Map a SignalProducer that contains an error to return a NoError

Question

I am working with ReactiveSwift 3.x in an iOS project and have been unable to map over an error provided by one SignalProducer into a different one.

My NoError SignalProducer is:

func foo() -> SignalProducer<Void, NoError>

The function being called within foo() that I want to map is:

func bar() -> SignalProducer<Data, MyError>

I currently have the following:

func foo() -> SignalProducer<Void, NoError> {
    // Stuff happens here...
    return bar()
        .map({ _ -> Void in
            return ()
        })
        .mapError({ error -> NoError in
            print(error.localizedDescription)
            // I do not want to handle this error
            return NoError
        })
}

But I am getting the error:

'mapError' produces 'SignalProducer< Void, F >', not the expected contextual result type 'SignalProducer< Void, NoError >'

Ultimately, I just want to print out the error, and then return.

Answer 1

Quack.

I had attempted some flatMapError work earlier, but got it to work with the following:

.flatMapError({ error -> SignalProducer<Void, NoError> in
    return SignalProducer.empty
    })