test

main.dart

import 'dart:async';

void main() {
  // create stream that emit Completer, and wait it
  ((() async* {
    try {
      final completer = Completer<void>();
      yield completer;
      await completer.future;
    } catch (_) {
      print('catch error');
    }
  })())
      .map((event) {
    // add error to completer
    event.completeError(Exception());

    return event;
  }).listen((_) => print('done'));
}