Url.Link not working in WebAPI

Question

Using the unit test below .. Iam trying to test my webapi.

[Test]
public void CheckControllerForCreate()
{
    var config = new HttpConfiguration();
    config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
    var request = new HttpRequestMessage(HttpMethod.Post, "http://localhost/api/product");
    var route = config.Routes.MapHttpRoute("Foo", "api/{controller}/{id}");
    var routeData = new HttpRouteData(route, new HttpRouteValueDictionary { { "controller", "products" } });
    var controller = new ProductController
    {
        ControllerContext = new HttpControllerContext(config, routeData, request),
        Request = request,
        Url = new UrlHelper(request)
    };

    controller.Request.Properties[HttpPropertyKeys.HttpConfigurationKey] = config;

    var result = controller.Create(new Product {Id = 4, Name = "Tomato Soup", Category = "Groceries", Price = 1});
}

[HttpPost]
public HttpResponseMessage Create(Product product)
{
    var url = Url;
    if (product == null)
        throw new HttpResponseException(new HttpResponseMessage{StatusCode = HttpStatusCode.BadRequest,ReasonPhrase = "Product is not specified"});
    products.Add(product);
    var response = Request.CreateResponse(HttpStatusCode.Created, product);
    string uri = Url.Link("Foo", product.Id);
    response.Headers.Location = new Uri(uri);
    return response;
}

The Create Action throws an exception because uri is null. Now, the Url helper is correctly picking up the RouteName , otherwise there would be a RouteName not found exception. I am assuming that somethign is wrong with my configuration.

I referred to http://www.peterprovost.org/blog/2012/06/16/unit-testing-asp-dot-net-web-api and several other posts for unit testing the controllers.

The WebAPI method is here on codeplex

http://aspnetwebstack.codeplex.com/SourceControl/changeset/view/1acb241299a8#src/System.Web.Http/Routing/UrlHelper.cs

Edit

I have narrowed it down to vpd being null in ( UrlHelper)

IHttpVirtualPathData vpd = configuration.Routes.GetVirtualPath(
                request: request,
                name: routeName,
                values: routeValues);

Can't seem to figure out why ?

Answer 1

You need to set the routeData into the request, the same way you did with the configuration:

controller.Request.Properties[HttpPropertyKeys.HttpRouteDataKey] = routeData;

Also you are incorrectly using the Url.Link helper. You haven't specified a controller nor you have indicated the id.

The code in your controller should look like this:

string uri = Url.Link("Foo", new { id = product.Id, controller = "product" });

---

UPDATE:

Here's a full example.

Controller:

public class ProductController : ApiController
{
    public HttpResponseMessage Create(int id)
    {
        var uri = Url.Link("Foo", new { id = id, controller = "product" });
        return Request.CreateResponse(HttpStatusCode.OK, uri);
    }
}

Test:

// arrange
var config = new HttpConfiguration();
config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
var request = new HttpRequestMessage(HttpMethod.Post, "http://localhost/api/product");
var route = config.Routes.MapHttpRoute("Foo", "api/{controller}/{id}");
var routeData = new HttpRouteData(route, new HttpRouteValueDictionary(new { controller = "product" }));
var controller = new ProductController
{
    ControllerContext = new HttpControllerContext(config, routeData, request),
    Request = request,
    Url = new UrlHelper(request)
};
controller.Request.Properties[HttpPropertyKeys.HttpConfigurationKey] = config;
controller.Request.Properties[HttpPropertyKeys.HttpRouteDataKey] = routeData;

// act
var result = controller.Create(4);

// assert
...