Fixed array delegate creator not being fully functional

[hgwood]

This is follow-up to #1010.

This implementation proposed in #1010 is incomplete. This is due to the test case not being sufficient. Here's the test case from #1010:

    public class ArrayOrObject {
        private final List<Object> objects;
        private final Object object;

        @JsonCreator public ArrayOrObject(List<Object> objects) {
            this.objects = objects;
            this.object = null;
        }

        @JsonCreator public ArrayOrObject(Object object) {
            this.objects = null;
            this.object = object;
        }
    }

The problem is that, to my surprise, a JSON array is deserializable into an instance of Object, so this test passes if the deserialization of both {} and [] go through the second creator, which is obviously not what I expect. Therefore, I have changed the test to the following:

    public class SomeObject {
        public String someField;
    }

    public class ArrayOrObject {
        private final List<SomeObject> objects;
        private final SomeObject object;

        @JsonCreator public ArrayOrObject(List<SomeObject> objects) {
            this.objects = objects;
            this.object = null;
        }

        @JsonCreator public ArrayOrObject(SomeObject object) {
            this.objects = null;
            this.object = object;
        }
    }

Now Jackson refuses to deserialize arrays into instances of SomeObject. Starting from there I completed the implementation so that the new test case passes.

[cowtowncoder]

Ah, yes, java.lang.Object is indeed the "wild card", capable of being bound from any and all JSON constructs.

Things may get even dicier with polymorphic types, as Type Id may be WRAPPER_ARRAY, in which case JSON Array is used for all kinds of Java types, including scalars.
But perhaps that is not problematic.

Thank you for further testing & fix, will merge.

[hgwood]

Thanks for those tips. I'll try to write further tests to demonstrate if WRAPPER_ARRAY is a problem or not.

[cowtowncoder]

@hgwood Thank you in advance!