                   b: 100 + _b,
                   aspects: const <String>{'a'},
                   child: Center(
                     child: Column(
                       mainAxisSize: MainAxisSize.min,
                       children: <Widget>[
                         showA,
                         showB,
                         showC,
                         const SizedBox(height: 24.0),
                         showABC,
                         const SizedBox(height: 24.0),
                         ElevatedButton(
                           child: const Text('Increment a'),
                           onPressed: () {
                             setState(() { _a += 1; });
                           },
                         ),
                         ElevatedButton(
                           child: const Text('Increment b'),
                           onPressed: () {
                             setState(() { _b += 1; });
                           },
                         ),
                         ElevatedButton(
                           child: const Text('Increment c'),
                           onPressed: () {
                             setState(() { _c += 1; });
                           },
                         ),
                       ],
                     ),
                   ),
                 ),
               );
             },
           ),
         );
       },
     );

     await tester.pumpWidget(MaterialApp(home: abcPage));
     expect(find.text('a: 100 [0]'), findsOneWidget);
     expect(find.text('b: 1 [0]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 100 b: 101 c: null'), findsOneWidget);

     await tester.tap(find.text('Increment a'));
     await tester.pumpAndSettle();
     // Verify that field 'a' was incremented, but only the showA
     // and showABC widgets were rebuilt.
     expect(find.text('a: 101 [1]'), findsOneWidget);
     expect(find.text('b: 1 [0]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 101 b: 101 c: null'), findsOneWidget);

     await tester.tap(find.text('Increment a'));
     await tester.pumpAndSettle();
     // Verify that field 'a' was incremented, but only the showA
     // and showABC widgets were rebuilt.
     expect(find.text('a: 102 [2]'), findsOneWidget);
     expect(find.text('b: 1 [0]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 102 b: 101 c: null'), findsOneWidget);

     // Verify that field 'b' was incremented, but only the showB
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment b'));
     await tester.pumpAndSettle();
     expect(find.text('a: 102 [2]'), findsOneWidget);
     expect(find.text('b: 2 [1]'), findsOneWidget);
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 102 b: 102 c: null'), findsOneWidget);

     // Verify that field 'c' was incremented, but only the showC
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment c'));
     await tester.pumpAndSettle();
     expect(find.text('a: 102 [2]'), findsOneWidget);
     expect(find.text('b: 2 [1]'), findsOneWidget);
     expect(find.text('c: 3 [1]'), findsOneWidget);
     expect(find.text('a: 102 b: 102 c: null'), findsOneWidget);
   });

   testWidgets('InheritedModel inner models supported aspect change', (WidgetTester tester) async {
     int _a = 0;
     int _b = 1;
     int _c = 2;
     Set<String>? _innerModelAspects = <String>{'a'};

     // Same as in abcPage in the "Inner InheritedModel shadows the outer one"
     // test except: the "Add b aspect" changes adds 'b' to the set of
     // aspects supported by the inner model.
     final Widget abcPage = StatefulBuilder(
       builder: (BuildContext context, StateSetter setState) {
         const Widget showA = ShowABCField(fieldName: 'a');
         const Widget showB = ShowABCField(fieldName: 'b');
         const Widget showC = ShowABCField(fieldName: 'c');

         // Unconditionally depends on the closest ABCModel ancestor.
         // Which is the inner model, for which b,c are null.
         final Widget showABC = Builder(
           builder: (BuildContext context) {
             final ABCModel abc = ABCModel.of(context)!;
             return Text('a: ${abc.a} b: ${abc.b} c: ${abc.c}', style: Theme.of(context).textTheme.headline6);
           },
         );

