LPMetadataProvider+Combine.swift

import LinkPresentation
import Combine

extension LPMetadataProvider {
    func startFetchingMetadataPublisher(for url: URL) -> AnyPublisher<LPLinkMetadata?, Error> {
        Future<LPLinkMetadata?, Error> { completion in
            self.startFetchingMetadata(for: url) { meta, error in
                guard let error = error else {
                    return completion(.success(meta))
                }
                
                completion(.failure(error))
            }
        }
        .handleEvents(receiveCancel: {
            self.cancel()
        })
        .eraseToAnyPublisher()
    }
}

let provider = LPMetadataProvider()
let cancellable: AnyCancellable = provider.startFetchingMetadataPublisher(for: URL(string: "https://apple.com")!)
    .receive(on: RunLoop.main)
    .sink(receiveCompletion: { completion in }) {
        print($0)
    }