Object-Oriented Reengineering Patterns
This reference details how to overturn legacy systems and comprehend difficulties, then reengineer the systems to comply with the new stipulations.
TABLE OF CONTENTS Object-Oriented Reengineering Patterns
Chapter 6: Tests: Your Life Insurance!
Overview
You are at the beginning of a reengineering project. You know that you will have to perform radical surgery on many parts of a valuable legacy system. You are wondering how you will be able to minimize the risks of changing a system on which your business depends: the risk of breaking features that used to work, the risk of spending too much effort on the wrong tasks, the risk of failing to integrate needed new functionality into the system, and the risk of further increasing maintenance costs.
The patterns presented in this cluster present effective ways of using tests in a reengineering context to reduce the risks posed by reengineering changes.
Caveat: Testing is a rich and important subject that can scarcely be covered in any depth in the few pages we devote to it in this chapter. We have done no more than identify a few of the more significant testing patterns that are especially relevant to reengineering projects, and briefly sketch out some of the key issues. Binder, for example, devotes an entire book to testing object-oriented systems [Bind99].
Forces
These patterns share common forces that concern various elements of risk for the evolution of the legacy system. Each pattern addresses some of these forces in order to achieve a certain balance between effort and risk. Certain forces are inherent to reengineering:
-
Legacy systems often do not have test procedures defined.
-
Changing parts of a system without introducing new bugs is a...
Copyright Elsevier Science (USA) 2003 under license agreement with Books24x7