         return Scaffold(
           body: StatefulBuilder(
             builder: (BuildContext context, StateSetter setState) {
               return ABCModel( // The "outer" model
                 a: _a,
                 b: _b,
                 c: _c,
                 child: ABCModel( // The "inner" model
                   a: 100 + _a,
                   b: 100 + _b,
                   aspects: _innerModelAspects,
                   child: Center(
                     child: Column(
                       mainAxisSize: MainAxisSize.min,
                       children: <Widget>[
                         showA,
                         showB,
                         showC,
                         const SizedBox(height: 24.0),
                         showABC,
                         const SizedBox(height: 24.0),
                         ElevatedButton(
                           child: const Text('Increment a'),
                           onPressed: () {
                             setState(() { _a += 1; });
                           },
                         ),
                         ElevatedButton(
                           child: const Text('Increment b'),
                           onPressed: () {
                             setState(() { _b += 1; });
                           },
                         ),
                         ElevatedButton(
                           child: const Text('Increment c'),
                           onPressed: () {
                             setState(() { _c += 1; });
                           },
                         ),
                         ElevatedButton(
                           child: const Text('rebuild'),
                           onPressed: () {
                             setState(() {
                               // Rebuild both models
                             });
                           },
                         ),
                       ],
                     ),
                   ),
                 ),
               );
             },
           ),
         );
       },
     );

     _innerModelAspects = <String>{'a'};
     await tester.pumpWidget(MaterialApp(home: abcPage));
     expect(find.text('a: 100 [0]'), findsOneWidget); // showA depends on the inner model
     expect(find.text('b: 1 [0]'), findsOneWidget); // showB depends on the outer model
     expect(find.text('c: 2 [0]'), findsOneWidget);
     expect(find.text('a: 100 b: 101 c: null'), findsOneWidget); // inner model's a, b, c

     _innerModelAspects = <String>{'a', 'b'};
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 100 [1]'), findsOneWidget); // rebuilt showA still depend on the inner model
     expect(find.text('b: 101 [1]'), findsOneWidget); // rebuilt showB now depends on the inner model
     expect(find.text('c: 2 [1]'), findsOneWidget); // rebuilt showC still depends on the outer model
     expect(find.text('a: 100 b: 101 c: null'), findsOneWidget); // inner model's a, b, c

     // Verify that field 'a' was incremented, but only the showA
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment a'));
     await tester.pumpAndSettle();
     expect(find.text('a: 101 [2]'), findsOneWidget); // rebuilt showA still depends on the inner model
     expect(find.text('b: 101 [1]'), findsOneWidget);
     expect(find.text('c: 2 [1]'), findsOneWidget);
     expect(find.text('a: 101 b: 101 c: null'), findsOneWidget);

     // Verify that field 'b' was incremented, but only the showB
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment b'));
     await tester.pumpAndSettle();
     expect(find.text('a: 101 [2]'), findsOneWidget); // rebuilt showB still depends on the inner model
     expect(find.text('b: 102 [2]'), findsOneWidget);
     expect(find.text('c: 2 [1]'), findsOneWidget);
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget);

     // Verify that field 'c' was incremented, but only the showC
     // and showABC widgets were rebuilt.
     await tester.tap(find.text('Increment c'));
     await tester.pumpAndSettle();
     expect(find.text('a: 101 [2]'), findsOneWidget);
     expect(find.text('b: 102 [2]'), findsOneWidget);
     expect(find.text('c: 3 [2]'), findsOneWidget); // rebuilt showC still depends on the outer model
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget);

     _innerModelAspects = <String>{'a', 'b', 'c'};
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 101 [3]'), findsOneWidget); // rebuilt showA still depend on the inner model
     expect(find.text('b: 102 [3]'), findsOneWidget); // rebuilt showB still depends on the inner model
     expect(find.text('c: null [3]'), findsOneWidget); // rebuilt showC now depends on the inner model
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c

     // Now the inner model supports no aspects
     _innerModelAspects = <String>{};
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 1 [4]'), findsOneWidget); // rebuilt showA now depends on the outer model
     expect(find.text('b: 2 [4]'), findsOneWidget); // rebuilt showB now depends on the outer model
     expect(find.text('c: 3 [4]'), findsOneWidget); // rebuilt showC now depends on the outer model
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c

