Widget test issue with DropdownButton #89905
Description
Description
I was trying to write tests to test for a DropdownButton. I made the tester to first tap on the DropdownButton to expand the options. But when I tried to make the tester to tap on one of the dropdown options, it failed to do so. It was giving error saying that the finder matched two widgets but realistically there should only be one that matches.
Steps to Reproduce
main.dart
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
static const String _title = 'Flutter Code Sample';
@override
Widget build(BuildContext context) {
return MaterialApp(
title: _title,
home: Scaffold(
appBar: AppBar(title: const Text(_title)),
body: const Center(
child: MyStatefulWidget(),
),
),
);
}
}
class MyStatefulWidget extends StatefulWidget {
const MyStatefulWidget({Key? key}) : super(key: key);
@override
State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
String dropdownValue = 'One';
@override
Widget build(BuildContext context) {
return DropdownButton<String>(
key: const Key('dropdownButton'),
value: dropdownValue,
onChanged: (String? newValue) {
setState(() {
dropdownValue = newValue!;
});
},
items: <String>['One', 'Two', 'Free', 'Four']
.map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(value),
);
}).toList(),
);
}
}widget_test.dart
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:hello_app/main.dart';
void main() {
testWidgets('dropdown button', (WidgetTester tester) async {
await tester.pumpWidget(MyApp());
await tester.tap(find.byKey(const Key('dropdownButton')));
await tester.pumpAndSettle();
await tester.tap(find.text('Two'));
final widget = find.byWidgetPredicate((widget) {
return widget is DropdownButton && widget.value == 'Two';
});
expect(widget, findsOneWidget);
});
}
The test would fail on the following line:
await tester.tap(find.text('Two'));Expected results:
The test should pass
Actual results:
The test failed when the tester tried to tap on one of the dropdown options
The following assertion was thrown running a test:
The finder "2 widgets with text "Two" (ignoring offstage widgets): [Text("Two", dependencies:
[MediaQuery, DefaultTextStyle]), Text("Two", dependencies: [DefaultTextStyle, MediaQuery])]" (used
in a call to "tap()") ambiguously found multiple matching widgets. The "tap()" method needs a single
target.
Logs
Analyze
No issues found! (ran in 4.7s)
Doctor
[✓] Flutter (Channel stable, 2.2.3, on macOS 11.5.2 20G95 darwin-x64, locale en-AU)
• Flutter version 2.2.3 at <scrubbed>
• Framework revision f4abaa0735 (2 months ago), 2021-07-01 12:46:11 -0700
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• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
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[✓] Connected device (2 available)
• macOS (desktop) • macos • darwin-x64 • macOS 11.5.2 20G95 darwin-x64
• Chrome (web) • chrome • web-javascript • Google Chrome 93.0.4577.63
• No issues found!