Flutter Recovering Stream Errors小技巧

class StreamErrorHandle<T> extends StreamTransformerBase<T, T> {
    final _controller = StreamController<T>.broadcast();
    final T? Function(Object error) onError;
    StreamErrorHandler({
        required this.onError,
    });
    @override
    Stream<T> bind(Stream<T> stream) {
        ...
    }
}

@override
Stream<T> bind(Stream<T> stream) {
    final sub = stream.handleError((error) {
        final value = onError(error);
        if (value != null) {
            _controller.sink.add(value);
        }
    }).listen(_controller.sink.add);
    _controller.onCancel = (){
        sub.cancel();
    };
    return _controller.stream;
}

extension Recover<T> on Stream<T> {
    Stream<T> onErrorRecoverWith(T? Functioon(Object error) onError) => transform(StreamErrorHandle<T>(onError: onError));
}

Stream<String> getNames() async* {
    yield 'Foo'.
    yield 'Bar';
    throw Exception('Something went wrong');
}
Future<void> testIt() async {
    final names = getNames().onErrorRecoverWith(
        (error) {
            error.log();
            return 'Baz';
        },
    );
    await for(final name in names){
        name.log(); // Foo, Bar, Baz
    }
}

import 'dart:developer' as devtools show log;
extension Log on Object {
    void log() => devtools.log(toString());
}