gistfile1.dart

import 'dart:io';
import 'dart:async';
import 'dart:math';
 
// The following function is part of a third-party package that you can't touch.
Future doCoolStuff() {
  var completer = new Completer();
 
  // Sometimes bad things happen.
  if (new Random().nextBool()) {
    new Timer(100, (t) {
      // how does a consumer of doCoolStuff catch this?
      throw new Exception('Oops, something bad happened');
    });
  }
 
  // Do some work for a second.
  new Timer(1000, (t) {
    print('good timer completed');
    completer.complete('We did cool things');
  });
 
  return completer.future;
}
 
// User side code following.
main() {
  try {
    doCoolStuff()
      .then((r) => print(r))
      .catchError((e) {
        print('caught from caughtError');
        print(e);
      });
  } catch (e) {
    print("caught in catch");
    print(e);
  }
 
  print('Done!');
}