Added mapping error handling

Sources/Extensions/Error/Error+NetworkExtensions.swift

@@ -0,0 +1,93 @@
+//
+//  Copyright (c) 2019 Touch Instinct
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+//
+
+import RxSwift
+
+public extension Error {
+
+    var requestError: RequestError? {
+        return self as? RequestError
+    }
+
+    /// Method that tries to serialize response from a mapping request error to a model
+    ///
+    /// - Parameter decoder: json decoder to decode response data
+    /// - Returns: optional target object
+    func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder()) -> T? {
+        guard let self = requestError, case .mapping(_, let response) = self else {
+            return nil
+        }
+
+        return try? decoder.decode(T.self, from: response)
+    }
+}
+
+public extension ObservableType {
+
+    /// Method that handles a mapping error and serialize response to a model
+    ///
+    /// - Parameters:
+    ///   - decoder: json decoder to decode response data
+    ///   - handler: closure that recieves serialized response
+    /// - Returns: Observable on caller
+    func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder(),
+                                          handler: @escaping (T?) -> ()) -> Observable<E> {
+            return self.do(onError: { error in
+                let mappingModel: T? = error.handleMappingError(with: decoder)
+                handler(mappingModel)
+            })
+    }
+}
+
+public extension PrimitiveSequence where Trait == SingleTrait {
+
+    /// Method that handles a mapping error and serialize response to a model
+    ///
+    /// - Parameters:
+    ///   - decoder: json decoder to decode response data
+    ///   - handler: closure that recieves serialized response
+    /// - Returns: Single on caller
+    func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder(),
+                                          handler: @escaping (T?) -> ()) -> PrimitiveSequence<Trait, Element> {
+            return self.do(onError: { error in
+                let mappingModel: T? = error.handleMappingError(with: decoder)
+                handler(mappingModel)
+            })
+    }
+}
+
+public extension PrimitiveSequence where Trait == CompletableTrait, Element == Never {
+
+    /// Method that handles a mapping error and serialize response to a model
+    ///
+    /// - Parameters:
+    ///   - decoder: json decoder to decode response data
+    ///   - handler: closure that recieves serialized response
+    /// - Returns: Completable
+    func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder(),
+                                          handler: @escaping (T?) -> ()) -> Completable {
+            return self.do(onError: { error in
+                let mappingModel: T? = error.handleMappingError(with: decoder)
+                handler(mappingModel)
+            })
+    }
+}