dart:async - runZoned defeats expected try-catch-finally behaviour

[JohnColeman-CTO]

Output from the code below is:

Got 0
Got 1
Got 2
Got 3
Got 4
Got 5
Got 6
Got 7
Got 8
Got 9
handled error: 9
Unhandled exception:
error: 9
#0      example (file:///Users/johncoleman/WebstormProjects/zones_events_micro_dart_tutorial/bin/main.dart:23:17)
<asynchronous suspension>
#1      main.<anonymous closure> (file:///Users/johncoleman/WebstormProjects/zones_events_micro_dart_tutorial/bin/main.dart:6:7)
<asynchronous suspension>
#2      main (file:///Users/johncoleman/WebstormProjects/zones_events_micro_dart_tutorial/bin/main.dart:5:5)
<asynchronous suspension>

Process finished with exit code 255

The printing of "handled error: 9" executes as expect but 2 other prints are never executed contrary to the normal understanding of try-catch-finally behaviour with respect to the code that is wrapped.

import 'dart:async';

main() async {
  try {
    await runZoned(() async {
      await example();
    }, onError: (error, stacktrace) {
      print('handled $error');
      throw error;
    });
  } catch (error) {
    print("caught $error"); // this does not print
  } finally {
    print("finally done"); // this does not print
  }
}

Future example() async {
  await for (var x in streamer()) {
    print('Got $x');
    if (x == 9) throw ('error: $x');
  }
}

Stream<int> streamer() async* {
  var duration = Duration(milliseconds: 100);
  for (var x = 0; x < 100; x++) {
    await Future.delayed(duration);
    yield x;
  }
}

[JohnColeman-CTO]

use completer