Do not retry on service unavailable

Author: mihai8804858

Sources/Core/Extensions/ErrorExtensions.swift

@@ -31,9 +31,10 @@ extension Error {
 
     var isRetryableWithBackoff: Bool {
         let isTooManyRequests = statusCode == ResponseStatus.tooManyRequests
+        let isServiceUnavailable = statusCode == ResponseStatus.serviceUnavailable
         let isServerError = ResponseStatus.serverErrorRange.contains(statusCode)
 
-        return isTooManyRequests || isServerError
+        return isTooManyRequests || (isServerError && !isServiceUnavailable)
     }
 
     var isRetryable: Bool {

Sources/Core/Models/Error/APIError.swift

@@ -57,6 +57,11 @@ public enum APIError: Swift.Error, Hashable, Sendable {
         statusCode == ResponseStatus.tooManyRequests
     }
 
+    /// Verify if API request failed with "serviceUnavailable" (503) status code.
+    public var isServiceUnavailable: Bool {
+        statusCode == ResponseStatus.serviceUnavailable
+    }
+
     /// Error response that was returned by the API.
     public var errorResponse: APIErrorResponse? {
         switch self {

Sources/Core/Models/Response/ResponseStatus.swift

@@ -32,5 +32,6 @@ public struct ResponseStatus: RawRepresentable, Hashable, Comparable, Sendable,
     public static let forbidden = ResponseStatus(rawValue: 403)
     public static let tooManyRequests = ResponseStatus(rawValue: 429)
     public static let serverError = ResponseStatus(rawValue: 500)
+    public static let serviceUnavailable = ResponseStatus(rawValue: 503)
     public static let networkConnectTimeoutError = ResponseStatus(rawValue: 599)
 }

Tests/Error/ErrorTests.swift

@@ -42,9 +42,11 @@ final class ErrorTests: XCTestCase {
         let badRequest = APIError(response: Response(model: Data(), statusCode: 400))
         let tooManyRequests = APIError(response: Response(model: Data(), statusCode: 429))
         let serverError = APIError(response: Response(model: Data(), statusCode: 500))
+        let serviceUnavailable = APIError(response: Response(model: Data(), statusCode: 503))
         XCTAssert(tooManyRequests.isRetryableWithBackoff)
         XCTAssert(serverError.isRetryableWithBackoff)
         XCTAssertFalse(badRequest.isRetryableWithBackoff)
+        XCTAssertFalse(serviceUnavailable.isRetryableWithBackoff)
     }
 
     func testDecodeErrorResponse() throws {