ExampleApiController.cs

[RoutePrefix("api/assemble/wip")]
public class AssembleWipItemController : ApiController
{
    private readonly IMediator _mediator;

    public AssembleWipItemController(IMediator mediator)
    {
        _mediator = mediator;
    }

    [Route("")]
    public WipItemResult Get([FromUri] GetModel input)
    {
        return _mediator.Send(input);
    }

    [Route("{wipId}")]
    public WipItemRepresentationModel GetById([FromUri] GetModelById input)
    {
        return _mediator.Send(input);
    }

    [Route("{wipId}/start")]
    [HttpPost]
    public StartWipResult Start([FromUri]StartWipModel input)
    {
        return _mediator.Send(input);
    }
}

Controller actions are a simple call to MediatR to dispatch the request to a handler that can be tested isolated from Web API.

We also use FluentValidation to validate the input models with Validators that also can be tested isolated from Web API