Unit Testing Issue

samSol 1

Dear All,

I want to add Unit testing functionality for my following code

public class MyImage
    {
        public string ImageID { get; set; }
        public string ImageFullName { get; set; }
        public string ImageURL { get; set; }
        public string ImageDimensions { get; set; }
    }
[Route("api/[controller]")]
    [ApiController]
    public class ImageController : ControllerBase
    {
        [HttpGet("{id}")]
        public string Get(string date)
        {
            string result = string.Empty;
            var url = "https://myurl.com";
            var httpRequest = (HttpWebRequest)WebRequest.Create(url);
            var httpResponse = (HttpWebResponse)httpRequest.GetResponse();
            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
            {
                result = streamReader.ReadToEnd();

            }
            return result;
        }

    }

Any help would be greatly appreciated

samSol 1 Reputation point

2021-06-03T18:45:55.75+00:00

Any one please?
AgaveJoe 26,146 Reputation points

2021-06-03T19:51:59.507+00:00

Your design is not unit testable. Plus the date parameter and MyImage class are not used so it is not clear why you are showing us these items.

Unit testable code typically revolves around an interface. This allows you to mock operations like making an HTTP request or fetching data from a database. Unit tests are usually only concerned with the data from an HTTP request or database query.

Can you explain the expected results if the unit test? What are you testing exactly?
Duane Arnold 3,216 Reputation points

2021-06-04T01:22:04.38+00:00

As stated, your code cannot be unit tested. IMHO, you need to take some unit testing classes and learn how to unit test.

If you were going to unit test the controller, the code you have in the controller action method would be moved to a class in the Models folder with the class using an Interface and the class/object would be dependency injected into the controller. Because DI of the object into the controller, you can use a mocking framework such as Moq and mocked out the object and returned some mocked/fake data in the unit test.
samSol 1 Reputation point

2021-06-04T02:54:41.713+00:00

My Unit test should return a valid JSON result. I want to use mock operations. A sample code would be greatly appreciated. My code is in the controller
Duane Arnold 3,216 Reputation points

2021-06-04T07:46:10.887+00:00
Your code CANNOT be in the controller if you expect to unit test it. The code has to be put into a class method with the class being created in the Models folder and the class' method is called by the controller's action method. The class/object in the Models folder has to be mocked out and mock data from mocked out object is returned from the mock.

[TestMethod]
public void GetReturnsProductWithSameId()
{
// Arrange
var mockRepository = new Mock<IProductRepository>();
mockRepository.Setup(x => x.GetById(42))
.Returns(new Product { Id = 42 });

var controller = new Products2Controller(mockRepository.Object); // Act IHttpActionResult actionResult = controller.Get(42); var contentResult = actionResult as OkNegotiatedContentResult<Product>; // Assert Assert.IsNotNull(contentResult); Assert.IsNotNull(contentResult.Content); Assert.AreEqual(42, contentResult.Content.Id);

}continued....
Duane Arnold 3,216 Reputation points

2021-06-04T08:13:13.25+00:00

The repository object the controller is using is DI into the controller in the real execution of the controller's action method, and during the unit test, the repositroy object is being mocked out in order to unit test the controller's action method. You also notice the highlighted .Return, which is returning a 42 a mocked ID = 42 (mocked data in the unit test from the mocked method in the mocked repository object. So in your mocking in your unit test, you can call a method in your test harness code to return some made up/mock Json data.

the example code is in the link.

https://learn.microsoft.com/en-us/aspnet/web-api/overview/testing-and-debugging/unit-testing-controllers-in-web-api

But on the other hand, I don't think you can unit test, becuase somehow you must mockout the httprequest() and the streamreader().. You can't do it that I know about. And there are satiations where code cannot be unit tested.

continued...
Duane Arnold 3,216 Reputation points

2021-06-04T08:18:08.597+00:00

The best you could hope for is doing a integration test (do it for real) using a unit test framework like nUnit and unit testing harness like MS Test.

https://www.artima.com/weblogs/viewpost.jsp?thread=126923