Flag Task.Delay(0) as being Task.CompletedTask

[Keboo]

Task.Delay(0) is the same as Task.CompletedTask
.NET Core
.NET Framework

Test cases:

Task.Delay(0);
Task.Delay(0, token);

Suggest:
We should suggest changing to Task.CompletedTask since that is what is going to happen anyway.

[adamskt]

@ascott18 Is there a Roslynator analyzer that catches this?

[ascott18]

@adamskt No, there isn't. This seems like such an unlikely thing for someone to do that I can't imagine its worth any effort to build such an analyzer ourselves, either.