runWithMinDuration

runWithMinDuration.dart

void main() async {
  final stopwatch = Stopwatch()..start();
  final res = await runWithMinDuration([
    myTask1,
    myTask2,
    myTask3,
  ], minDuration: Duration(seconds: 5));
  print("Result: $res Execution time: ${stopwatch.elapsed.inSeconds}sec");
}

typedef Future<T> Task<T>();

Future<List<T>> runWithMinDuration<T>(List<Task<T>> tasks,
    {Duration minDuration: const Duration(seconds: 5)}) async {
  final fMinDur = Future.delayed(minDuration);
  List<Future<T>> fTasks = tasks.map((t) => t()).toList(growable: false);
  return (await Future.wait([fMinDur, ...fTasks])).sublist(1).cast();
}

Future<int> myTask1() async {
  await Future.delayed(Duration(seconds: 1));
  return 1;
}

Future<int> myTask2() async {
  await Future.delayed(Duration(seconds: 2));
  return 2;
}

Future<int> myTask3() async {
  await Future.delayed(Duration(seconds: 3));
  return 3;
}