     // Now the inner model supports all aspects
     _innerModelAspects = null;
     await tester.tap(find.text('rebuild'));
     await tester.pumpAndSettle();
     expect(find.text('a: 101 [5]'), findsOneWidget); // rebuilt showA now depends on the inner model
     expect(find.text('b: 102 [5]'), findsOneWidget); // rebuilt showB now depends on the inner model
     expect(find.text('c: null [5]'), findsOneWidget); // rebuilt showC now depends on the inner model
     expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c
   });
 }
	// 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 'package:flutter/foundation.dart';
	import 'package:flutter/material.dart';
	import 'package:flutter_test/flutter_test.dart';

	// A simple "flat" InheritedModel: the data model is just 3 integer
	// valued fields: a, b, c.
	class ABCModel extends InheritedModel<String> {
	const ABCModel({
	Key? key,
	this.a,
	this.b,
	this.c,
	this.aspects,
	required Widget child,
	}) : super(key: key, child: child);

	final int? a;
	final int? b;
	final int? c;

	// The aspects (fields) of this model that widgets can depend on with
	// inheritFrom.
	//
	// This property is null by default, which means that the model supports
	// all 3 fields.
	final Set<String>? aspects;

	@override
	bool isSupportedAspect(Object aspect) {
	return aspect == null \|\| aspects == null \|\| aspects!.contains(aspect);
	}

	@override
	bool updateShouldNotify(ABCModel old) {
	return !setEquals<String>(aspects, old.aspects) \|\| a != old.a \|\| b != old.b \|\| c != old.c;
	}

	@override
	bool updateShouldNotifyDependent(ABCModel old, Set<String> dependencies) {
	return !setEquals<String>(aspects, old.aspects)
	\|\| (a != old.a && dependencies.contains('a'))
	\|\| (b != old.b && dependencies.contains('b'))
	\|\| (c != old.c && dependencies.contains('c'));
	}

	static ABCModel? of(BuildContext context, { String? fieldName }) {
	return InheritedModel.inheritFrom<ABCModel>(context, aspect: fieldName);
	}
	}

	class ShowABCField extends StatefulWidget {
	const ShowABCField({ Key? key, required this.fieldName }) : super(key: key);

	final String fieldName;

	@override
	State<ShowABCField> createState() => _ShowABCFieldState();
	}

	class _ShowABCFieldState extends State<ShowABCField> {
	int _buildCount = 0;

	@override
	Widget build(BuildContext context) {
	final ABCModel abc = ABCModel.of(context, fieldName: widget.fieldName)!;
	final int? value = widget.fieldName == 'a' ? abc.a : (widget.fieldName == 'b' ? abc.b : abc.c);
	return Text('${widget.fieldName}: $value [${_buildCount++}]');
	}
	}

	void main() {
	testWidgets('InheritedModel basics', (WidgetTester tester) async {
	int _a = 0;
	int _b = 1;
	int _c = 2;

	final Widget abcPage = StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	const Widget showA = ShowABCField(fieldName: 'a');
	const Widget showB = ShowABCField(fieldName: 'b');
	const Widget showC = ShowABCField(fieldName: 'c');

	// Unconditionally depends on the ABCModel: rebuilt when any
	// aspect of the model changes.
	final Widget showABC = Builder(
	builder: (BuildContext context) {
	final ABCModel abc = ABCModel.of(context)!;
	return Text('a: ${abc.a} b: ${abc.b} c: ${abc.c}');
	},
	);

	return Scaffold(
	body: StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	return ABCModel(
	a: _a,
	b: _b,
	c: _c,
	child: Center(
	child: Column(
	mainAxisSize: MainAxisSize.min,
	children: <Widget>[
	showA,
	showB,
	showC,
	showABC,
	ElevatedButton(
	child: const Text('Increment a'),
	onPressed: () {
	// Rebuilds the ABCModel which triggers a rebuild
	// of showA because showA depends on the 'a' aspect
	// of the ABCModel.
	setState(() { _a += 1; });
	},
	),
	ElevatedButton(
	child: const Text('Increment b'),
	onPressed: () {
	// Rebuilds the ABCModel which triggers a rebuild
	// of showB because showB depends on the 'b' aspect
	// of the ABCModel.
	setState(() { _b += 1; });
	},
	),
	ElevatedButton(
	child: const Text('Increment c'),
	onPressed: () {
	// Rebuilds the ABCModel which triggers a rebuild
	// of showC because showC depends on the 'c' aspect
	// of the ABCModel.
	setState(() { _c += 1; });
	},
	),
	],
	),
	),
	);
	},
	),
	);
	},
	);

