async-await-network-requests-02.swift

struct AlbumsFetcher {
    
    enum AlbumsFetcherError: Error {
        case invalidURL
        case missingData
    }
    
    static func fetchAlbums(completion: @escaping (Result<[Album], Error>) -> Void) {
        
        // Create URL
        guard let url = URL(string: "https://itunes.apple.com/search?term=taylor+swift&entity=album") else {
            completion(.failure(AlbumsFetcherError.invalidURL))
            return
        }
        
        // Create URL session data task
        URLSession.shared.dataTask(with: url) { data, _, error in

            if let error = error {
                completion(.failure(error))
                return
            }
            
            guard let data = data else {
                completion(.failure(AlbumsFetcherError.missingData))
                return
            }
            
            do {
                // Parse the JSON data
                let iTunesResult = try JSONDecoder().decode(ITunesResult.self, from: data)
                completion(.success(iTunesResult.results))
            } catch {
                completion(.failure(error))
            }
            
        }.resume()
    }
}