type alias for Checks, converting from Some to error

[tyrcho]

I have identified a recurring pattern in our project using ZIO.

We want to fail when some function returns Some(x) and succeed when it returns None.

I'm thinking of defining a method like this one:

def noneOrFail[E,O](o:Option[O], f:O=>E):IO[E,Unit]=
    ZIO.fromEither(o.toLeft(())).mapError(f)
    // similar implementation
    //ZIO.getOrFailUnit(o).flip.mapError(f) 

And maybe a new type Alias

type Check[E] = IO[E, Unit]

Is there a more standard way to do this with ZIO?
Otherwise, is this an extension you'd be interested to add ?

[adamgfraser]

I think variants of getOrFail that expect the None case would be fine. Check type alias seems a little specialized to me.

[tyrcho]

thanks for the reply. I agree for the type alias.

about noneOrFail, would you like me to submit a PR ? only the ZIO trait needs a change, right ?

[adamgfraser]

I think it would be a constructor so it would go on the ZIO companion object, right? When we add methods to the companion object we also add aliases for them to the companion objects for the various ZIO type aliases like Task with the appropriate constraints.

[tyrcho]

Here is the PR : #4851

I struggled with the unit tests.

[tyrcho]

cleaned the format + signed the CLA

[tyrcho]

actually, I'll let this open until the feature is available in the next release

[adamgfraser]

I think if we have implemented the feature we should close the issue even if it is not in the latest release yet.