How to combine 2 publishers and erase values to Void?

Question

I have 2 publishers where I want to perform an action based on either response. I don't care about the values. I'm trying to do something like this:

var hasChangedPublisher: AnyPublisher<(Void, Void), Never> {
    Publishers.CombineLatest(
        preferences.publisher,
        state.$permissionStatus
    ).eraseToAnyPublisher()
}

If preferences.publisher fires first but not the other, I want to fire. If state.$permissionStatus fires but not the other, I want to fire. I don't really want to CombineLatest, but not sure how to fire if either emit.

Is there a way to produce an even if either fire but more elegantly erase its values?

Answer 1

You're looking for Merge instead of CombineLatest. Your code for this would look a bit like the following:

var hasChangedPublisher: AnyPublisher<Void, Never> {
  preferences.publisher
    .merge(state.$permissionStatus)
    .map({ _ in
      return () // transform to Void
    })
    .eraseToAnyPublisher()
}