Firebase Functions in swift does not return anything if there is no Internet - swift

Question

There is a function that is triggered after the AccountKit authorization, it calls the Firebase Function to validate the token on Facebook and returns a userId if everything is confirmed, and registers the user if he has not yet been registered.
It works fine when Internet is available, but while offline - Firebase function does not return or throw any errors or at least nil results, and I would like it to return an error such as No internet connection or ANYTHING that could be catched.
Digging web and APIReference brought no results. Does the call of firebase function really not return anything in such cases (offline)?
func checkUserCredentials(phoneNumber: String, FBId: String, Token: String) {
functions.httpsCallable("checkUserCredentials").call(["phone":"\(phoneNumber)", "FBId":"\(FBId)", "Token":"\(Token)"])
{ (result, error) in
if let error = error as NSError?
{
if error.domain == FunctionsErrorDomain
{
let code = FunctionsErrorCode(rawValue: error.code)
let message = error.localizedDescription
}
}
if let userDoc = (result?.data as? [String: Any])?["userID"] as? String
{
DispatchQueue.main.async(execute: { self.performSegue(withIdentifier: "StartTheApp", sender: self) })
}
} }

Answer 1

I recommend checking for a network connection before making any network request. That way you're not dependent on the vagaries of whichever library you're using to talk to the network.
I use Reachability to check for a network connection before performing any requests (which I then perform using Alamofire). Below is a sample function to check for network:
import Reachability
...
func networkIsReachable(shouldShowAlert: Bool) -> Bool {
if let reachability: Reachability = Reachability(), reachability.connection != .none {
return true
}
if shouldShowAlert {
let alertController = UIAlertController(title: "Error", message: "No internet connection.", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))
present(alertController, animated: true, completion: nil)
}
return false
}
Since I'm using this function all throughout my codebase, I even moved it into an extension so as not to violate DRY principle.
Updating your code to use this function would look like this:
func checkUserCredentials(phoneNumber: String, FBId: String, Token: String) {
guard let networkIsReachable(shouldShowAlert: true) else {
// network is not reachable, and user has been shown an error message
return
}
// now perform network request
// ...
}