enums.dart

void main() {
  hello();
}

enum RequestType1 { image, video }

extension on String {
  T getEnum<T extends Enum>(List<T> values) {
    return values.firstWhere(
      (e) => describeEnum(e) == this,
      orElse: () => throw Exception('Invalid enum value'),
    );
  }
}

extension on Enum {
  String getString() => describeEnum(this);
}

String describeEnum(Object enumEntry) {
  final String description = enumEntry.toString();
  final int indexOfDot = description.indexOf('.');
  assert(
    indexOfDot != -1 && indexOfDot < description.length - 1,
    'The provided object "$enumEntry" is not an enum.',
  );
  return description.substring(indexOfDot + 1);
}

void hello() {
  printEnum('video'.getEnum<RequestType1>(RequestType1.values));
}

void printEnum(RequestType1 requestType1) => print(requestType1.getString());