Watch out if you do work based tests or trials as part of your recruitment process that you are very clear about this with your applicants and they know that it is part of the recruitment process and that they won’t be paid. The law is clear, you can’t use work–based trials in the assessment process for anything except assessing the applicants skills.
If you use work-based tests or trials (and you should) take a look at Employment New Zealand’s guidance on this here