Return Future<void> from a sync function in Dart-CodePudding

I have a function to override and I want it to do nothing. The base class function is abstract. I have two options for implementation:

// option 1
@override
Future<void> cancelReadStream() async {}

// option 2
@override
Future<void> cancelReadStream() {
  return Future.value();
}

Dart code metrics tells me to avoid redundant async, so I thought it is best to return a Future<void>. Is Future.value() the best way to return a Future<void>?

CodePudding user response：

I would go with option 1, it's just the most solid implementation. Dart metrics can be a little invasive sometimes, I would just ignore it. Once you actually write any async code the warning will disappear anyway.

CodePudding user response：

I'd argue that the code metrics are wrong.

It's exactly the third item they list:

A value is returned and it will be impliclty wrapped in a future. async is shorter than Future.value(...).

In this case the value is null, and it's returned implicitly, but it's still shorter than Future<void>.value(null);

The code

@override
Future<void> cancelReadStream() async {}

is perfectly reasonable and readable. It's an asynchronous function (returns a future), which does nothing before completing that future.

I'd consider reporting it to the DCM team, as a false positive.