Verifying that interactions never happened
In this recipe, we will verify the following two cases:
A specified method on a mock was never executed
The methods on the mock were executed
You might wonder whether there is any reason to check that a method on a mock was never executed. Well, imagine that your company is paying plenty of money for a bank transfer (let's assume that it's done via a web service). Having such business requirements where if some initial conditions were not met the bank transfer should not take place, you can check whether the method was executed.
If you actually need to verify that no more interactions took place on the mock, then perhaps you shouldn't actually have done this (check the link, http://monkeyisland.pl/2008/07/12/should-i-worry-about-the-unexpected/, for Szczepan Faber's article on that topic). If it's not a business requirement, you should not worry about the unexpected; perhaps, some additional methods of the mock can actually be executed if it doesn't...