typealias swift的问题

我的代码

import Foundation    
import UIKit
import FirebaseAuth


typealias Completion = (errMsg: String?, data: AnyObject?) -> Void 

class AuthenticationDatabase{


    var database = Database()


    func register(user: [UITextField], onComplete: Completion?)-> String{
        Auth.auth().createUser(withEmail: user[0].text, password:user[1].text) { (user, error) in
            if(error != nil){
                self.handleFirebaseError
            }
        }



    }

    func Login(UserInfo: [String]){

    }
    func logOut(){


    }
    func handleFirebaseError(error: NSError, onComplete:Completion?){
        print(error.localizedDescription)
        if let errorCode = AuthErrorCode(rawValue: error.code){
            switch (errorCode){
            case .errorCodeInvalidEmail:
            onComplete?(errMsg: "Invalid Email", data: nil)
            break
            case .errorCodeWrongPassword:
            onComplete?(errMsg: "invalid Password", data: nil)
            break
            default:
                onComplete?(errMsg: "There was a problem Authenticating. Try again.",data: nil)
            }
        }
    }





}