Spock - return nested spies / mocks

Hi! Some time ago I have written an article about Mockito and using RETURNS_DEEP_STUBS when working with JAXB. Quite recently we have faced a similliar issue with deeply nesetd JAXB and the awesome testing framework written in Groovy called Spock. Natively Spock does not support creating deep stubs or spies so we needed to create a workaround for it and this article will show you how to do it.

Mockito - RETURNS_DEEP_STUBS for JAXB

Sorry for not having written for some time but I was busy with writing the JBoss Drools Refcard for DZone and I am in the middle of writing a book about Mockito so I don't have too much time left for blogging...

Anyway quite recently on my current project I had an interesting situation regarding unit testing with Mockito and JAXB structures. We have very deeply nested JAXB structures generated from schemas that are provided for us which means that we can't change it in anyway.