Async/await in List.forEach()

You need to use Future.forEach.

main() async {
  print("main start");
  await asyncOne();
  print("main end");
}

asyncOne() async {
  print("asyncOne start");
  await Future.forEach([1, 2, 3], (num) async {
    await asyncTwo(num);
  });
  print("asyncOne end");
}

asyncTwo(num) async
{
  print("asyncTwo #${num}");
}

I don't think it's possible to achieve what you want with the forEach method. However it will work with a for loop. Example;

asyncOne() async {
  print("asyncOne start");
  for (num number in [1, 2, 3])
    await asyncTwo(number);
  print("asyncOne end");
}

I know this is an old question, but I'll leave here a new answer, hoping this help someone in the future.

You can use forEach for what you're trying to achieve by doing something like this:

  asyncOne() async {
  print("asyncOne start");
  await Future.forEach([1, 2, 3],(num) async {
    await asyncTwo(num);
  });
  print("asyncOne end");
}