Alamofire RequestRetrier with timeout error handling

Question

I'm using RequestRetrier to automatically renew access_token for my API. But in each request function I would like to catch timeout error, but .case(let error) in .responseJSON body never executes, because of (I guess) retrier that I add to my accessSessionManager . Here's how it looks like:

lazy var accessSessionManager: SessionManager = {
    let configuration = URLSessionConfiguration.default
    configuration.timeoutIntervalForRequest = Configuration.timeout
    configuration.timeoutIntervalForResource = Configuration.timeout
    let sessionManager = Alamofire.SessionManager(configuration: configuration)
    let oAuth2Handler = OAuth2Handler()
    sessionManager.retrier = oAuth2Handler
    sessionManager.adapter = oAuth2Handler
    return sessionManager
}()


func changeName(newName: String,completionHandler: ((_ success: Bool, _ error: String?) -> ())?) {
    guard let accessToken = self.getAccessToken() else { return }
    let parameters = ["access_token": accessToken,  "name": newName] as [String : Any]
    self.accessSessionManager.request(Constants.nameUrl, method: .get, parameters: parameters).responseJSON { response in
            switch response.result {
            case .success(let json):
                let jsonDict = JSON(json)
                if let success = jsonDict["success"].bool {
                    completionHandler?(success, nil)
                }

            case .failure(let error):
                if error._code == NSURLErrorTimedOut {
                    completionHandler?(false, "Please check your Internet connection and try again!")
                } else if response.response?.statusCode == 400 {
                    completionHandler?(false, "Sorry, name not found")
                } else if response.response?.statusCode != 401 {
                    completionHandler?(false, error.localizedDescription)
                }
            }
        }
    }
}

....
....
 class OAuth2Handler {

 //MARK: - Adapter
   func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
    if let url = urlRequest.url {
        guard let accessToken = self.getAccessToken() else { return  urlRequest }
        let newUrl = addOrUpdateQueryStringParameter(url: "\(url)", key: "access_token", value: accessToken)
        let newRequest = URLRequest(url: URL(string: newUrl)!)
        return newRequest
    }

    return urlRequest
}
 // MARK: - RequestRetrier
  func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion) {
    lock.lock() ; defer { lock.unlock() }
    if let response = request.task?.response as? HTTPURLResponse {
        if response.statusCode == 401 {
            requestsToRetry.append(completion)
            if !isRefreshing {
                refreshTokens { [weak self] succeeded, accessToken, refreshToken in
                    guard let strongSelf = self else { return }
                    strongSelf.lock.lock() ; defer { strongSelf.lock.unlock() }

                    if let accessToken = accessToken, let refreshToken = refreshToken {
                        strongSelf.accessToken = accessToken
                        strongSelf.refreshToken = refreshToken
                        strongSelf.updateAccessToken(accessToken: accessToken, refreshToken: refreshToken)
                    }
                    strongSelf.requestsToRetry.forEach { $0(succeeded, 0.0) }
                    strongSelf.requestsToRetry.removeAll()
                }
            }
        } else {
            completion(false, 0.0)
        }
    }
}

So, basically error handling performs in should function, not in .case(let error) in my function.

Answer 1

You are not validating your request. Therefor it will let every request be a succes. Try validating your request by adding a validate() after the request but before the response:

self.accessSessionManager.request(...).validate().responseJSON { ... }

You can find custom ways to change the behavior what is and what is not accepted by the validate() function in their readme

Answer 2

Ok, so there's my very stupid mistake, basically completion(false,0,0) was never executed if error occurred in should function. Everything works if it looks something like this:

// MARK: - RequestRetrier
func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion) {
lock.lock() ; defer { lock.unlock() }
    if let response = request.task?.response as? HTTPURLResponse {
        if response.statusCode == 401 {
            requestsToRetry.append(completion)
            if !isRefreshing {
                refreshTokens { [weak self] succeeded, accessToken, refreshToken in
                    guard let strongSelf = self else { return }
                    strongSelf.lock.lock() ; defer { strongSelf.lock.unlock() }

                    if let accessToken = accessToken, let refreshToken = refreshToken {
                       strongSelf.accessToken = accessToken
                       strongSelf.refreshToken = refreshToken
                       strongSelf.updateAccessToken(accessToken: accessToken, refreshToken: refreshToken)
                   }
                   strongSelf.requestsToRetry.forEach { $0(succeeded, 0.0) }
                   strongSelf.requestsToRetry.removeAll()
               }
            }
        } else {
           completion(false, 0.0)
    } else {
       completion(false,0.0)
    }
}