analyzer: convert async to sync function and vice versa

[kasperpeulen]

I would wish that some refactoring like this existed in webstorm:
refactor async to sync function (and vice versa)

I guess this is something for the analyzer ? For example, say I begin my program like this:

void main(List<String> arguments) {
  ...
}

After a while I find out that I need it to be async. I would like that I could refactor this, with just one shortcut to:

Future main(List<String> arguments) async {
  ...
}

Also things like:

bool get dartIsAwesome => true;

should then become:

Future<bool> get dartIsAwesome async => true;

[srawlins]

Agree

[FMorschel]

Here is the CL for the missing Remove async assist/fix https://dart-review.googlesource.com/c/sdk/+/420720

[FMorschel]

Sorry, the above got abandoned in favor of this new CL https://dart-review.googlesource.com/c/sdk/+/425602. I'll review both to make sure I'm not forgetting anything.

Edit: done.