TrySkipIssCustomErrors.cs

/// <summary>
/// Bypasses IIS7 custom Errors.
/// </summary>
public class TrySkipIisCustomErrors : FilterAttribute, IActionFilter
{
  public void OnActionExecuting(ActionExecutingContext filterContext)
  {
    filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
  }

  public void OnActionExecuted(ActionExecutedContext filterContext) { }
}

public class when_communicating_raw_errors_to_a_client : concerns<TrySkipIisCustomErrors>
{
  private ActionExecutingContext _filterContext;
  private HttpResponseBase _response;

  protected override void context()
  {
    var handler = new TrySkipIisCustomErrors();

    var httpContext = fake<HttpContextBase>();
    _response = stub<HttpResponseBase>();
    httpContext
      .Stub(c => c.Response)
      .Return(_response);

    _filterContext = new ActionExecutingContext {HttpContext = httpContext};

    handler.OnActionExecuting(_filterContext);
  }

  [Specification]
  public void skip_iis7_custom_errors()
  {
    _response.TrySkipIisCustomErrors.should_be_true();
  }
}