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// 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/widgets.dart';
import 'package:flutter_test/flutter_test.dart';
void main() {
testWidgets('Can call setState from didUpdateWidget', (WidgetTester tester) async {
await tester.pumpWidget(const Directionality(
textDirection: TextDirection.ltr,
child: WidgetUnderTest(text: 'hello'),
));
expect(find.text('hello'), findsOneWidget);
expect(find.text('world'), findsNothing);
final _WidgetUnderTestState state = tester.state<_WidgetUnderTestState>(find.byType(WidgetUnderTest));
expect(state.setStateCalled, 0);
expect(state.didUpdateWidgetCalled, 0);
await tester.pumpWidget(const Directionality(
textDirection: TextDirection.ltr,
child: WidgetUnderTest(text: 'world'),
));
expect(find.text('world'), findsOneWidget);
expect(find.text('hello'), findsNothing);
expect(state.setStateCalled, 1);
expect(state.didUpdateWidgetCalled, 1);
});
}
class WidgetUnderTest extends StatefulWidget {
const WidgetUnderTest({super.key, required this.text});
final String text;
@override
State<WidgetUnderTest> createState() => _WidgetUnderTestState();
}
class _WidgetUnderTestState extends State<WidgetUnderTest> {
late String text = widget.text;
int setStateCalled = 0;
int didUpdateWidgetCalled = 0;
@override
void didUpdateWidget(WidgetUnderTest oldWidget) {
super.didUpdateWidget(oldWidget);
didUpdateWidgetCalled += 1;
if (oldWidget.text != widget.text) {
// This setState is load bearing for the test.
setState(() {
text = widget.text;
});
}
}
@override
void setState(VoidCallback fn) {
super.setState(fn);
setStateCalled += 1;
}
@override
Widget build(BuildContext context) {
return Text(text);
}
}