MockingLegacyCode is not about making fun of other people's code, it's about MockObject''''''s.

LegacyCode, especially when it is SpaghettiCode, can be quite hard to test. One powerful technique for UnitTestingLegacyCode is using MockObject''''''s. I've found that there is a moderately steep cost to set up the initial MockObject''''''s, but the payoff is big because MockObject''''''s have a high reuse factor. 

AlittleMockGoesAlongWay.  See MockingInManyLanguages for examples.

----

CategoryMockObjects | CategoryTesting