ASP.Net MVC：使用 ValidationAttribute 和 IClientValidatable 时如何编写单元测试代码

Question

很抱歉在这里发布类似的问题。我对 asp.net mvc 有点熟悉，但在单元测试中非常新。不要以为我知道很多，只是看看我在 stackoverflow 中的声誉。

我想知道如何为IsValid 和IEnumerable<ModelClientValidationRule> GetClientValidationRules 编写单元测试代码

我在这里粘贴我的代码，包括我的模型。所以任何人都帮我为上述两个功能编写单元测试代码。我是单元测试新手，使用 VS2013 和使用 VS 单元测试框架。

我的主要问题是如何专门为这个函数编写单元测试代码IEnumerable<ModelClientValidationRule> GetClientValidationRules

所以这是我的完整代码。如果可能，任何经常使用单元测试的人请查看并提供代码和建议。谢谢

型号

public class DateValTest
    {
        [Display(Name = "Start Date")]
        [DataType(DataType.Date), DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}", ApplyFormatInEditMode = true)]
        public DateTime? StartDate { get; set; }

        [Display(Name = "End Date")]
        [DataType(DataType.Date), DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}", ApplyFormatInEditMode = true)]
        [DateGreaterThanAttribute(otherPropertyName = "StartDate", ErrorMessage = "End date must be greater than start date")]
        public DateTime?  EndDate { get; set; }
    }

自定义验证码

public class DateGreaterThanAttribute : ValidationAttribute, IClientValidatable
    {
        public string otherPropertyName;
        public DateGreaterThanAttribute() { }
        public DateGreaterThanAttribute(string otherPropertyName, string errorMessage)
            : base(errorMessage)
        {
            this.otherPropertyName = otherPropertyName;
        }

        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            ValidationResult validationResult = ValidationResult.Success;
            try
            {
                // Using reflection we can get a reference to the other date property, in this example the project start date
                var containerType = validationContext.ObjectInstance.GetType();
                var field = containerType.GetProperty(this.otherPropertyName);
                var extensionValue = field.GetValue(validationContext.ObjectInstance, null);
                if(extensionValue==null)
                {
                    //validationResult = new ValidationResult("Start Date is empty");
                    return validationResult;
                }
                var datatype = extensionValue.GetType();

                //var otherPropertyInfo = validationContext.ObjectInstance.GetType().GetProperty(this.otherPropertyName);
                if (field == null)
                    return new ValidationResult(String.Format("Unknown property: {0}.", otherPropertyName));
                // Let's check that otherProperty is of type DateTime as we expect it to be
                if ((field.PropertyType == typeof(DateTime) || (field.PropertyType.IsGenericType && field.PropertyType == typeof(Nullable<DateTime>))))
                {
                    DateTime toValidate = (DateTime)value;
                    DateTime referenceProperty = (DateTime)field.GetValue(validationContext.ObjectInstance, null);
                    // if the end date is lower than the start date, than the validationResult will be set to false and return
                    // a properly formatted error message
                    if (toValidate.CompareTo(referenceProperty) < 1)
                    {
                        validationResult = new ValidationResult(ErrorMessageString);
                    }
                }
                else
                {
                    validationResult = new ValidationResult("An error occurred while validating the property. OtherProperty is not of type DateTime");
                }
            }
            catch (Exception ex)
            {
                // Do stuff, i.e. log the exception
                // Let it go through the upper levels, something bad happened
                throw ex;
            }

            return validationResult;
        }

        public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
        {
            var rule = new ModelClientValidationRule
            {
                ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
                ValidationType = "isgreater",
            };
            rule.ValidationParameters.Add("otherproperty", otherPropertyName);
            yield return rule;
        }
    }

Answer 1

你要做的是测试如果EndDate的值小于StartDate的值，那么模型是无效的，即IsValid()方法会抛出一个ValidationException

// Test that if the end date is less than the start date its invalid
[TestMethod]
[ExpectedException(typeof(ValidationException))]
public void TestEndDateIsInvalidIfLessThanStartDate()
{
    // Initialize a model with invalid values
    DateValTest model = new DateValTest(){ StartDate = DateTime.Today, EndDate = DateTime.Today.AddDays(-1) };
    ValidationContext context = new ValidationContext(model);
    DateGreaterThanAttribute attribute = new DateGreaterThanAttribute("StartDate");
    attribute.Validate(model.EndDate, context);   
}

当你运行测试时，if 会成功。相反，如果您要使用

初始化模型

DateValTest model = new DateValTest(){ StartDate = DateTime.Today, EndDate = DateTime.Today.AddDays(1) };

测试会失败，因为模型是有效的。