Validation of [Required] attribute failing in xUnit test with Entity Framework Core

Question

In this class library (targeting .NET Standard 2.0 and .NET Framework 4.6.1), I am doing data validation at the data context level, as these classes may be used by non-web applications, so I'm following the example from https://github.com/dotnet/efcore/issues/9662 in a static helper class:

internal static ICollection<ValidationResult> ValidateChanges(DbContext context)
{
    var modifiedEntries = context.ChangeTracker.Entries()
                                 .Where(x => x.State == EntityState.Added || 
                                             x.State == EntityState.Modified);
    List<ValidationResult> validationResults = new List<ValidationResult>();

    foreach (var entry in modifiedEntries)
    {
        var validationContext = new ValidationContext(entry);
        Validator.TryValidateObject(entry, validationContext, validationResults, true);
    }

    return validationResults;
}

My POCO (simplified):

public class Person
{
    [Required]
    public int Id { get; set; }
    [Required]
    public string FirstName { get; set; }
    [Required]
    public string LastName { get; set; }
    // other properties
}

My unit test (simplified):

[Fact]
public void TestDataValidation()
{
    IPersonService svc = _container.Resolve<IPersonService>();
    Person p = svc.Get(1);
    string origValue = p.FirstName;
    p.FirstName = string.Empty;

    try
    {
        Assert.Throws<ValidationException>(() => svc.Update(p, p.Id));
    }
    catch (Xunit.Sdk.XunitException) // ValidationException not thrown
    {
        // restore original value

        throw;
    }
}

The service class method:

    public virtual TEntity Update(TEntity entity, TKey key)
    {
        if (entity == null)
            throw new ArgumentNullException(nameof(entity));

        ((IDatabaseContext)Context).BeginTransaction();
        TEntity dbEntity = Get(key);
        Context.Entry(dbEntity).CurrentValues.SetValues(entity);
        ((IDatabaseContext)Context).Commit();
        return entity;
    }

The Commit() method:

public abstract class DatabaseContext<TContext> : DbContext, IDatabaseContext
    where TContext : DbContext
{
    public void Commit()
    {
        ICollection<ValidationResult> validationResults = DbContextHelper.ValidateChanges(this);
        if (validationResults.Count > 0)
        {
            foreach (ValidationResult validationResult in validationResults)
            {
                string message = string.Format("{0}: {1}", string.Join(", ", validationResult.MemberNames.ToArray()), validationResult.ErrorMessage);
                throw new ValidationException(message);
            }
        }
        base.Commit();
    }
}

When I execute the test, the validation complete fails. When I put a break point in the middle of the foreach loop of the validation method, this is what I see:

modifiedEntries has one item (as expected)
entry.CurrentValues["FirstName"] is an empty string (as expected)
When you view it in the debugger watch list, entry.CurrentValues.Properties[5] shows {Property: Person.FirstName (string) Required} (seems right)
validationContext.Items shows Count = 0 (wait, what? shouldn't this be 1?)

Then when I reach the end of the validation method, validationResults is empty, even though there definitely should be something in there.

According to Data annotations attributes not working in asp net core you need AddDataAnnotations() on the ServiceCollection, but that's in ASP.NET MVC Core. Is there something similar I needed to do for my unit test application? Am I missing anything else?

Thanks in advance

Can Ürek · Accepted Answer · 2021-10-22 22:33:57Z

0

You can try something like that

//Assert
foreach (var item in ValidateModel(itemToCreate))
{
    if(!string.IsNullOrEmpty(item.ErrorMessage)) throw new ValidationException(item.ErrorMessage); 
}

/////

private static IList<ValidationResult> ValidateModel(object model)
{
    var validationResults = new List<ValidationResult>();
    var ctx = new ValidationContext(model, null, null);
    Validator.TryValidateObject(model, ctx, validationResults, true);
    return validationResults;
}

answered Oct 22, 2021 at 22:33

Can Ürek

66112 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Validation of [Required] attribute failing in xUnit test with Entity Framework Core

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related