flutter riverpod: how to test asyncvalue.error? - flutter

Question

I am having trouble testing my Riverpod FutureProvider when it returns an AsyncValue.error.
I tried the test as shown below:
// Future provider
final ipsProvider = FutureProvider.autoDispose((_) => IpRepository().fetchIps());
// Widget to be tested
class ExampleWidget extends ConsumerWidget {
#override
Widget build(BuildContext context, ScopedReader watch) {
// hooks
AsyncValue<List<Ip>> ips = watch(ipsProvider);
return Container(
child: ips.when(
data: (data) => randomWidget,
loading: () => progressIndicator,
error: (_, stack) => Text('YesMan'),
),
);
}
}
// Test: I am trying to find a Text widget containing message 'YesMan'
testWidgets('ExampleWidget | error', (WidgetTester tester) async
await tester.pumpWidget(
ProviderScope(
overrides: [
ipsProvider.overrideWithValue(AsyncValue.error('randomErrorMessage')),
],
child: MaterialApp(
home: Builder(builder: (context) {
return ExampleWidget();
}),
),
),
);
final finderError = find.text('YesMan');
expect(finderError, findsOneWidget);
});
I expected the test to return a text widget with message 'randomError', but instead it throws an exception as below:
══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK The following message was thrown running a test: randomErrorMessage When the exception was thrown, this was the stack:
Any idea on how to test AsyncValue.error cases in Riverpod?
Thank you

Answer 1

instead of overrideWithValue try overrideProvider and run a future.error so FutureProvider catch it
class ExampleWidget extends ConsumerWidget {
#override
Widget build(BuildContext context, ScopedReader watch) {
// hooks
AsyncValue<String> ips = watch(ipsProvider);
return Container(
child: ips.when(
data: (data) => SizedBox(),
loading: () => CircularProgressIndicator(),
error: (_, stack) => Text('YesMan'),
),
);
}
}
testWidgets('ExampleWidget | error', (WidgetTester tester) async {
await tester.pumpWidget(
ProviderScope(
overrides: [
ipsProvider.overrideWithProvider(FutureProvider((_) => Future.error('error'))),
],
child: MaterialApp(
home: Builder(builder: (context) {
return ExampleWidget();
}),
),
),
);
expect(find.byType(CircularProgressIndicator), findsOneWidget);
await tester.pump();
final finderError = find.text('YesMan');
expect(finderError, findsOneWidget);
});