Moya: RxSwift flatMap "Unable to infer closure type in the current context", Migration from 8 to 11

[simonbromberg]

✨ Moya/RxSwift version 11.0.2, installed via Cocoapods

I am updating my project (from 8.0.5) to use the latest version of Moya (11.0.2) because I have other co-dependencies I want to update, and I am unsure as to how to update the following code in my project:

let provider = RxMoyaProvider<MyAPIService>()
return provider.request(endpoint)
    .filterSuccessfulStatusAndRedirectCodes()
    .mapJSON()
    .flatMap { response -> Observable<Any> in
        // etc
    }

because I am getting this vague compiler error in Xcode on the flatMap line (after changing RxMoyaProvider to MoyaProvider and inserting an rx between provider. and request):

Unable to infer closure type in the current context

I thought maybe it was a matter of changing flatMap to compactMap but then I get:

Value of type 'PrimitiveSequence' has no member 'compactMap'

I also checked to see what the autocomplete uses for flatMap and it gives me:

.flatMap({ (<#Any#>) -> PrimitiveSequence<SingleTrait, R> in
    <#code#>
})

which I'm not sure what to make of…

I am asking this as a question, doubt there's any kind of bug here. I'm not even entirely sure if this is really specific to Moya, or more of an RxSwift thing…

[simonbromberg]

Oh looks like what I am missing is an .asObservable() in there…

Relevant question #1423

FIxes the compiler error, but network requests still not working. Code inside the flatMap not being called at all.

[simonbromberg]

And, based on the providers documentation:

Always remember to retain your providers, as they will get deallocated if you fail to do so.

So I moved the provider to a stored variable in the class containing the network method, and now calls are going through.

I have also developed a better understanding of the distinction between Observables and Singles as a result of this investigation.