	await tester.pumpWidget(MaterialApp(home: abcPage));

	expect(find.text('a: 0 [0]'), findsOneWidget);
	expect(find.text('b: 1 [0]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 0 b: 1 c: 2'), findsOneWidget);

	await tester.tap(find.text('Increment a'));
	await tester.pumpAndSettle();
	// Verify that field 'a' was incremented, but only the showA
	// and showABC widgets were rebuilt.
	expect(find.text('a: 1 [1]'), findsOneWidget);
	expect(find.text('b: 1 [0]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 1 b: 1 c: 2'), findsOneWidget);

	// Verify that field 'a' was incremented, but only the showA
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment a'));
	await tester.pumpAndSettle();
	expect(find.text('a: 2 [2]'), findsOneWidget);
	expect(find.text('b: 1 [0]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 2 b: 1 c: 2'), findsOneWidget);

	// Verify that field 'b' was incremented, but only the showB
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment b'));
	await tester.pumpAndSettle();
	expect(find.text('a: 2 [2]'), findsOneWidget);
	expect(find.text('b: 2 [1]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 2 b: 2 c: 2'), findsOneWidget);

	// Verify that field 'c' was incremented, but only the showC
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment c'));
	await tester.pumpAndSettle();
	expect(find.text('a: 2 [2]'), findsOneWidget);
	expect(find.text('b: 2 [1]'), findsOneWidget);
	expect(find.text('c: 3 [1]'), findsOneWidget);
	expect(find.text('a: 2 b: 2 c: 3'), findsOneWidget);
	});

	testWidgets('Looking up an non existent InheritedModel ancestor returns null', (WidgetTester tester) async {
	ABCModel? inheritedModel;

	await tester.pumpWidget(
	Builder(
	builder: (BuildContext context) {
	inheritedModel = InheritedModel.inheritFrom(context);
	return Container();
	},
	),
	);
	// Shouldn't crash first of all.

	expect(inheritedModel, null);
	});

	testWidgets('Inner InheritedModel shadows the outer one', (WidgetTester tester) async {
	int _a = 0;
	int _b = 1;
	int _c = 2;

	// Same as in abcPage in the "InheritedModel basics" test except:
	// there are two ABCModels and the inner model's "a" and "b"
	// properties shadow (override) the outer model. Further complicating
	// matters: the inner model only supports the model's "a" aspect,
	// so showB and showC will depend on the outer model.
	final Widget abcPage = StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	const Widget showA = ShowABCField(fieldName: 'a');
	const Widget showB = ShowABCField(fieldName: 'b');
	const Widget showC = ShowABCField(fieldName: 'c');

	// Unconditionally depends on the closest ABCModel ancestor.
	// Which is the inner model, for which b,c are null.
	final Widget showABC = Builder(
	builder: (BuildContext context) {
	final ABCModel abc = ABCModel.of(context)!;
	return Text('a: ${abc.a} b: ${abc.b} c: ${abc.c}', style: Theme.of(context).textTheme.headline6);
	},
	);

	return Scaffold(
	body: StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	return ABCModel( // The "outer" model
	a: _a,
	b: _b,
	c: _c,
	child: ABCModel( // The "inner" model
	a: 100 + _a,
	b: 100 + _b,
	aspects: const <String>{'a'},
	child: Center(
	child: Column(
	mainAxisSize: MainAxisSize.min,
	children: <Widget>[
	showA,
	showB,
	showC,
	const SizedBox(height: 24.0),
	showABC,
	const SizedBox(height: 24.0),
	ElevatedButton(
	child: const Text('Increment a'),
	onPressed: () {
	setState(() { _a += 1; });
	},
	),
	ElevatedButton(
	child: const Text('Increment b'),
	onPressed: () {
	setState(() { _b += 1; });
	},
	),
	ElevatedButton(
	child: const Text('Increment c'),
	onPressed: () {
	setState(() { _c += 1; });
	},
	),
	],
	),
	),
	),
	);
	},
	),
	);
	},
	);

