Minor Description
Three issues related to temp files that tests generate – these should be touched up for hygiene but are not urgent.
Modules have a log4j.properties which directs the unit-test.log output file to a directory like [module]/target/unit-test.log. But this ends up creating [module]/[module]/target/unit-test.log instead of former.
The work/ directory is not deleted by "mvn clean", in the parent and in modules. Neither is the checkpoint/ directory created under the various external modules.
Many tests create a temp directory, which is not usually deleted. This can be largely resolved by calling deleteOnExit() at creation and trying to call Utils.deleteRecursively consistently to clean up, sometimes in an "@After" method.
(If anyone seconds the motion, I can create a more significant change that introduces a new test trait along the lines of LocalSparkContext, which provides management of temp directories for subclasses to take advantage of.)