unawaited_return_in_try_block

Returning a 'Future' without 'await' inside a try block.

The analyzer produces this diagnostic when a Future is returned from within a try block, in an async function, without awaiting the returned Future.

The following code produces this diagnostic because the Future returned from futureString is returned without using await. This can lead to unexpected behavior because exceptions thrown by the Future won't be caught by the catch block.

Future<String> futureString(Future<String> value) async {
  try {
    return value;
  } catch (e) {
    print(e);
    return 'default';
  }
}

Add await before the returned Future:

Future<String> futureString(Future<String> value) async {
  try {
    return await value;
  } catch (e) {
    print(e);
    return 'default';
  }
}