Building a customized instance fails on circular references

    [TestFixture]
    public class TestAutoFixture4
    {
        [Test]
        [AutoMoqData]
        public void CreatingAnDummyObjectShouldNotThrow(IFixture fixture)
        {
            fixture.Invoking(x => x.Create<DummyObject>()).ShouldNotThrow();
        }

        [Test]
        [AutoMoqData]
        public void BuildingAnDummyObjectShouldNotThrow(IFixture fixture)
        {
            fixture.Invoking(x => x.Build<DummyObject>().Create()).ShouldNotThrow();
        }
    }

    public class DummyObject
    {
        public Guid Id { get; set; }
        public DummyObject CircularRef { get; set; }
    }

    public class AutoMoqDataAttribute : AutoDataAttribute
    {
        public AutoMoqDataAttribute()
            : base(new Fixture()
                 .Customize(
                    new DummyCustomization()
                ))
        { }
    }

    public class DummyCustomization : ICustomization
    {
        public void Customize(IFixture fixture)
        {
            fixture.Customize<DummyObject>(c =>
                c.Without(x => x.CircularRef)
            );
        }
    }

Just updated AutoFixture from 3.50.6 to 4.0.0.

The above code works perfectly on 3.50.6, but only the first test (using fixture.Create) passes using 4.0.0 (.NET 4.6.2, NUnit3.7.1, FluentAssertions 4.19.4).

The test using fixture.Build fails, even if the injected customization specifies not to resolve the circular reference.

Did I miss something in the changelog or is it a bug ?

Thanks in advance 😃

[zvirja]

Do you think the Omitter approach can solve the problem ? I didn’t know this class and will definitely try it anyway.

If you rewrite your customization as following, all the tests will start to pass:

public class DummyCustomization : ICustomization
{
    public void Customize(IFixture fixture)
    {
        // Don't populate the DummyObject.CircularRef property.
        fixture.Customizations.Add(
            new Omitter(
                new EqualRequestSpecification(
                    typeof(DummyObject).GetProperty(nameof(DummyObject.CircularRef)))));
    }
}

Therefore, yep, it should fix your issue 😉 Also this approach doesn’t look too cumbersome, so should be acceptable.

Please let me know if you have further questions on your question.

[zvirja]

@Dev-I-Ant Awesome, thanks for the feedback! 😃