Sprout Method

Sprout Method is a technique that one can use when one has to write a new feature into a system. The code will be formulated as new code, and you want to put the new code into a new method and call it where the new functionality needs to be.

The reason for Sprout method is that sometimes you cannot write unit test for the code that you want to change but you can use Test Driven Development to write unit test for the new code, so that at least the new code would be tested.

See http://taswar.zeytinsoft.com/learn-the-sprout-method-for-adding-new-functionality/for someone's explaination.