I know how I am going to measure my code

Recent blog of Uncle Bob got me curious about the new metric he mentioned there: Change Risk Analysis and Predictions - in short - CRAP.

It is based on putting together cyclomatic complexity of code and its coverage by unit tests. While the increase of the first represents worsening of code base that leads to the bugs, the increase of second one helps fighting code rot by allowing refactoring and showing bugs when they occur. In theory, of course, your mileage might vary.

In my opinion they are good candidates to put into one combined metrics because for example code coverage alone does not say much. Let's say we have 80% coverage. It does not say if last 20% does not need tests because it is too simple to break or just too hard to test. But when complexity raises value of metric and code coverage lowers it, then with correct threshold it can point nicely to places that deserve your attention.

So I was interested to see how results of my recent work will stand this test. It took me some time to make crap4j running correctly, because there is some problem with inner classes in test classes and the only way to set up CRAP4J_HOME that worked for me was to modify ANT_OPTS.

I was quite delighted by seeing 0% of CRAP in several of small modules I have tried it on. Unfortunately I did not have time to try it with older and bigger modules (not to mention results would be polluted by code of others and I wanted to see my results to give a boost to my ego ;-) ). I might do that later, but I will not publish any results here.

Here are some screenshots:

In my opinion it is very nice metric, with fantastic name (it was the name that caught my attention). I can imagine it is the name that can create interesting peer pressure if applied in the team. On the other hand, I cannot imagine worse name from manager's point of view. Which manager would like to see report with such a juicy name on his desk showing him how poorly his subordinates work :-) Which manager would not be afraid to show it to his superiors/peers?