Code coverage: I'm hooked (05 Nov 2015)

In a small Java project which I inherited, I learned about the code base by bringing the code under test, i.e. by writing unit tests starting with the lower-level parts of the code and continuing on up to the its external API layers. This already was quite a fruitful exercise, as it allowed me to make changes in the code very quickly, relying on the unit tests to alert me of any breakage I caused along the way.

• TBD: Cobertura versus Java 7
• TBD: JaCoCo 0.75 versus Jenkins plugin

Code coverage report not working with Jenkins plugin for JaCoCo^?. https://issues.jenkins-ci.org/browse/JENKINS-28652 hints that this may be due to a version mismatch between the Jenkins plugin and JaCoCo^?, so I am downgrading to JaCoCo^? 0.7.4 to test this hypothesis.

Using code coverage, I identified small areas in the code which had not been executed yet by unit tests. Almost each of the tests I added uncovered another corner case I had not considered yet, or which taught me something about the codebase. Examples: TBD

• https://search.maven.org/#search|ga|1|a%3A%22jacoco-maven-plugin%22
• https://github.com/cobertura/cobertura
• https://stackoverflow.com/questions/10869127/maven-build-causes-verifyerror-with-java-1-7
• http://mail.openjdk.java.net/pipermail/jdk7-dev/2011-September/002261.html
• https://stackoverflow.com/questions/8151470/cobertura-java-7-support
• https://wiki.jenkins-ci.org/display/JENKINS/JaCoCo+Plugin
• https://dzone.com/articles/jacoco-jenkins-plugin

TBD:

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