itirokob

func test_didFetchAuthorizationCredential_shouldCallDelegatesDidCompleteWithCredential() {
  //Given
  let sut = AppleAuthenticationProvider()
  sut.delegate = delegateSpy
  let mockedCredential: ASAuthorizationAppleIDCredentialProtocol = MockedCredential()
  
  //When
  sut.didFetch(authorizationCredential: mockedCredential)
  
  //Then

itirokob

public func authorizationController(controller: ASAuthorizationController, didCompleteWithAuthorization authorization: ASAuthorization) {
  // Call didFetch(authorizationCredential:)
}

//To test didFetch(authorizationCredential:), mock ASAuthorizationAppleIDCredentialProtocol and 
//assert that your delegate is being called properly
func didFetch(authorizationCredential: ASAuthorizationAppleIDCredentialProtocol) {
  let credential = mapCredential(from: authorizationCredential)
  delegate?.didCompleteWith(credential: credential)
}

itirokob

protocol ASAuthorizationAppleIDCredentialProtocol {
    var fullName: PersonNameComponents? { get }
    var email: String? { get }
    var user: String { get }
    var authCode: String? { get }
    var idToken: String? { get }
}

extension ASAuthorizationAppleIDCredential: ASAuthorizationAppleIDCredentialProtocol {}