單元測試MetadataType

Question

我工作的一個ASP.NET MVC 2應用程序和測試我的ViewModels像這樣

[TestMethod] 
public void EmailNeedsToBeSet() 
{ 
    var pvm = new ProfileViewModel {Email = ""}; 
    var validationResults = new ValidationResults(); 
    var result = Validator.TryValidateObject(pvm, new ValidationContext(pvm, null, null), validationResults, true); 
    Assert.IsFalse(result); 
    Assert.IsTrue(validationResults.ContainsField<ProfileViewModel>(m => m.Email)); 
} 

需要Email屬性，這TestMethod的正常工作

我的問題是現在：我如何在測試之前測試MetaData類？驗證結果總是如此。或者這不可能？我的元數據類

實施例：

[MetadataType(typeof (UserMetaData))] 
public partial class User 
{ 
    public class UserMetaData 
    { 
     [Required(ErrorMessageResourceName = "Required", 
     ErrorMessageResourceType = typeof (ValidationStrings))] 
     [LocalizedDisplayName("LoginName", NameResourceType = typeof (Fields))] 
     [StringLength(64)] 
     public string Login { get; set; } 
    } 
} 

Answer 1

下面是如何我單元測試這種類型的代碼：

[TestMethod] 
    public void IsValid_Returns_ValidationResult_Errors_When_Properties_With_Meta_Data_Are_Not_Valid() 
    { 
     var sut = new User 
         { 
          Login = "too long!!!" 
         }; 

     var actual = sut.IsValid(); 

     Assert.IsNotNull(actual); 
     Assert.AreEqual(1, actual.Count); 
     Assert.AreEqual(1, actual[0].MemberNames.Count()); 
     var firstValidationError = actual[0]; 
     Assert.AreEqual("Login", firstValidationError.MemberNames.First()); 
     Assert.AreEqual("The field Login must be a string with a maximum length of 4.", firstValidationError.ErrorMessage); 
    } 

    [TestMethod] 
    public void IsValid_Returns_Empty_List_Of_Errors_When_Properties_With_Meta_Data_Are_Valid() 
    { 
     var sut = new User 
         { 
          Login = "abcd" 
         }; 

     var actual = sut.IsValid(); 

     Assert.IsNotNull(actual); 
     Assert.AreEqual(0, actual.Count); 
    } 

[MetadataType(typeof(UserMetaData))] 
public partial class User : BaseEntity 
{ 
    public string Login { get; set; } 

    public class UserMetaData 
    { 
     [Required]    
     [StringLength(4)]  
     public string Login { get; set; } 
    } 
} 

public abstract class BaseEntity 
{ 
    protected BaseEntity() 
    { 
     RegisterMetadata(); 
    } 

    private void RegisterMetadata() 
    { 
     var currentType = GetType(); 

     var metadataType = GetMetadataType(); 

     if (metadataType == null) 
      return; 

     var descriptorProvider = new AssociatedMetadataTypeTypeDescriptionProvider(currentType, metadataType); 
     TypeDescriptor.AddProviderTransparent(descriptorProvider, currentType); 
    } 

    private Type GetMetadataType() 
    { 
     var attribute = Attribute.GetCustomAttributes(this.GetType()).ToList().Find(t => t is MetadataTypeAttribute); 

     return (attribute != null) 
        ? ((MetadataTypeAttribute)attribute).MetadataClassType 
        : null; 
    } 

    public virtual List<ValidationResult> IsValid() 
    { 
     var validationErrors = new List<ValidationResult>(); 
     var context = new ValidationContext(this, null, null); 
     Validator.TryValidateObject(this, context, validationErrors, true); 

     return validationErrors; 
    } 
}