Ask HN: Compensation for a test working day instead of job interview

I recently applied for a job as software engineer. To assess my skills and get to know the team they want me to work for one day at their company on a proposed problem.

Basically, I think this a good approach. However, from my perspective, I felt that the effort/risk taken by the company and by me is unbalanced and therefore requested some compensation for the "test working day" during the first telephone interview. What do you think? Is this appropriate?