public async Task UpdateTest() { var idToUpdate = Guid.Parse("164661d5-aeff-445a-8d35-5815ba7d92bb"); var newString = "nice"; var ToUpdate = new TestMongoObject() { Id = idToUpdate, CoolString = newString }; var json = JsonConvert.SerializeObject(ToUpdate); var stringContent = new StringContent(json, UnicodeEncoding.UTF8, "application/json"); using (var server = CreateServer()) { var putResponse = await server.CreateClient() .PutAsync(Put.UpdateTestData(idToUpdate), stringContent); putResponse.EnsureSuccessStatusCode(); var getResponse = await server.CreateClient() .GetAsync(Get.TestDataById(idToUpdate)); var jsonString = await getResponse.Content.ReadAsStringAsync(); var result = JsonConvert.DeserializeObject <TestMongoObject>(jsonString); Assert.Equal(newString, result.CoolString); } }