AuthenticationInterceptor(Alamofire5.2) retry process doesn't work well - ios

Question

I have a question about the AuthenticationInterceptor added in Alamofire 5.2.
I am using AuthenticationInterceptor to refresh the oAuth token.
https://github.com/Alamofire/Alamofire/blob/master/Documentation/AdvancedUsage.md#authenticationinterceptor
The code I'm trying is below.
struct OAuthCredential: AuthenticationCredential {
let accessToken: String
let refreshToken: String
let userID: String
let expiration: Date
// Require refresh if within 5 minutes of expiration
var requiresRefresh: Bool { Date(timeIntervalSinceNow: 60 * 5) > expiration }
}
class OAuthAuthenticator: Authenticator {
func apply(_ credential: OAuthCredential, to urlRequest: inout URLRequest) {
urlRequest.headers.add(.authorization(bearerToken: credential.accessToken))
}
func refresh(_ credential: OAuthCredential,
for session: Session,
completion: #escaping (Result<OAuthCredential, Error>) -> Void) {
// Request to refresh token
let request = Session.default.request(
URL(string: "URL for token refresh")!,
method: .patch,
parameters: ["refresh_token": credential.refreshToken]
)
request.responseJSON { response in
// Get new Credential information
// ~~~~~~
completion(.success(newCredential))
}
}
func didRequest(_ urlRequest: URLRequest,
with response: HTTPURLResponse,
failDueToAuthenticationError error: Error) -> Bool {
return response.statusCode == 401
}
func isRequest(_ urlRequest: URLRequest, authenticatedWith credential: OAuthCredential) -> Bool {
let bearerToken = HTTPHeader.authorization(bearerToken: credential.accessToken).value
return urlRequest.headers["Authorization"] == bearerToken
}
}
// ~~~~~~
let session = Session.default
let urlRequest = try! URLRequest(
url: URL(string: "https://api.example/docs")!,
method: .get
)
session.request(urlRequest, interceptor: interceptor).responseJSON { response in
// ~~~~~
}
What I don't know is whether didRequest and isRequest are sometimes called. I debugged while pasting a breakpoint when I got a 401 error, but it didn't stop at the above method.
The reason those methods weren't called was that they would always be returned on the line below.
https://github.com/Alamofire/Alamofire/blob/4f72b95b49c22e445e1866712f719698fa11c30c/Source/AuthenticationInterceptor.swift#L297
I couldn't find a case that didn't go through this line.
I would like to know the case where two methods are called.

Answer 1

try to call a .validate()
session.request(urlRequest, interceptor: interceptor).validate().responseJSON { response in
// ~~~~~
}