Sunday, March 20, 2011

Extreme Programming Installed, Chapters 28-30

Reference Information
Extreme Programming Installed
Jeffries, et al
Addison-Wesley Professional, 2000



Summary
Chapter twenty-eight, called Balancing Hopes and Fears, gives an example from the author's past. His team had decided to retain certain legacy reporting procedures from some software that was being replaced to help with a faster transition. The team did not understand much of the older system, even the parts that they were hanging on to. This fact is not documented on any charts, and was hanging over the team's heads as they approached delivery. However, the team decided to come together and discuss the problem so that the team could be more confident in themselves. The situation arose because there was a large portion of the code which had no acceptance tests since they were legacy.


Chapter twenty-nine, entitled Testing Improves Code, presents a very short example from Rich Garzaniti. The premise is that Rich had to refactor some troublesome code. Upon writing the tests, he discovered that a method needed to be modified and moved some code into a helper function. This change made the code simpler and more easy to understand. The author says that code that cannot be easily tested is typically not refactored properly. He also says that writing tests first will ensure that these situations do not arise frequently.


Chapter thirty presents an example from using extreme programming with Java. A corporate database system was being replaced by a newer one and the author's team was responsible for writing the replacement. The project used Javascript and LDAP. At first, each code change required up to ten minutes before its results could be seen. In addition, the poor setup led to many files being corrupted. The author downloaded a debugger and started writing test cases and was able to get the system straightened out relatively easily. By using testing and refactoring he was able to fix the system and also make future changes that much easier.


Opinion
There is no relevant material to evoke any sort of interest or opinion. The examples are very simple, yet dense, and do not offer anything that was not already presented earlier in the book.



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