使用Swift回调处理程序时无法通过平台通道返回值

func fetchData(completion: @escaping (Result<Data, Error>) -> Void) {
    let url = URL(string: "https://api.example.com/data")!
    let task = URLSession.shared.dataTask(with: url) { data, response, error in
        if let error = error {
            completion(.failure(error))
            return
        }
        guard let data = data else {
            completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "No data received"])))
            return
        }
        completion(.success(data))
    }
    task.resume()
}

import PromiseKit

func fetchData() -> Promise<Data> {
    return Promise { seal in
        let url = URL(string: "https://api.example.com/data")!
        let task = URLSession.shared.dataTask(with: url) { data, response, error in
            if let error = error {
                seal.reject(error)
            } else if let data = data {
                seal.fulfill(data)
            }
        }
        task.resume()
    }
}

import Combine

func fetchData() -> AnyPublisher<Data, Error> {
    return URLSession.shared.dataTaskPublisher(for: URL(string: "https://api.example.com/data")!)
        .map { $0.data }
        .eraseToAnyPublisher()
}