added RestSharpExtensions to help validate REST response

NzbDrone.Core/Rest/RestSharpExtensions.cs

@@ -0,0 +1,70 @@
+using System.Net;
+using NLog;
+using NzbDrone.Common.EnsureThat;
+using NzbDrone.Common.Serializer;
+using RestSharp;
+
+namespace NzbDrone.Core.Rest
+{
+    public static class RestSharpExtensions
+    {
+        private static readonly Logger Logger = LogManager.GetLogger("RestExtensions");
+
+        public static IRestResponse ValidateResponse(this IRestResponse response, IRestClient restClient)
+        {
+            Ensure.That(() => response).IsNotNull();
+
+            if (response.Request == null && response.ErrorException != null)
+            {
+                throw response.ErrorException;
+            }
+
+            Ensure.That(() => response.Request).IsNotNull();
+            Ensure.That(() => restClient).IsNotNull();
+
+            Logger.Debug("Validating Responses from [{0}] [{1}] status: [{2}] body:[{3}]", response.Request.Method, restClient.BuildUri(response.Request), response.StatusCode, response.Content);
+
+            if (response.ResponseUri == null)
+            {
+                Logger.ErrorException("Error communicating with server", response.ErrorException);
+                throw response.ErrorException;
+            }
+
+            switch (response.StatusCode)
+            {
+                case HttpStatusCode.OK:
+                    {
+                        return response;
+                    }
+                default:
+                    {
+                        Logger.Warn("[{0}] [{1}] Failed. [{2}]", response.Request.Method, response.ResponseUri.ToString(), response.StatusCode);
+                        throw new RestException(response, restClient);
+                    }
+            }
+        }
+
+        public static T Read<T>(this IRestResponse restResponse, IRestClient restClient) where T : class, new()
+        {
+            restResponse.ValidateResponse(restClient);
+
+            return Json.Deserialize<T>(restResponse.Content);
+        }
+
+        public static T ExecuteAndValidate<T>(this IRestClient client, IRestRequest request) where T : class, new()
+        {
+            return client.Execute(request).Read<T>(client);
+        }
+
+        public static IRestResponse ExecuteAndValidate(this IRestClient client, IRestRequest request)
+        {
+            return client.Execute(request).ValidateResponse(client);
+        }
+
+
+        public static void AddQueryString(this IRestRequest request, string name, object value)
+        {
+            request.AddParameter(name, value.ToString(), ParameterType.GetOrPost);
+        }
+    }
+}