Creating an Observable around an async/await method using RxSwift

Question

I am using the AWS Amplify library https://github.com/aws-amplify/amplify-swift to communicate with the Cognito service. Most of the functions have been rewritten using the new async/await approach.

Looking at the following method:

func fetchAuthSession() async throws -> AuthSession {
    return try await Amplify.Auth.fetchAuthSession()
}

How can I wrap the await call to return an Observable<AuthSession> using RxSwift?

Answer 1

Use Observable.create to create an Observable.

Use Task { ... } to perform async work.

Use Task { ... } inside Observable.create to perform async work in an Observable.

Something like this should work:

let authSessionObservable: Observable<AuthSession> = Observable.create { observer in
    let task = Task {
        do {
            let session = try await Amplify.Auth.fetchAuthSession()
            observer.on(.next(session))
            observer.on(.completed)
        } catch {
            observer.on(.error(error))
        }
    }
    return Disposables.create {
        task.cancel()
    }
}