In NetBeans IDE 7.2, JaCoCo is supported natively, i.e., out of
the box, as a code coverage engine for Maven projects, since Cobertura does not work with JDK 7 language constructs. (Although, note that Cobertura is supported as well
in NetBeans IDE 7.2.) It isn't part of NetBeans IDE 7.2 Beta, so don't even try there; you need some development build from after that. I downloaded
the latest development build today.
To enable JaCoCo features
in NetBeans IDE, you need do no different to what you'd do when enabling JaCoCo
in Maven itself, which is rather wonderful.
In both cases, all you need to do is add this to
the "plugins" section of your POM:
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.5.7.201204190339</version>
<executions>
<execution>
<goals>
<goal>prepare-agent</goal>
</goals>
</execution>
<execution>
<id>report</id>
<phase>prepare-package</phase>
<goals>
<goal>report</goal>
</goals>
</execution>
</executions>
</plugin>
Now you're done and ready to examine
the code coverage of your tests, whether they are JUnit or TestNG. At this point, i.e., for no other reason than that you added
the above snippet into your POM, you will have a new Code Coverage menu when you right-click on
the project node:
If you click Show Report above,
the Code Coverage Report window opens. Here, once you've run your tests, you can actually see how many classes have been covered by your tests, which is pretty useful since 100% tests passing doesn't mean much when you've only tested one class, as you can see very graphically below:
Then, when you click
the bars
in the Code Coverage Report window,
the class under test is shown, with
the methods for which tests exist highlighted
in green and those that haven't been covered
in red:
(Note: Of course, striving for 100% code coverage is a bit nonsensical. For example, writing tests for your getters and setters may not be
the most useful way to spend one's time. But being able to measure, and visualize, code coverage is certainly useful regardless of
the percentage you're striving to achieve.)
Best of all about all this is that everything you see above is available out of
the box in NetBeans IDE 7.2. Take a look at what else NetBeans IDE 7.2 brings for
the first time to
the world of Maven:
http://wiki.netbeans.org/NewAndNoteworthyNB72#Maven
