Writing an Ant task for Jumble mutation tester

Jumble is a pretty neat tool for doing mutation testing on your Java code, to see how effective your JUnit tests are at catching small changes to the test subjects. It works by mutating bytecode rather than source (a la Jester), and so is much faster to execute. However, I was sad to see that there is no accompanying Ant task or Maven plugin. Running Jumble in either of these tools could certainly be accomplished by simply cooking up a Java VM invocation with the appropriate command line arguments...but I think it'd be useful to have tasks/plugins that, among other things, fail the build if a class's Jumble score dips below a defined threshold. Many code coverage tools (e.g. Cobertura) have such provisions in their Ant/Maven tasks/plugins.

So, I'm undertaking to write an Ant task for Jumble. Initially it will invoke the tool via its CLI and scrape the output for scores, but ultimately I'd like to integrate the task more tightly with Jumble's API. Hopefully that API lends itself well to being hooked into.

Written on June 1, 2008