Using Generic Methods to test restful webservices from JSON format…

When testing webservices, you find that there common methods when GETting and POSTing to restful webservices. The common pattern is to open a connection, setting your headers (Adding Auth, etc…), downloading JSON string then finally deserializing. Woudn’t be great to just re-use these patterns and not worry about the object being serialized and deserialized? There’s many ways to do this and here’s 2 examples that I wrote at least for both GET and POST requests. Note that there are many variations for this. I could combine both into 1 method but let’s just split them for now.

For GET:

public static async Task<T> RequestGet<T>(string resturl)
        {
            using (var httpclient = new HttpClient())
            {
                httpclient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("<Auth>",
                    ConfigurationManager.AppSettings["<AuthKey>"]);
                var response = await httpclient.GetAsync(resturl);
                responsecontent = await response.Content.ReadAsStringAsync();
                var returnobject = JsonConvert.DeserializeObject<T>(responsecontent);
                return returnobject;
            }
        }

For POST:

public static async Task<T> RequestPost<T>(string jasonstringcontent,string resturl)
      {
          using (var httpclient = new HttpClient())
          {
              var stringContent = new StringContent(jasonstringcontent);
              httpclient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("<Auth>",
                  ConfigurationManager.AppSettings["<AuthKey>"]);
              stringContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
              var response = await httpclient.PostAsync(resturl, stringContent);
              responsecontent = await response.Content.ReadAsStringAsync();
              var returnobject = JsonConvert.DeserializeObject<T>(responsecontent);
              return returnobject;
          }
      }

To use these methods, you can call them directly or re-use them as reference from other helper methods, for example:

For GET:

public static  List<SomeObject> GetObjects(string WebServicesurl)
    {
        var uri = String.Format("{0}queryparam?format=Json", WebServicesurl);
        Task<List<SomeObject>> response = RequestGet<List<SomeObject>>(uri);
        return response.Result;
    }

Now the actual Test Method would be:

[TestMethod]
      public void ValidateGetObjects()
      {
          List<SomeObject> allobjects = HelperClassWebApi.GetObjects(webservicesurl);
          Assert.IsTrue(allobjects .Count >= 5);
          Console.WriteLine("Test Case Passed for GetObjects");
      }

For POST:

[TestMethod]
        public void ValidatGetUserAuthToken()
        {
            string jsonstringparams =
                "{ \"Password\": \"" + logoninfo.Password + "\", \"UserId\": \"" + logoninfo.Username + "\"}";
            string uri = String.Format("{0}/authtoken?format=Json", webservicesurl);
            var clienttoken = HelperClassWebApi.RequestPost<AuthTokenResponse>(jsonstringparams, uri);
            Assert.IsTrue(!string.IsNullOrWhiteSpace(clienttoken.Result.MyAccountAuthToken));
            Console.WriteLine("Test Case Passed for: customers/myaccount/authtoken");
        }

Generics are awesome!