[rntrg]

I have found that heavy use of mocking tools couples tests tightly to the design, resulting in great difficulty when I need to redactor. To me, the ideal is that I can change my design as I see fit without difficulty. My tests specify what my application does - how it behaves, not how it is structured. In my experience, this entails minimizing the number of points where tests touch production code, i.e. keeping the test suite DRY.

I do use test doubles, including mocks, where things become difficult or slow to test (generally application boundaries). But keep in mind that every line of mocking code costs more than an equivalent line of the alternative.