unnecessary_await_in_return

Unnecessary 'await'.

The analyzer produces this diagnostic when an async function or method returns an await expression and the static type of the awaited Future is a subtype of the declared return type.

The await is unnecessary because returning a Future from an async function already produces a Future that completes with the same result.

The analyzer doesn't report this diagnostic for await expressions inside a try block because removing the await changes how errors from the awaited Future are handled.

The following code produces this diagnostic because the function f has a return type of Future<int> and returns an awaited Future whose static type is also Future<int>:

Future<int> f(Future<int> future) async {
  return await future;
}

Remove the unnecessary await:

Future<int> f(Future<int> future) async {
  return future;
}