TDD:在ASP.NET MVC 3中测试DataAnnotations的最佳实践是什么？

Question

我正在使用ASP.NET MVC 3和DataAnnotations参与一个项目.我们在ViewModels类中有DataAnnotations.

你如何为这些验证编写单元测试？

ViewModel示例:

public class AchievementVM
{
    [Required(ErrorMessage = "The title field is required.")]
    [StringLength(100, ErrorMessage = "Title must be 100 characters or less.")]
    public string Title { get; set; }
}

谢谢!

Answer 1

.NET框架附带一个Validator类,可以单独执行验证逻辑.要测试的代码可能如下所示:

var achievement = new AchievementVM();
var context = new ValidationContext(achievement, 
    serviceProvider: null, items: null);
var results = new List<ValidationResult>();

var isValid = Validator.TryValidateObject(achievement, context, results, true);

Assert.IsTrue(results.Any(vr => vr.ErrorMessage == "The title field is required."));

achievement.Title = "Really really long title that violates "
    + "the range constraint and should not be accepted as "
    + "valid input if this has been done correctly.";

Validator.TryValidateObject(achievement, context, results, true);

Assert.IsTrue(results.Any(vr => vr.ErrorMessage == "Title must be 100 characters or less."));

无需自定义实用程序来搜索属性的存在.Validator类为您完成工作,并且与MVC基础结构一样填充ValidationResult集合.

关于这种方法的好文章可以在K. Scott Allen的博客上找到.

Answer 2

请参阅此处：单元测试 ASP.NET DataAnnotations 验证

另外，您可以使用反射来查看类的属性是否具有任何必要的属性。