Inheritance: System.Web.Mvc.ActionFilterAttribute
        public void IsValidForRequestThrowsIfControllerContextIsNull()
        {
            // Arrange
            AjaxOnlyAttribute attr = new AjaxOnlyAttribute();

            // Act & assert
            Assert.ThrowsArgumentNull(
                delegate { attr.IsValidForRequest(null, null); }, "controllerContext");
        }
        public void IsValidForRequestReturnsTrueIfHeaderIsPresent()
        {
            // Arrange
            AjaxOnlyAttribute attr = new AjaxOnlyAttribute();
            ControllerContext controllerContext = GetControllerContext(containsHeader: true);

            // Act
            bool isValid = attr.IsValidForRequest(controllerContext, null);

            // Assert
            Assert.True(isValid);
        }