diff --git a/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache b/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache
index e20d8bf3e52..311b4bf3b31 100644
--- a/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache
@@ -173,6 +173,12 @@ extension KeyedDecodingContainerProtocol {
 
 }
 
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
+
 {{#usePromiseKit}}extension RequestBuilder {
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func execute() -> Promise<Response<T>>  {
         let deferred = Promise<Response<T>>.pending()
diff --git a/modules/openapi-generator/src/main/resources/swift5/Models.mustache b/modules/openapi-generator/src/main/resources/swift5/Models.mustache
index cf561f12e95..97ea6459774 100644
--- a/modules/openapi-generator/src/main/resources/swift5/Models.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/Models.mustache
@@ -25,6 +25,7 @@ protocol JSONEncodable {
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache b/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache
index 3bdcc13331e..c1e6e80b9fb 100644
--- a/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache
@@ -181,20 +181,25 @@ private var urlSessionStore = SynchronizedDictionary<String, URLSession>()
     }
     
     fileprivate func processRequestResponse(urlRequest: URLRequest, data: Data?, response: URLResponse?, error: Error?, completion: @escaping (_ result: Result<Response<T>, Error>) -> Void) {
-        
+
         guard let httpResponse = response as? HTTPURLResponse else {
             completion(.failure(ErrorResponse.error(-2, nil, DecodableRequestBuilderError.nilHTTPResponse)))
             return
         }
-        
+
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
             
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ private var urlSessionStore = SynchronizedDictionary<String, URLSession>()
             
         case is Void.Type:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             completion(.success(Response(response: httpResponse, body: nil)))
             
         default:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -323,44 +318,34 @@ private var urlSessionStore = SynchronizedDictionary<String, URLSession>()
             completion(.failure(ErrorResponse.error(-2, nil, DecodableRequestBuilderError.nilHTTPResponse)))
             return
         }
-        
+
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
             
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
             
         case is Void.Type:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             completion(.success(Response(response: httpResponse, body: nil)))
             
         case is Data.Type:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             completion(.success(Response(response: httpResponse, body: data as? T)))
             
         default:
             
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-            
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 66f407c1c5f..e5511b3aa37 100644
--- a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Models.swift
index b5f1df522b5..65c14f85267 100644
--- a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ internal enum DownloadException: Error {
 internal enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index 5282c1d239d..7128797f067 100644
--- a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ internal class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ internal class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ internal class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionReques
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 4bfdc722770..736702ea5dd 100644
--- a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -173,6 +173,12 @@ extension KeyedDecodingContainerProtocol {
 
 }
 
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
+
 extension RequestBuilder {
     public func execute() -> Promise<Response<T>> {
         let deferred = Promise<Response<T>>.pending()
diff --git a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index f0a59876722..339f484cd9d 100644
--- a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return
diff --git a/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Extensions.swift b/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Extensions.swift
index 74fcfcf2ad4..93ed6b90b37 100644
--- a/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Extensions.swift
+++ b/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Extensions.swift
@@ -171,3 +171,9 @@ extension KeyedDecodingContainerProtocol {
     }
 
 }
+
+extension HTTPURLResponse {
+    var isStatusCodeSuccessful: Bool {
+        return Array(200 ..< 300).contains(statusCode)
+    }
+}
diff --git a/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Models.swift b/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Models.swift
index b9757b6cbc1..41997535f82 100644
--- a/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Models.swift
+++ b/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/Models.swift
@@ -25,6 +25,7 @@ public enum DownloadException: Error {
 public enum DecodableRequestBuilderError: Error {
     case emptyDataResponse
     case nilHTTPResponse
+    case unsuccessfulHTTPStatusCode(Error?)
     case jsonDecoding(DecodingError)
     case generalError(Error)
 }
diff --git a/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/URLSessionImplementations.swift
index 4ed152fdd63..762ea264b2f 100644
--- a/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/test/swift5/default/TestClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -187,14 +187,19 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
@@ -236,20 +241,10 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
         }
 
@@ -324,43 +319,33 @@ open class URLSessionDecodableRequestBuilder<T: Decodable>: URLSessionRequestBui
             return
         }
 
+        guard httpResponse.isStatusCodeSuccessful else {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, DecodableRequestBuilderError.unsuccessfulHTTPStatusCode(error))))
+            return
+        }
+
+        if let error = error {
+            completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
+            return
+        }
+
         switch T.self {
         case is String.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             let body = data.flatMap { String(data: $0, encoding: .utf8) } ?? ""
 
             completion(.success(Response<T>(response: httpResponse, body: body as? T)))
 
         case is Void.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: nil)))
 
         case is Data.Type:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             completion(.success(Response(response: httpResponse, body: data as? T)))
 
         default:
 
-            if let error = error {
-                completion(.failure(ErrorResponse.error(httpResponse.statusCode, data, error)))
-                return
-            }
-
             guard let data = data, !data.isEmpty else {
                 completion(.failure(ErrorResponse.error(httpResponse.statusCode, nil, DecodableRequestBuilderError.emptyDataResponse)))
                 return