COVIDSafe code from version 1.1

CovidSafe/API/CovidRequestRetrier.swift

@@ -0,0 +1,30 @@
+//
+//  CovidRequestInterceptor.swift
+//  CovidSafe
+//
+//  Copyright © 2020 Australian Government. All rights reserved.
+//
+
+import Foundation
+import Alamofire
+final class CovidRequestRetrier: Alamofire.RequestInterceptor {
+    private let numRetries: Int
+    private var retriesExecuted: Int = 0
+    
+    init(retries: Int) {
+        self.numRetries = retries
+    }
+
+    func retry(_ request: Request, for session: Session, dueTo error: Error, completion: @escaping (RetryResult) -> Void) {
+        guard let response = request.task?.response as? HTTPURLResponse, response.statusCode == 403 else {
+            /// The request did not fail due to a 403 Forbidden response.
+            let isServerTrustEvaluationError = error.asAFError?.isServerTrustEvaluationError ?? false
+            if ( retriesExecuted >= numRetries || isServerTrustEvaluationError) {
+                return completion(.doNotRetryWithError(error))
+            }
+            retriesExecuted += 1
+            return completion(.retryWithDelay(1.0))
+        }
+        return completion(.doNotRetryWithError(error))
+    }
+}