	await tester.pumpWidget(MaterialApp(home: abcPage));
	expect(find.text('a: 100 [0]'), findsOneWidget);
	expect(find.text('b: 1 [0]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 100 b: 101 c: null'), findsOneWidget);

	await tester.tap(find.text('Increment a'));
	await tester.pumpAndSettle();
	// Verify that field 'a' was incremented, but only the showA
	// and showABC widgets were rebuilt.
	expect(find.text('a: 101 [1]'), findsOneWidget);
	expect(find.text('b: 1 [0]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 101 b: 101 c: null'), findsOneWidget);

	await tester.tap(find.text('Increment a'));
	await tester.pumpAndSettle();
	// Verify that field 'a' was incremented, but only the showA
	// and showABC widgets were rebuilt.
	expect(find.text('a: 102 [2]'), findsOneWidget);
	expect(find.text('b: 1 [0]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 102 b: 101 c: null'), findsOneWidget);

	// Verify that field 'b' was incremented, but only the showB
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment b'));
	await tester.pumpAndSettle();
	expect(find.text('a: 102 [2]'), findsOneWidget);
	expect(find.text('b: 2 [1]'), findsOneWidget);
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 102 b: 102 c: null'), findsOneWidget);

	// Verify that field 'c' was incremented, but only the showC
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment c'));
	await tester.pumpAndSettle();
	expect(find.text('a: 102 [2]'), findsOneWidget);
	expect(find.text('b: 2 [1]'), findsOneWidget);
	expect(find.text('c: 3 [1]'), findsOneWidget);
	expect(find.text('a: 102 b: 102 c: null'), findsOneWidget);
	});

	testWidgets('InheritedModel inner models supported aspect change', (WidgetTester tester) async {
	int _a = 0;
	int _b = 1;
	int _c = 2;
	Set<String>? _innerModelAspects = <String>{'a'};

	// Same as in abcPage in the "Inner InheritedModel shadows the outer one"
	// test except: the "Add b aspect" changes adds 'b' to the set of
	// aspects supported by the inner model.
	final Widget abcPage = StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	const Widget showA = ShowABCField(fieldName: 'a');
	const Widget showB = ShowABCField(fieldName: 'b');
	const Widget showC = ShowABCField(fieldName: 'c');

	// Unconditionally depends on the closest ABCModel ancestor.
	// Which is the inner model, for which b,c are null.
	final Widget showABC = Builder(
	builder: (BuildContext context) {
	final ABCModel abc = ABCModel.of(context)!;
	return Text('a: ${abc.a} b: ${abc.b} c: ${abc.c}', style: Theme.of(context).textTheme.headline6);
	},
	);

	return Scaffold(
	body: StatefulBuilder(
	builder: (BuildContext context, StateSetter setState) {
	return ABCModel( // The "outer" model
	a: _a,
	b: _b,
	c: _c,
	child: ABCModel( // The "inner" model
	a: 100 + _a,
	b: 100 + _b,
	aspects: _innerModelAspects,
	child: Center(
	child: Column(
	mainAxisSize: MainAxisSize.min,
	children: <Widget>[
	showA,
	showB,
	showC,
	const SizedBox(height: 24.0),
	showABC,
	const SizedBox(height: 24.0),
	ElevatedButton(
	child: const Text('Increment a'),
	onPressed: () {
	setState(() { _a += 1; });
	},
	),
	ElevatedButton(
	child: const Text('Increment b'),
	onPressed: () {
	setState(() { _b += 1; });
	},
	),
	ElevatedButton(
	child: const Text('Increment c'),
	onPressed: () {
	setState(() { _c += 1; });
	},
	),
	ElevatedButton(
	child: const Text('rebuild'),
	onPressed: () {
	setState(() {
	// Rebuild both models
	});
	},
	),
	],
	),
	),
	),
	);
	},
	),
	);
	},
	);

