Automatic testing of ApiController

Question

I have an ApiController and would like to test it with unit tests including the routing.

An example:

[RoutePrefix(\"prefix\")]
public class          


        

Answer 1

Its possible by using postman or fiddler to test with url param..

Answer 2

1. Create an OWIN StartUp class using Microsoft ASP.NET Web API 2.2 OWIN package:

   public class Startup
   { 
       public void Configuration(IAppBuilder builder)
       {
           var config = new HttpConfiguration();
   
           builder.UseWebApi(config);
   
           config.MapHttpAttributeRoutes();
           config.EnsureInitialized();
       }
   }
   

2. Use Microsoft ASP.NET Web API 2.2 Self Host package in your tests (used NUnit for example):

   [Test]
   [TestCase(10, 5, 15)]
   [TestCase(1, 2, 3)]
   // add your test cases
   public async Task AdditionTests(int a, int b, int result) 
   {
       // Arrange
       var address = "http://localhost:5050";
   
       using (WebApp.Start<Startup>(address))
       {
           var client = new HttpClient();
   
           var requestUri = $"{address}/prefix/{a}?id2={b}";
   
           // Act
           var response = await client.GetAsync(requestUri);
   
           // Assert
           Assert.IsTrue(await response.Content.ReadAsAsync<int>() == result);
       }
   }
   

Answer 3

That is an integration test, not a unit test. If you wanted to automate this you would have to have a tool that would launch/host your web api and then execute requests against it.

If you wanted to keep it as a unit test though you could validate the attributes on the class and the method and check the values.

var type = typeof(Controller);
var attributeRoutePrefix = type.GetCustomAttribute(typeof(RoutePrefixAttribute)) as RoutePrefixAttribute;
Assert.IsNotNull(attributeRoutePrefix);
Assert.AreEqual("prefix", attributeRoutePrefix.Prefix);

var methodAttribute = type.GetMethod(nameof(Controller.Add)).GetCustomAttribute(typeof(RouteAttribute)) as RouteAttribute;
Assert.IsNotNull(methodAttribute);
Assert.AreEqual("id1", methodAttribute.Template);

Answer 4

I wrote a little helper class for in-memory integration testing that can be called as part of the test suit.

internal interface IHttpTestServer : IDisposable {
    HttpConfiguration Configuration { get; }
    HttpClient CreateClient();
}

internal class HttpTestServer : IHttpTestServer {
    HttpServer httpServer;

    public HttpTestServer(HttpConfiguration configuration = null) {
        httpServer = new HttpServer(configuration ?? new HttpConfiguration());
    }

    public HttpConfiguration Configuration {
        get { return httpServer.Configuration; }
    }

    public HttpClient CreateClient() {
        var client = new HttpClient(httpServer);
        return client;
    }

    public void Dispose() {
        if (httpServer != null) {
            httpServer.Dispose();
            httpServer = null;
        }
    }

    public static IHttpTestServer Create(HttpConfiguration configuration = null) {
        return new HttpTestServer(configuration);
    }
}

And would then use it like this

[TestMethod]
public async Task HttpClient_Should_Get_OKStatus_From_InMemory_Hosting() {

    using (var server = new HttpTestServer()) {

        MyWebAPiProjectNamespace.WebApiConfig.Configure(server.Configuration);

        var client = server.CreateClient();

        string url = "http://localhost/prefix/10?id2=5";
        var expected = 15;

        var request = new HttpRequestMessage {
            RequestUri = new Uri(url),
            Method = HttpMethod.Get
        };

        request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        using (var response = await client.SendAsync(request)) {
            Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
            var result = await response.Content.ReadAsAsync<int>();
            Assert.AreEqual(expected, result);
        }
    }
}

This will configure an in-memory test server that the test can make calls to using its httpclient. It is in essence an end-to-end integration test.