Get function signature for main()

test.dart

import 'dart:io';

typedef void EmptyFunc();
typedef void OneFunc(List<String> _);

myMain1(List<String> _) {
}

myMain2() {
}

int getType(fn) {
  if (fn is EmptyFunc) {
    return 1;
  } else {
    return 2;
  }
}

main() {
  print(getType(myMain1));
  print(getType(myMain2));
}