Network FrameworkのNWConnectionをasync/awaitで使うためのextension

NWConnection+Concurrency.swift

//
//  NWConnection+Concurrency.swift
//  AsyncNetwork
//
//  Created by trickart on 2026/02/06.
//

import Foundation
import Network

public extension NWConnection {
    func start(queue: DispatchQueue) async throws {
        try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
            stateUpdateHandler = { [weak self] state in
                switch state {
                case .setup, .waiting, .preparing:
                    break
                case .ready:
                    self?.stateUpdateHandler = nil
                    continuation.resume()
                case .failed(let error):
                    self?.stateUpdateHandler = nil
                    continuation.resume(throwing: error)
                case .cancelled:
                    break
                @unknown default:
                    break
                }
            }
        }
    }

    func receive(minimumIncompleteLength: Int, maximumLength: Int) async throws -> Data? {
        try await withCheckedThrowingContinuation { continuation in
            self.receive(minimumIncompleteLength: minimumIncompleteLength, maximumLength: maximumLength) { data, _, _, error in
                if let error = error {
                    continuation.resume(throwing: error)
                    return
                } else {
                    continuation.resume(returning: data)
                }
            }
        }
    }

    func receiveStream(minimumIncompleteLength: Int, maximumLength: Int) -> AsyncThrowingStream<Data?, Error> {
        return AsyncThrowingStream<Data?, Error> { continuation in
            @Sendable func receiveRecursively() {
                self.receive(minimumIncompleteLength: minimumIncompleteLength, maximumLength: maximumLength) { data, _, isComplete, error in
                    if let error = error {
                        continuation.finish(throwing: error)
                        return
                    }

                    continuation.yield(data)

                    if isComplete {
                        continuation.finish()
                    } else {
                        receiveRecursively()
                    }
                }
            }

            receiveRecursively()
        }
    }

    func send(content: Data?) async throws {
        try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
            send(content: content, completion: .contentProcessed({ error in
                if let error {
                    continuation.resume(throwing: error)
                } else {
                    continuation.resume()
                }
            }))
        }
    }
}