Source: minitest/minitest#440 (comment)
kytrinyx commented on Jul 15, 2014 I would highly recommend separating out the two tests, and on the one hand asserting that your code handles the exception in the way you want it to, and on the other hand, that a collaborator calls the method that you expect it to call (without making assertions about what happens when it does).
Here's an example of the first type of test, using a stub:
class Cupcake
class SpectacularError < RuntimeError; end