StatusCodeResult or ResponseMessageResult

Question

I've seen a response being sent two different ways from Web API.

return ResponseMessage(new HttpResponseMessage(HttpStatusCode.UnsupportedMediaType));

or

return StatusCode(HttpStatusCode.UnsupportedMediaType);

Both end up sending a 415 back to the caller. I've looked at the MSDN documentation for the two result classes but still can't figure out what the difference is or why I would choose one over the other.

Solution

Use StatusCodeResult for easy unit testability.

Example(in xUnit):

var result = Assert.IsType<StatusCodeResult>(valuesController.Blah(data));
Assert.Equal(415, result.StatusCode);

Responding to comment: I would prefer something like below:

public IHttpActionResult Get(int id)
{
    if(id == 10)
    {
        return StatusCode(HttpStatusCode.NotFound);
    }

    return Ok("Some value");
}

rather than:

public IHttpActionResult Get(int id)
{
    if(id == 10)
    {
        return ResponseMessage(Request.CreateResponse(HttpStatusCode.NotFound));
    }

    return Ok("Some value");
}

Comments

[Craig W.]

I can do the same thing with the ResponseMessageResult. If I have a variable result that is of type ResponseMessageResult I can reference result.Response.StatusCode.

[Kiran]

@CraigW: I updated the post with an example. For this simple scenario what you mention equally works but you can look at the above examples and notice that its less code to write too.

[Craig W.]

I absolutely agree it's less code to write (my original post basically had what you wrote in your expanded example). Other than that though I still don't see a functional difference between using one of the types over the other.