Chaining Customizations with Autofixture

Question

I know that Autofixture stops building object when it finds ISpecimenBuilder which can satisfy the request. So when I apply several consequent customizations, all but the last one get ignored. How do I combine the customizations instead? In other words, how do I modify this snippet:

fixture.Customize<SomeClass>(ob => ob.With(x => x.Id, 123)); // this customization is ignored
fixture.Customize<SomeClass>(ob => ob.With(x => x.Rev, 4341)); // only this one takes place

To be equivalent with this snippet:

fixture.Customize<SomeClass>(ob => ob
    .With(x => x.Id, 123)
    .With(x => x.Rev, 4341)); // both customization are applied

Answer 1

Here is what I came up with:

public class CustomFixture : Fixture
{
    public CustomFixture ()
    {
        this.Inject(this);
    }

    private readonly List<object> _transformations = new List<object>();

    public void DelayedCustomize<T>(Func<ICustomizationComposer<T>, ISpecimenBuilder> composerTransformation)
    {
        this._transformations.Add(composerTransformation);
    }

    public void ApplyCustomize<T>()
    {
        this.Customize<T>(ob =>
        {
            return this._transformations.OfType<Func<ICustomizationComposer<T>, ISpecimenBuilder>>()
                .Aggregate(ob, (current, transformation) => (ICustomizationComposer<T>)transformation(current));
        });
    }

}

And the usage:

var fixture = new CustomFixture();

fixture.DelayedCustomize<SomeClass>(ob => ob.With(x => x.Id, 123)); 
fixture.DelayedCustomize<SomeClass>(ob => ob.With(x => x.Rev, 4341)); 
fixture.ApplyCustomize<SomeClass>();

var obj = fixture.Create<SomeClass>();
// obj.Id == 123
// obj.Rev == 4341

Not ideal because of the need of ApplyCustomize.