	_innerModelAspects = <String>{'a'};
	await tester.pumpWidget(MaterialApp(home: abcPage));
	expect(find.text('a: 100 [0]'), findsOneWidget); // showA depends on the inner model
	expect(find.text('b: 1 [0]'), findsOneWidget); // showB depends on the outer model
	expect(find.text('c: 2 [0]'), findsOneWidget);
	expect(find.text('a: 100 b: 101 c: null'), findsOneWidget); // inner model's a, b, c

	_innerModelAspects = <String>{'a', 'b'};
	await tester.tap(find.text('rebuild'));
	await tester.pumpAndSettle();
	expect(find.text('a: 100 [1]'), findsOneWidget); // rebuilt showA still depend on the inner model
	expect(find.text('b: 101 [1]'), findsOneWidget); // rebuilt showB now depends on the inner model
	expect(find.text('c: 2 [1]'), findsOneWidget); // rebuilt showC still depends on the outer model
	expect(find.text('a: 100 b: 101 c: null'), findsOneWidget); // inner model's a, b, c

	// Verify that field 'a' was incremented, but only the showA
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment a'));
	await tester.pumpAndSettle();
	expect(find.text('a: 101 [2]'), findsOneWidget); // rebuilt showA still depends on the inner model
	expect(find.text('b: 101 [1]'), findsOneWidget);
	expect(find.text('c: 2 [1]'), findsOneWidget);
	expect(find.text('a: 101 b: 101 c: null'), findsOneWidget);

	// Verify that field 'b' was incremented, but only the showB
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment b'));
	await tester.pumpAndSettle();
	expect(find.text('a: 101 [2]'), findsOneWidget); // rebuilt showB still depends on the inner model
	expect(find.text('b: 102 [2]'), findsOneWidget);
	expect(find.text('c: 2 [1]'), findsOneWidget);
	expect(find.text('a: 101 b: 102 c: null'), findsOneWidget);

	// Verify that field 'c' was incremented, but only the showC
	// and showABC widgets were rebuilt.
	await tester.tap(find.text('Increment c'));
	await tester.pumpAndSettle();
	expect(find.text('a: 101 [2]'), findsOneWidget);
	expect(find.text('b: 102 [2]'), findsOneWidget);
	expect(find.text('c: 3 [2]'), findsOneWidget); // rebuilt showC still depends on the outer model
	expect(find.text('a: 101 b: 102 c: null'), findsOneWidget);

	_innerModelAspects = <String>{'a', 'b', 'c'};
	await tester.tap(find.text('rebuild'));
	await tester.pumpAndSettle();
	expect(find.text('a: 101 [3]'), findsOneWidget); // rebuilt showA still depend on the inner model
	expect(find.text('b: 102 [3]'), findsOneWidget); // rebuilt showB still depends on the inner model
	expect(find.text('c: null [3]'), findsOneWidget); // rebuilt showC now depends on the inner model
	expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c

	// Now the inner model supports no aspects
	_innerModelAspects = <String>{};
	await tester.tap(find.text('rebuild'));
	await tester.pumpAndSettle();
	expect(find.text('a: 1 [4]'), findsOneWidget); // rebuilt showA now depends on the outer model
	expect(find.text('b: 2 [4]'), findsOneWidget); // rebuilt showB now depends on the outer model
	expect(find.text('c: 3 [4]'), findsOneWidget); // rebuilt showC now depends on the outer model
	expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c

	// Now the inner model supports all aspects
	_innerModelAspects = null;
	await tester.tap(find.text('rebuild'));
	await tester.pumpAndSettle();
	expect(find.text('a: 101 [5]'), findsOneWidget); // rebuilt showA now depends on the inner model
	expect(find.text('b: 102 [5]'), findsOneWidget); // rebuilt showB now depends on the inner model
	expect(find.text('c: null [5]'), findsOneWidget); // rebuilt showC now depends on the inner model
	expect(find.text('a: 101 b: 102 c: null'), findsOneWidget); // inner model's a, b, c
	});
	}