Is it worth testing the return type and value of a method call that is designed for chaining? It is conceivable that a fellow programmer could accidentally change the return type to void and remove the return while furiously refactoring some methods? This would potentially break a lot of code for an unsuspecting user.
However, I feel like I would be testing code structure rather than code functionality. Is this a reasonable thing to test? Or is it just a big waste of time?