Swift Concurrency: Await of one task from multiple tasks

AwaitAuth.swift

import Foundation

actor Auth {
    private var tokenRefresh: Task<String, Error>?

    private var _token: String?
    private var counter: Int = 0
    
    func token() async throws -> String {
        if var tokenRefresh {
            try await tokenRefresh.value
        }

        let task = Task<String, Error> {
            let token = try await self.refreshToken()
            self._token = token
            return token
        }
        self.tokenRefresh = task
        return try await task.value
    }

    func refreshToken() async throws -> String {
        if let token = _token { return token }
        let newToken = "token \(counter)"
        counter += 1
        _token = newToken
        return newToken
    }
}

actor Networking {
    var auth = Auth()

    func perform(request: (String) -> Void) async throws {
        let token = try await auth.token()
        request(token)
    }
}

let x = Networking()
for _ in 0...10 {
    Task.detached {
        try await x.perform {
            print($0)
        }
    }
}

/**
token 0
token 0
token 0
token 0
token 0
token 0
token 0
token 0
token 0
token 0
token 0
*/