如何对自定义验证属性进行单元测试

Question

我有一个自定义的asp.net mvc类验证属性.我的问题是如何对其进行单元测试？测试类具有属性是一回事,但这实际上不会测试其中的逻辑.这是我想测试的.

[Serializable]
[EligabilityStudentDebtsAttribute(ErrorMessage = "You must answer yes or no to all questions")]
public class Eligability
{
    [BooleanRequiredToBeTrue(ErrorMessage = "You must agree to the statements listed")]
    public bool StatementAgree { get; set; }

    [Required(ErrorMessage = "Please choose an option")]
    public bool? Income { get; set; }

.....为简洁而删除}

[AttributeUsage(AttributeTargets.Class)]
public class EligabilityStudentDebtsAttribute : ValidationAttribute
{
    // If AnyDebts is true then 
    // StudentDebts must be true or false

    public override bool IsValid(object value)
    {
        Eligability elig = (Eligability)value;
        bool ok = true;
        if (elig.AnyDebts == true)
        {
            if (elig.StudentDebts == null)
            {
                ok = false;
            }
        }
        return ok;

    }
}

我试着按如下方式编写测试,但这不起作用:

[TestMethod]
public void Eligability_model_StudentDebts_is_required_if_AnyDebts_is_true()
{

   // Arrange
   var eligability = new Eligability();
   var controller = new ApplicationController();

   // Act
   controller.ModelState.Clear();
   controller.ValidateModel(eligability);
   var actionResult = controller.Section2(eligability,null,string.Empty);

   // Assert
   Assert.IsInstanceOfType(actionResult, typeof(ViewResult));
   Assert.AreEqual(string.Empty, ((ViewResult)actionResult).ViewName);
   Assert.AreEqual(eligability, ((ViewResult)actionResult).ViewData.Model);
   Assert.IsFalse(((ViewResult)actionResult).ViewData.ModelState.IsValid);
}

在ModelStateDictionary不包含这个自定义属性的关键.它仅包含标准验证属性的属性.

为什么是这样？

测试这些自定义属性的最佳方法是什么？

Answer 1

您的属性EligabilityStudentDebtsAttribute只是一个标准类,就像其他一切一样,只需对IsValid()方法进行单元测试.如果它工作正常,请相信Framework该属性正常工作.

所以:

[Test]
public void AttibuteTest()
{
   // arrange
   var value = //.. value to test - new Eligability() ;
   var attrib = new EligabilityStudentDebtsAttribute();

   // act
   var result = attrib.IsValid(value);

   // assert
   Assert.That(result, Is.True)
}

Answer 2

您的自定义验证属性可能取决于其他属性的状态.在这种情况下,您可以使用System.ComponentModel.DataAnnotations.Validator静态方法,例如:

var model = ...
var context = new ValidationContext(model);
var results = new List<ValidationResult>();
var isValid = Validator.TryValidateObject(model, context, results, true);
Assert.True(isValid);

Answer 3

我发现它IsValid不适用于字符串等简单类型。例如，如果您对不是对象的字符串查询参数进行验证。此外，直接在属性上测试值更容易，而无需提供整个对象。它还允许检查错误消息。它是这样工作的：

string input = "myteststring";
var myAttribute = new MyAttribute()
var result = attribute.GetValidationResult(input, new ValidationContext(input));

var isSuccess = result == ValidationResult.Success;
var errorMessage = result?.ErrorMessage;

此代码仅测试输入值的验证，而不测试其他内容。

PS我已经在 dotnet core 中对此进行了测试，但我认为这也适用于普通的 dotnet。